１）科学研究費補助金
平成 21~25 年度、科学技術研究機構（JST）戦略的創造研究推進事業（CREST）「異種接合GaN 横型トランジスタのインバータ展開」
平成 21~24 年度、基盤研究(A)「電子準位制御と新ゲート構造による窒化ガリウム系トラン
ジスタの高信頼化」
平成 21~22 年度、特定領域研究（公募研究）「Ⅲ族窒化物半導体混晶の欠陥準位・表面準位の評価と制御」平成 20~21 年度、日本学術振興会二国間事業共同研究、「半導体ナノワイヤ構造を利用した次世代集積回路の展開」、中国側代表者は呉南健教授（中国科学院半導体研究所）
平成 19~20 年度、特定領域研究（公募研究）、「Ⅲ族窒化物半導体混晶の欠陥準位・表面準位の評価と制御」平成 17~18 年度、基盤研究(B)「欠陥制御・界面制御に基づく窒化ガリウム系デバイス構造の高信頼化」

２）招待講演（2008 年以降）
1.

T. Hashizume, Y. Hori and C. Mizue, (Invited) “Interface control technologies of GaN-based
MOS structures for high-efficiency power switching transistors”, Workshop on Dielectrics in
Microellectronics (WoDiM 2010), Bratislava, Slovak, June 28-30, 2010.

2.

T. Hashizume and K. Ohi, (Invited) “Current controllability and stability of multi-mesa-channel
AlGaN/GaN HEMTs”, 2010 International Meeting for Future of Electron Devices, Kansai(IMFEDK), Osaka, May 13- 14, 2010.

3.

T. Hashizume, (Invited) "Effects of plasma processing on surface properties of GaN and AlGaN(Invited)", 2nd International Symposium on Advanced Plasma Science and its Applications for
Nitrides and Nanomaterials (ISPlasma-2010), Mar. 8-10, Nagoya, Japan

4.

T. Hashizume, (Invited) "Characterization and control of GaN and AlGaN surfaces forhigh-performance GaN-based transistors", Huang Kun Forum, Chinese Academy of Science,
Nov. 6, 2009, Beijin, China.

5.

T. Hashizume, (Invited) "Surface control of GaN alloys for photonic and electronic devices",
Society of Photographic Instrumentation Engineers (SPIE), Photonics West, San Hose, CA, Jan.
25-29, 2009.

6.

T. Hashizume, (Invited) "Surface control structures for high-performance AlGaN/GaN HEMTs",
7th International Conference on Advanced Semiconductor Devices and Microsystems (ASDAM
2008), Smolenice, Slovakia, October 12-16, 2008.

7.

T. Hashizume, (Invited) "Surface control of AlGaN for the stability improvement of AlGaN/GaN
HEMTs", 66th Device Research Conference (DRC-66), Univ. California, Santa Barbara, USA,
June 23-25, 2008.

8.

橋詰 保、「窒化物半導体の表面・界面制御とパワートランジスタ展開」、日本学術振興会アモルファス・ナノ材料第１４７委員会第１０８回研究会、2010 年 7 月 9 日、主婦会

館、東京。
9.

橋詰 保、「AlGaN の深い電子準位と表面ポテンシャル」、応用物理学会応用電子物性分科会研究会、2010 年 5 月 21 日、大阪大学銀杏会館、大阪。

10. 橋詰 保、「窒化物半導体の特徴とデバイス展開」、第 27 回無機材料に関する最近の研究成果発表会-材料研究の最前線から-、2010 年 1 月 25 日、東海大学校友会館、東京。
11. 橋詰 保、「窒化物半導体の MIS 界面電子準位」、日本学術振興会第 154 委員会・第 162
委員会合同研究会、2009 年 10 月 26 日、東京。
12. 橋詰 保、「AlGaN の 表 面 制 御 と ト ラ ン ジ ス タ 応 用 」、電気学会超高速デバイス研究会、2009 年 3 月 9 日、熱海。
13. 橋詰 保、「GaN および AlGaN の欠陥準位と表面準位」、科学技術交流財団第４回窒化物
半導体応用研究会、2009 年 1 月 23 日、名古屋工業大学。
14. 橋詰 保、「GaN 系トランジスタの現状と信頼性」、パワーデバイス用シリコンおよび関連半導体材料に関する研究会、2008 年 12 月 8-9 日、新潟大学。
15. 橋詰 保、「AlGaN のバルク準位・表面準位とそのデバイス動作特性への影響」、日本学術振興会第 162 委員会ワイドギャップ半導体光・電子デバイス第 59 回研究会，2008 年 7月 19 日，東京。

３）学術論文（2007 年以降）
1.

