Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1080/1536383X.2022.2146672

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.35848/1347-4065/ac9319

Language：Others   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) is performed using carbon nanowalls (CNWs) for ionization-assisting substrates. The CNWs (referred to as high-quality CNWs) in the present study were grown using a radical-injection plasma-enhanced chemical vapor deposition (RI-PECVD) system with the addition of oxygen in a mixture of CH4 and H2 gases. High-quality CNWs were different with respect to crystallinity and C–OH groups, while showing similar wall-to-wall distances and a wettability comparable to CNWs (referred to as normal CNWs) grown without O2. The efficiency of SALDI was tested with both parameters of ion intensity and fragmental efficiency (survival yield (SY)) using N-benzylpyridinuim chloride (N-BP-CI). At a laser fluence of 4 mJ/cm2, normal CNWs had an SY of 0.97 and an ion intensity of 0.13, while 5-sccm-O2– high-quality CNWs had an SY of 0.89 and an ion intensity of 2.55. As a result, the sensitivity for the detection of low-molecular-weight analytes was improved with the high-quality CNWs compared to the normal CNWs, while an SY of 0.89 was maintained at a low laser fluence of 4 mJ/cm2. SALDI-MS measurements available with the high-quality CNWs ionization-assisting substrate provided high ionization and SY values.

DOI： 10.3390/nano13010063

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.vacuum.2022.111351

Web of Science

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Language：Others   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

We evaluated the power generation characteristics of a polymer electrolyte fuel cell (PEFC) composed of Pt-supported carbon nanowalls (CNWs) and a microporous layer (MPL) of carbon black on carbon paper (CP) as catalyst support materials. CNWs, standing vertically on highly crystallizing graphene sheets, were synthesized on an MPL/CP by plasma-enhanced chemical vapor deposition (PECVD) using inductively coupled plasma (ICP). Pt nanoparticles were supported on the CNW surface using the liquid-phase reduction method. The three types of voltage loss, namely those due to activated polarization, resistance polarization, and diffusion polarization, are discussed for the power generation characteristics of the PEFC using the Pt/CNWs/MPL/CP. The relationship between the height or gap area of the CNWs and the voltage loss of the PEFC is demonstrated, whereby the CNW height increased with the extension of growth time. The three-phase interface area increased with the increase in the CNW height, resulting in mitigation of the loss due to activated polarization. The gap area of the CNWs varied when changing the CH4/H2 gas ratio. The loss due to diffusion polarization was reduced by enlarging the gap area, due to the increased diffusion of fuel gas and discharge of water. The secondary growth of the CNWs caused the three-phase interface area to decrease as a result of platinum aggregation, impedance of the supply of ionomer dispersion solution to the bottom of the CNWs, and inhibition of fuel gas and water diffusion, which led to the loss of activated and diffuse polarizations. The voltage losses can be mitigated by increasing the height of CNWs while avoiding secondary growth.

DOI： 10.3390/c8030044

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Language：English   Publishing type：Research paper (scientific journal)  

Flake-shaped carbon nanomaterials with nitrogen (N) and iron (Fe) addition, so-called carbon nanoflakes (CNFLs), were synthesized by the in-liquid plasma using two different kinds of additive agents, such as hemin and iron (II) phthalocyanine (FePc). According to scanning electron microscopy images and Raman spectra, CNFLs with a size of at least 100 nm order were formed regardless of types of additive agents, and crystallinity of six-membered ring structures was improved as additive agents increased. Photoelectron spectra showed that pyridinic N contents increased from 1.05% to 2.02% with increasing FePc, while those decreased from 0.34% to 0.14% with hemin. In the oxygen reduction reaction, onset potential values also increased from 0.71 to 0.79 eV with increasing FePc, while those decreased from 0.60 to 0.47 eV with hemin. These results suggested that the catalytic activity of CNFLs was effectively improved by the increase of pyridinic N by the in-liquid plasma synthesis with FePc. In contrast, the electron transfer numbers reached 3.81 when hemin increased, although those were less than 2.88 in the cases using FePc. These results mean that the in-liquid plasma synthesis method of CNFLs using FePc has the potential to further improve its catalytic activity.

DOI： 10.1002/ppap.202100203

Scopus

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Language：English   Publishing type：Research paper (scientific journal)  

Effects of Carbon Nanowalls (CNWs) Substrates on Soft Ionization of Low-Molecular-Weight Organic Compounds in Surface-Assisted Laser Desorption/Ionization Mass Spectrometry (SALDI-MS)
Carbon nanowalls (CNWs), which are vertically oriented multi-layer graphene sheets, were employed in surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) measurements to detect low-molecular-weight organic compounds. CNWs substrates with widely different wall-to-wall distances from 142 to 467 nm were synthesized using a radical-injection plasma-enhanced chemical vapor deposition (RI-PECVD) system with nanosecond pulse biasing to a sample stage. When survival yield (SY) values of N-benzylpyridinium chloride (N-BP-Cl) were examined, which is commonly used to evaluate desorption/ionization efficiency, a narrower wall-to-wall distance presented a higher SY value. The highest SY value of 0.97 was realized at 4 mJ/cm(2) for the highest-density CNWs with a wall-to-wall distance of 142 nm. The laser desorption/ionization effect of arginine, an amino acid, was also investigated. When CNWs with a narrower wall-to-wall distance were used, the signal-to-noise (SN) ratios of the arginine signals were increased, while the intensity ratios of fragment ions to arginine signals were suppressed. Therefore, the CNWs nanostructures are a powerful tool when used as a SALDI substrate for the highly efficient desorption/ionization of low-molecular-weight biomolecules.

DOI： 10.3390/nano11020262

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.carbon.2020.07.052

Language：English   Publishing type：Research paper (scientific journal)  

Measurements of nitrogen atom density in a microwave-excited plasma jet produced under moderate pressures
Using a microwave-excited plasma source based on a microstrip line, we have generated a nitrogen plasma jet at a moderate pressure in the range from 1 to 10 kPa. The densities of nitrogen (N) atoms produced by the plasma jet were measured with a vacuum ultraviolet absorption spectroscopy. The results show that the plasma jet is able to provide a high density of N atoms at least 4.5 x 10(14) cm(-3)at 1.5 kPa. The N atom densities vary widely with the change in gas flow rate and substrate placement. We expect that this plasma source will provide a high performance as an advanced N radical source in various applications. (c) 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

DOI： 10.1002/tee.23194

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.apsusc.2020.146533

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1116/6.0000124

Language：Others   Publishing type：Research paper (scientific journal)  

© 2020 The Japan Society of Applied Physics. In-plane modification of hexagonal boron nitride (hBN) is demonstrated via plasma in solution without acid/base addition. Electron spin resonance spectroscopy clearly reveals an increase in nitrogen vacancies in the hBN plane. This could be a simple route to functionalizing the two-dimensional surface of hBN. Simultaneously, hydroxylation occurs, accompanied by an increase in the zeta potential.

DOI： 10.35848/1882-0786/ab916c

Language：English   Publishing type：Research paper (scientific journal)  

Gas-phase and film analysis of hydrogenated amorphous carbon films: Effect of ion bombardment energy flux on sp² carbon structures
Hydrogenated amorphous carbon (a-C:H) films comprise nanoclustering graphites (nc-G), fused aromatic rings (nR), and olefinic chain clusters (nC) of sp(2)-bonded carbons in an sp a matrix. In this study, the sp(2) composition of the nc-G, nR and nC in a-C:H films is found to be determined by the ion bombardment energy flux (Gamma(Ei)), which can be estimated as the product of ion bombardment energy and ion flux onto the deposited surface, in plasma-enhanced chemical vapor deposition using a plasma mixture of H-2 and CH4 gases with the H radical injection method. The sp(2) composition is analyzed using Raman spectroscopy and near-edge X-ray absorption structure spectroscopy. a-C:H becomes increasingly graphitized with increasing Gamma(Ei). The precise control of the sp(2) C structure composition can be achieved by controlling the very-high-frequency input power and radio frequency input bias power via the ion flux and ion bombardment energy.

DOI： 10.1016/j.diamond.2019.107651

Language：Others   Publishing type：Research paper (scientific journal)  

© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Nanometer-size graphene sheets (nanographene) were synthesized by the in-liquid plasma method employing a mixture of alcohols. Pure methanol in-liquid plasma was found to not synthesize any nanographene. Pure ethanol synthesized nanographene with high crystallinity. Highly crystalline nanographene with a narrow full width-half maximum of the Raman scattering G-band (FWHMG) was obtained by mixing 1-butanol with methanol. This is due to the formation of carbon ring structures being inhibited by the addition of methanol. The ratio of added methanol determined the nanographene crystallinity and yield under a trade-off relationship, allowing the crystallinity and nanographene yield to be controlled by controlling the ratio. Gas chromatography-mass spectrometric analysis of by-products in the liquids’ supernatant showed that the crystallinity of the synthesized nanographene correlated with the ratio of carbon over oxygen of the alcohol precursors (C/O), i. e., the amount of hydroxyl groups in the liquids, and hence controlling the C/O ratio can be used to control the graphene crystallinity in the in-liquid plasma synthesis.

DOI： 10.1002/cnma.201900676

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s40820-020-0395-5

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1063/1.5127863

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1116/1.5114831

Language：English   Publishing type：Research paper (scientific journal)  

Oxidative stress-dependent and -independent death of glioblastoma cells induced by non-thermal plasma-exposed solutions
Non-thermal atmospheric pressure plasma has been widely used for preclinical studies in areas such as wound healing, blood coagulation, and cancer therapy. We previously developed plasma-activated medium (PAM) and plasma-activated Ringer's lactate solutions (PAL) for cancer treatments. Many in vitro and in vivo experiments demonstrated that both PAM and PAL exhibit anti-tumor effects in several types of cancer cells such as ovarian, gastric, and pancreatic cancer cells as well as glioblastoma cells. However, interestingly, PAM induces more intracellular reactive oxygen species in glioblastoma cells than PAL. To investigate the differences in intracellular molecular mechanisms of the effects of PAM and PAL in glioblastoma cells, we measured gene expression levels of antioxidant genes such as CAT, SOD2, and GPX1. Microarray and quantitative real-time PCR analyses revealed that PAM elevated stress-inducible genes that induce apoptosis such as GADD45α signaling molecules. PAL suppressed genes downstream of the survival and proliferation signaling network such as YAP/TEAD signaling molecules. These data reveal that PAM and PAL induce apoptosis in glioblastoma cells by different intracellular molecular mechanisms.

DOI： 10.1038/s41598-019-50136-w

Language：English   Publishing type：Research paper (scientific journal)  

Atmospheric Pressure Plasma-Treated Carbon Nanowalls' Surface-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (CNW-SALDI-MS)
Carbon nanowalls (CNWs), vertically standing highly crystallizing graphene sheets, were used in the application of a surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI-TOF-MS). The CNW substrates solved the issues on interferences of matrix molecules and alkali metal addition ions in low-weight molecule detection. Before SALDI sample preparations, the hydrophobic CNW was treated by atmospheric pressure plasma for exposing hydrophilicity to the CNWs' surface. Detection of water soluble amino acids, arginine, was demonstrated.

DOI： 10.3390/c5030040

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/acsabm.9b00178

Language：English   Publishing type：Research paper (scientific journal)  

Plasma-activated solution alters the morphological dynamics of supported lipid bilayers observed by high-speed atomic force microscopy
The effects of plasma-activated Ringer's lactate solution (PAL) on supported lipid bilayers (SLBs) as a cell membrane model were investigated. PAL has selective killing effects on cancer cells. High-speed atomic force microscopy revealed alterations in the morphological dynamics of SLBs in PAL. SLB islands decreased approximately 20-fold faster in the presence of PAL compared to Ringer's lactate solution without plasma treatment. The effect of plasma treatment on the Ringer's lactate solution produced PAL components that account for the observed effects on cell membranes, such as removal of lipid molecules from the edges of SLBs and the following SLBs shrinkage. (C) 2019 The Japan Society of Applied Physics

DOI： 10.7567/1882-0786/ab1a58

Language：English   Publishing type：Research paper (scientific journal)  

A 65-nm CMOS Fully Integrated Analysis Platform Using an On-Chip Vector Network Analyzer and a Transmission-Line-Based Detection Window for Analyzing Circulating Tumor Cell and Exosome

DOI： 10.1109/TBCAS.2018.2882472

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1088/1361-6463/ab03c4

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1116/1.5083970

Language：English   Publishing type：Research paper (scientific journal)  

Effects of 3D structure on electrochemical oxygen reduction characteristics of Pt- nanoparticle-supported carbon nanowalls

DOI： 10.1088/1361-6463/aaf8e0

Language：English   Publishing type：Research paper (scientific journal)  

Control of sp2-C cluster incorporation of amorphous carbon films grown by H-radical-injection CH4/H2 plasma-enhanced chemical vapor deposition
Amorphous carbon (a-C) thin films were deposited under the control of C-2 radical density using radical-injection plasma-enhanced chemical vapor deposition (RI-PECVD) with CH4/H-2 plasma. By actinometric monitoring of C-2 emission intensities, the plasma parameters were precisely controlled by changing in CH4-containing plasma excitation power independent of H-2 plasma excitation. The control of the incorporation of sp2-C clusters in the a-C films during the a-C film depositions is demonstrated by tailoring Raman positions vs. full widths at half maxima for the G band around 1580 cm(-1) to the RI-PECVD parameters. (C) 2019 The Japan Society of Applied Physics

DOI： 10.7567/1347-4065/aafd49

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1021/acsanm.8b02201

Language：English   Publishing type：Research paper (scientific journal)  

Real-time control of a wafer temperature for uniform plasma process

DOI： 10.1109/ISSM.2018.8651183

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.7567/1347-4065/aaf92a

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.7567/1882-0786/aaf469

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/ppap.201800175

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.7567/1347-4065/aaec87

Language：English   Publishing type：Research paper (scientific journal)  

Electrochemical Reaction in Hydrogen Peroxide and Structural Change of Platinum Nanoparticle-Supported Carbon Nanowalls Grown Using Plasma-Enhanced Chemical Vapor Deposition

DOI： 10.3390/c5010007

Language：English   Publishing type：Research paper (scientific journal)  

Effects of Ion Bombardment Energy Flux on Chemical Compositions and Structures of Hydrogenated Amorphous Carbon Films Grown by a Radical-Injection Plasma-Enhanced Chemical Vapor Deposition

DOI： 10.3390/c5010008

Language：English   Publishing type：Research paper (scientific journal)  

Liquid dynamics in response to an impinging low-temperature plasma jet

DOI： 10.1088/1361-6463/aaf460

Language：English   Publishing type：Research paper (scientific journal)  

Pt nanoparticle-supported carbon nanowalls electrode with improved durability for fuel cell applications using C2F6/H2 plasma-enhanced chemical vapor deposition
The electrochemical durability of Pt nanoparticles-supported carbon nanowalls (Pt/CNWs) determined from potential cycle tests was 88% performance after 20 000 cycles and 50% performance around 140 000 cycles when the CNWs were fabricated by the C2F6/H-2 plasma-enhanced chemical vapor deposition system (C2F6-CNWs). Even after the extended start/stop-simulation tests of fuel cell Pt/C2F6-CNWs, Pt was aggregated; however, the morphological structure of the CNWs was maintained and no corrosion was evident from scanning electron microscopy observations and Raman analysis. For graphene-based catalyst supports, i.e., the Pt/C2F6-CNWs, graphene crystallinity is essential to extend electrochemical durability by inhibiting corrosion during fuel cell operation. (C) 2018 The Japan Society of Applied Physics

DOI： 10.7567/1882-0786/aaf0ab

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1063/1.5050819

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3390/mi9110565

Language：English   Publishing type：Research paper (scientific journal)  

Time Evolution Of Reactive Oxygen Nitrogen Species in Plasma-Activated Essential Media and Water

DOI： 10.1109/PLASMA.2017.8496057

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.7567/JJAP.57.106502

Language：English   Publishing type：Research paper (scientific journal)  

Elevated-temperature etching of gallium nitride (GaN) in dual-frequency capacitively coupled plasma of CH<inf>4</inf>/H<inf>2</inf> at 300–500 °C

DOI： 10.1016/j.vacuum.2018.07.040

Language：English   Publishing type：Research paper (scientific journal)  

Graphenes of nanometer-scale grain size (nanographenes) were synthesized using in-liquid plasmas with alcohols or hydrocarbons. This method of nanographene synthesis showed a trade-off relationship between crystallinity and synthesis rate. The high crystallinity of nanographenes synthesized with alcohols was evaluated from the small full width at half maxima (FWHM) of the G band in Raman scattering spectra. On the other hand, in the case of using hydrocarbons such as n-hexane and benzene, a significantly high synthesis rate was obtained but the crystallinity of nanographenes was low. It was found that hydroxyl groups and oxygen atoms of liquid sources play important roles in determining the crystallinity of synthesized nanographenes.

DOI： 10.7567/JJAP.57.026201

Language：English   Publishing type：Research paper (scientific journal)  

Giant graphene flakes on the micron scale were synthesized and grown in plasmas in liquid-phase pure ethanol with added iron phthalocyanine (FePc) in a solvent. At atmospheric pressure, plasmas were generated in the gas phase filled with Ar and in the liquid phases comprising bubbles and liquid solutions. In the mixture of FePc in ethanol, nanographene sheets aggregated to form giant graphene flakes, as confirmed by the D, G, and 2D bands in the corresponding Raman spectra. Therefore, a bottom-up approach of graphite synthesis from pure ethanol with additives and a catalyst was realized by in-liquid plasma processing.

DOI： 10.7567/APEX.11.015102

Language：English   Publishing type：Research paper (scientific journal)  

The liquid-phase chemical kinetics of a cell culture basal medium during treatment by an argonfed, non-equilibrium atmospheric-pressure plasma source were investigated using real-time ultraviolet absorption spectroscopy and colorimetric assays. Depth- and time-resolved NO2- and NO3- concentrations were strongly inhomogeneous and primarily driven by convection during and after plasma-liquid interactions. H2O2 concentrations determined from deconvolved optical depth spectra were found to compensate for the optical depth spectra of excluded reactive species and changes in dissolved gas content. Plasma-activated media remained weakly basic due to NaHCO3 buffering, preventing the H+-catalyzed decomposition of NO2- seen in acidic plasma-activated water. An initial increase in pH may indicate CO2 sparging. Furthermore, the pH-dependency of UV optical depth spectra illustrated the need for pH compensation in the fitting of optical depth data. Published by AIP Publishing.

DOI： 10.1063/1.4999256

Language：English   Publishing type：Research paper (scientific journal)  

A mechanism of the cytotoxicity of plasma-activated medium (PAM) is revealed by examining the intracellular effects of reactive oxygen nitrogen species (RONS) and lipid oxidation. PAM is cell culture medium activated by irradiation using non-equilibrium atmospheric-pressure plasma using pure Ar gas in ambient air. Extracellular RONS in PAM induced the apoptotic death of HeLa cells. Temporal changes in intracellular RONS, such as ONOO-, NO, and O2-, were analyzed. Intracellular RONS generation in HeLa cells following incubation in PAM triggered activation of the caspase cascade pathway and lipid peroxidation of intracellular membranes to induce apoptosis.

DOI： 10.1002/ppap.201700123

Language：English   Publishing type：Research paper (scientific journal)  

The formation of surface roughness during ion irradiation was suppressed by photon/radical pretreatment of a photoresist with HBr or H-2 plasmas. The opposite sequence of treatment after ion irradiation enhanced the surface roughness. The enhancement of roughness after post-treatment was not correlated with a decrease in the film thickness, reactions of Br radicals at the surface, or with the presence of the amorphous carbon-like layer generated by ion irradiation because similar modification was observed for the pretreatment. Fourier transform infrared spectroscopy analysis revealed that the intensities of peaks originated from the C=O absorption of methacrylic acid and methacrylate groups were decreased by irradiation with vacuum ultraviolet light at wavelengths in the range between 115 and 170 nm emitted from HBr or H2 plasmas. The removal of the C=O groups possibly generated dangling bonds and induced crosslinking reactions of the photoresist polymers. The nonuniformity of crosslinking reactions on the roughened photoresist intensively increased the surface roughness. (C) 2017 American Vacuum Society.

DOI： 10.1116/1.4994218

Language：English   Publishing type：Research paper (scientific journal)  

For polymer electrolyte fuel cell applications, carbon nanowalls (CNWs) were synthesized by radical-injection plasma-enhanced chemical vapor deposition, and a high density of Pt nanoparticles (> 10(12) cm(-2)) was supported on the CNWs using a supercritical fluid deposition system. The high potential cycle tests were applied and the electrochemical surface area of the Pt nanoparticle-supported CNWs did not change significantly, even after 20 000 high potential cycles. According to transmission electron microscopy observations, the mean diameter of Pt changed slightly after the cycle tests, while the crystallinity of the CNWs evaluated using Raman spectroscopy showed almost no change.

