Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Yamamoto Keisuke Last modified date:2018.10.19

Assistant Professor / Department of Internationalization and Future Conception / Faculty of Engineering Sciences


Papers
1. Keisuke Yamamoto, Ryutaro Noguchi, Masatoshi Mitsuhara, Minoru Nishida, Toru Hara, Dong Wang, Hiroshi Nakashima , Wide range control of Schottky barrier heights at metal/Ge interfaces with nitrogen-contained amorphous interlayers formed during ZrN sputter deposition, Semiconductor Science and Technology, 10.1088/1361-6641/aae4bd, 33, 11, 114011, 2018.10.
2. Hiroshi Nakashima, Hayato Okamoto, Keisuke Yamamoto, Dong Wang, Achievement of Ultralow Contact Resistivity of Metal/n+-Ge Contacts with Zr-N-Ge Amorphous Interlayer
, ECS Transactions, 10.1149/08004.0097ecst , 80, 4, 97-106, 2017.10, [URL].
3. Hidenori Higashi, Kouhei Kudo, Keisuke Yamamoto. Shinya Yamada, Takeshi Kanashima, Isao Tsunoda, Hiroshi Nakashima, Kohei Hamaya , Electrical properties of pesudo-single-crystalline Ge films grown by Au-induced layer exchange crystallization at 250oC
, Journal of Applied Physics, 10.1063/1.5031469, 123, 21, 215704-1-215704-7, 2018.06, [URL].
4. Takayuki Maekura, Kentaro Tanaka, Chisato Motoyama, Ryota Yoneda, Keisuke Yamamoto, Hiroshi Nakashima, Dong Wang, Effect of n-type doping level on direct band gap electroluminescence intensity for asymmetric metal/Ge/metal diodes
, Semiconductor Science and Technology, 10.1088/1361-6641/aa827f, 32, 10, 104001, 2017.08, [URL].
5. T. Kanashima, R. Yamashiro, M. Zenitaka, Keisuke Yamamoto, Dong Wang, J. Tadano, S. Yamada, H. Nohira, Hiroshi Nakashima, K. Hamaya, Electrical properties of epitaxial Lu- or Y-doped La2O3/La22O3/Ge high-k gate-stacks, Materials Science in Semiconductor Processing, 10.1016/j.mssp.2016.11.016, 70, 1, 260-264, 2016.11, [URL].
6. Yuta Nagatomi, Tomoki Tateyama, Shintaro Tanaka, Keisuke Yamamoto, Dong Wang, Hiroshi Nakashima, Achievement of low parasitic resistance in Ge n-channel metal-oxide-semiconductor field-effect transistor using embedded TiN-source/drain structure, Semiconductor Science and Technology, 10.1088/1361-6641/32/3/035001, 32, 3, 035001, 2016.11, [URL].
7. Yuta Nagatomi, Tomoki Tateyama, Shintaro Tanaka, Wei-Chen Wen, Taisei Sakaguchi, Keisuke Yamamoto, Liwei Zhao, Dong Wang, Hiroshi Nakashima, Mechanism of mobility enhancement in Ge p-channel metal-oxide-semiconductor field-effect transistor due to introduction of Al atoms into SiO2/GeO2 gate stack, Materials Science in Semiconductor Processing, 10.1016/j.mssp.2016.11.014, 70, 1, 246-253, 2016.11, [URL].
8. Keisuke Yamamoto, Hayato Okamoto, Dong Wang, Hiroshi Nakashima, Fabrication of asymmetric Ge Schottky tunneling source n-channel field-effect transistor and its characterization of tunneling conduction, Materials Science in Semiconductor Processing, 10.1016/j.mssp.2016.09.024, 70, 1, 283-287, 2016.10, [URL].
9. Kenji Kasahara, Hidenori Higashi, Mario Nakano, Yuta Nagatomi, Keisuke Yamamoto, Hiroshi Nakashima, Kohei Hamaya, Effect of post annealing on hole mobility of pseudo-single-crystalline germanium films on glass substrates, Materials Science in Semiconductor Processing, 10.1016/j.mssp.2016.07.004, 70, 1, 68-72, 2016.10, [URL].
10. Yuichi Fujita, Michihiro Yamada, Yuta Nagatomi, Keisuke Yamamoto, Shinya Yamada, Kentarou Sawano, Takeshi Kanashima, Hiroshi Nakashima, Kohei Hamaya, A low-temperature fabricated gate-stack structure for Ge-based MOSFET with ferromagnetic epitaxial Heusler-alloy/Ge electrodes, Japanese Journal of Applied Physics, 10.7567/JJAP.55.063001, 55, 6, 063001-1-063001-4, 2016.04, [URL].
11. Takayuki Maekura, Keisuke Yamamoto, Dong Wang, Hiroshi Nakashima, Influences of metal/Ge contact and surface passivation on direct band gap light emission and detection for asymmetric metal/Ge/metal diodes, Japanese Journal of Applied Physics, 10.7567/JJAP.55.04EH08, 55, 4S, 04EH08-1-04EH08-5, 2016.03, [URL].