N. Harada, Y. Hori, N. Azumaishi, K. Ohi and T. Hashizume, “Formation of recessed-oxide gate
for normally-off AlGaN/GaN HEMTs using a selective electrochemical oxidation”, Appl. Phys.
Express 4, Art. No. 021002 (2011)2.

C. Mizue, Y. Hori, M. Miczek, and T. Hashizume, “Capacitance-voltage characteristics of
Al2O3/AlGaN/GaN structures and state density distribution at Al2O3/AlGaN interface”, Jpn. J.
Appl. Phys. 50, Art. No. 021001 (2011).

3.

E. Ogawa and T. Hashizune, “Variation of Chemical and Photoluminescence Properties of
Mg-Doped GaN Caused by High-Temperature Process”, Jpn. J. Appl. Phys. 50, Art. No. 021002(2011).

4.

C.-Y. Hu, T. Hashizume, K. Ohi, M. Tajima, “Trapping effect evaluation of gateless AlGaN/GaN
heterojunction field-effect transistors using transmission-line-model method”, Appl. Phys. Lett.
97, Art. No. 222103 (2010).

5.

T. Yoshida and T. Hashizume, “Air-Gap Capacitance-Voltage Analyses of p-InP Surfaces
Covered with Natural Oxide”, Appl. Phys. Express 3, Art. No. 116601 (2010).

6.

K. Ooyama, K. Sugawara, S. Okuzaki, H. Taketomi, H. Miyake, K. Hiramatsu, and T.
Hashizume, “Deep electronic levels of AlxGa1-xN with a wide range of Al composition grown bymetal-organic vapor phase epitaxy”, Jpn. J. Appl. Phys. 49, Art. No. 101001 (2010)

7.

Y. Hori, C. Mizue, and T. Hashizume, “Process conditions for improvement of electricalproperties of Al2O3/n-GaN structures prepared by atomic layer deposition”, Jpn. J. Appl. Phys. 49,
Art. No. 080201 (2010). JJAP編集委員会より「SPOTLIGHTS」としてJJAPホームページに紹介される。（http://jjap.jsap.jp/spotlights/index.html）

8.

D. Gregušova, R. Stoklas, C. Mizue, Y. Hori, J. Novák, T. Hashizume, and P. Kordoš, “Trapstates in AlGaN/GaN metal-oxide-semiconductor structures with Al2O3 prepared by atomic layer
deposition”, J. Appl. Phys. 107, Art. No. 106104(2010).

9.

M. Akazawa, T. Matsuyama, T. Hashizume, M. Hiroki, S. Yamahata, and N. Shigekawa, "Smallvalence-band offset of In0.17Al0.83N/GaN heterostructure grown by metal-organic vapor phase
epitaxy", Appl. Phys. Lett. 96, Art. No. 132104 (2010).

10. T. Kubo, H. Taketomi, H. Miyake, K. Hiramatsu, and T. Hashizume, "Variation of surface
potentials of Si-doped AlxGa1-xN (0 < x < 0.87) grown on AlN/sapphire template bymetal-organic vapor phase epitaxy", Appl. Phys. Express 3, Art. No. 021004(2010).
11. K. Ohi and T. Hashizume, "Drain current stability and controllability of threshold voltage andsubthreshold current in a multi-mesa-channel AlGaN/GaN high electron mobility transistor", Jpn.
J. Appl. Phys. 48, in press, (2009).
12. K. Sugawara, J. Kotani and T. Hashizume, "Near-midgap deep levels in Al0.26Ga0.74N grown bymetal-organic chemical vapor deposition", Appl. Phys. Lett. 94, Art. No. 152106-1-3 (2009).
13. M. Miczek, B. Adamowicz, C. Mizue and T. Hashizume, "Simulations of C-V-T Behavior of
Metal/Insulator/AlGaN and Metal/Insulator/AlGaN/GaN Structures", Jpn. J. Appl. Phys. 48, Art.
No. 04C092-1-6 (2009).
14. T. Hashizume, N. Shiozaki and K. Ohi, "Surface control of GaN alloys for photonic andelectronic devices (Invited) ", Proc. of SPIE, Gallium Nitride Materials and Devices IV, vol.
7216, 7216-0U-1, 2009.
15. N. Shiozaki and T. Hashizume, "Improvements of Electronic and Optical Characteristics ofn-GaN-based structures by Photoelectrochemical Oxidation in Glycol Solution", J. Appl. Phys.
105, Art. No. 064912-1-6(2009).
16. T. Kimura and T. Hashizume, "Effect of carbon incorporation on electric properties of n-type
GaN surfaces", J. Appl. Phys. 105, Art. No. 014503-1-5(2009).
17. C. Mizue, J. Kotani, M. Miczek, and T. Hashizume, "UV-induced variation of interface potential
in the AlOx/n-GaN structure", Jpn. J. Appl. Phys. 48, Art. No. 020201-1-3 (2009).
18. T. Tajima, J. Kotani and T. Hashizume, "Effects of native oxide formation on AlGaN on DC
characteristics of AlGaN/GaN high-electron-mobility transistors", Jpn. J. Appl. Phys. 48, Art. No.
020203-1-3 (2009).
19. T. Uesugi, T. Kachi, M. Sugimoto, T. Matsuyama, C. Mizue, and T. Hashizume, "Deposition ofaluminum oxide layer on GaN using diethyl-aluminum-ethoxide as a precursor", J. Appl. Phys.
104, Art. No. 016103-1-3(2008).