DOI： 10.1088/1361-6463/aa8131

Language：English   Publishing type：Research paper (scientific journal)  

The multiplex coherent anti-Stokes Raman scattering microscopy allowed label-free visualization of cytoplasmic lipid droplets (LDs). The LDs, which act to conserve energy storage, are usually accumulated during the normal apoptosis of HeLa cells with activation of caspase-3/7 leading to downregulation of the fatty acid catabolism pathways. During cultivating in nonthermal plasma-activated medium (PAM), while the activation of caspase-3/7 was induced, the authors found that a dynamic exhaustion of the intracellular LDs, underlying the metabolic mechanism of the PAM-induced apoptotic cell death of HeLa cells. (c) 2017 American Vacuum Society.

DOI： 10.1116/1.4997170

Language：English   Publishing type：Research paper (scientific journal)  

Surface chemical reactions on the GaN surface with Cl radicals are thermally enhanced in the high-temperature Cl2 plasma etching of GaN, resulting in the formation of etch pits and thereby, a roughened surface. Simultaneous irradiation of ultraviolet (UV) photons in Cl2 plasma emissions with wavelengths of 258 and 306nm reduces the surface chemical reactions because of the photodissociation of both Ga and N chlorides, which leads to a suppression of the increase in surface roughness. Compared with Si-related materials, we point out that photon-induced reactions should be taken into account during the plasma processing of wide-bandgap semiconductors. (C) 2017 The Japan Society of Applied Physics

DOI： 10.7567/APEX.10.086502

Language：English   Publishing type：Research paper (scientific journal)  

For the etching of organic films in H-2/N-2 plasma, etched profiles are significantly determined by substrate temperature. Here, we control the substrate temperature variation within 3 degrees C during processing by modulating the plasma-discharge time. The evolution of the cross-sectional profile of line-and-space patterns was observed every 10 s. At 60 and 100 degrees C, sidewall etching was observed during overetching, but not at 20 degrees C. During the main etching, the sidewalls were protected by the adsorption of by-products at various temperatures. Moreover, we investigated the temperature dependence of protection layer formation by analyzing the surface components of the organic film. The CN layer formed by N radicals has a protective effect that depends on the components of the CN layer. It was found that the ratio of C-N sp(3) to C-N sp(2) in the sidewall was highest at 100 degrees C. By evaluating the radical contribution to CN layer formation, C-N sp3 bonds were observed to be formed by ions and radiation-assisted reaction. (C) 2017 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.56.076202

Language：English   Publishing type：Research paper (scientific journal)  

The InN films were deposited on GaN surfaces at a low temperature of 200 degrees C by radical-enhanced metal organic chemical vapor deposition (REMOCVD). The REMOCVD system can provide N radicals from the plasma of a N-2-H-2 mixture gas without using ammonia. Two types of GaN substrate, bulk GaN and GaN on Si(111), were used. The growth mode was modeled as a step flow on the basis of surface morphology observation by atomic force microscopy. (C) 2017 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.56.06HE08

Language：English   Publishing type：Research paper (scientific journal)  

Interactions between non-equilibrium atmospheric-pressure plasma (NEAPP) and living cells were examined using multiplex coherent anti-Stokes Raman scattering (CARS) microscopy. Our multiplex CARS analyses revealed that NEAPP irradiation generates short-lived radicals that induce a decrease in the mitochondrial activity of budding yeast cells.

DOI： 10.1039/c7cp00489c

Language：English   Publishing type：Research paper (scientific journal)  

A diffusion process associated with the real sub-Laplacian Delta(b), the real part of the complex Kohn-Spencer Laplacian (sic)(b), on a strictly pseudoconvex CR manifold is constructed by H. Kondo and S. Taniguchi [A construction of diffusion processes associated with sub-Laplacian on CR manifolds and its applications. J. Math. Soc. Japan 69(1) (2017), 111-125]. In this paper, we investigate the diagonal short time asymptotics of the heat kernel corresponding to the diffusion process by using Watanabe's asymptotic expansion and give a representation for the asymptotic expansion of heat kernels which shows a relationship to the geometric structure.

DOI： 10.2206/kyushujm.71.65

Language：English   Publishing type：Research paper (scientific journal)  

We present experimentally determined spatial profiles of the interelectrode electron density (n(e)) in dual-frequency capacitively coupled plasmas in which the negative direct current (dc) bias voltage (V-dc) is superposed; in the experiment, 13 MHz (P-low) was applied to the lower electrode and 60 MHz (P-high) to the upper electrode. The bulk n(e) increased substantially with increases in the external power, P-high, P-low, and with increases in V-dc. When P-low was insufficient, the bulk n(e) decreased as the V-dc bias increased. The bulk n(e) increased due to its dependence on V-dc, especially for |V-dc| > 500 V. This may correspond to the sheath voltages (V-s) of the lower electrode. The n(e) values in front of the upper electrode were coupled with the V-dc: the V-dc dependence first decreased and then increased. The dc currents (I-dc) of the upper electrode were collected when a large P-low was applied. The value of I-dc at the threshold value of V-dc approximate to V-s (e.g. -500 V) increased with an increase in n(e). When |V-dc| exceeded the threshold, the spatial n(e) profile and the I-dc dependence were changed relative to the electrical characteristics of the dc superposition; this led to a change in the location of the maximum n(e), the width of the area of n(e) depletion in front of the electrodes, and a transition in the electron heating modes.

DOI： 10.1088/1361-6463/aa60f7

Language：English   Publishing type：Research paper (scientific journal)  

We here report the production of highly spherical protein nanoparticles based on the domain-swapping oligomerization of a circularly permuted trimeric protein, major histocompatibility complex (MHC) class II associated chaperonin. The size distribution of the nanoparticles can be adjusted to between 40 and 100 nm in diameter, and thus, these particles are suitable as drug carriers following purification under basic conditions. Our approach involves no harsh treatments and could provide an alternative approach for protein nanoparticle formation.

DOI： 10.1021/acs.bioconjchem.6b00735

Language：English   Publishing type：Research paper (scientific journal)  

Microcrystalline hydrogenated silicon films were produced at a high deposition rate of about 2nm/s by using a capacitively coupled plasma under a practical pressure of around 1 kPa. The SiH4 source gas was almost fully dissociated when highly diluted with H-2 gas, and the dominant species in the gas phase were found to be SiH3 radicals, which are film-growth precursors, and H atoms. The absolute density of these species was measured as the partial pressure of SiH4 gas was varied. With the increasing SiH4 gas flow rate, the SiH3 radical density, which was on the order of 10(12) cm(-3), increased linearly, while the H-atom density remained constant at about 10(12) cm(-3). The film growth mechanism was described in terms of precursors, based on the measured flux of SiH3 radicals and H atoms, and the relative fraction of higher-order radicals. Published by AIP Publishing.

DOI： 10.1063/1.4974821

Language：English   Publishing type：Research paper (scientific journal)  

This work demonstrated a process for the atomic-scale etching of SiO2 films, consisting of alternating nanometer-thick fluorocarbon film deposition with O-2 plasma irradiation in a capacitively coupled plasma reactor. Ar plasma etching after fluorocarbon film deposition tends to suffer from nanometer- or subnanometer-thick carbon films deposited on the SiO2 surface and chamber walls. These carbon films cause various problems, such as reductions in the etching rate per cycle and degradation of the SiO2 quality. In contrast, in our two-step process, O-2 plasma removes carbon atoms in such fluorocarbon films. This process therefore allows the atomic scale etching of SiO2 films without any residue or surface contamination. Additionally, since the etching rate per cycle plateaus as both the etching time and deposition time are extended, it is unnecessary to uniformly deposit a fluorocarbon film over the wafer. (C) 2016 American Vacuum Society.

DOI： 10.1116/1.4971171

Language：English   Publishing type：Research paper (scientific journal)  

In the field of microfluidics, it is possible to facilitate liquid transport through microsized holes with large slip lengths by lowering the friction at the interface between the flow and the inner surface of the holes. In this paper, we discuss the use of nonequilibrium atmospheric-pressure plasma to modify the surface wettability of microsized holes in glass substrates that are similar to those used as flow channels in glass microfiltration devices. In our experiments, liquid transport flows were driven by internal Laplace pressure differences based on the surface tensions of droplets placed on the front and back sides of the tested substrates.

DOI： 10.1109/TPS.2016.2571721

Language：English   Publishing type：Research paper (scientific journal)  

Amorphous carbon (a-C) films are deposited using a radical-injection plasma-enhanced chemical vapor deposition (RI-PECVD) system employing a mixture of H-2 and CH4 gases. Variations in the structural and electronic properties of the resulting films with changes in the residence times of radical species and molecules are investigated by varying the total gas flow rate from 50 to 400sccm. With decreasing residence time, the deposition rate is found to gradually increase, reaching a maximum value at a residence time of 6ms, after which a decrease was observed. Optical emission spectra showed that the relative intensity of the CH emission increased with decreasing residence time. These results indicate a change in the dominant radical species resulting from suppression of the dissociation of radicals and molecules. Increasing amorphization and an obvious increase in the Tauc gap from 0.6 to 0.9eV are found with decreasing residence time, while there is little change in the hydrogen content of the films. From these data, it is evident that control over the structural properties and optical bandgap of a-C films can be realized by optimizing the distribution of radical species.

DOI： 10.1002/ppap.201500229

Language：English   Publishing type：Research paper (scientific journal)  

In hydrogenated amorphous carbon films, deposited using a radical-injection plasma-enhanced chemical vapor deposition system, the chemical bonding structure was analyzed by near-edge X-ray absorption fine-structure spectroscopy. With a change in the residence times of source gases in a reactor, whereby total gas flow rates of H-2/CH4 increased from 50 to 400 sccm, sp(2)-C fractions showed the minimum value at 150 sccm, while H concentration negligibly changed according to the results of secondary ion mass spectroscopy. On the other hand, widths of sigma* C-C peaks increased with decreasing gas residence time, which indicates an increase in the fluctuation of bonding structures. (C) 2016 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.55.040305

Language：English  

DOI： 10.7567/JJAP.55.01A001

Language：English   Publishing type：Research paper (scientific journal)  

Actual Si wafer temperatures during plasma etching processes were temporally measured using a real-time wafer-temperature monitoring system with autocorrelation-type frequency-domain low-coherence interferometry. Indeed, the Si wafer temperature, which was 20 degrees C before the process, rapidly increased in 10 s. Then, the temperature rise gradually slowed, but continued to increase and reached 45 degrees C after 600 s. This can be due to the fact that there exists a heat source for the wafer other than the plasma. Reasonably, the Si wafer was found to be sensitive to the temperature of the disk covering the area around the wafer, i.e., the focus ring. Usually, the temperature of the focus ring is not controlled and causes the radial distribution of Si wafer temperature. Consequently, the Si wafer temperature should be controlled with the temperature increase of other heat sources, especially the focus ring. (C) 2016 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.55.01AB04

Language：English   Publishing type：Research paper (scientific journal)  

A wafer temperature feedback control system during plasma processing with rapid, precise, and real-time temperature monitoring employing frequency-domain low-coherence interferometry was developed. To keep the temperature within a specific range, plasma was actively switched on and off, controlled by signals from a monitoring system. It was applied to an organic film etching process with an H-2 and N-2 mixture gas plasma. The organic material etching yield from atomic hydrogen has a relatively high sensitivity to temperature, and a constant temperature is required to achieve precise etching profiles. This system maintained the wafer temperature within a few degrees for H-2/N-2 plasma discharges. Duty ratios per discharge gradually decreased because the temperature of the chamber component parts around the wafer increased. The trench width etched in the organic film increased with increasing wafer temperature. This is because of a temperature dependence balance between the etching reaction and protection film formation on the trench sidewall.

DOI： 10.1109/TSM.2015.2470554

Language：English   Publishing type：Research paper (scientific journal)  

The development of two new types of high-density, electroless plated microelectrode arrays for CMOS-based high-sensitivity direct bacteria and HeLa cell counting are presented. For emerging high-sensitivity direct pathogen counting, two technical challenges must be addressed. One is the formation of a bacteria-sized microelectrode, and the other is the development of a high-sensitivity and high-speed amperometry circuit. The requirement for microelectrode formation is that the gold microelectrodes are required to be as small as the target cell. By improving a self-aligned electroless plating technique, the dimensions of the microelectrodes on a CMOS sensor chip in this work were successfully reduced to 1.2 mu M x 2.05 mu M. This is 1/20th of the smallest size reported in the literature. Since a bacteria-sized microelectrode has a severe limitation on the current flow, the amperometry circuit has to have a high sensitivity and high speed with low noise. In this work, a current buffer was inserted to mitigate the potential fluctuation. Three test chips were fabricated using a 0.6-mu M CMOS process: two with 1.2 mu M x 2.05 mu M (1024 x 1024 and 4 x 4) sensor arrays and one with 6-mu M square (16 x 16) sensor arrays; and the microelectrodes were formed on them using electroless plating. The uniformity among the 1024 1024 electrodes arranged with a pitch of 3.6 mu M x 4.45 mu M was optically verified. For improving sensitivity, the trenches on each microelectrode were developed and verified optically and electrochemically for the first time. Higher sensitivity can be achieved by introducing a trench structure than by using a conventional microelectrode formed by contact photolithography. Cyclic voltammetry (CV) measurements obtained using the 1.2 mu M x 2.05 mu M 4 x 4 and 6-mu M square 16 x 16 sensor array with electroless-plated microelectrodes successfully demonstrated direct counting of the bacteria-sized microbeads and HeLa cells.

DOI： 10.1109/TBCAS.2015.2479656

Language：English   Publishing type：Research paper (scientific journal)  

The high sensitivity in response, selectivity and reversibility was achieved on a carbon nanowall-based sensor for the vapor detection of volatile organic compounds, which were tested by an electrical resistance method during adsorption and desorption cycles. The maze-like structure of two different carbon nanowalls with wall-to-wall distances of 100 nm and 300 nm were prepared on a silicone substrate by a plasma-enhanced chemical vapor deposition system while varying processing parameters. Four organic vapors: iso-pentane
diethyl ether
acetone
and methanol
were selected in order to evaluate the relationship between the change in resistance, molecular weight of the adsorbent and the polarity. The results show that the carbon nanowalls with average wall distance 100 nm exhibit substantially enhanced electrical response to all volatile organic compound vapors used in comparison with the nanowalls with 300 nm wall distance as well as entangled multiwall carbon nanotube networks.

DOI： 10.1039/c5ra12000d

Language：English   Publishing type：Research paper (scientific journal)  

Plasma-induced damage (PID) during plasma-etching processes was suppressed by the application of Cl-2 plasma etching at an optimal temperature of 400 degrees C, based on results of evaluations of photoluminescence (PL), stoichiometric composition, and surface roughness. The effects of ions, photons, and radicals on damage formation were separated from the effects of plasma using the pallet for plasma evaluation (PAPE) method. The PID was induced primarily by energetic ion bombardments at temperatures lower than 400 degrees C and decreased with increasing temperature. Irradiations by photons and radicals were enhanced to form the PID and to develop surface roughness at temperatures higher than 400 degrees C. Consequently, Cl-2 plasma etching at 400 degrees C resulted optimally in low damage and a stoichiometric and smooth GaN surface. (C) 2015 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.54.06GB04

Language：English   Publishing type：Research paper (scientific journal)  

The gas phase fragmentations of perfluoro-propyl-vinyl ether (PPVE, C5F10O) are studied experimentally. Dominant fragmentations of PPVE are found to be the result of a dissociative ionization reaction, i.e., CF3+ via direct bond cleavage, and C2F3O- and C3F7O- via electron attachment. Regardless of the appearance energy of around 14.5 eV for the dissociative ionization of CF3+, the observed ion efficiency for the CF3+ ion was extremely large the order of 10(-20)cm(-2), compared with only 10(-21)cm(-2) for the other channels. PPVE characteristically generated CF3+ as the largest abundant ion are advantageous for use of feedstock gases in plasma etching processes. (c) 2015 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.54.040301

Language：English   Publishing type：Research paper (scientific journal)  

Etching rates of silicon nitrides (SiN), SiO2, and poly-Si films for CH2F2 plasmas diluted with rare gases are presented by comparing the effects of flow rates of CH2F2 and dilution gases (Ar and Kr). The SiO2 etching rate was considered to be controlled by ion fluxes of the incident CHF2+ and CH2F+ under the conditions for the selective etching of SiO2 and SiN over poly-Si. Interestingly, the SiN etching rate was considerably affected by the dilution gas used. The SiN surface reaction was promoted by F-rich chemistry in the Ar-diluted CH2F2 plasma with a relatively high density of F atoms. (c) 2015 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.54.040303

Language：English   Publishing type：Research paper (scientific journal)  

Ion densities of CH2F+ and CHF2+ were determined by dissociative ionization pathways in channels of charge exchange collisions, i.e. CH2F2 + M+--> CH2F+ + F + M* and CHF2+ + H + M* [M = Ar, Kr] in CH2F2 plasmas diluted by a rare gas [M]. These channels simultaneously generated counter fragments of charge-neutral H and F atoms of interest for plasma etching processes. In Ar-diluted plasmas, CH2F+ ions predominated due to dissociative ionization between Ar+ [ca. 15.8 eV] and C-F appearance [dissociative ionization] energy [ca. 16 eV] to form CH2F+. In contrast, for Kr-diluted plasmas, C-H appearance energy [ca. 13.8 eV] predominated to produce a larger amount of CHF2+ ions due to a similar channel for charge exchange collisions between Kr+[ca. 14 eV] and CH2F2. Thus, adding the ratio of Ar and Kr gas to CH2F2 plasmas provided control over the fraction of CH2F+ and CHF2+ ion densities.

DOI： 10.1088/0022-3727/48/4/045202

Language：English   Publishing type：Research paper (scientific journal)  

We have compared in detail the robust characteristics of an autocorrelation-type frequency-domain low-coherence interferometry (ACT-FD-LCI) system without a reference mirror with those of the conventional frequency-domain low-coherence interferometry (FD-LCI) system with a reference mirror. The standard deviation of temperature measurement was less than 0.04 degrees C at temperatures below 550 degrees C for a typical thickness of 480 mu m, as determined from the measured optical path length. The robustness of performance against disturbances has been markedly improved, as compared with a precision of 0.28 degrees C in the conventional FD-LCI system with the reference mirror. In particular, we have confirmed that the ACT-FD-LCI system has a large tolerance to disturbances due to dispersion and changes in the polarization of the signal light owing to the removal of the reference mirror. (C) 2015 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.54.01AB03

Language：English   Publishing type：Research paper (scientific journal)  

The effect of carbon nanowalls (CNWs) on the culturing rate and morphological control of cervical cancer cells (HeLa cells) was investigated. CNWs with different densities were grown using plasma-enhanced chemical vapor deposition and subjected to post-growth plasma treatment for modification of the surface terminations. Although the surface wettability of the CNWs was not significantly dependent on the CNW densities, the cell culturing rates were significantly dependent. Morphological changes of the cells were not significantly dependent on the density of CNWs. These results indicate that plasma-induced surface morphology and chemical terminations enable nanobio applications using carbon nanomaterials. (C) 2014 AIP Publishing LLC.

DOI： 10.1063/1.4902054

Language：English   Publishing type：Research paper (scientific journal)  

In plasma etching processes, temporal changes in atom densities need to be avoided since the ratio of atom densities is known to directly determine feature profiles. For H-2 and N-2 mixture plasmas, temporal changes in H and N atom densities are affected by chamber wall conditions, particularly after air exposure. Here we demonstrate that a new feedback control system recently developed by us could autonomously recover atom densities to the intended values in real time, on the basis of vacuum ultraviolet absorption spectroscopy measurements. Real-time process control is thus crucially achieved to suppress fluctuations in feature profiles due to plasma etching.