12. Dong Wang, Hiroshi Nakashima, Keisuke Yamamoto, Takayuki Maekura, Direct band gap light emission and detection at room temperature in bulk germanium diodes with HfGe/Ge/TiN structure, Thin Solid Films, 10.1016/j.tsf.2015.09.074, 2015.10, [URL].
13. Hiroshi Nakashima, Keisuke Yamamoto, Dong Wang, Electrical Properties of Group 4 Metal-Nitride/Ge Contacts and the Application to Ge Optoelectronic Devices, ECS Transactions, 10.1149/06910.0055ecst, 69, 10, 55-66, 2015.10, [URL].
14. Kenji Kasahara, Yuta Nagatomi, Keisuke Yamamoto, H. Higashi, M. Nakano, Shinya Yamada, Dong Wang, Hiroshi Nakashima, Kohei Hamaya, Electrical properties of pseudo-single-crystalline germanium thin-film-transistors fabricated on glass substrates, Applied Physics Letters, 10.1063/1.4932376 , 107, 14, 142102-1-142102-5, 2015.10, [URL].
15. Keisuke Yamamoto, Ryutaro Noguchi, Mitsuhara Masatoshi, Minoru Nishida, Toru Hara, Dong Wang, Hiroshi Nakashima, Electrical and structural properties of group-4 transition-metal nitride (TiN, ZrN, and HfN) contacts on Ge, Journal of Applied Physics, 10.1063/1.4930573, 118, 11, 115701-1-115701-12, 2015.09, [URL].
16. Yuta Nagatomi, Shintaro Tanaka, Yuichi Nagaoka, Keisuke Yamamoto, Dong Wang, Hiroshi Nakashima, Fabrication of PtGe/Ge contacts with high on/off ratio and its application to metal source/drain Ge p-channel MOSFETs, Japanese Journal of Applied Physics, 10.7567/JJAP.54.070306, 54, 7, 070306-1-070306-4, 2015.06, [URL].
17. Dong Wang, Takayuki Maekura, Sho Kamezawa, Keisuke Yamamoto, Hiroshi Nakashima, Direct band gap electroluminescence from bulk germanium at room temperature using an asymmetric fin type metal/germanium/metal structure, Applied Physics Letters, 10.1063/1.4913261, 107, 7, 071102-1-071202-3, 2015.02, [URL].
18. Yuta Nagatomi, Yuichi Nagaoka, Keisuke Yamamoto, Dong Wang, Hiroshi Nakashima, Investigation of Al-PMA Effect on Al2O3/GeOx/Ge Gate Stack, ECS Transactions, 10.1149/06406.0261ecst, 64, 8, 261, 2014.10, [URL].
19. Keisuke Yamamoto, Mitsuhara Masatoshi, Keisuke Hiidome, Ryutaro Noguchi, Minoru Nishida, DONG WANG, Hiroshi Nakashima, Role of an interlayer at a TiN/Ge contact to alleviate the intrinsic Fermi-level pinning position toward the conduction band edge
, Applied Physics Letters, 10.1063/1.4870510, 104, 14, 132109-1-132109-5, 2014.04, [URL].
20. DONG WANG, Nagatomi Yuta, Kojima Shuta, Yamamoto Keisuke, Hiroshi Nakashima, Low-temperature fabrication of Y2O3/Ge gate stacks with ultrathin GeOx interlayer and low interface states density characterized by a reliable deep-level transient spectroscopy method, Thin Solid Films, 10.1016/j.tsf.2013.10.065, 557, 288-291, 2014.04, [URL].
21. Yamamoto Keisuke, DONG WANG, Hiroshi Nakashima, Fabrication of Metal-Nitride/Si Contacts with Low Electron Barrier Height, ECS Transactions, 10.1149/05809.0053ecst, 58, 9, 53, 2013.10, [URL].
22. Hiroshi Nakashima, Yamamoto Keisuke, DONG WANG, Development of Metal Source/Drain Ge-CMOS Using TiN/Ge and HfGe/Ge contacts, ECS Transactions, 10.1149/05809.0167ecst, 58, 9, 167, 2013.10, [URL].
23. Yamamoto Keisuke, Takahiro Sada, DONG WANG, Hiroshi Nakashima, Dramatic enhancement of low electric-field hole mobility in metal source/drain Ge p-channel metal-oxide-semiconductor field-effect transistors by introduction of Al and Hf into SiO2/GeO2 gate stack, Applied Physics Letters, 10.1063/1.4821546, 103, 12, 122106, 2013.09, [URL].