20. M. Miczek, C. Mizue, T. Hashizume, and B. Adamowicz, "Effects of interface states andtemperature on the C-V behavior of metal/insulator/AlGaN/GaN heterostructure capacitors", J.
Appl. Phys. 103, Art. No. 104510-1-11(2008).
21. K. Ooyama, H. Kato, M. Miczek, and T. Hashizume, "Temperature-dependent interface-state
response in an Al2O3/n-GaN structure", Jpn. J. Appl. Phys. 47, 5426-5428 (2008).
22. T. Tamura, J.Kotani, S.Kasai, and T. Hashizume, "Nearly temperature-independent saturation
drain current in a multi-mesa-channel AlGaN/GaN high-electron-mobility transistor", Appl. Phys.
Express 1, Art. No. 023001(2008).
23. J. Kotani, M. Tajima, S. Kasai and T. Hashizume, "Mechanism of surface conduction in thevicinity of Schottky gates on AlGaN/GaN heterostructures", Appl. Phys. Lett. 91, Art. No.
093501(2007).
24. E. Ogawa, T. Hashizume, S. Nakazawa, T. Ueda and T. Tanaka, "Chemical andPotential-Bending Characteristics of SiNx/AlGaN Interfaces Prepared by In Situ Metal-Organic
Chemical Vapor Deposition", Jpn. J. Appl. Phys. 46, L590-592 (2007).
25. M. Kaneko, T. Hashizume, V. A. Odnoblyudov and C. W. Tu, "Electrical and deep-level
characterization of GaP1-xNx grown by gas-source molecular beam epitaxy", J. Appl. Phys. 101,
103707-1-5(2007).
26. N. Shiozaki, T. Sato and T. Hashizume, "Formation of Thin Native Oxide Layer on n-GaN by
Electrochemical Process in Mixed Solution with Glycol and Water", Jpn. J. Appl. Phys. 46,
1471-1473(2007).
27. T. Kimura, S. Ootomo, T. Nomura, S. Yoshida, and T. Hashizume, " Solid-Phase Diffusion of
Carbon into GaN Using SiNx/CNx/GaN Structure", Jpn. J. Appl. Phys. 46, L224-226(2007).

４）国際会議発表論文（2007 年以降）
1.

S. Okuzaki, K. Sugawara, H. Taketomi, H. Miyake, K. Hiramatsu and T. Hashizume, “Deeplevel characterization of MOVPE-grown AlGaN with high Al compositions”, 2010
International Conference on Solid-State Devices and Materials (SSDM2010), Tokyo, Sep.
22-24, 2010.

2.

Y. Hori, C. Mizue and T. Hashizume, “Effects of fabrication processes on electrical properties of
Al2O3/n-GaN structures prepared by atomic layer deposition”, 2010 International Workshop on
Nitride Semiconductors (IWN-2010), Tampa, USA, Sep. 19- 24, 2010.

3.

K. Ohi and T. Hashizume, 2Current Controllability and Stability in Multi-Mesa-Channel
AlGaN/GaN HEMT”, 2010 International Workshop on Nitride Semiconductors (IWN-2010),
Tampa, USA, Sep. 19- 24, 2010.

4.