DOI： 10.1088/0022-3727/47/42/422002

Language：English   Publishing type：Research paper (scientific journal)  

Real time vacuum ultraviolet absorption spectroscopic (VUVAS) measurements revealed that temporal changes in absolute atom densities in H-2 and N-2 mixture gas (H-2/N-2) plasmas were affected by the conditions of the reactor inner wall-surface made of anodically-oxidized aluminum. Depending on preceding processes prior to the H-2/N-2 plasma process, N and H atom densities decreased for a nitrided wall surface, while no change occurred for a hydrogenated surface. Thus, the process history was revealed in the loss-properties of atoms on the reactor wall-surfaces. Suppressing the temporal variations in the gas-phase atom density is crucially important for realizing the precise control of the material processing with a high reproducibility. (C) 2014 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.53.050301

Language：English   Publishing type：Research paper (scientific journal)  

For utilization in future electronic application of graphene materials, nitrogen (N) atom doping into graphene sheets is an important technology. We investigated the electrical conduction of carbon nanowalls (CNWs), consisting of stacks of graphene sheets standing vertically on substrates. By post-treatment for 30 s, the electrical conductivity of CNWs increased. On the other hand, as the post-treatment time increased, the electrical conductivity decreased. According to Hall measurement, the carrier density decreased with increasing post-treatment time, while the carrier mobility increased. Consequently, the electrical conduction of the CNWs was successfully controlled by N-2 plasma treatment. (C) 2014 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.53.040307

Language：English   Publishing type：Research paper (scientific journal)  

A method combining of two-photon absorption laser-induced fluorescence and vacuum ultra-violet absorption spectroscopy is constructed and used to get the fine spatial distribution of O generated by a planar type of Ar/O-2 non-equilibrium atmospheric-pressure plasma jet. The O density in the quasi-uniform region, which occupies about 80&#37; of the total plasma width, is as high as 10(15) cm(-3). The lifetime of O is estimated to be about 360 +/- 60 mu s. The loss of O atoms is due to the three-body reaction of O + O2 + Ar -> O-3 + Ar confirmed by a simple calculation with a few rate equations. The results are very useful for the simulation of Ar/O-2 plasmas, the design of large-scale planar plasma jets and the development of their potential applications.

DOI： 10.1088/0963-0252/23/2/025004

Language：English   Publishing type：Research paper (scientific journal)  

Carbon nanowalls (CNWs), which are three-dimensional carbon nanomaterials consisting of stacks of graphene sheets vertically standing on substrates, possess a mazelike architecture containing high-density graphene edges and large-area plane surfaces. A selective morphological modification technique for the surfaces of CNWs after their growth has been developed employing hydrogen peroxide (H2O2) solution. It was found that oxidative radicals in H2O2 solution formed characteristic nanometer-scale asperities on the CNW surface without etching from the top edges. Photoelectron spectra indicate that hydroxyl adsorption and subsequent reactions at the edge and plane of graphene contribute to the selective morphological change on the CNW surface. (C) 2014 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.53.040305

Language：English   Publishing type：Research paper (scientific journal)  

Cauliflorous nanographene sheets were hierarchically regrown on the spearlike structures of carbon nanowalls (CNWs) produced by O-2-plasma etching. The spears on the CNWs acted as a stem for the growth of flowerlike flaky nanographene sheets, where the root of the nanoflower was located at a defect or disordered site. The defects on the graphitic structures were induced by irradiation with oxygen-related radicals and ions in the O-2-based plasmas and acted as sites for the nucleation of flowerlike nanographene. The porous carbon nanostructures regrown after O-2-plasma treatment have a relatively higher surface area and are thus promising materials for electrochemical applications. (C) 2014 The Japan Society of Applied Physics

DOI： 10.7567/APEX.7.046201

Language：English   Publishing type：Research paper (scientific journal)  

Gallium nitride (GaN) films have been grown by using our newly developed Radical-Enhanced Metalorganic Chemical Vapor Deposition (REMOCVD) system This system has three features: (1) application of very high frequency (60 MHz) power in order to increase the plasma density, (2) introduction of H-2 gas together with N-2 gas in the plasma discharge region to generate not only nitrogen radicals but also active NHx molecules, and (3) radical supply under remote plasma arrangement with suppression of charged ions and photons by employing a Faraday cage. Using this new system, we have studied the effect of the trimethylgallium (TMG) source now rate and of the plasma generation power on the GaN crystal quality by using scanning electron microscopy (SEM) and double crystal X-ray diffraction (XRD). We found that this REMOCVD allowed the growth of epitaxial GaN films of the wurtzite structure of (0001) orientation on sapphire substrates with a high growth rate of 0.42 mu m/h at a low temperature of 800 degrees C. The present REMOCVD is a promising method for GaN growth at relatively low temperature and without using costly ammonia gas. (C) 2014 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jcrysgro.2014.01.014

Language：English   Publishing type：Research paper (scientific journal)  

We report on successful control of the density of carbon nanowalls (CNWs) synthesized using radical-injection plasma-enhanced chemical vapor deposition (RI-PECVD) employing CH4/H-2 plasma, by varying the total pressure and discharge power during growth. As the total pressure was decreased or the power was increased, the density of CNWs decreased in conjunction with an increase in the H atom density measured using actinometric optical emission spectroscopy. The electrical conductivity of the films was found to be determined by the number of CNWs per unit length, i.e., the linear density. We demonstrated that the electrical properties could be controlled while maintaining the crystal quality and chemical bonding state of the synthesized CNWs in the RI-PECVD. (C) 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.carbon.2013.11.014

Language：English   Publishing type：Research paper (scientific journal)  

Chemical reactions during plasma-enhanced atomic layer deposition of SiO2 films employing aminosilane and O-2/Ar plasma at 50 degrees C
We report the temporal evolution of surface species observed in situ using attenuated total reflection Fourier transform infrared absorption spectroscopy (ATR-FTIR) during plasma-enhanced atomic layer deposition (PE-ALD) of SiO2 films employing aminosilane and an O-2/Ar plasma at a temperature of 50 degrees C. Reversals in the appearance of IR absorbance features associated with SiO-H, C-H-x, and Si-H proved to coincide with the self-limiting reaction property in ALD. Our IR results indicate that an O-2/Ar plasma can both removed CHx groups and transform SiH surface species to SiOH. In addition, SiO2 deposition was confirmed by a continuous increase in Si-O absorbance with each PE-ALD step, which becomes stable after several cycles. On the basis of our results, the mechanism of low temperature SiO2 PE-ALD was discussed. (C) 2014 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.53.010305

Language：English   Publishing type：Research paper (scientific journal)  

Purpose: Nonequilibrium atmospheric pressure plasma (NEAPP) therapy has recently been focused on as a novel medical practice. Using cells with acquired paclitaxel/cisplatin resistance, we elucidated effects of indirect NEAPP-activated medium (NEAPP-AM) exposure on cell viability and tumor growth in vitro and in vivo. Methods: Using chronic paclitaxel/cisplatin-resistant ovarian cancer cells, we applied indirect NEAPP-exposed medium to cells and xenografted tumors in a mouse model. Furthermore, we examined the role of reactive oxygen species (ROS) or their scavengers in the above-mentioned EOC cells. Results: We assessed the viability of NOS2 and NOS3 cells exposed to NEAPP-AM, which was prepared beforehand by irradiation with NEAPP for the indicated time. In NOS2 cells, viability decreased by approximately 30&#37; after NEAPP-AM 120-sec treatment (P&lt
0.01). The growth-inhibitory effects of NEAPP-AM were completely inhibited by N-acetyl cysteine treatment, while L-buthionine-[S, R]-sulfoximine, an inhibitor of the ROS scavenger used with NEAPP-AM, decreased cell viability by 85&#37; after NEAPP-AM 60-sec treatment(P&lt
0.05) and by 52&#37; after 120 sec, compared to the control (P&lt
0.01). In the murine subcutaneous tumor-formation model, NEAPP-AM injection resulted in an average inhibition of the NOS2 cell-inoculated tumor by 66&#37; (P&lt
0.05) and NOS2TR cell-inoculated tumor by 52&#37; (P&lt
0.05), as compared with the control. Conclusion: We demonstrated that plasma-activated medium also had an anti-tumor effect on chemo-resistant cells in vitro and in vivo. Indirect plasma therapy is a promising treatment option for EOC and may contribute to a better patient prognosis in the future. © 2013 Utsumi et al.

DOI： 10.1371/journal.pone.0081576

Language：English   Publishing type：Research paper (scientific journal)  

We report the fabrication of organic nanorods with a diameter of approximately 10 nm and a height of 106.8 nm (a high aspect ratio of 10.5) armored by Pt nanoparticles. Our results demonstrate that Pt particles deposited by metalorganic supercritical chemical fluid deposition (MOCFD) covering the entire deposition area play important roles in not only etch resistance, especially in protecting the sidewalls, but also the formation of electroconductive Pt/C composites, which were found to have field emission properties. (C) 2013 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.52.120203

Language：English   Publishing type：Research paper (other academic)  

We have developed an atmospheric pressure microwave plasma system with a microwave antenna consisting of two microwave guides, which have a discharge line with 41 slots. The antenna is set against a movable stage with a heater in a process chamber. The process gas used is a 1&#37; H2 gas diluted by Ar gas. We clarified various characteristics, such as gas temperature, electron density, and hydrogen radical density, using this system, and found that the gas temperature is about 1000 K, the electron density is 1 × 1015 cm-3, and the H radical density is 1 × 1016 cm -3 at the slot under the condition of a 10 GHz, 1.5 kW, pulsed microwave with a pulsed voltage of 2.5, a pulsed frequency of 4 kHz, and a duty ratio of 0.16. © 2013 The Japan Society of Applied Physics.

DOI： 10.7567/JJAP.52.11NE01

Language：English   Publishing type：Research paper (scientific journal)  

Rapid high-precision temperature monitoring systems for silicon wafers applicable even during plasma processing have been developed using frequency-domain low-coherence interferometry without a reference mirror. It was found to have a precision of 0.04 degrees C, a response time of 1 ms, and a large tolerance to mechanical vibrations and fiber vending when monitoring the temperature of commercial Si wafers. The performance is a substantial improvement over the previous precision of 0.11 degrees C measured in a few seconds using a time-domain method. It is, therefore, a powerful real-time technique to monitor rapidly varying wafer temperatures with high precision. (C) 2013 AIP Publishing LLC.

DOI： 10.1063/1.4827426

Language：English   Publishing type：Research paper (scientific journal)  

Carbon nanowalls (CNWs) consist of walls of thin graphite with thicknesses of a few tens of nanometers that stand vertically on a substrate. For modification of their structure after growth, we developed a method utilizing etching with oxygen atoms generated by an inductively coupled oxygen plasma. We found that oxygen atoms etched CNWs selectively from the top edges without etching reaction of the wall surface as the graphitic planes. This can provide a method for realizing carbon nanoelectronics by selective modification of the edges without oxidation of the graphene planes. (c) 2013 The Japan Society of Applied Physics

DOI： 10.7567/APEX.6.095201

Language：English   Publishing type：Research paper (scientific journal)  

Carbon nanowalls (CNWs) are self-assembled, free-standing, few-layered graphenenano-structures with large surface area, and thin graphene edges. For their application to nanobiotechnology, the effects of chemisorbed species on surface wettability were investigated. The surfaces of as-grown CNWs obtained using CH4/H-2 mixture were hydrophilic. After Ar atmospheric pressure plasma treatments for up to 30s, the contact angles of water droplets on the CNWs decreased from 51 degrees to 5 degrees, owing to a result of oxidation only at edges and surface defects. They increased up to 147 degrees by CF4 plasma treatment at low pressure. The wide-range control of surface wettability of CNWs was realized by post-growth plasma treatments. We also demonstrated detection of bovine serum albumin using surface-modified CNWs as electrodes.

DOI： 10.1002/ppap.201200141

Language：English   Publishing type：Research paper (scientific journal)  

Carbon nanowalls (CNWs) are self-assembled, free-standing, few-layered graphenenano-structures with large surface area, and thin graphene edges. For their application to nanobiotechnology, the effects of chemisorbed species on surface wettability were investigated. The surfaces of as-grown CNWs obtained using CH4/H-2 mixture were hydrophilic. After Ar atmospheric pressure plasma treatments for up to 30s, the contact angles of water droplets on the CNWs decreased from 51 degrees to 5 degrees, owing to a result of oxidation only at edges and surface defects. They increased up to 147 degrees by CF4 plasma treatment at low pressure. The wide-range control of surface wettability of CNWs was realized by post-growth plasma treatments. We also demonstrated detection of bovine serum albumin using surface-modified CNWs as electrodes.

DOI： 10.1002/ppap.201200141

Language：English   Publishing type：Research paper (scientific journal)  

The growth of single-walled carbon nanotubes (SWCNTs) was carried out on SiO2/Si substrates with Pt catalysts at 400, 450, and 700 degrees C using an alcohol gas source method in a high vacuum, and the grown SWCNTs were characterized by Raman spectroscopy. By optimizing the ethanol pressure, we could grow SWCNTs even at 400 and 450 degrees C. By reducing the growth temperature, both the diameter and diameter distribution of the SWCNTs were markedly decreased, and the diameters for most of the SNWTs grown at 400 degrees C were estimated to be below 1 nm from the Raman results. Transmission electron microscopy (TEM) observation showed that the reduction in SWCNT diameter was caused by the decrease in catalyst size with decreasing temperature. (c) 2013 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.52.06GD02

Language：English   Publishing type：Research paper (scientific journal)  

Surface morphology on high-temperature plasma-etched gallium nitride
We report the surface morphology of gallium nitride (GaN) films during the argon and nitrogen plasma etching at elevated temperatures up to 800°C. For Ar plasma at high substrate temperatures above 600°C, Ar⁺ ion bombardment dissociates Ga-N bonds by the preferential removal of nitrogen, which promotes roughness of the GaN surface by the aggregation of gallium atoms. In N₂ plasma exposure, the N/Ga remains stoichiometric with higher values above 0.85, and the surface is not significantly roughened, even higher at 600°C. Therefore, the aggregation of metallic Ga induces surface roughening during ion-enhanced etching of GaN with elevated substrate temperatures.

DOI： 10.14723/tmrsj.38.325

Language：English   Publishing type：Research paper (scientific journal)  

We report the damageless surface morphology of gallium nitride (GaN) films during argon and nitrogen plasma etching at elevated temperatures up to 600 degrees C. For Ar plasma bombardment at high substrate temperatures of around 600 degrees C, Ar+ ion bombardment dissociates Ga-N bonds by the preferential removal of nitrogen, which promotes roughness of the GaN surface by the aggregation of gallium atoms. For the N-2 plasma one, the N/Ga remains stoichiometric with higher values above 0.69, and the surface is not significantly roughened, even at 600 degrees C. Therefore, the aggregation of metallic Ga induces surface roughening during ion-enhanced etching of GaN at elevated substrate temperatures. (C) 2013 The Japan Society of Applied Physics

DOI： 10.7567/APEX.6.056201

Language：English   Publishing type：Research paper (scientific journal)  

The wavelength dependence of SiNx:H/Si interface defect generation caused by vacuum ultraviolet (VUV)/UV radiation from plasma etching processes was investigated. VUV radiation (lambda < 200 nm) had almost no impact on the generation of defects at the SiNx:H/Si interface, since all the radiation in this wavelength range was absorbed in the upper SiNx:H film. However, UV radiation (200 < lambda < 400 nm) was able to reach the underlying SiNx:H/Si interface and damage the interface. Direct UV radiation reaching the SiNx : H/Si interface dissociated the chemical bonds at the interface and generated interface-trapped charges. The estimated total energy of absorbed photons (E-total; 200 < lambda < 400 nm) at the interface layer seems to be proportional to the interface-trapped charge density (D-it) measured by capacitance-voltage measurement. However, the mechanism underlying the relationship between E-total and D-it is not yet clear. Visible radiation (lambda > 400 nm) had no influence on damage generation on the SiNx:H/Si structure, since the visible radiation was transmitted through upper SiNx:H film and underlying interface layer. The results revealed that UV radiation transmitted through the upper dielectrics can cause the electrical characteristics of underlying metal-oxide-semiconductor (MOS) devices to fluctuate. (C) 2013 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.52.05ED01

Language：English   Publishing type：Research paper (scientific journal)  

Nanoparticles of the anatase phase of TiO2 (2.7 +/- 0.7 nm) with a high density of 10(12) cm(-2) were supported on the entire surface of carbon nanowalls (CNWs) by employing metal organic chemical fluid deposition in supercritical carbon dioxide at a substrate temperature of 180 degrees C. For decomposing methylene blue under ultraviolet irradiation, a high photocatalytic decomposition rate of 6 mg/h was obtained for 1 mg of TiO2 supported on CNWs. (C) 2013 The Japan Society of Applied Physics

DOI： 10.7567/APEX.6.045103

Language：English   Publishing type：Research paper (scientific journal)  

We report an observed relationship between chemical modifications and physical morphological roughness on a photoresist for ArF excimer laser photolithography in fluorocarbon plasma beam irradiation. At the very beginning period, three stages of characteristics of chemical changes occurred upon surface roughening or wrinkling of the photoresist; (1) a rapid reduction of C=O bonds, (2) gradual formation of a fluorocarbon layer, and graphitic (sp(2)-C) or amorphous (sp(3)-C) carbon layer; (3) as elapsed incubation phase, i.e. lag, where reached a steady state of chemical changes for fluorocarbon ion irradiation on the surface; finally morphological changes initiated. Those processes evolved within dose of 6 x 10(15) cm(-2) for ion energy of a few hundred eV.

DOI： 10.1088/0022-3727/46/10/102001

Language：English   Publishing type：Research paper (scientific journal)  

We have characterized Nb hydrides synthesized in high-pressure supercritical water by hard X-ray photoelectron spectroscopy. Comparison is made, in particular, of the Nb 2p core level spectra and valence band ones for the Nb hydride specimens in different stages of hydrogenation with those for Nb oxide and metallic references. The Nb 2p core level spectra of the Nb hydride specimens synthesized at relatively low temperature show an intense Nb 2O5 component and a shoulder structure, which is attributed to Nb hydrides, at the high binding energy side of a metallic component of the Nb metal. The valence band spectra of the Nb hydride specimens also show a broad band at the binding energy EB between 5 and 9 eV, which is ascribed mainly to Nb oxides. The present results indicate that the surface of the synthesized Nb hydrides is covered with several 10 nm thick Nb oxides and suggest that the Nb hydrides are formed deep inside the specimens. The Nb 2p chemical shift implies the Nb valence of +1.4 for the synthesized hydride NbHx. © 2013 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.elspec.2013.02.006

Language：English   Publishing type：Research paper (scientific journal)  

A high-density radical source (HDRS) was developed by optimizing the antenna structure and introducing an external magnetic field to plasma. Nitrogen radical generation by the HDRS at a density of 2.3 x 10(12) atoms cm(-3), which was one order higher than that for the conventional radical source (CRS), was achieved. The HDRS- and CRS-assisted InGaN growth in molecular beam epitaxy (MBE) was carried out. For the HDRS case, a diffraction peak in the X-ray rocking curve of the grown InGaN films showed a narrower peak, which width below 600 arcsec even with a high growth rate of 1.4 mu m/h for InGaN. MBE with the assistance of HDRS has a great potential in the growth of nitride films with a lower mosaicity and a higher growth rate. (C) 2013 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.52.021001

Language：English   Publishing type：Research paper (scientific journal)  

The etching rates of low-dielectric-constant (low-k), porous SiOCH (p-SiOCH) films were increased by nitrogen-added Ar/C5F10O plasma etching in dual-frequency (60 MHz/2 MHz)-excited parallel plate capacitively coupled plasma. Previously, perfluoropropyl vinyl ether [C5F10O] provided a very high density of CF3+ ions [Nagai et al.: Jpn. J. Appl. Phys. 45 (2006) 7100]. Surface nitridation on the p-SiOCH surface exposed to Ar/N-2 plasma led to the etching of larger amounts of p-SiOCH in Ar/C5F10O plasma, which depended on the formation of bonds such as =C(sp(2))=N(sp(2))- and -C(sp) N(sp). (C) 2013 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.52.020204

Language：English   Publishing type：Research paper (scientific journal)  

The etching rates of low-dielectric-constant (low-k), porous SiOCH (p-SiOCH) films were increased by nitrogen-added Ar/C5F10O plasma etching in dual-frequency (60 MHz/2 MHz)-excited parallel plate capacitively coupled plasma. Previously, perfluoropropyl vinyl ether [C5F10O] provided a very high density of CF3+ ions [Nagai et al.: Jpn. J. Appl. Phys. 45 (2006) 7100]. Surface nitridation on the p-SiOCH surface exposed to Ar/N-2 plasma led to the etching of larger amounts of p-SiOCH in Ar/C5F10O plasma, which depended on the formation of bonds such as =C(sp(2))=N(sp(2))- and -C(sp) N(sp). (C) 2013 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.52.020204

Language：English   Publishing type：Research paper (scientific journal)  

A high-density radical source (HDRS) was developed by optimizing the antenna structure and introducing an external magnetic field to plasma. Nitrogen radical generation by the HDRS at a density of 2.3 x 10(12) atoms cm(-3), which was one order higher than that for the conventional radical source (CRS), was achieved. The HDRS- and CRS-assisted InGaN growth in molecular beam epitaxy (MBE) was carried out. For the HDRS case, a diffraction peak in the X-ray rocking curve of the grown InGaN films showed a narrower peak, which width below 600 arcsec even with a high growth rate of 1.4 mu m/h for InGaN. MBE with the assistance of HDRS has a great potential in the growth of nitride films with a lower mosaicity and a higher growth rate. (C) 2013 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.52.021001

Language：English   Publishing type：Research paper (scientific journal)  