24. D. Wang, S. Kojima, K. Sakamoto, K. Yamamoto, H. Nakashima, An accurate characterization of interface-state by deep-level transient spectroscopy for Ge metal-insulator-semiconductor capacitors with SiO2/GeO2 bilayer passivation, Journal of Applied Physics, 10.1063/1.4759139, 112, 8, 083707, 2012.10, [URL].
25. K. Yamamoto, K. Harada, H. Yang, D. Wang, H. Nakashima, Fabrication of TiN/Ge Contact with Extremely Low Electron Barrier Height, Japanese Journal of Applied Physics, 10.1143/JJAP.51.070208, 51, 7, 070208, 2012.07, [URL].
26. K. Yamamoto, T. Yamanaka, K. Harada, T. Sada, K. Sakamoto, S. Kojima, H. Yang, D. Wang, H. Nakashima, Schottky Source/Drain Ge Metal-Oxide-Semiconductor Field-Effect Transistors with Directly Contacted TiN/Ge and HfGe/Ge Structures, Applied Physics Express, 10.1143/APEX.5.051301, 5, 5, 051301, 2012.05, [URL].
27. M. Iyota, K. Yamamoto, D. Wang, H. Yang, H. Nakashima, Ohmic contact formation on n-type Ge by direct deposition of TiN, Applied Physics Letters, 10.1063/1.3590711, 98, 19, 192108, 2012.05, [URL].
28. K. Yamamoto, T. Yamanaka, R. Ueno, K. Hirayama, H. Yang, D. Wang, H. Nakashima, Source/drain junction fabrication for Ge metal-oxide-semiconductor field-effect transistors, Thin Solid Films, 10.1016/j.tsf.2011.10.047, 520, 8, 3382, 2012.02, [URL].
29. D. Wang, K. Yamamoto, H. Gao, H. Yang, H. Nakashima, Defect Evaluation by Photoluminescence for Uniaxially Strained Si-On-Insulator, Journal of the Electrochemical Society, 10.1149/2.037112jes, 158, 12, H1221, 2011.11, [URL].
30. H. Nakashima, Y. Iwamura, K. Sakamoto, D. Wang, K. Hirayama, K. Yamamoto, H. Yang, Postmetallization annealing effect of TiN-gate Ge metal-oxide-semiconductor capacitor with ultrathin SiO2/GeO2 bilayer passivation, Applied Physics Letters, 10.1063/1.3601480, 98, 25, 252102, 2011.06, [URL].
31. K. Yamamoto, R. Ueno, T. Yamanaka, K. Hirayama, H. Yang, D. Wang, H. Nakashima, High-Performance Ge Metal-Oxide-Semiconductor Field-Effect Transistors with a Gate Stack Fabricated by Ultrathin SiO2/GeO2 Bilayer Passivation, Applied Physics Express, 10.1143/APEX.4.051301, 4, 5, 051301, 2011.04, [URL].
32. D. Wang, K. Yamamoto, H. Gao, H. Yang, H. Nakashima, Defect Evaluation by Photoluminescence for Uniaxially Strained Si-On-Insulator, ECS Transactions, doi: 10.1149/1.3567723, 34, 1, 1117, 2011.03, [URL].
33. H. Nakashima, Y. Sugimoto, Y. Suehiro, K. Yamamoto, M. Kajiwara, K. Hirayama, D. Wang, Electrical and structural evaluations of high-k gate dielectrics fabaricated using plasma oxidation and the subsequent anneling for a Hf/SiO2/Si structure, Semiconductor Science and Technology, 10.1088/0268-1242/23/12/125020, 23, 12, 125020, 2008.12, [URL].
34. Y. Sugimoto, K. Yamamoto, M. Kajiwara, Y. Suehiro, D. Wang, H. Nakashima, Dependences of effective work functions of TaN on HfO2 and SiO2 on post-metallization anneal, Thin Solid Films, 10.1016/j.tsf.2008.08.058, 517, 1, 204, 2008.11, [URL].
35. Y. Sugimoto, M. Kajiwara, K. Yamamoto, Y. Suehiro, D. Wang, H. Nakashima, Effective work function modulation of TaN metal gate on HfO2 after postmetallization annealing, Applied Physics Letters, 10.1063/1.2783472, 91, 11, 112105, 2007.09, [URL].
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37. Y. Sugimoto, K. Yamamoto, H. Nakashima, Electrical and Structural Properties of TaN Gate Electrodes Fabricated by Wet Etching Using NH4OH/H2O2 Solution and Hf Metal Hard Mask, Japanese Journal of Applied Physics, 10.1143/JJAP.46.L211, 46, 8, L211, 2007.02, [URL].
38. Y. Sugimoto, H. Adachi, K. Yamamoto, D. Wang, Hideharu Nakashima, Hiroshi Nakashima, Electrical characterization of high-k gate dielectrics fabricated using plasma oxidation and post-deposition annealing of a Hf/SiO2/Si structure, Materials Science in Semiconductor Processing, 10.1016/j.mssp.2006.10.020, 9, 6, 1031, 2006.12, [URL].