E. Ogawa and T. Hashizume, “Effects of Mg-doping density and high-temperature annealing on
deep levels in Mg-doped GaN”, 2010 International Workshop on Nitride Semiconductors(IWN-2010), Tampa, USA, Sep. 19- 24, 2010.

5.

N. Harada and T. Hashizume, “A recessed oxide gate structure for threshold voltage control in
AlGaN/GaN HEMTs by electrochemical process”, 2010 International Workshop on Nitride
Semiconductors (IWN-2010), Tampa, USA, Sep. 19- 24, 2010.

6.

C. Mizue and T. Hashizume, “C-V characterization of ALD-Al2O3 insulated gates on
AlGaN/GaN structure”, Workshop on Dielectrics in Microellectronics (WoDiM 2010),
Bratislava, Slovak, June 28-30, 2010.

7.

T. Yoshida and T. Hashizume, “Air-gap capacitance-voltage analysis of p-InP surfaces”, 22ndInternational Conference on Indium Phosphide and Related Materials (IPRM2010), Takamatsu,
May 31- June 4, 2010.

8.

Y. Hori, C. Mizue and T. Hashizume, "Interface state properties of Al2O3/n-GaN prepared byatomic layer deposition", International Meeting for Future of Electron Devices, Kansai(IMFEDK), Osaka, May 13- 14, 2010.

9.

K. Sugawara, T. Kubo, H. Taketomi, H. Miyake, K. Hiramatsu and T. Hashizume,"Characterization of Schottky interface properties and deep levels of AlxGa1-xN (0.25<x<0.68)
grown by MOVPE", 8th International Conference on Nitride Semiconductors (ICNS-8), Oct.
18-23, 2009, Jeju, Korea.

10. K. Ohi and T. Hashizume, "Multi-Mesa-Channel Structure for Improvement of Gate
Controllability and Current Stability in AlGaN/GaN HEMTs", 8th International Conference on
Nitride Semiconductors (ICNS-8), Oct. 18-23, 2009, Jeju, Korea.
11. E. Ogawa and T. Hashizume, "Mg accumulation and defect formation at p-GaN surfaces caused
by a high-temperature annealing", 8th International Conference on Nitride Semiconductors(ICNS-8), Oct. 18-23, 2009, Jeju, Korea.
12. C. Mizue, Y. Hori, M. Miczek and T. Hashizume, "Characterization of interface electronic statesin ALD-Al2O3/AlGaN/GaN structures", 8th International Conference on Nitride Semiconductors(ICNS-8), Oct. 18-23, 2009, Jeju, Korea.
13.

M. Tajima and T. Hashizume, " Correlation between surface leakage current and operation
degradation of AlGaN/GaN HEMTs", 8th International Conference on Nitride Semiconductors(ICNS-8), Oct. 18-23, 2009, Jeju, Korea.