Modification of an advanced ArF excimer lithographic photoresist by 400 eV Ar ion irradiation was observed in situ in real time using both infrared spectroscopy and a quartz microbalance sensor. The photoresist sputtering yields had a characteristic behavior; the sputtering yields were higher than unity at the beginning, until an ion dose of 2 x 10(16) ions cm(-2). Thereafter, the yields decreased immediately to almost zero and remained constant with the yield at zero until a dose of approximately 4 x 10(16) ions cm(-2) was reached. At larger doses, the yields increased again and reached a steady-state value of approximately 0.6. This development of the sputtering yield after the onset of ion bombardment is explained by an ion-induced modification of the photoresist that includes preferential sputtering of individual groups, argon ion implantation and the generation of voids. All these effects must be taken into account to assess line-edge-roughness on a photoresist subjected to highly energetic ion irradiation. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4772996]

DOI： 10.1063/1.4772996

Language：English   Publishing type：Research paper (scientific journal)  

The surface loss probability of H radicals was investigated in SiH4/H-2 plasma using vacuum ultraviolet resonance absorption spectroscopy. The surface loss probability was calculated from the decay curve of the H radical density in the plasma afterglow and increased with the SiH4 flow rate. Silicon thin films deposited on the chamber wall were analyzed to investigate the relation between the surface loss probability and the surface condition. The surface reaction of H radicals is influenced by deposition precursors, such as SiH3 radicals. The density of H radicals significantly decreased with heating of the chamber wall up to 473 K. The surface loss probability of H radicals was estimated to be ca. 1 at 473 K. Quantitative measurements of the surface loss probability of H radicals in SiH4/H-2 plasma are expected to be particularly important for understanding the surface reactions that occur during the deposition of silicon thin films. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4773104]

DOI： 10.1063/1.4773104

Language：English   Publishing type：Research paper (scientific journal)  

The surface loss probability of H radicals was investigated in SiH4/H-2 plasma using vacuum ultraviolet resonance absorption spectroscopy. The surface loss probability was calculated from the decay curve of the H radical density in the plasma afterglow and increased with the SiH4 flow rate. Silicon thin films deposited on the chamber wall were analyzed to investigate the relation between the surface loss probability and the surface condition. The surface reaction of H radicals is influenced by deposition precursors, such as SiH3 radicals. The density of H radicals significantly decreased with heating of the chamber wall up to 473 K. The surface loss probability of H radicals was estimated to be ca. 1 at 473 K. Quantitative measurements of the surface loss probability of H radicals in SiH4/H-2 plasma are expected to be particularly important for understanding the surface reactions that occur during the deposition of silicon thin films. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4773104]

DOI： 10.1063/1.4773104

Language：English   Publishing type：Research paper (scientific journal)  

Carbon nanowalls (CNWs), a self-organized network of vertically standing few-layer graphenes, were synthesized by inductively coupled plasma-enhanced chemical vapor deposition (ICP-CVD) employing methane and argon mixtures. Significant interest exists in clarifying the nucleation mechanism of CNWs and controlling their nucleation. We have investigated the early growth stage of CNWs on the catalyst-free substrate and the titanium (Ti)-nanoparticle-catalyzed substrate. In the case of catalyst-free growth of CNWs, there was an induction period of 1-5 min before the onset of vertical nanographene growth and an interface layer exists between the vertical nanographenes and the surface of Si and SiO2 substrates. Meanwhile, in the case of the growth on the Ti nanoparticle-coated SiO2 substrates, the nanographenes were directly nucleated from the Ti nanoparticles without forming a base layer within 30 s, while no nucleation was observed on the SiO2 surface at this period. These results suggest the possibility of area-selective growth of CNWs by controlling the substrate biasing to suppress the nucleation selectively from the catalyst-free surface. (C) 2013 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.52.01AK05

Language：English   Publishing type：Research paper (scientific journal)  

A plasma-enhanced chemical deposition system with hydrogen radical-injection (RI) is proposed for the fabrication of hydrogenated microcrystalline silicon (mu c-Si: H) thin films. The plasma parameters and resultant growth characteristics obtained with the RI-capacitively coupled plasma (RI-CCP) system excited with 60MHz power were compared with those obtained using a conventional CCP (C-CCP) system. The absolute density of hydrogen (H) radicals was measured by vacuum ultraviolet laser absorption spectroscopy (VUVLAS) to evaluate the effect of RI for controlling the H radical density. A higher density of H radicals was achieved with RI-CCP than with C-CCP by H RI. The crystallinity factor, preferential orientation, defect density, microstructure, and post-deposition oxidation of Si thin films deposited using C-CCP and RI-CCP were investigated. Crystallinity factor of 0.6 was realized with high deposition rate of about 2 nm/s even under a low plasma density using RI-CCP. The defect density of mu c-Si: H thin films prepared using RI-CCP was lower than that in thin films prepared using C-CCP. In addition, post-deposition oxidation of the films with RI-CCP was lower than that with C-CCP. The high performance of RI-CCP for the fabrication of mu c-Si:H thin films for solar cell devices is also demonstrated. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4778608]

DOI： 10.1063/1.4778608

Language：English   Publishing type：Research paper (scientific journal)  

A plasma-enhanced chemical deposition system with hydrogen radical-injection (RI) is proposed for the fabrication of hydrogenated microcrystalline silicon (mu c-Si: H) thin films. The plasma parameters and resultant growth characteristics obtained with the RI-capacitively coupled plasma (RI-CCP) system excited with 60MHz power were compared with those obtained using a conventional CCP (C-CCP) system. The absolute density of hydrogen (H) radicals was measured by vacuum ultraviolet laser absorption spectroscopy (VUVLAS) to evaluate the effect of RI for controlling the H radical density. A higher density of H radicals was achieved with RI-CCP than with C-CCP by H RI. The crystallinity factor, preferential orientation, defect density, microstructure, and post-deposition oxidation of Si thin films deposited using C-CCP and RI-CCP were investigated. Crystallinity factor of 0.6 was realized with high deposition rate of about 2 nm/s even under a low plasma density using RI-CCP. The defect density of mu c-Si: H thin films prepared using RI-CCP was lower than that in thin films prepared using C-CCP. In addition, post-deposition oxidation of the films with RI-CCP was lower than that with C-CCP. The high performance of RI-CCP for the fabrication of mu c-Si:H thin films for solar cell devices is also demonstrated. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4778608]

DOI： 10.1063/1.4778608

Language：English   Publishing type：Research paper (scientific journal)  

In a dual-frequency-excited parallel plate capacitively coupled plasma employing a heptafluoro-cyclo-pentene (C5HF7) gas with addition of O2 and dilution in Ar gas, highly selective etching of SiO2 at selectivities of 40 against Si3N4 and 57 against polycrystalline Si was realized. Gas phase fluorocarbon species containing H atoms such as CxHFy (x &gt
2) played key roles in the selective deposition of thick hydrofluorocarbon films that covered the Si3N4 and polycrystalline silicon (poly-Si) surfaces and in the selective etching of SiO2 over the photoresist, SiN, and Si. © 2013 The Japan Society of Applied Physics.

DOI： 10.7567/JJAP.52.016201

Language：English   Publishing type：Research paper (scientific journal)  

Microwave plasma is one of the high-density plasmas and has been extensively used for the growth of diamond and aligned carbon nanotubes for more than a decade. However, the conventional microwave plasma of the cylindrical resonant cavity type is not suitable for the synthesis of graphene. The plasma ball produced in the resonant cavity provides a number of important species as well as ions, while deposits are damaged by the excess ion bombardment since the substrate is exposed to the plasma ball. To simply control the position of the plasma ball and reduce the ion bombardment on the substrate surface, a grounded molybdenum mesh was installed over the substrate plate to realize a remote plasma configuration. As a result, the distance between the plasma ball and the copper substrate was increased, and few-layer graphene-based films were successfully synthesized in 1 min on copper substrates placed on the entire region of a substrate holder 10 cm in diameter by using conventional microwave-plasma enhanced chemical vapor deposition. (C) 2013 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.52.01AK04

Language：English   Publishing type：Research paper (scientific journal)  

Carbon nanowalls (CNWs) can be described as self-assembled, vertically standing, few-layered graphene sheet nanostructures. In order to demonstrate the usefulness of CNWs in fuel cell application, CNWs were directly grown on carbon fiber paper (CFP) using the inductively coupled plasma-enhanced chemical vapor deposition (ICP-CVD) method. Subsequently, highly dispersed platinum (Pt) nanoparticles were formed on the surface of CNWs using metal-organic chemical fluid deposition (MOCFD) employing a supercritical fluid (SCF). Moreover, a single proton exchange membrane (PEM) fuel cell unit using a Pt-supported CNW/CFP electrode was constructed, and its voltage-current characteristics were measured. This configuration ensures that all the supported Pt nanoparticles are in electrical contact with the external electrical circuit. Such a design would improve Pt utilization and potentially decrease Pt usage. Pt-supported CNWs grown on CFP will be well suited to the application in electrodes of fuel cells. (C) 2013 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.52.01AK03

Language：English   Publishing type：Research paper (scientific journal)  

Modification of an advanced ArF excimer lithographic photoresist by 400 eV Ar ion irradiation was observed in situ in real time using both infrared spectroscopy and a quartz microbalance sensor. The photoresist sputtering yields had a characteristic behavior; the sputtering yields were higher than unity at the beginning, until an ion dose of 2 x 10(16) ions cm(-2). Thereafter, the yields decreased immediately to almost zero and remained constant with the yield at zero until a dose of approximately 4 x 10(16) ions cm(-2) was reached. At larger doses, the yields increased again and reached a steady-state value of approximately 0.6. This development of the sputtering yield after the onset of ion bombardment is explained by an ion-induced modification of the photoresist that includes preferential sputtering of individual groups, argon ion implantation and the generation of voids. All these effects must be taken into account to assess line-edge-roughness on a photoresist subjected to highly energetic ion irradiation. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4772996]

DOI： 10.1063/1.4772996

Language：English   Publishing type：Research paper (other academic)  

Silicon-on-insulator (SOI) wafers made by direct wafer bonding are widely used as starting substrates for microelectromechanical systems (MEMS) fabrication. Adding another layer next to the SiO2 SOI, or replacing it with another material, will be a way to tailor the SOI wafers further. Atomic layer deposition (ALD) can be used to deposit pinhole-free nanometer-thin conformal and smooth inorganic films at low temperatures, making it of interest for many applications in MEMS. In this work, the direct wafer bonding of ALD TiO2, and Al2O3 for reference, is investigated, eventually in order to fabricate SOI wafers with buried ALD oxides. Finding suitable process conditions for TiO2 bonding was challenging: bonding could not be made for TiO2 deposited directly on SiO2 or Si, and annealing at 1100°C gave non-continuous Ti-containing layers. Using a 2-nm Al2O3 under-layer and annealing at 700°C gave void-free bonding with continuous TiO2 and a bond strength of approximately 1600 mJ/m2, enabling the fabrication of SOI wafers with buried TiO2. © 2012 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.sna.2012.05.006

Language：English   Publishing type：Research paper (scientific journal)  

In the recovery of photoluminescence intensities for band-edge emissions at around 3.47 eV in the case of gallium nitride (GaN), we have studied the individual roles of hydrogen atoms (H) and hydrogen ions (H-n(+)). Surface defects such as nitrogen vacancies created by plasma etching were passivated by H termination. By utilizing hydrogen plasmas, we clarified the recovery efficiency by optical and stoichiometrical improvements with respect to the balance between the fluxes of H and H-n(+). By deflecting H-n(+) by applying an electric field, the efficiency was improved using an identical H dosage, since the simultaneous irradiation of the energetic H-n(+) promoted the desorption of the formed passivated Ga-H bonds. (C) 2012 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.51.111002

Language：English   Publishing type：Research paper (scientific journal)  

The properties of thin-film silicon grown by plasma enhanced chemical vapor deposition were investigated with respect to the flux ratio of hydrogen radical to film precursor. The absolute density and translational temperature of H radicals in SiH4/H-2 capacitively coupled plasma were measured using vacuum ultraviolet laser absorption spectroscopy. The flux of effective H radicals to the surface reactions was estimated from the results. The flux of effective film precursor for deposition was estimated from the deposition rate, so that the critical flux ratio of H radicals to film precursor to obtain suitable film properties was identified to be approximately 65-70. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4764065]

DOI： 10.1063/1.4764065

Language：English   Publishing type：Research paper (scientific journal)  

We report the kinetic analysis of free radicals on fungal spores of Penicillium digitatum interacted with atomic oxygen generated plasma electric discharge using real time in situ electron spin resonance (ESR) measurements. We have obtained information that the ESR signal from the spores was observed and preliminarily assignable to semiquinone radical with a g-value of around 2.004 and a line width of approximately 5G. The decay of the signal is possibly linked to the inactivation of the fungal spore. The real-time in situ ESR has proven to be a useful method to elucidate plasma-induced surface reactions on biological specimens. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4733387]

DOI： 10.1063/1.4733387

Language：English   Publishing type：Research paper (scientific journal)  

We report the kinetic analysis of free radicals on fungal spores of Penicillium digitatum interacted with atomic oxygen generated plasma electric discharge using real time in situ electron spin resonance (ESR) measurements. We have obtained information that the ESR signal from the spores was observed and preliminarily assignable to semiquinone radical with a g-value of around 2.004 and a line width of approximately 5G. The decay of the signal is possibly linked to the inactivation of the fungal spore. The real-time in situ ESR has proven to be a useful method to elucidate plasma-induced surface reactions on biological specimens. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4733387]

DOI： 10.1063/1.4733387

Language：English   Publishing type：Research paper (scientific journal)  

Background: Pandemic influenza A(H1N1) 2009 virus was first detected in Japan in May 2009 and continued to circulate in the 2010-2011 season. This study aims to characterize human influenza viruses circulating in Japan in the pandemic and post-pandemic periods and to determine the prevalence of antiviral-resistant viruses.Methods: Respiratory specimens were collected from patients with influenza-like illness on their first visit at outpatient clinics during the 2009-2010 and 2010-2011 influenza seasons. Cycling probe real-time PCR assays were performed to screen for antiviral-resistant strains. Sequencing and phylogenetic analysis of the HA and NA genes were done to characterize circulating strains.Results and Conclusion: In the pandemic period (2009-2010), the pandemic influenza A(H1N1) 2009 virus was the only circulating strain isolated. None of the 601 A(H1N1) pdm09 virus isolates had the H275Y substitution in NA (oseltamivir resistance) while 599/601 isolates (99.7&#37;) had the S31N substitution in M2 (amantadine resistance). In the post-pandemic period (2010-2011), cocirculation of different types and subtypes of influenza viruses was observed. Of the 1,278 samples analyzed, 414 (42.6&#37;) were A(H1N1) pdm09, 525 (54.0&#37;) were A(H3N2) and 33 (3.4&#37;) were type-B viruses. Among A(H1N1) pdm09 isolates, 2 (0.5&#37;) were oseltamivir-resistant and all were amantadine-resistant. Among A(H3N2) viruses, 520 (99.0&#37;) were amantadine-resistant. Sequence and phylogenetic analyses of A(H1N1) pdm09 viruses from the post-pandemic period showed further evolution from the pandemic period viruses. For viruses that circulated in 2010-2011, strain predominance varied among prefectures. In Hokkaido, Niigata, Gunma and Nagasaki, A(H3N2) viruses (A/Perth/16/2009-like) were predominant whereas, in Kyoto, Hyogo and Osaka, A(H1N1) pdm09 viruses (A/New_York/10/2009-like) were predominant. Influenza B Victoria(HA)-Yamagata(NA) reassortant viruses (B/Brisbane/60/2008-like) were predominant while a small proportion was in Yamagata lineage. Genetic variants with mutations at antigenic sites were identified in A(H1N1) pdm09, A(H3N2) and type-B viruses in the 2010-2011 season but did not show a change in antigenicity when compared with respective vaccine strains.

DOI： 10.1371/journal.pone.0036455

Language：English   Publishing type：Research paper (scientific journal)  

The effect of in-situ exposure of n-GaN damaged by Cl-2 plasma to atomic hydrogen (H radicals) at room temperature was investigated. We found that the PL intensities of the band-edge emission, which had been drastically reduced by plasma-beam irradiation at a Cl ion dose of 5 x 10(16) cm(-2), recovered to values close to those of as-grown samples after H radical exposure at a dose of 3.8 x 10(17) cm(-2). XPS revealed the appearance of a peak at a binding energy of 18.3 eV, which is tentatively assigned to Ga-H, and confirmed the removal of Cl after Hradical exposure. Copyright 2012 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License. [http://dx.doi.org/10.1063/1.4729448]

DOI： 10.1063/1.4729448

Language：English   Publishing type：Research paper (scientific journal)  

The effect of in-situ exposure of n-GaN damaged by Cl-2 plasma to atomic hydrogen (H radicals) at room temperature was investigated. We found that the PL intensities of the band-edge emission, which had been drastically reduced by plasma-beam irradiation at a Cl ion dose of 5 x 10(16) cm(-2), recovered to values close to those of as-grown samples after H radical exposure at a dose of 3.8 x 10(17) cm(-2). XPS revealed the appearance of a peak at a binding energy of 18.3 eV, which is tentatively assigned to Ga-H, and confirmed the removal of Cl after Hradical exposure. Copyright 2012 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License. [http://dx.doi.org/10.1063/1.4729448]

DOI： 10.1063/1.4729448

Language：English   Publishing type：Research paper (scientific journal)  

Two independent ovarian cancer cell lines and fibroblast controls were treated with nonequilibrium atmospheric pressure plasma (NEAPP). Most ovarian cancer cells were detached from the culture dish by continuous plasma treatment to a single spot on the dish. Next, the plasma source was applied over the whole dish using a robot arm. In vitro cell proliferation assays showed that plasma treatments significantly decreased proliferation rates of ovarian cancer cells compared to fibroblast cells. Flow cytometry and western blot analysis showed that plasma treatment of ovarian cancer cells induced apoptosis. NEAPP could be a promising tool for therapy for ovarian cancers. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3694928]

DOI： 10.1063/1.3694928

Language：English   Publishing type：Research paper (scientific journal)  

Ultrahigh-speed synthesis of high-crystallinity nanographene was realized using an alcohol in-liquid plasma, which was generated from a nonequilibrium microhollow atmospheric-pressure plasma with an ultrahigh electron density. The synthesis rates of carbon materials were 0.61 and 1.72 mg/min using ethanol and butanol, respectively. Multilayer nanographene structures obtained using ethanol had an interlayer spacing of 0.33 nm, corresponding to that of (002) planes in graphite. The G-, D-, D'-, and 2D- band peaks in the Raman spectrum also confirmed the formation of nanographene. The mechanism of gradual growth of six-membered ring structures was clarified by gas chromatography of the filtrate. (c) 2012 The Japan Society of Applied Physics

DOI： 10.1143/APEX.5.035101

Language：English   Publishing type：Research paper (scientific journal)  

Two independent ovarian cancer cell lines and fibroblast controls were treated with nonequilibrium atmospheric pressure plasma (NEAPP). Most ovarian cancer cells were detached from the culture dish by continuous plasma treatment to a single spot on the dish. Next, the plasma source was applied over the whole dish using a robot arm. In vitro cell proliferation assays showed that plasma treatments significantly decreased proliferation rates of ovarian cancer cells compared to fibroblast cells. Flow cytometry and western blot analysis showed that plasma treatment of ovarian cancer cells induced apoptosis. NEAPP could be a promising tool for therapy for ovarian cancers. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3694928]

DOI： 10.1063/1.3694928

Language：English   Publishing type：Research paper (scientific journal)  

Photon-enhanced etching of SiNx:H films caused by the interaction between vacuum ultraviolet (VUV)/ultraviolet (UV) radiation and radicals in the fluorocarbon plasma was investigated by a technique with a novel sample setup of the pallet for plasma evaluation. The simultaneous injection of UV radiation and radicals causes a dramatic etch rate enhancement of SiNx:H films. Only UV radiation causes the film shrinkage of SiNx:H films owing to hydrogen desorption from the film. Capacitance-voltage characteristics of SiNx:H/Si substrates were studied before and after UV radiation. The interface trap density increased monotonically upon irradiating the UV photons with a wavelength of 248 nm. The estimated effective interface trap generation probability is 4.74 x 10(-7) eV(-1 center dot)photon(-1). Therefore, the monitoring of the VUV/UV spectra during plasma processing and the understanding of its impact on the surface reaction, film damage and electrical performance of underlying devices are indispensable to fabricate advanced devices. (c) 2012 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.51.026201

Language：English   Publishing type：Research paper (scientific journal)  

Photon-enhanced etching of SiNx:H films caused by the interaction between vacuum ultraviolet (VUV)/ultraviolet (UV) radiation and radicals in the fluorocarbon plasma was investigated by a technique with a novel sample setup of the pallet for plasma evaluation. The simultaneous injection of UV radiation and radicals causes a dramatic etch rate enhancement of SiNx:H films. Only UV radiation causes the film shrinkage of SiNx:H films owing to hydrogen desorption from the film. Capacitance-voltage characteristics of SiNx:H/Si substrates were studied before and after UV radiation. The interface trap density increased monotonically upon irradiating the UV photons with a wavelength of 248 nm. The estimated effective interface trap generation probability is 4.74 x 10(-7) eV(-1 center dot)photon(-1). Therefore, the monitoring of the VUV/UV spectra during plasma processing and the understanding of its impact on the surface reaction, film damage and electrical performance of underlying devices are indispensable to fabricate advanced devices. (c) 2012 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.51.026201

Language：English   Publishing type：Research paper (scientific journal)  

Super hydrophobic and super hydrophilic surface treatment methods for carbon nanowalls (CNWs) which are carbon nanostructures consisting of stacks of graphene sheets vertically standing on substrates and having ultra high aspect ratios of over 50, were developed using atmospheric pressure plasma, and their mechanisms were discussed on the basis of the elemental compositions of surfaces. The contact angle of water droplet on CNWs markedly decreased from 137.3 to 6.2 degrees with the atmospheric pressure plasma treatments using Ar gas. This indicates the super hydrophobic and super hydrophilic transition of CNW surfaces. Although a morphological change was hardly found, the surface compositions of fluorine and oxygen atoms markedly changed after the plasma treatment for only 5s. Furthermore, the treatment time dependence of the surface tension of CNWs indicates two different mechanisms at earlier and later stages of surface modification using atmospheric pressure plasma. (C) 2012 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.51.01AJ07

Language：English   Publishing type：Research paper (scientific journal)  

The precise etching of organic films with a low dielectric constant (low-k) in a dual-frequency capacitively coupled plasma etching reactor with a plasma generation of 100 MHz and an applied bias of 2 MHz employing a gas mixture of hydrogen and nitrogen was performed by real-time control of the densities of hydrogen (H) and nitrogen (N) radicals based on real-time measurement of the Si substrate temperature. H and N radical densities were monitored near the sidewall of the reactor by vacuum ultraviolet absorption spectroscopy, and temperature was monitored by an optical fiber-type low-coherence interferometer. On the basis of the results of surface analysis by X-ray photoelectron spectroscopy, etched profiles were effectively determined from the chemical component of protection layers on the sidewall of the etched pattern affected by the ratio of H/(H + N) and substrate temperature. As the etching feature evolves, the ratio of radical density should be controlled temporally to maintain vertical profiles according to the change in substrate temperature. As a result, we have successfully realized an organic film with a vertical feature. These results indicate the need for autonomous control of the etch process based on real-time information on the plasma process for the next-generation ultrafine etching. (C) 2012 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.51.016202

Language：English   Publishing type：Research paper (scientific journal)  

Superpositioning of negative dc bias in dual-frequency capacitively coupled plasmas (dc-superposed (DS)-CCP) was realized for the selective etching of carbon-doped silicon oxide (SiOCH) films over carbon-doped amorphous silicon (SiC) films, while the dc bias exceeded about -800 V. When a dc bias of -1200 V was superposed on 60 MHz VHF power on the top electrode opposed to a wafer on the bottom electrode biased with 13.56 MHz power, a selectivity of above 50 for SiOCH over SiC was obtained. From characterization of the plasma density and various chemical species in the gaseous phase, such as CF(2), CF and atomic N, the density of CF(2) significantly decreased with the application of dc bias ranging from -800 to -1200V. This indicated that CF(2) radicals were consumed at the surface of the counter electrode which was made of silicon. The bulk densities of the species including CF(2) were decreased, especially due to excess surface loss caused by the bombardment of highly energetic ions accelerated by the superposed dc bias, as well as the rf sheath for the superposition of the negative dc bias. The DS-CCP technology is thus concluded to be indispensable for yielding highly selective etching of SiOCH over SiC.

DOI： 10.1088/0022-3727/45/2/025203

Language：English   Publishing type：Research paper (scientific journal)  

Super hydrophobic and super hydrophilic surface treatment methods for carbon nanowalls (CNWs) which are carbon nanostructures consisting of stacks of graphene sheets vertically standing on substrates and having ultra high aspect ratios of over 50, were developed using atmospheric pressure plasma, and their mechanisms were discussed on the basis of the elemental compositions of surfaces. The contact angle of water droplet on CNWs markedly decreased from 137.3 to 6.2 degrees with the atmospheric pressure plasma treatments using Ar gas. This indicates the super hydrophobic and super hydrophilic transition of CNW surfaces. Although a morphological change was hardly found, the surface compositions of fluorine and oxygen atoms markedly changed after the plasma treatment for only 5s. Furthermore, the treatment time dependence of the surface tension of CNWs indicates two different mechanisms at earlier and later stages of surface modification using atmospheric pressure plasma. (C) 2012 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.51.01AJ07

Language：English   Publishing type：Research paper (scientific journal)  

The modification of porous low-dielectric (low-k) SiOCH films by ashing plasma irradiation and subsequent exposure to air was investigated by in situ characterizations. Porous blanket SiOCH film surfaces were treated by a H-2 or H-2/N-2 plasma in a 100-MHz capacitively coupled plasma reactor. The individual or combined effects of light, radicals, and ions generated by the plasmas on the chemical bonds in the porous SiOCH films were characterized using an in situ evaluation and by in situ Fourier-transform infrared reflection absorption spectroscopy (IR-RAS). In situ IR-RAS analysis revealed that the number of Si-OH, Si-H, and Si-NH2 bonds increased while the number of Si-CH3 bonds decreased during exposure to a H-2 or H-2/N-2 plasma. Subsequent air exposure increased the number of Si-OH bonds by modifying Si-O-Si structures. The experimental results indicate that light emitted from a H-2 or H-2/N-2 plasma can break Si-CH3 and Si-O-Si bonds and thereby generate dangling bonds. Radicals (e. g., NxHy and H radicals) can break Si-CH3 and Si-O-Si bonds and Si-NH2, Si-H, and Si-OH bonds could be formed. Si-NH2, Si-H, and dangling bonds react with moisture in the air cause the formation of Si-OH bonds. The dehydroxylation reaction on Si-OH was found to be the origin of Si-O-Si network structures. The mechanism of the degradation of porous low-k SiOCH films induced by a H-2 or H-2/N-2 plasma is discussed based on the in situ characterization results. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3671547]

DOI： 10.1063/1.3671547

Language：English   Publishing type：Research paper (scientific journal)  

The electronic and crystal structures of carbon nanowalls (CNWs) were analyzed using synchrotron x-rays. Although they have branchless graphene sheets with high crystallinities comparable to those of highly oriented pyrolytic graphite, they also have small amount of fluorine atoms and slightly large interlayer spacing of basal plane. Soft x-ray emission spectra indicate that CNWs have similar but not identical electronic structures to HOPG. Such the chemical and crystallographic structures might be one of factors to induce characteristic electrical features of the CNWs. (C) 2011 American Institute of Physics. [doi:10.1063/1.3659470]

DOI： 10.1063/1.3659470

Language：English   Publishing type：Research paper (scientific journal)  

We have investigated the control of the interfacial properties of Al2O3/Ge gate stack structures by the radical nitridation technique. In the Al2O3/Ge structures formed by the atomic layer deposition method, the interface state density increases with the deposition temperature due to the decrease in the thickness of the Ge oxide interlayer. On the other hand, the hysteresis width of the capacitance-voltage (C-V) characteristics decreases with increasing deposition temperature, which indicates a decrease in the oxide trap density near the interface. We also investigated the control of the interfacial structure by the radical nitridation of Al2O3/Ge to form an interfacial structure after the deposition of a high-k dielectric layer. The results of X-ray photoelectron spectroscopy reveal that an Al2O3/Ge3N4/GeO2/Ge stack structure is formed after the radical nitridation owing to the minimal oxygen diffusion into the Al2O3/Ge interface. Furthermore, the interfacial mixing is suppressed after radical nitridation at less than 300 degrees C. As a result, we can decrease the interface state density of the Al2O3/Ge sample after the radical nitridation by more than one order of magnitude compared with that without radical nitridation. (C) 2011 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.50.10PE02

Language：English  

Impacts of CF+, CF
Photoresists used in advanced ArF-excimer laser lithography are not tolerant enough for plasma etching processes. Degradation of photoresists during etching processes might cause not only low selectivity, but also line edge roughness (LER) on the sidewalls of etched patterns. For a highly accurate processing, it is necessary to understand the mechanisms of etching photoresists and to construct a new plasma chemistry that realizes a nano scale precise pattern definition. In this study, the modified layers formed on the surface of a photoresist by the bombardment of fluorocarbon ions of CF+, CF₂+, and CF₃+, and argon (Ar) ions were analyzed by X-ray photoelectron spectroscopy (XPS). The etching yield of the modified steady-state surface was almost dependent on the mass of incident ion species. The surface composition was modified with increasing dosage of each ion species, and reached a specific steady state that was dependent on the ion species. The bombardment of F-rich ion species such as CF₂+ and CF₃+ resulted in the formation of not only fluorocarbon layers, but also graphite like structures on the surface. On the basis of these results, the surface reaction for the ion-beam-induced modification was discussed.

DOI： 10.1143/JJAP.50.08JE05

Language：English   Publishing type：Research paper (scientific journal)  

Photoresists used in advanced ArF-excimer laser lithography are not tolerant enough for plasma etching processes. Degradation of photoresists during etching processes might cause not only low selectivity, but also line edge roughness (LER) on the sidewalls of etched patterns. For a highly accurate processing, it is necessary to understand the mechanisms of etching photoresists and to construct a new plasma chemistry that realizes a nano scale precise pattern definition. In this study, the modified layers formed on the surface of a photoresist by the bombardment of fluorocarbon ions of CF+, CF2+, and CF3+, and argon (Ar) ions were analyzed by X-ray photoelectron spectroscopy (XPS). The etching yield of the modified steady-state surface was almost dependent on the mass of incident ion species. The surface composition was modified with increasing dosage of each ion species, and reached a specific steady state that was dependent on the ion species. The bombardment of F-rich ion species such as CF2+ and CF3+ resulted in the formation of not only fluorocarbon layers, but also graphite like structures on the surface. On the basis of these results, the surface reaction for the ion-beam-induced modification was discussed. (C) 2011 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.50.08JE05

Language：English   Publishing type：Research paper (scientific journal)  

Two-dimensionally standing graphene sheets, i.e., carbon nanowalls (CNWs), were synthesized on a Si substrate employing a capacitively coupled fluorocarbon plasma-enhanced chemical vapor deposition system together with H radical injection. To apply CNWs in electronic devices and/or membrane filters, we have demonstrated the reactive ion etching (RIE) of CNWs. RIE employing H-2/N-2 gases showed that the CNW films were anisotropically etched at a relatively high rate of more than 250 nm/min. However, the 10-nm-thick interface layer between a CNW film and the Si substrate remained and the interface layer was not completely etched. In contrast, RIE employing Ar/H-2 gases enabled us to completely remove the interface layer. Ar/H-2 RIE was also carried out from the bottom surface of CNW films after exfoliating them from the Si substrate. As a result, a free-standing CNW film of 550 nm thickness without an interface layer as a membrane filter was successfully formed. (C) 2011 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.50.075101

Language：English   Publishing type：Research paper (scientific journal)  

We have demonstrated the control of interfacial properties of Pr-oxide/Ge gate stack structure by the introduction of nitrogen. From C-V characteristics of Al/Pr-oxide/Ge3N4/Ge MOS capacitors, the interface state density decreases without the change of the accumulation capacitance after annealing. The TEM and TED measurements reveal that the crystallization of Pr-oxide is enhanced with annealing and the columnar structure of cubic-Pr2O3 is formed after annealing. From the depth profiles measured using XPS with Ar sputtering for the Pr-oxide/Ge3N4/Ge stack structure, the increase in the Ge component is not observed in a Pr-oxide film and near the interface between a Fr-oxide film and a Ge substrate. In addition, the N component segregates near the interface region, amorphous Pr-oxynitride (PrON) is formed at the interface. As a result, Pr-oxide/PrON/Ge stacked structure without the Ge-oxynitride interlayer is formed. (C) 2011 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.sse.2011.01.029

Language：English   Publishing type：Research paper (scientific journal)  

We report on the surface modification of poly(tetrafluoroethylene) (PTFE) as an example of soft materials and biomaterials that occur under plasma discharge by kinetics analysis of radical formation using in situ real-time electron spin resonance (ESR) measurements. During irradiation with hydrogen plasma, simultaneous measurements of the gas-phase ESR signals of atomic hydrogen and the carbon dangling bond (C-DB) on PTFE were performed. Dynamic changes of the C-DB density were observed in real time, where the rate of density change was accelerated during initial irradiation and then became constant over time. It is noteworthy that C-DBs were formed synergistically by irradiation with both vacuum ultraviolet (VUV) and atomic hydrogen. The in situ real-time ESR technique is useful to elucidate synergistic roles during plasma surface modification.

DOI： 10.1021/jz2002937

Language：English   Publishing type：Research paper (scientific journal)  

We report on the surface modification of poly(tetrafluoroethylene) (PTFE) as an example of soft materials and biomaterials that occur under plasma discharge by kinetics analysis of radical formation using in situ real-time electron spin resonance (ESR) measurements. During irradiation with hydrogen plasma, simultaneous measurements of the gas-phase ESR signals of atomic hydrogen and the carbon dangling bond (C-DB) on PTFE were performed. Dynamic changes of the C-DB density were observed in real time, where the rate of density change was accelerated during initial irradiation and then became constant over time. It is noteworthy that C-DBs were formed synergistically by irradiation with both vacuum ultraviolet (VUV) and atomic hydrogen. The in situ real-time ESR technique is useful to elucidate synergistic roles during plasma surface modification.

DOI： 10.1021/jz2002937

Language：English   Publishing type：Research paper (scientific journal)  

We have demonstrated the control of interfacial properties of Pr-oxide/Ge gate stack structure by the introduction of nitrogen. From C-V characteristics of Al/Pr-oxide/Ge3N4/Ge MOS capacitors, the interface state density decreases without the change of the accumulation capacitance after annealing. The TEM and TED measurements reveal that the crystallization of Pr-oxide is enhanced with annealing and the columnar structure of cubic-Pr2O3 is formed after annealing. From the depth profiles measured using XPS with Ar sputtering for the Pr-oxide/Ge3N4/Ge stack structure, the increase in the Ge component is not observed in a Pr-oxide film and near the interface between a Fr-oxide film and a Ge substrate. In addition, the N component segregates near the interface region, amorphous Pr-oxynitride (PrON) is formed at the interface. As a result, Pr-oxide/PrON/Ge stacked structure without the Ge-oxynitride interlayer is formed. (C) 2011 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.sse.2011.01.029

Language：English   Publishing type：Research paper (scientific journal)  

An ultrahigh density over 10(13) cm(-2) of 2 nm diameter Pt nanoparticles was obtained by metal-organic chemical supercritical fluid deposition over the entire surface of vertically standing stacked graphene sheets (carbon nanowalls) on a substrate. The correlation between the surface defect density of graphene sheets and the density of Pt nanoparticles were investigated to clarify the support mechanism. The density of Pt nanoparticles increased with increase in the surface defect density. In addition, the semispherical cross-sectional shape of the nanoparticles indicated nucleation at the surface defects on the graphene sheets (98/100). (C) 2011 American Institute of Physics. [doi: 10.1063/1.3583672]

DOI： 10.1063/1.3583672

Language：English   Publishing type：Research paper (scientific journal)  

On a plasma etch reactor for a wafer of 300 mm in diameter, the spatial distributions of the absolute densities of CF and CF2 radicals, electron density (n(e)), and the gas temperature (T-g) of N-2 were measured employing the dual frequency of negative dc voltage superposed to a very high frequency (VHF) of 60 MHz capacitively coupled plasma (DS-2f-CCP) with the cyclic-(c-)C4F8/Ar/N-2 gas mixture. The dc bias was superposed on the upper electrode with a frequency of 60 MHz. The distributions of electron and radical densities were uniform within a diameter of about 260 mm, and took a monotonic decay in regions outside a diameter of 260 mm on the reactor for 300mm wafers in the reactor. It was found that only CF2 density at the radial position between 150 and 180 mm, corresponding to the position of the Si focus ring, dropped, while CF density took a uniform distribution over a diameter of 260 mm. Additionally, at this position, the rotational temperature of N-2 gas increased to be 100 K larger than that at the center position. CF2 radical density was markedly affected by the modified surface loss probability of the material owing to coupling with surface temperature. (C) 2011 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.50.056101

Language：English   Publishing type：Research paper (scientific journal)  

Nanofabrication processes employing reactive plasma, such as etching and deposition, were discussed in this paper on the basis of knowledge of reactive species in the plasma. The processing characteristics were studied based on the absolute density measurements of radicals and ions. In the case of organic low-k film etching employing N-H plasma, H and N radicals have different roles from each other; the H radicals contribute to the chemical etching, while the N radicals form the protection layer. Therefore, the ratio of H and N radical densities is an important factor for determining the etching performance. Furthermore, the radical injection technique, an active way to control the composition of radicals in the reaction field, was successfully applied to grow carbon nanowalls, self-organized, free-standing, layered graphenes. For example, with increasing density ratio of H and fluorocarbon (CFx) radicals, the density of carbon nanowalls decreases. In addition, according to the carbon nanowalls' growth by the simultaneous irradiation of CFx radicals, hydrogen atoms and Ar ions, the ion bombardment is crucial for the nucleation and vertical growth of carbon nanowalls. Identification and characterization of radicals and ions in the processing plasma could open the way to the precise controls of nano-scale plasma processing.

DOI： 10.1088/0022-3727/44/17/174027

Language：English   Publishing type：Research paper (scientific journal)  

Nanofabrication processes employing reactive plasma, such as etching and deposition, were discussed in this paper on the basis of knowledge of reactive species in the plasma. The processing characteristics were studied based on the absolute density measurements of radicals and ions. In the case of organic low-k film etching employing N-H plasma, H and N radicals have different roles from each other; the H radicals contribute to the chemical etching, while the N radicals form the protection layer. Therefore, the ratio of H and N radical densities is an important factor for determining the etching performance. Furthermore, the radical injection technique, an active way to control the composition of radicals in the reaction field, was successfully applied to grow carbon nanowalls, self-organized, free-standing, layered graphenes. For example, with increasing density ratio of H and fluorocarbon (CFx) radicals, the density of carbon nanowalls decreases. In addition, according to the carbon nanowalls' growth by the simultaneous irradiation of CFx radicals, hydrogen atoms and Ar ions, the ion bombardment is crucial for the nucleation and vertical growth of carbon nanowalls. Identification and characterization of radicals and ions in the processing plasma could open the way to the precise controls of nano-scale plasma processing.

DOI： 10.1088/0022-3727/44/17/174027

Language：English   Publishing type：Research paper (scientific journal)  

An ultrahigh density over 10(13) cm(-2) of 2 nm diameter Pt nanoparticles was obtained by metal-organic chemical supercritical fluid deposition over the entire surface of vertically standing stacked graphene sheets (carbon nanowalls) on a substrate. The correlation between the surface defect density of graphene sheets and the density of Pt nanoparticles were investigated to clarify the support mechanism. The density of Pt nanoparticles increased with increase in the surface defect density. In addition, the semispherical cross-sectional shape of the nanoparticles indicated nucleation at the surface defects on the graphene sheets (98/100). (C) 2011 American Institute of Physics. [doi: 10.1063/1.3583672]

DOI： 10.1063/1.3583672

Language：English   Publishing type：Research paper (scientific journal)  

We have investigated the local leakage current in Pr-oxide thin films formed on Si(001) and Si(111) substrate by conductive atomic force microscopy. In Pr-oxide films formed on Si(111) substrates, many current leakage spots are observed in current images compared to that on Si(001) substrates. We found that the current conduction mechanism in Pr-oxide films is considered a Poole-Frenkel conduction. The X-ray photoelectron spectroscopy analysis revealed that cubic Pr2O3 is preferentially formed near the Pr-oxide/Si(111) interface compared with Si(001) samples. We also found that O-2 annealing effectively reduces the leakage current in Pr-oxide films. It is considered that oxygen vacancies in Pr-oxide dominate the leakage current of oxide thin films. (C) 2011 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.50.04DA08

Language：English   Publishing type：Research paper (scientific journal)  

In this letter, we have investigated the structural properties of thick InGaN layers grown on GaN by plasma-assisted molecular beam epitaxy, using two growth rates of 1.0 and 3.6 angstrom/s. A highly regular superlattice (SL) structure is found to be spontaneously formed in the film grown at 3.6 angstrom/s but not in the film grown at 1.0 angstrom/s. The faster grown film also exhibits superior structural quality, which could be due to the surface roughness suppression caused by kinetic limitation, and the inhibition of the Frank-Read dislocation generation mechanism within the spontaneously formed SL structure. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3574607]

DOI： 10.1063/1.3574607

Language：English   Publishing type：Research paper (scientific journal)  

In this study, we investigated the valence state and chemical bonding state of Pr in a Pr oxide/PrON/Ge structure. We clarified the relationship between the valence state of Pr and the Pr oxide/Ge interfacial reaction using Pr oxide/Ge and Pr oxide/PrON/Ge samples. We found the formation of three Pr oxide phases in Pr oxide films; hexagonal Pr2O3 (h-Pr2O3) (Pr3+), cubic Pr2O3 (c-Pr2O3) (Pr3+), and c-PrO2 (Pr4+). We also investigated the effect of a nitride interlayer on the interfacial reaction in Pr oxide/Ge gate stacks. In a sample with a nitride interlayer (Pr oxide/PrON/Ge), metallic Pr-Pr bonds are also formed in the c-Pr2O3 film. After annealing in H-2 ambient, the diffusion of Ge into Pr oxide is not observed in this sample. Pr-Pr bonds probably prevent the interfacial reaction and Ge oxide formation, considering that the oxygen chemical potential of this film is lower than that of a GeO2/Ge system. On the other hand, the rapid thermal oxidation (RTO) treatment terminates the O vacancies and defects in c-Pr2O3. As a result, c-PrO2 with tetravalent Pr is formed in the Pr oxide/PrON/Ge sample with RTO. In this sample, the leakage current density is effectively decreased in comparison with the sample without RTO. Hydrogen termination works effectively in Pr oxide/PrON/Ge samples with and without RTO, and we can achieve an interface state density of as low as 4 x 10(11) eV(-1) .cm(-2). (C) 2011 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.50.04DA17

Language：English   Publishing type：Research paper (scientific journal)  

We have investigated the local leakage current in Pr-oxide thin films formed on Si(001) and Si(111) substrate by conductive atomic force microscopy. In Pr-oxide films formed on Si(111) substrates, many current leakage spots are observed in current images compared to that on Si(001) substrates. We found that the current conduction mechanism in Pr-oxide films is considered a Poole-Frenkel conduction. The X-ray photoelectron spectroscopy analysis revealed that cubic Pr2O3 is preferentially formed near the Pr-oxide/Si(111) interface compared with Si(001) samples. We also found that O-2 annealing effectively reduces the leakage current in Pr-oxide films. It is considered that oxygen vacancies in Pr-oxide dominate the leakage current of oxide thin films. (C) 2011 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.50.04DA08

Language：English   Publishing type：Research paper (scientific journal)  

Carbon nanowalls (CNWs) are two-dimensional carbon nanostructures consisting of stacked graphene sheets standing vertically on the substrate. The sharp edges of CNWs provide us with opportunities for applications as electron field emitter arrays. The effects of nitrogen plasma (NP) treatment on the surface of CNWs have been investigated in order to improve the electron field emission properties. The electron emission current from the edges of CNWs was drastically increased by the NP treatment. Morphological and chemical changes in the CNWs after the NP treatment were characterized using scanning electron microscopy, Raman spectroscopy, and x-ray photoelectron spectroscopy. (C) 2011 American Institute of Physics. [doi:10.1063/1.3532114]

DOI： 10.1063/1.3532114

Language：English   Publishing type：Research paper (scientific journal)  

Carbon nanowalls (CNWs) are two-dimensional carbon nanostructures consisting of stacked graphene sheets standing vertically on the substrate. The sharp edges of CNWs provide us with opportunities for applications as electron field emitter arrays. The effects of nitrogen plasma (NP) treatment on the surface of CNWs have been investigated in order to improve the electron field emission properties. The electron emission current from the edges of CNWs was drastically increased by the NP treatment. Morphological and chemical changes in the CNWs after the NP treatment were characterized using scanning electron microscopy, Raman spectroscopy, and x-ray photoelectron spectroscopy. (C) 2011 American Institute of Physics. [doi:10.1063/1.3532114]

DOI： 10.1063/1.3532114

Language：English   Publishing type：Research paper (scientific journal)  

A non-equilibrium atmospheric pressure plasma jet excited by 60-Hz ac power was diagnosed by laser Thomson and laser Raman scattering. We obtained the spatial distributions of the electron density, electron temperature, and gas temperature. The results show that the plasma can generate an electron density of up to 10(21) m(-3), an electron temperature of approximately 1 eV, and a gas temperature as low as approximately 700 K, indicating that the plasma is in the non-equilibrium state. The laser scattering diagnostic method and the obtained data are useful in the application of the non-equilibrium atmospheric pressure plasma jet. (C) 2011 The Japan Society of Applied Physics

DOI： 10.1143/APEX.4.026101

Language：Japanese   Publishing type：Research paper (scientific journal)  

Growth of Pr Oxide Films by Atomic Layer Deposition Using Pr(EtCp)_3, and Their Electrical Properties
&nbsp;&nbsp;Growth properties and electrical properties of Pr oxide films by an atomic layer deposition (ALD) technique using Pr(EtCp)₃ are discussed in this paper. Slef-limiting growth of Pr oxide films at a rate of 0.07 nm/cycle and a thickness variation of less than 2&#37; on 3-in. Si wafers were obtained. Polycrystalline cubic Pr₂O₃ films were grown on Si(001) substrates, while epitaxial growth of the cubic Pr₂O₃ film was found on a Si(111) substrate. Relatively fine capacitance-voltage curves were obtained for the Al/ALD-Pr oxide/Si(001) capacitors. The interface state density between the 130&deg;C-grown ALD-Pr oxide film and the Si(001) substrate is about 1&times;10¹¹ cm^&minus;2 eV^&minus;1. The dielectric constant of the ALD-Pr oxide film grown at 250&deg;C was determined to be about 18, assuming that the dielectric constant of the interlayer is similar to that of SiO₂.

DOI： 10.3131/jvsj2.54.110

Language：English   Publishing type：Research paper (scientific journal)  

A non-equilibrium atmospheric pressure plasma jet excited by 60-Hz ac power was diagnosed by laser Thomson and laser Raman scattering. We obtained the spatial distributions of the electron density, electron temperature, and gas temperature. The results show that the plasma can generate an electron density of up to 10(21) m(-3), an electron temperature of approximately 1 eV, and a gas temperature as low as approximately 700 K, indicating that the plasma is in the non-equilibrium state. The laser scattering diagnostic method and the obtained data are useful in the application of the non-equilibrium atmospheric pressure plasma jet. (C) 2011 The Japan Society of Applied Physics

DOI： 10.1143/APEX.4.026101

Language：Japanese  

Language：Japanese  

Language：Japanese  

Language：Japanese  

Language：English   Publishing type：Research paper (scientific journal)  

For an innovation of molecular-beam-epitaxial (MBE) growth of gallium nitride (GaN), the measurements of absolute densities of N, H, and NH3 at the remote region of the radical source excited by plasmas have become absolutely imperative. By vacuum ultraviolet absorption spectroscopy (VUVAS) at a relatively low pressure of about 1 Pa, we obtained a N atom density of 9 x 10(12) cm(-3) for a pure nitrogen gas used, a H atom density of 7 x 10(12) cm(-3) for a gas composition of 80&#37; hydrogen mixed with nitrogen gas were measured. The maximum density 2 x 10(13) cm(-3) of NH3 was measured by quadruple mass spectrometry (QMS) at H-2/(N-2 + H-2) = 60&#37;. Moreover, we found that N atom density was considerably affected by processing history, where the characteristic instability was observed during the pure nitrogen plasma discharge sequentially after the hydrogen-containing plasma discharge. These results indicate imply the importance of establishing radical-based processes to control precisely the absolute densities of N, H, and NH3 at the remote region of the radical source. (C) 2011 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.50.01AE03

Language：English   Publishing type：Research paper (scientific journal)  

For an innovation of molecular-beam-epitaxial (MBE) growth of gallium nitride (GaN), the measurements of absolute densities of N, H, and NH3 at the remote region of the radical source excited by plasmas have become absolutely imperative. By vacuum ultraviolet absorption spectroscopy (VUVAS) at a relatively low pressure of about 1 Pa, we obtained a N atom density of 9 x 10(12) cm(-3) for a pure nitrogen gas used, a H atom density of 7 x 10(12) cm(-3) for a gas composition of 80&#37; hydrogen mixed with nitrogen gas were measured. The maximum density 2 x 10(13) cm(-3) of NH3 was measured by quadruple mass spectrometry (QMS) at H-2/(N-2 + H-2) = 60&#37;. Moreover, we found that N atom density was considerably affected by processing history, where the characteristic instability was observed during the pure nitrogen plasma discharge sequentially after the hydrogen-containing plasma discharge. These results indicate imply the importance of establishing radical-based processes to control precisely the absolute densities of N, H, and NH3 at the remote region of the radical source. (C) 2011 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.50.01AE03

Language：English   Publishing type：Research paper (scientific journal)  

Carbon nanowalls (CNWs), vertically standing graphene sheets, grown by the radical injection plasma-enhanced chemical vapor deposition system were analyzed by spectroscopic ellipsometry. The refractive indexes (n), extinction coefficients (k), and optical band gaps (E(g)) of evolutionary growth layers were evaluated using the Tauc-Lorentz model with the effective medium approximation. It was observed that an amorphous carbon interfacial layer with n of 1.9-2.0 was formed prior to the growth of CNWs with n of 1.2-1.5. Moreover, the imaginary parts of complex dielectric functions analyzed using the Tauc-Lorentz model indicate the possibility that the CNWs have semiconducting features. (C) 2010 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.49.060220

Language：English   Publishing type：Research paper (scientific journal)  

Formation processes of Ge3N4 by radical nitridation and electrical properties of Pr-oxide/Ge3N4/Ge structure were investigated. Stoichiometric Ge3N4 is Successfully formed by the radical nitridation at temperatures from 50 to 600 degrees C. Change in the nitridation temperature dependence of the saturated thickness of the Ge3N4 suggests different dominant diffusion species. Leakage current density through the Ge3N4 is minimized at a nitridation temperature of 300 degrees C. The XPS analyses of the Pr-oxide/Ge3N4/Ge suggest decomposition of Ge3N4 during atomic layer deposition of the Pr-oxide and formation of Pr-oxynitride at the Pr-oxide/Ge interface. An interface state density in the Al/Pr-oxide/Ge3N4/Ge capacitor is drastically reduced by forming gas annealing. (C) 2009 Published by Elsevier B.V.

DOI： 10.1016/j.tsf.2009.10.094

Language：English   Publishing type：Research paper (scientific journal)  

Praseodymium (Pr) oxide films were grown by metal-organic chemical-vapor-deposition (CVD) using Pr(EtCp)(3). Using H2O as an oxidant, Pr2O3 films with columnar structures are formed and its C concentration can be reduced to about one-tenth compared with the case using O-2. Activation energy of 0.37 eV is derived for this CVD using H2O. This CVD-Pr oxide film deposited at 300 degrees C has a dielectric constant of 26 +/- 3. Furthermore, conduction band offset of 1.0 +/- 0.1 eV and trap levels of 0.40 +/- 0.02 and 0.22 +/- 0.02 eV in the CVD-Pr2O3/Si structure were also determined by current conduction characteristics.

DOI： 10.1063/1.3275706

Language：English   Publishing type：Research paper (scientific journal)  

Plasma surface treatment of polymers has been carried out with argon/oxygen mixture plasmas driven by multiple low-inductance antenna units. Kinetic energy distribution of argon ions from the argon/oxygen mixture plasmas onto polymers showed considerable suppression of ion energies sufficiently less than 10 eV. Polyethyleneterephthalate (PET) films were exposed to argon/oxygen mixture plasma for 1-5 min on a water-cooled substrate holder. The etching depth of PET surface increased with increasing plasma-exposure time and the etching rate was 118 nm/min. Surface roughness of PET surface (root-mean-square value) increased from 0.5 nm to 2.7 nm with increasing plasma-exposure time from 0 min (original sample) to states of the PET surface. The HXPES analyses exhibited nano-surface modification of the PET surface without suffering degradation of molecular structures beneath. (C) 2009 Elsevier B.V. all rights reserved.

DOI： 10.1016/j.tsf.2009.07.161

Language：English   Publishing type：Research paper (scientific journal)  

We have proposed a novel method to form by microfabrication a uniaxial tensile strained Ge layer due to the elastic strain relaxation of a Si1-xGex buffer layer on a Si(0 0 1) substrate. A fully strain-relaxed Ge layer on a compressive strained Si0.60Ge0.40 Was epitaxially grown on Si(0 0 1) substrate and striped mesa lines were fabricated with a line width of 250 nm along the [1 1 0] direction. The strain of the Si0.60Ge0.40 layer was found to be elastically relaxed only along the direction perpendicular to the lines and a uniaxial tensile strained Ge layer was thus formed. The value of tensile strain of the Ge layer is estimated to be 0.25&#37;. (C) 2009 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.sse.2009.08.001

Language：English   Publishing type：Research paper (scientific journal)  

We have proposed a novel method to form by microfabrication a uniaxial tensile strained Ge layer due to the elastic strain relaxation of a Si1-xGex buffer layer on a Si(0 0 1) substrate. A fully strain-relaxed Ge layer on a compressive strained Si0.60Ge0.40 Was epitaxially grown on Si(0 0 1) substrate and striped mesa lines were fabricated with a line width of 250 nm along the [1 1 0] direction. The strain of the Si0.60Ge0.40 layer was found to be elastically relaxed only along the direction perpendicular to the lines and a uniaxial tensile strained Ge layer was thus formed. The value of tensile strain of the Ge layer is estimated to be 0.25&#37;. (C) 2009 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.sse.2009.08.001

Language：English   Publishing type：Research paper (scientific journal)  

Effects of Atomic Layer Deposition-Al2O3 Interface Layers on Interfacial Properties of Ge Metal-Oxide-Semiconductor Capacitors
We have investigated the interfacial control effects of the atomic layer deposition (ALD)-Al2O3 on the crystalline and electronic characteristics of LaAlO3/Ge metal-oxide-semiconductor (MOS) structures. X-ray photoelectron spectroscopic analysis revealed that Al2O3/Ge interfaces are much more stable than LaAlO3/Ge and La2O3/Ge interfaces for the formation of Ge oxides owing to the interfacial reaction. For the LaAlO3/ALD-Al2O3/Ge structure, Al2O3 interfacial layers with thicknesses less than 1 nm effectively suppress the interfacial reaction between LaAlO3 and Ge. The thickness of Ge oxides formed at the ALD-Al2O3/Ge interface decreases with increasing Al2O3 thickness and the stack structure is thermally stable against postdeposition annealing at 600 degrees C. These results indicate that interfacial reaction mainly arises during the sputtering-LaAlO3 deposition, not the ALD-Al2O3 deposition. On the other hand, capacitance equivalent oxide thickness decreases with increasing interfacial ALD-Al2O3 thickness, because the formation of Ge oxides at the interface is effectively suppressed by ALD-Al2O3 interfacial layers. It can be concluded that ALD-Al2O3 is promising as an interfacial control layer between Ge substrates and high-k dielectrics. (C) 2009 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.48.05DA04

Language：English   Publishing type：Research paper (scientific journal)  

The dependences of crystalline structures and resistivity of Hf-Si-N films on nitrogen content were investigated in this study. The nitrogen (N) content of Hf-Si-N films increases with increasing N-2 concentration in a N-2/Ar mixture ambient used in sputtering, and saturates to about 59&#37; at N-2 concentrations of 4.8&#37; and above. This indicates that all Hf and Si atoms form HfN and Si3N4 in the films, respectively. From X-ray diffraction (XRD) profiles, nanocrystallites exist even in as-deposited films with saturated N content. However, they hardly grow after post deposition annealing (PDA) at 900 degrees C. The resistivity values are almost constant at N-2 concentrations of 4.8&#37; and below. On the other hand, they significantly increase with increasing N-2 concentration above 4.8&#37; and consequently become unmeasurable at N-2 concentrations of 13.0&#37; and above. The XRD profiles indicate that nanocrystallites segregating in those films are related to Hf3N4. (c) 2009 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.48.045505

Language：English   Publishing type：Research paper (scientific journal)  

The annealing temperature and thickness dependences of electrical properties of mictamict Ti-Si-N gate metal-oxide-semiconductor (MOS) capacitors, and their relationships with the crystalline structure were investigated. The nanocrystallites in mictamict Ti-Si-N films sputtered in over 3.0&#37; N-2 ambient hardly grow even after postdeposition annealing (PDA) at temperatures below 900 degrees C. As the N-2 concentration increases up to 3&#37;, the resistivity of the Ti-Si-N films increases owing to an increase in the amount of Si3N4 components and the development of the amorphization. On the other hand, the resistivity decreases with increasing N-2 concentration above 3&#37;. This is attributed to the formation of Ti3N4 components, as revealed by X-ray photoelectron spectroscopy (XPS) analysis. The changes in resistivity and effective work function are also extremely small. Additionally, even when the Ti-Si-N film thickness is reduced to 5 nm, the Pt/Ti-Si-N stacked gate electrode maintains almost the same effective work function (4.6 eV). (C) 2009 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.48.04C012

Language：English   Publishing type：Research paper (scientific journal)  

High-density and similarly-sized Si nanodots were formed by annealing ultra-thin amorphous Si (a-Si) films deposited on SiO2/Si substrates in vacuum. Dependences of density and diameter of the Si nanodots on the a-Si film thickness and, annealing temperature and time were investigated by scanning electron microscopy. It is found that drastic increase (decrease) in the density (diameter) occurred at an a-Si thickness of 1 nm. By agglomeration of sub-nanometer thick a-Si films, a density larger than 10(12) cm(-2), an average diameter smaller than 5 nm, and a dispersion of diameter less than 15&#37; were achieved. (c) 2008 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.tsf.2008.08.079

Language：English   Publishing type：Research paper (scientific journal)  

We report silicide and germanide technology for ohmic contacts and metal gates of MOSFETs in this paper. We have investigated the control technology of NiSi/Si contact properties by incorporating third elements such as Ge and C for future ULSI applications. The work function and resistivity of various Ni and Pt germanides have been also examined as metal gate materials. The low resistivity and tunable work function of these silicides and germanides are desirable for future CMOS devices. (c) 2008 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.tsf.2008.08.097

Language：English   Publishing type：Research paper (other academic)  

Analysis of Uniaxial Tensile Strain in Microfabricated Ge/Si1-x Gex Structures on Si(001) Substrates

Language：Japanese   Publishing type：Research paper (scientific journal)  

Fabrication of Pr oxide by MOCVD and evaluation of its electrical properties

Language：English   Publishing type：Research paper (scientific journal)  

The crystal structures and electrical characteristics of Ti-Si-N metal-oxide-semi conductor (MOS) gate electrodes in the mictamict state, which is a comprehensive term referring to amorphous structures both with and without nanocrystals, were investigated. By increasing the N-2 concentration of the sputtering ambient, the nitrogen (N) content of the Ti-Si-N films increased and consequently the Ti-Si-N films did not crystallize. At a N-2 concentration of more than 3.0&#37;, the N content of the films was almost constant at about 53&#37;, which indicates that all Ti and Si atoms deposited in the form of TiN and Si3N4, respectively. In such Ti-Si-N films with a saturated N content, only 2-3-nm-grain-size nanocrystallites formed, which were embedded in amorphous layers even after post-deposition annealing (PDA) above 900 degrees C. At the same time, with increasing N2 concentration of the sputtering ambient, the change in the film resistivity after the PDA became smaller and the capacitance equivalent thickness (CET) fluctuation gradually ceased to occur. The work function of the mictamict Ti-Si-N gate electrodes, which were deposited in 5.0&#37; N-2 ambient and annealed at 500 degrees C, was determined to be 4.6eV.

DOI： 10.1143/JJAP.47.2420

Language：English   Publishing type：Research paper (scientific journal)  

The crystal structures and electrical characteristics of Ti-Si-N metal-oxide-semi conductor (MOS) gate electrodes in the mictamict state, which is a comprehensive term referring to amorphous structures both with and without nanocrystals, were investigated. By increasing the N-2 concentration of the sputtering ambient, the nitrogen (N) content of the Ti-Si-N films increased and consequently the Ti-Si-N films did not crystallize. At a N-2 concentration of more than 3.0&#37;, the N content of the films was almost constant at about 53&#37;, which indicates that all Ti and Si atoms deposited in the form of TiN and Si3N4, respectively. In such Ti-Si-N films with a saturated N content, only 2-3-nm-grain-size nanocrystallites formed, which were embedded in amorphous layers even after post-deposition annealing (PDA) above 900 degrees C. At the same time, with increasing N2 concentration of the sputtering ambient, the change in the film resistivity after the PDA became smaller and the capacitance equivalent thickness (CET) fluctuation gradually ceased to occur. The work function of the mictamict Ti-Si-N gate electrodes, which were deposited in 5.0&#37; N-2 ambient and annealed at 500 degrees C, was determined to be 4.6eV.

DOI： 10.1143/JJAP.47.2420

Language：English  

Development of high-density radical source for radical nitridation process in ULSI technology development of high-density radical source for radical nitridation process in ULSI technology

Language：Japanese  

Language：Japanese  

Language：Japanese  

Language：English  

Structural and Electrical Properties of Metal-germanide MOS Gate Electrodes

Language：Japanese   Publishing type：Research paper (scientific journal)  

Initial Stage of Processes and Energy Bandgap Formation in Nitridation of Silicon Surface Using Nitrogen Radicals
&nbsp;&nbsp;Initial stage of processes and energy bandgap formation in nitridation of silicon surfaces using nitrogen radicals have been studied. According to scanning tunneling microscopy observations and scanning tunneling spectroscopy measurements, at the initial stage of nitridation, linear defects perpendicular to dimmer rows were formed to coincide with an initial nitridation reaction preferentially at backbonds of surface Si atoms. After the nitride formation, the surface roughness depends only on substrate temperature regardless of radio frequency (RF) power, which means that the growth mode of nitrides is attributed to the surface migration. Contrary, the energy bandgap of silicon nitrides is significantly affected by not only substrate temperature but also RF power. Absorption and emission spectroscopy results suggest that the contribution of the excited-state nitrogen atoms to the nitridation increases with increasing the RF power. Control of surface migration and radical species is crucial to form the monolayer-thick nitride layer with both an atomically flat surface and a wide energy bandgap.

DOI： 10.3131/jvsj.50.665

Language：English   Publishing type：Research paper (other academic)  

Pr-oxide-based dielectric films on Ge substrates

Language：English   Publishing type：Research paper (other academic)  

Surface treatment of Ge(001) surface by radical nitridation

Language：English  

Development of new high-density radical sources and its application to radical nitridation of Ge surfaces

Language：English   Publishing type：Research paper (scientific journal)  

The composition ratio dependence of electrical (work function and resistivity) and structural properties in metal (Ni,Pt)-germanide gate electrodes was investigated for metal-oxide-semiconductor (MOS) devices. X-ray diffraction and cross-sectional transmission electron microscopy clearly revealed that metal-germanide MOS gate electrodes with a single Ni-germanide (Ni-Ge) or Pt-germanide (Pt-Ge) phase can be formed by controlling the thicknesses of the deposited metal and Ge. The resistivities of both Ni-Ge and Pt-Ge were lower than that of conventional polycrystalline silicon (poly-Si) gate electrodes. From the capacitance-voltage characteristics, the work functions of the Ni-Ge gate electrodes were measured to be from 4.6 to 4.9 eV, and those of the Pt-Ge gate electrodes were from 4.9 to 5.3 eV. With increasing metal (Ni,Pt) content, the work function of Ni-Ge decreased, while that of Pt-Ge increased. This composition dependence of the work function of the metal-germanide can be explained by considering the electronegativity of the pure metals that are often used.

DOI： 10.1143/JJAP.46.1865

Language：English   Publishing type：Research paper (scientific journal)  

The surface profiles and energy bandgap of sub-nanometer-thick silicon nitride layers, which were formed by radical nitridation, were analyzed by scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). According to the STM results, the surface roughness of the nitride layers depends only on substrate temperature regardless of radio frequency (RF) power, which indicates that the growth mode of the silicon nitride layer in radical nitridation is attributed to the surface silicon atom migration but does not depend on the types of nitrogen radical. In contrast, STS spectra show that the energy bandgap of the silicon nitride layer is significantly changed with not only substrate temperature but also RF power. The densities of nitrogen radicals were analyzed by absorption and emission spectroscopy, which suggests that the contribution of the excited-state nitrogen atoms to radical nitridation increases as RF power increases. The monolayer-thick nitride layer with both an atomically flat surface and a wide energy bandgap can be formed under appropriate conditions, because they are limited by different thermaly activated features.

DOI： 10.1143/JJAP.46.71

Language：Japanese  

Language：English   Publishing type：Research paper (scientific journal)  

We have investigated dislocation morphology and strain relaxation mechanisms of SiGe and Ge sub-micron wide striped mesa lines patterned on Si(0 0 1) substrates. The patterning of SiGe and Ge layers principally leads to asymmetric elastic strain relaxation. Post-patterning anneal induces 60 degrees dislocation introduction to relax the strain but the narrower the line width the more dominant is the elastic strain relaxation. In the case of 250 nm wide SiGe lines, 60 degrees dislocation introduction along the line is critically suppressed so that asymmetric strain distribution is realized. On the other hand, for the Ge line structure, pre-formed pure edge dislocations elongate along both orthogonal directions at the heterointerface independent of the line geometry even with the line width of 250 nm. Thus strain relaxation occurs symmetrically and rigidly. These results can be explained by deference of the introduction and propagation mechanisms of 60 degrees and pure-edge dislocations.

DOI： 10.1088/0268-1242/22/1/S31

Language：Japanese  

Language：English  

Dislocation structure and strain relaxation of SiGe and Ge sub-micron stripe lines on Si(001) substrates

Language：English  

Interfacial structure of HfON/SiN/Si gate stacks

Language：English  

Systematic characterization of Ni full silicide in sub-100 nm gate regions

Language：Others   Publishing type：Research paper (other academic)  

The chemical structures of SiO2/Si interfaces were studied by photoelectron spectroscopy using high-brilliance soft X-ray with photon energy ranging from 500 to 1500 eV at Super Photon ring 8 GeV(SPring-8) and it is able to probe a depth of about 1.2 to 3 nm with energy resolution of 100 meV. On the other hand, high-brilliance hard X-ray with photon energy ranging from 6 to 10 keV is able to probe a depth of about 8.5 to 12.5 nm with energy resolution of 100 meV. Hard photoelectron spectroscopy are particularly useful for studying the composition and the chemical structure of transition layer at high-k dielectric/silicon interface. © World Scientific Publishing Company.

DOI： 10.1142/S0129156406003680

Language：English   Publishing type：Research paper (scientific journal)  

We have investigated an initial stage of titanium nitride (TiN) growth on SiO2 Substrates by ultrahigh-vacuum chemical vapor deposition with TiCl4 and NH3 as source materials. The behaviors of nucleation and grain growth of TiN have been clarified by atomic force microscopy and transmission electron microscopy. It was found that TiN film formation at ail initial stage consists of three stages. which are characteristic of the lateral and subsequent vertical growth processes of grains. Deposition time dependence of the lateral growth of TiN grains clearly indicates that a process at 550 degrees C is limited by the surface reaction, irrespective of the TiCl4 flow rate and a pretreatment for the substrates before the deposition. The pretreatment affects in the generation of additional nucleation sites on the SiO2 surface but does not affect the mechanisms of nucleation and Grain Growth.

DOI： 10.1143/JJAP.45.49

Language：English   Publishing type：Research paper (scientific journal)  

We have studied the processes of local degradation through current leakage leading to breakdown in gate SiO2 films by conductive atomic force microscopy (C-AFM). Electrical stress was applied to the SiO2 films in the form of metal-oxide-semiconductor capacitors. Leakage current spots caused by holes trapped at stress-induced defects appeared in current images of the stressed SiO2 films. During the C-AFM observation at the same area with a high electric field, currents at these leakage spots gradually increased and the breakdown finally occurred at these sites, whereas at background regions other than the leakage spots, leakage currents gradually decreased. In contrast, in the case of nonstressed SiO2 films, the breakdown occurs without showing any predictive signs. Degradation and breakdown mechanisms depending on the stress condition are discussed.

DOI： 10.1143/JJAP.44.7582

Language：English   Publishing type：Research paper (other academic)  

Nanoscale Observations for Degradation Phenomena in SiO_2 and High-k Gate Insulators Using Conductive-Atomic Force Microscopy

Language：English   Publishing type：Research paper (scientific journal)  

A floating-gate memory with surface-nitrided Si nanocrystals buried in a SiO2 matrix has been fabricated employing radical nitridation. Si nanocrystals with a number density higher than I X 10(12)CM(-2) and an average grain size smaller than 6 nm have been grown using an ultrathin amorphous Si layer predeposited on the SiO2 surface. Since the radical nitridation of the formed Si nanocrystals effectively suppresses excess oxidation of nanocrystals during the control oxide formation, the Si nanocrystals have been successfully buried in the SiO2 matrix without losing their number density, grain size and fine spherical shape. Electrical properties of the floating-gate memory were also examined. A flat band voltage shift larger than I V, which is consistent with the number density of Si nanocrystals, was observed in capacitance-voltage measurements.

DOI： 10.1143/JJAP.44.5687

Language：English   Publishing type：Research paper (scientific journal)  

We studied local leakage currents induced in stressed gate SiO2 films and their time dependence by conductive atomic force microscopy (C-AFM). The current-voltage characteristics of the leakage currents detected in the C-AFM observations indicate Fowler-Nordheim tunneling currents enhanced by holes trapped in the stressed SiO2 films. By repeated C-AFM observations at the same area, it was found that individual spot currents decrease at different rates. This result indicates hole detrapping with different time constants from the stress-induced defects that have different features.

DOI： 10.1143/JJAP.43.4683

Language：English   Publishing type：Research paper (scientific journal)  

We have demonstrated the detection of manometer-scale current-leakage sites in electrically stressed gate SiO2 films using a conductive atomic force microscope (C-AFM). Prior to C-AFM observations, the gate SiO2 films in metal-oxide-semiconductor capacitors were subjected to constant-current Fowler-Nordheim (FN) stress. Details of image contrasts and the relationship between the surface topography and the current image of the SiO2 films were examined. Two types of contrast were clearly observed in the current image: a sharp bright spot reflecting local current leakage were caused by hole trapping at stress-induced defects and a fuzzy bright contrasts originating from the SiO2 thickness fluctuation. The dependence of C-AFM images on the electron injection direction during FN stress application and the SiO2 film thickness clearly reveals that the stress-induced defects are distributed in the region within 2.6 nm from the SiO2/Si substrate interface.

DOI： 10.1143/JJAP.43.4679

Language：English   Publishing type：Research paper (scientific journal)  

Si nanocrystal growth using an amorphous Si (a-Si) layer pre-deposited on a SiO2 surface has been performed by ultra-high-vacuum chemical vapor deposition (UHV-CVD). It has been shown that high-density Si nanocrystals are formed by Si2H6 irradiation on to an a-Si surface and that Si atoms supplied from the a-Si layer contribute to the growth of Si nanocrystals. By changing the thickness of the a-Si layer, the number density and size of Si nanocrystals can be controlled systematically. A number density of 1.0 x 10(12) cm(-2) and an average diameter of 9.1 nm were achieved for Si nanocrystals on the SiO2/Si substrate in the case of using a 0.3-nm-thick a-Si layer. Si nanocrystals were successfully buried in a SiO2 matrix by post deposition processes and their diameters were found to range from 6 to 10 nm.

DOI： 10.1143/JJAP.43.3779

Language：English  

Nanoscale analysis of degradation phenomena in MOS gate insulators using conductive atomic force microscopy

Language：English  

Thickness dependence of microscopic current-voltage characteristics in stressed SiO2 films

Language：English   Publishing type：Research paper (scientific journal)  

We have investigated microscopically the current leakage characteristics of SiO2 gate films in metal-oxide-semiconductor structure capacitors subjected to the Fowler-Nordheim (FN) constant current stress using a conductive atomic force microscope (C-AFM). Current images of C-AFM clearly reveal the leakage current spots in the samples in which the stress induced leakage current was confirmed by the macroscopic current-voltage (I-V) measurement. On the other hand, in the sample after the repeated macroscopic I-V measurement, there is a shift in threshold voltage for the appearance of current spots and its value directly corresponds to the voltage shift observed in the macroscopic capacitance-voltage measurements for this sample. The total number of current spots observable in the C-AFM scanned area critically depends on the substrate voltage: the spot number initially increases with the voltage to a certain value then decreases. The visibility of the current spot is well explained by the holes trapped locally at defect sites created in the stressed SiO2.

DOI： 10.1143/JJAP.43.1843

Language：English   Publishing type：Research paper (scientific journal)  

We have developed a method of microscopically analyzing the degradation of gate SiO2 films in actual metal-oxide-semiconductor (MOS) devices by conductive atomic force microscopy (C-AFM). In C-AFM images of electrically stressed SiO2 films, leakage current spots on a nanometer scale were successfully observed. The observed current spots show characteristic behaviors similar to the transient stress-induced leakage current which can be detected by macroscopic electrical measurements using MOS capacitors. The appearance of the current spots is discussed on the basis of the mechanism by which holes are trapped and detrapped by stress-induced defects in SiO2 films.

DOI： 10.1143/JJAP.43.L144

Language：English  

Local discharging of carriers at nanometer scale defects in gate SiO2 thin films observed by conducting atomic force microscopy

Language：English   Publishing type：Research paper (scientific journal)  

We have fabricated Si metal-oxide-semiconductor held-effect transistors of small dimensions using focused-ion-beam (FIB) implantation and SiO2 implantation masks with the width of 63-118 nm and have investigated the Coulomb blockade phenomena in these devices. The source and drain regions are formed by FIB implantation with a beam diameter of about 100 nm and the effective channel length is estimated to be 27-82 nm. Periodic oscillations of conductance, which are considered to be Coulomn blockade osillations, are observed at temperatures below 13 K. The measured oscillation period of V-G is 1.2-3.1 V and the gate capacitance is estimated to be 0.053-0.14aF for different channel lengths. Furthermore, it is found the the oscillation period of V-G increases as the channel length increases, which indicates that the dot radius decreases with increasing channel length. Large negative magnetoresistance is distinctly observed at the top of oscillation peaks and, on the other hand, only weak magnetoresistance is obtained at the bottoms.

DOI： 10.1143/JJAP.38.7222

Language：English   Publishing type：Research paper (scientific journal)  

We have investigated the Coulomb blockade in gate-controlled hopping conduction systems made up of small-dimensional focused ion beam (FIB) implanted wires having a small non-implanted gap. Dot structures are formed in the gap by potential fluctuations caused by dispersed Ga impurities and implantation-induced defects. In the present work, the samples were subjected to two thermal treatment methods: furnace annealing at 600 degrees C for 30 min and rapid thermal annealing (RTA) at 900 degrees C for 30 s. In both samples, the conductance oscillates by varying the gate voltage at low temperatures, in which the nearest-neighbor hopping conduction is dominant. In the samples annealed by RTA, the oscillation amplitude becomes much larger compared with that of samples annealed at 600 degrees C, which suggests that implantation-induced defects are annihilated by the thermal treatment at high temperatures. There coexist periodic and random peaks in the observed oscillation, which originate from the Coulomb blockade and hopping path changes, respectively. From obtained measurements, the dot size is estimated to be about 24 nm for the sample annealed at 600 degrees C and 14 nm for the sample annealed at 900 degrees C. The width of tunneling barrier of the sample annealed at 900 degrees C was estimated to be about 14-17 nm.

DOI： 10.1143/JJAP.38.1843

Language：Japanese  

Venue：神奈川工科大学   Country：Other  

Language：Japanese  

Venue：名古屋大学   Country：Other  

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Venue：山形大学   Country：Other  

Language：Japanese  

Country：Other  

Language：Japanese  

Venue：名古屋大学   Country：Other  

Language：Japanese  

Venue：山形大学   Country：Other  

Language：Japanese  

Venue：名古屋工業大学   Country：Other  

Language：Japanese  

Venue：名古屋大学   Country：Other  

Language：Japanese  

Venue：名古屋大学   Country：Other  

Language：Japanese  

Country：Other  

Language：Japanese  

Venue：山形大学   Country：Other  

Language：Japanese  

Venue：神奈川工科大学   Country：Other  

Language：Japanese  

Venue：山形大学   Country：Other  

Language：Japanese  

Venue：山形大学   Country：Other  

Language：Japanese  

Venue：山形大学   Country：Other  

Language：English  

Country：Other  

Control of crystalline and electronic structures of carbon nanowalls for their device applications

Language：English  

Venue：Nagoya Institute of Technology   Country：Other  

Development and Application of Electron Beam-Excited Plasma System using Hollow Cathode Electron Source

Language：English  

Country：Other  

Dispersive Optical Elements for TMT

Language：English  

Country：Other  

Hard X-ray photoelectron spectroscopy analysis for organic-inorganic hybrid materials formation

Language：English  

Country：Other  

Ni suicide and germanide technology for contacts and metal gates in MOSFET applications

Language：English  

Country：Other  

Electrical properties and bonding structures of germanium nitride/Ge(100) structures formed by radical nitridation

Language：English  

Country：Other  

Strain relaxation of patterned Ge and SiGe layers on Si(001) substrates

Language：English  

Country：Other  

Preparation and evaluation of NiGe gate electrodes for metal-oxide- semiconductor devices

Language：Japanese  

Venue：山形大学   Country：Other  

Language：English  

Venue：Long Beach, California, USA   Country：Other  

PlasmaInduced Surface Roughness of ArF Photoresist Examined by Plasma-Beam Processes

Language：English  

Venue：Okazaki Conference Center, Okazaki, Japan   Country：Other  

Radical Density Control in H2/N2 Plasma Based on In-situ Monitoring with Vacuum Ultra Violet Absorption Spectroscopy

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Venue：Busan, Korea   Country：Other  

Rapid precise measurements of film-covered-substrate temperatures during plasma processes

Language：English  

Venue：Long Beach, California, USA   Country：Other  

Reaction Mechanism at the Sidewall of Through Si via (TSV) Etching by SF6/O2/SiF4 Plasma

Language：English  

Venue：Nagoya University, Japan   Country：Other  

Real time temperature measurements of film-covered-substrate employing fourier domain low coherence interferometer during plasma processes

Language：English  

Venue：同志社大学 京田辺キャンパス   Country：Other  

Real-time / In-situ Electron Spin Resonance Analysis of Chemical Reactions on Silicon-Nitride with CF4 Gas Plasma

Language：English  

Venue：Okazaki Conference Center, Okazaki, Japan   Country：Other  

Real-time / in-situ electron spin resonance analysis of plasma surface interactions

Language：English  

Venue：Nagoya University, Japan   Country：Other  

Real-time variation of sputtering yield of Ar ion for ArF photoresist during Ar plasma exposure

Language：English  

Venue：Wasington, USA   Country：Other  

Recovery of Plasma-Damaged GaN by in situ Radical Exposure

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Venue：Westin Hotel Princeton, Princeton New Jersey, United States   Country：Other  

Reduction of Mechanism of Surface Roughness on ArF-Photoresist Using C5HF7 Gas Plasma

Language：English  

Venue：Sungkyunkwan University, Suwon & Hanhwa Resort Seorak, Sokcho,   Country：Other  

Reduction of surface roughness on ArF-photoresist by C5HF7 gas plasma

Language：English  

Venue：Nagoya University, Japan   Country：Other  

Relation between gaseous radicals and μc-Si film property in SiH4/H2 plasma CVD

Language：English  

Venue：Nagoya University, Japan   Country：Other  

Sequential exposure of N and H atoms for recovery of plasma-damaged GaN

Language：Japanese  

Venue：神奈川工科大学   Country：Other  

Study on mechanism of gallium nitride growth employing a plasma-enhanced metal-organic chemical vapor deposition

Language：English  

Venue：Nagoya University, Japan   Country：Other  

Study on mechanism of ultrahigh speed synthesis of high crystallinity nanographene employing in-liquid plasma

Language：English  

Venue：Nagoya University, Japan   Country：Other  

Study on precursor adsorption and reaction within SiO2 growth cycle of low temperature plasma-enhanced atomic layer deposition using in-situ ATR-FTIR

Language：English  

Venue：Nagoya University, Japan   Country：Other  

Subsequent temporal change of gaseous H and N radical density in H2/N2 plasma after air exposure and its control

Language：English  

Venue：Nagoya University, Japan   Country：Other  

Superior properties of carbon nanowalls as cell scaffolds

Language：English  

Venue：Wasington, USA   Country：Other  

Surface Analysis of GaN at Elevated Substrate Temperature

Language：English  

Venue：Gero Synergy Center "ACTIVE" Gifu , JAPAN   Country：Other  

Temperature measurement of carbon nanowall / silicon substrateusing super-continuum light source on low-coherence interferometry

Language：English  

Venue：Nagoya University, Japan   Country：Other  

The atmospheric pressure plasmas

Language：Japanese  

Country：Other  

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Venue：同志社大学 京田辺キャンパス   Country：Other  

Language：Japanese  

Venue：同志社大学 京田辺キャンパス   Country：Other  

Language：English  

Venue：神奈川工科大学   Country：Other  

Language：Japanese  

Venue：東京大学本郷キャンパス   Country：Other  

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Venue：同志社大学 京田辺キャンパス   Country：Other  

Language：Japanese  

Venue：アクトシティ浜松・研修交流センター S会場   Country：Other  

Language：Japanese  

Venue：アクトシティ浜松・研修交流センター S会場   Country：Other  

Language：Japanese  

Venue：アクトシティ浜松・研修交流センター S会場   Country：Other  

Language：Japanese  

Venue：アクトシティ浜松・研修交流センター S会場   Country：Other  

Language：Japanese  

Venue：同志社大学 京田辺キャンパス   Country：Other  

Language：Japanese  

Venue：同志社大学 京田辺キャンパス   Country：Other  

Language：Japanese  

Venue：神奈川工科大学   Country：Other  

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Venue：神奈川工科大学   Country：Other  

Language：Japanese  

Venue：アクトシティ浜松・研修交流センター S会場   Country：Other  

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Venue：アクトシティ浜松・研修交流センター S会場   Country：Other  

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Venue：同志社大学 京田辺キャンパス   Country：Other  

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Venue：アクトシティ浜松・研修交流センター S会場   Country：Other  

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Venue：アクトシティ浜松・研修交流センター S会場   Country：Other  

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Venue：アクトシティ浜松・研修交流センター S会場   Country：Other  

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Venue：アクトシティ浜松・研修交流センターS会場   Country：Other  

Language：Japanese  

Venue：同志社大学京田辺キャンパス   Country：Other  

Language：Japanese  

Venue：同志社大学京田辺キャンパス   Country：Other  

Language：Japanese  

Venue：神奈川工科大学   Country：Other  

Language：Japanese  

Venue：アクトシティ浜松・研修交流センター S会場   Country：Other  

Language：Japanese  

Venue：アクトシティ浜松・研修交流センター S会場   Country：Other  

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Venue：WINCあいち，名古屋   Country：Other  

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Venue：同志社大学 京田辺キャンパス   Country：Other  

Language：Japanese  

Venue：同志社大学 京田辺キャンパス   Country：Other  

Effect of boron doping on crystalline structures and electrical properties of amorphous carbon films grown by radical-injection plasma-enhanced chemical vapor deposition

Language：Japanese  

Venue：名古屋大学豊田講堂・シンポジオンホール   Country：Other  

Language：Japanese  

Venue：WINCあいち，名古屋   Country：Other  

Language：Japanese  

Venue：同志社大学 京田辺キャンパス   Country：Other  

Language：Japanese  

Venue：アクトシティ浜松・研修交流センター S会場   Country：Other  

Language：Japanese  

Venue：アクトシティ浜松・研修交流センター S会場   Country：Other  

Language：Japanese  

Venue：同志社大学 京田辺キャンパス   Country：Other  

Language：Japanese  

Venue：神奈川工科大学   Country：Other  

Language：Japanese  

Venue：同志社大学 京田辺キャンパス   Country：Other  

Language：Japanese  

Venue：神奈川工科大学   Country：Other  

Language：Japanese  

Venue：神奈川工科大学   Country：Other  

Language：Japanese  

Venue：神奈川工科大学   Country：Other  

Language：Japanese  

Venue：神奈川工科大学   Country：Other  

Language：Japanese  

Venue：アクトシティ浜松・研修交流センター S会場   Country：Other  

Language：Japanese  

Venue：アクトシティ浜松・研修交流センター S会場   Country：Other  

Language：Japanese  

Venue：アクトシティ浜松・研修交流センター S会場   Country：Other  

Language：Japanese  

Venue：名古屋大学豊田講堂・シンポジオンホール   Country：Other  

Language：English  

Venue：Takeda Sentanchi Building, Asano campus of the University of Tokyo   Country：Other  

A High Temperature Plasma Etching of GaN and Its Reaction Mechanism

Language：English  

Venue：Takeda Sentanchi Building, Asano campus of the University of Tokyo   Country：Other  

A reduction of degradation on ArF photoresist by C5HF7 plasma etching and its mechanism

Language：Japanese  

Venue：なごやサイエンスパーク、サイエンス交流プラザ大会議室   Country：Other  

Language：English  

Venue：Yokohama, Japan,   Country：Other  

Advanced Plasma Science and Technologies for Nanostructure Control of Carbon Nanomaterials

Language：English  

Venue：Takeda Sentanchi Building, Asano campus of the University of Tokyo   Country：Other  

An in-situ sequential H and N radical exposure process for recovery of plasma-damaged GaN

Language：English  

Venue：Edinburgh, Scotland, UK   Country：Other  

Analysis of Photoresist Surface Modified by Fluorocarbon lons and Radicals

Language：English  

Venue：Edinburgh, Scotland, UK   Country：Other  

Analysis of Photoresist Surface Modified by Fluorocarbon lons and Radicals

Language：English  

Venue：Plasma Bioscience Research Center, Kwangwoon University, Seoul, Korea,   Country：Other  

Atmospheric Pressure Plasma Processes and their Diagnostics for Life Sciences

Language：Japanese  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Change of GaAs Surface Properties by Irradiation of Cl2 Ions

Language：English  

Venue：Cerklje na Gorenskem, Slovenia (EU)   Country：Other  

Comprehensive study of atmospheric pressure plasma

Language：English  

Venue：Tampa Convention Center in Florida   Country：Other  

Control of Surface Properties on Plasma-Etched Gallium Nitride (GaN)

Language：English  

Venue：Ramada Plaza Jeju Hotel, Jeju, Korea,   Country：Other  

Critical Factors of Synthesis Rate and Crystallinity of Nanographene in Ultrahigh-Speed Nanographene Synthesis Employing Alcohol Plasma

Language：English  

Venue：Tampa Convention Center in Florida   Country：Other  

Crystalline and Electrical Properties of Vertically-Laminated Carbon Nanowalls formed by Two-Step Growth Method

Language：English  

Venue：Kyoto International Conference Center,   Country：Other  

Edge Termination on Electrical Properties of Vertically-grown Graphene Sheets Employing N2/H2 Mixture Plasma

Language：English  

Venue：Ramada Plaza Jeju Hotel, Jeju, Korea,   Country：Other  

Edge and Surface Modification of Nanographenes in Carbon Nanowalls by Hydrogen Peroxide Treatments

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Effect of Nitrogen Doping on Photoconductivity of Amorphous Carbon Films Grown by Radical-injection Plasma-enhanced Chemical Vapor Deposition

Language：English  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Effect of nitrogen doping on photoconductivity of amorphous carbon films grown by radical-injection plasma-enhanced chemical vapor deposition

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Effects of Carbon Nanowall Scaffold on HeLa Cell Culture

Language：English  

Venue：Warsaw University of Technology - POLAND   Country：Other  

Effects of Edge Termination on Crystalline and Electronic Structures of Carbon Nanowalls by Post-growth Nitrogen Plasma Treatment

Language：English  

Venue：Yokohama, Japan,   Country：Other  

Effects of Hydrogen Peroxide Treatment on Nanostructures in Carbon Nanowalls

Language：English  

Venue：BEXCO(#43 APEC-ro, Haeundae-gu, Busan)   Country：Other  

Effects of Hydrogen Peroxide Treatment on Nanostructures in Carbon Nanowalls

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Effects of Hydroxyl Radical on Nanographene Surfaces in Carbon Nanowalls

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Effects of Pulse Bias on Crystallographic Properties of Amorphous Carbon Films Grown by Plasma-enhanced Chemical Vapor Deposition

Language：English  

Country：Other  

Electron Spin Resonance (ESR) observation of radicals on biological organism interacted with plasmas

Language：English  

Venue：Edinburgh, Scotland, UK   Country：Other  

Electron Spin Resonance (ESR) study of Radicals on Biological Organism Created by Interaction with Plasma

Language：English  

Venue：Convention Center / Marriott Marquis, San Francisco,   Country：Other  

Electron Spin Resonance (ESR) Observation of Radicals on Biological Organism Interacted with Plasmas, WW-2.6

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Evaluation of Relationship between μC-Si Film Property and Flux Ratio of H Radicals to Film Precursors

Language：English  

Venue：the AT&T Conference Center on The University of Texas at Austin campus, Texas,   Country：Other  

Fabrication of graphene-based films using remote plasma CVD

Language：English  

Venue：Yokohama, Japan,   Country：Other  

Field Electron Emitter Fabricated by Plasma Etching of Organic Material

Language：English  

Venue：BEXCO(#43 APEC-ro, Haeundae-gu, Busan)   Country：Other  

Field Electron Emitter Fabricated by Plasma Etching of Organic Material

Language：English  

Venue：Sungkyunkwan University, Suwon, Korea   Country：Other  

Formation of 10-nm Organic Pillars by Plasma Etch with Pt particle masks and their Field Emission Properties.

Language：Japanese  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Generation Mechanism of Ions and Radicals in CHxFy Etching Plasmas

Language：English  

Venue：Warsaw University of Technology - POLAND   Country：Other  

Gradual transition of chemical structures at initial growth stage of carbon nanowalls

Language：English  

Venue：the Mercure Hotel, Brisbane, Australia   Country：Other  

Healing Process of Plasma-damaged Gallium Nitride (GaN)

Language：English  

Venue：Sungkyunkwan University, Suwon, Korea   Country：Other  

High Resolution Temperature Monitoring System of Semiconductor Substrate Using Fourier Domain Low Coherence Interferometer

Language：English  

Venue：Sungkyunkwan University, Suwon, Korea   Country：Other  

High Resolution Temperature Monitoring System of Semiconductor Substrate Using Fourier Domain Low Coherence Interferometer

Language：English  

Venue：Takeda Sentanchi Building, Asano campus of the University of Tokyo   Country：Other  

High performances of microcrystalline Si thin film formation for a solar cell by measurement and control of hydrogen radicals in the SiH4/H2 plasma

Language：English  

Venue：Castelo de Santiago da Barra, Viana do Castelo, Potugal,   Country：Other  

High-speed synthesis and crystalinity control of nanographene using inliquid plasma in alcohol

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Highly Selective Etching of Dielectrics over SiC Film by DC Superposed Dual-Frequency CCP

Language：English  

Venue：Takeda Sentanchi Building, Asano campus of the University of Tokyo   Country：Other  

Highly selective etching of gap-fill dielectrics over SiC and SiN by the dc-bias superposed dual-frequency CCP

Language：English  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Identification of ESR signals arisen from Penicillium digitatum spores-2

Language：English  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Impact of Last Reactor Condition to Radical Density in Subsequent H2/N2 plasma and its Control

Language：English  

Venue：Yokohama, Japan,   Country：Other  

In Situ XPS Analysis of ArF Photoresist Modification Caused by Fluorocarbon Ions and Radicals

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Influence of Last Condition in Plasma Reactor on Gaseous Radical Density

Language：English  

Venue：Tampa Convention Center in Florida   Country：Other  

Interface Trap Generation by VUV/UV Radiation from Fluorocarbon Plasma

Language：English  

Venue：Yokohama, Japan,   Country：Other  

Investigation of Hydrogen Radical Kinetics during ArF 193nm Photoresist Processing for Ultimate CMOS Technology Development

Language：English  

Venue：BEXCO(#43 APEC-ro, Haeundae-gu, Busan)   Country：Other  

Investigation of Hydrogen Radical Kinetics during ArF 193nm Photoresist Processing for Ultimate CMOS Technology Development

Language：English  

Venue：Tampa Convention Center in Florida   Country：Other  

Investigation of Plasma-Surface Interactions Between Hydrogen Radical and Chemically Amplified Photoresist

Language：English  

Venue：Renaissance Austin Hotel,Austin, Texas   Country：Other  

Investigation of modification of ArF photoresist during plasma etching processes

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Low Temperature Deposition and Characteristics of GaN Thin Film by HF-PECVD

Language：English  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Language：English  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Measuring Metal Elements in Food Products Using Ar Atmospheric Pressure Plasma

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Mechanism and Control of Roughness Formation on ArF Photoresist by C5HF7 Etching Plasma

Language：English  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Mechanism of Etching and Generating Active Species in CHxFy Plasma

Language：English  

Venue：Tampa Convention Center in Florida   Country：Other  

Mechanism of Generating Ions and Radicals in Fluorocarbon Plasma Investigated by Reaction Model Analysis

Language：English  

Venue：Kyushu University   Country：Other  

Mechanism of Generating Ions and Radicals in C3F6O Plasma

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Microcrystal Orientation of Silicon Thin Film Deposited with Hydrogen Radical Injection Plasma Enhanced CVD

Language：English  

Venue：Kyushu University   Country：Other  

Modification of ArF Photoresist Caused by Irradiation of Fluorocarbon Plasma-beam

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Non-Contact Temperature Measurement of Sapphire Substrate for GaN using Frequency Domain Low Coherence Interferometry

Language：English  

Venue：Warsaw University of Technology - POLAND   Country：Other  

Nucleation control of self-organized vertical nano-graphenes using inductively coupled plasma enhanced chemical vapor deposition

Language：English  

Venue：Takeda Sentanchi Building, Asano campus of the University of Tokyo   Country：Other  

Nucleation mechanism of self-organized vertical nano-graphenes grown using inductively coupled plasma enhanced chemical vapor deposition

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Observation of Plasma-Exposed GaN Surface at High Temperature

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Optical Properties of Carbon Nano Walls in Terahertz Frequencies Region

Language：English  

Venue：Takeda Sentanchi Building, Asano campus of the University of Tokyo   Country：Other  

Photon-stimulated surface reaction and generation of damage to hydrogenated silicon nitride in fluorocarbon plasma

Language：English  

Venue：Takeda Sentanchi Building, Asano campus of the University of Tokyo   Country：Other  

Plasma surface modification of carbon nanowalls for biosensor application

Language：English  

Venue：Takeda Sentanchi Building, Asano campus of the University of Tokyo   Country：Other  

Plasma-Biological Surface Interaction for Food Hygiene: Real-time in situ Electron Spin Resonance Measurements

Language：English  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Properties of GaAs surface by ion irradiation of chlorine

Language：English  

Venue：Sungkyunkwan University, Suwon, Korea   Country：Other  

Reaction mechanism of plasma etching using hydrogen-containing fluorocarbon gas

Language：English  

Venue：Sungkyunkwan University, Suwon, Korea   Country：Other  

Reaction mechanism of plasma etching using hydrogen-containing fluorocarbon gas

Language：English  

Venue：Edinburgh, Scotland, UK   Country：Other  

Real time in situ Electron Spin Resonance (ESR) study of Surface Reaction on Polymer Interacted with Plasma

Language：English  

Venue：Yokohama, Japan,   Country：Other  

Real-time / In-situ Electron Spin Resonance Analysis of Surface Reactions on Organic / Biological Materials Interacted with Plasmas

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Reconsideration on Effects of H Radicals on Thin Film Surfaces in Plasma Enhanced Chemical Vapor Deposition employing SiH4/H2 Gases

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Recovery of Plasma-Damaged GaN by Employing Exposure of Radicals

Language：English  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Relationship between Ion Energy and Highly Selective SiO2 Etching Characteristics using C5HF7 Gas

Language：English  

Venue：Orlean, France,   Country：Other  

Selective Killing of Ovarian Cancer Cells through Induction of Apoptosis by a Nonequilibrium Atmospheric Pressure Plasma (NEAPP)

Language：English  

Venue：Convention Center / Marriott Marquis, San Francisco,   Country：Other  

Selective Killing of Ovarian Cancer Cells through Induction of Apoptosis by a Nonequilibrium Atmospheric Pressure Plasma, WW-2.4

Language：English  

Country：Other  

Selective killing of ovarian cancer cells through induction of apoptosis by a nonequilibrium atmospheric pressure plasma

Language：English  

Venue：Sungkyunkwan University, Suwon, Korea   Country：Other  

Selective killing of ovarian cancer cells through induction of apoptosis by nonequilibrium atmospheric pressure plasma

Language：English  

Venue：Sungkyunkwan University, Suwon, Korea   Country：Other  

Selective killing of ovarian cancer cells through induction of apoptosis by nonequilibrium atmospheric pressure plasma

Language：Japanese  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Language：English  

Country：Other  

Silicon full wafer bonding with atomic layer deposited titanium dioxide and aluminum oxide intermediate films

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Spectroscopic Determination of Radical Densities in SiH4/H2 Plasma

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Studies on Plasma Etching of Si3N4 Employing New Alternative Gas, C5HF7

Language：English  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Study on reaction mechanism of plasma-enhanced atomic layer deposition of SiO2 using in-situ ATR-FTIR

Language：English  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Study on synthesis mechanisms of nano-graphene materials employing alcohol in-liquid plasma

Language：English  

Venue：Tampa Convention Center in Florida   Country：Other  

Subsequent Temporal Change of Gaseous H and N Radical Density in Plasma after Different Processes

Language：English  

Venue：Yokohama, Japan,   Country：Other  

Surface Roughness on Plasma-Etched Gallium Nitride (GaN)

Language：English  

Venue：the AT&T Conference Center on The University of Texas at Austin campus, Texas,   Country：Other  

Temperature measurement of substrate with a thin film using low-coherence interference

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

The Formation of the Insulating Film with Atmospheric Pressure Plasma-Enhanced Chemical Vapor Deposition by Hexamethyldisiloxan Mist

Language：English  

Venue：Kyoto University ROHM Plaza, Kyoto, Japan,   Country：Other  

Two-Step Supporting of High-Density Metal Nanoparticle Catalysts on Carbon Nanowalls using Supercritical Fluid

Language：English  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Vibrational Sum-Frequency-Generation (SFG))Spectroscopic study-2

Language：Japanese  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Language：Japanese  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Language：Japanese  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Language：Japanese  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Language：Japanese  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Language：Japanese  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Language：Japanese  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Language：Japanese  

Venue：東京大学 生産技術研究所 An棟 コンベンションホール   Country：Other  

Language：Japanese  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Language：Japanese  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Language：Japanese  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Language：Japanese  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Language：Japanese  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Language：Japanese  

Venue：愛媛大学城北地区・松山大学文京キャンパス   Country：Other  

Language：Japanese  

Venue：山形大学   Country：Other  

Language：English  

Venue：Shenzhen Convention&Exhibition Center   Country：Other  

Advanced Plasma Nanotechnology fir Control Synthesis and Biomedical Applications of Carbon Nanomaterials

Language：English  

Venue：Nagoya Institute of Technology   Country：Other  

Affection of Hydrophilic and Hydrophobic of Carbon Nanowalla Using Plasma Surface Trearment

Language：English  

Venue：山形大学   Country：Other  

Ar Flow Rate Dependence of Emission Intensity of Metal Atoms in Atmospheric Pressure Atomization Plasma

Language：English  

Venue：Nagoya Institute of Technology   Country：Other  

Area-selective of Carbon Nanowalls by Using Catalyzed Substrate

Language：English  

Venue：名古屋大学   Country：Other  

Atom Behaivior of Ultrahigh Density 60 Hz Atmospheric Pressure Plasma under Ar ambient Conditions

Language：English  

Venue：SaltLakeCity   Country：Other  

Behavior of radicals in SiH4/H2 plasma for fabrication of solar cell using silicon thin film

Language：Japanese  

Venue：名古屋大学   Country：Other  

Language：Japanese  

Venue：神奈川工科大学   Country：Other  

Language：English  

Venue：Nagoya Institute of Technology   Country：Other  

C5HF7 Chemistry for Highly Selective Etch of SiO2 over Si

Language：Japanese  

Venue：山形大学   Country：Other  

Language：Japanese  

Venue：石川県立音楽堂   Country：Other  

Language：Japanese  

Venue：名古屋大学   Country：Other  

Language：Japanese  

Venue：山形大学   Country：Other  

Language：English  

Venue：Québec City Convention Center   Country：Other  

Carbon nanowalls: growth mechanism and nucleation control

Language：English  

Venue：Strunjan   Country：Other  

Carbon nanowalls:synthesis and application

Language：English  

Venue：Takayama Public Cultural Hall   Country：Other  

Chemical Modeling of Etch Process Using C3F6O Alternative Gas

Language：English  

Venue：Takayama Public Cultural Hall   Country：Other  

Chemical Modeling of Etch Process Using C3F6O Alternative Gas

Language：English  

Country：Other  

Chemical structures of initial growth surfaces of carbon nanowalls by angle-resolved X-ray photoelectron spectroscopy

Language：English  

Venue：Osaka University   Country：Other  

Chemical structures of initial growth surfaces of carbon nanowalls by angle-resolved X-ray photoelectron spectroscopy

Language：English  

Venue：Takayama Public Cultural Hall   Country：Other  

Control of Bridging Growth and Electrical properties of Single Carbon Nanowalls

Language：English  

Venue：World EXPOCenter   Country：Other  

Controlled Synthesis of Carbon Nanowalls and their Characterization Employing Synchrotron X-ray

Language：English  

Venue：Strunjan   Country：Other  

Controlled Synthesis of Carbon Nanowalls for Functional Device Applications