14. T. Kubo, K. Sugawara, H. Taketomi, H. Miyake, K. Hiramatsu and T. Hashizume, "Chemical andElectronic Properties of MOVPE-grown AlxGa1-xN Surfaces (0.25 < x < 0.68)", 8th International
Conference on Nitride Semiconductors (ICNS-8), Oct. 18-23, 2009, Jeju, Korea.
15. Y. Hori, C. Mizue, K. Ooyama, M. Miczek and T. Hashizume, "Chemical and electronic
properties of ALD-Al2O3/AlGaN interfaces", 2009 International Conference on Solid-State
Devices and Materials (SSDM2009), Sendai, Oct. 7-8.
16. N. Harada, N. Shiozaki, and T. Hashizume, "Electrochemical oxidation of GaN for surface
control of GaN-based device structures, 2009 International Conference on Solid-State Devices
and Materials (SSDM2009), Sendai, Oct. 7-8.
17. K. Ooyama, C. Mizue, Y. Hori and T. Hashizume, "Interface characterization of Al2O3/n-GaN
structure prepared by atomic layer deposition", 2009 Asia-Pacific Workshop on Fundamental andApplication of Advanced Semiconductor Devices (AWAD 2009), Jun. 24-26, 2009, Busan,
Korea.
18. E. Ogawa and T. Hashizume, "Effects of high-temperature anneal on surface properties ofMg-doped GaN", 2009 International Meeting for Future of Electron Devices, Kansai (IMFEDK),
Osaka, May 14- 15, 2009.
19. T. Kimura and T. Hashizume, " Characterization of GaN surfaces after high-temperatureannealing and carbon diffusion", 2008 Asia-Pacific Workshop on Fundamental and Applicationof Advanced Semiconductor Devices (AWAD 2008), Jul. 9-11, 2008, Sapporo.
20. K. Ohi, T. Tamura, J. Kotani and T. Hashizume, "Mesa-gate AlGaN/GaN HEMTs having
narrow-width channels", 2008 International Conference on Solid-State Devices and Materials(SSDM2008), Tsukuba, Sep. 21-23.
21. K. Sugawara, J. Kotani and T. Hashizume, "Near-midgap deep levels in MOVPE-grown
AlGaN", 2008 International Conference on Solid-State Devices and Materials (SSDM2008),
Tsukuba, Sep. 21-23.
22. Nanako Shiozaki, Taketomo Sato, Tamotsu Hashizume, "Control of Electronic States at n-GaN
Surfaces by Photoelectrochemical Oxidation in Glycol Solution", 2008 International Workshop
on Nitride Semiconductors (IWN-2008), Montreux, Switzerland, Oct. 5- 10, 2008.
23. Takshi Kimura and Tamotsu Hashizume, "Impurity incorporation and Ga outdiffusion at n-GaN
surfaces during high-temperature annealing processes", 2008 International Workshop on Nitride
Semiconductors (IWN-2008), Montreux, Switzerland, Oct. 5- 10, 2008.
24. Chihoko Mizue and Tamotsu Hashizume, "Depletion layer modulation at the Al2O3/n-GaN
interface under UV-illumination", 2008 International Workshop on Nitride Semiconductors(IWN-2008), Montreux, Switzerland, Oct. 5- 10, 2008.
25. Eri Ogawa and Tamotsu Hashizume, "Variation of Mg density and conductivity at p-GaN
surfaces caused by high-temperature anneal", 2008 International Workshop on Nitride
Semiconductors (IWN-2008), Montreux, Switzerland, Oct. 5- 10, 2008.
26. Masafumi Tajima and Tamostu Hashizume, "Impacts of Surface of Oxidation andOxynitridation on DC Characteristics of AlGaN/GaN HEMTs", 2008 International Workshop
on Nitride Semiconductors (IWN-2008), Montreux, Switzerland, Oct. 5- 10, 2008.
27. Takahiro Tamura, Junji Kotani, Seiya Kasai, Tamotsu Hashizume, "Highly Thermal Stability ofDrain Current in Multi-Mesa-Gate AlGaN/GaN HEMTs", The 34th International Symposiumon Compound Semiconductors (ISCS-34), Oct. 15-18, 2007, Kyoto.
28. T. Kimura and T. Hashizume, "Effects of carbon diffusion on electrical and optical properties ofn-GaN", 7th International Conference on Nitride Semiconductors (ICNS-7), Sep. 16-21, 2007,
Las Vegas, USA.
29. M. Tajima, A. Basile, J. Kotani, T. Hashizume, "Operation Robustness of AlGaN/GaN HEMTs
with an Ultrathin-Al-Layer Based Surface Control", 7th International Conference on Nitride
Semiconductors (ICNS-7), Sep. 16-21, 2007, Las Vegas, USA.
30. N. Shiozaki, F. Ishikawa, A. Trampert, H. T. Grahn, T.Hashizume, "High-quality native oxide of
GaN for surface passivation formed by photo-enhanced electrochemical process", 7thInternational Conference on Nitride Semiconductors (ICNS-7), Sep. 16-21, 2007, Las Vegas,
USA.
31. E. Ogawa, M. Sugimoto, T. Kachi, T. Uesugi, N. Soejima, T. Hashizume, "Correlation between
chemical and electrical properties of p-GaN surfaces subjected to halogen-based plasma", 7thInternational Conference on Nitride Semiconductors (ICNS-7), Sep. 16-21, 2007, Las Vegas,
USA.
32. J. Kotani, M. Tajima, S. Kasai, and T. Hashizume, "Mechanism of surface current in the vicinityof Schottky gate formed on AlGaN/GaN heterostructure", 7th International Conference on
Nitride Semiconductors (ICNS-7), Sep. 16-21, 2007, Las Vegas, USA.
33. M. Miczek, C. Mizue and T. Hashizume, "The effects of interface states on C-V behavior of
insulated gates on AlGaN/GaN heterostructures", 7th International Conference on Nitride
Semiconductors (ICNS-7), Sep. 16-21, 2007, Las Vegas, USA.
34. K. Ooyama, H. Kato, M. Miczek and T. Hashizume, " Dynamic response of interface statecharges in GaN MIS structures", 2007 International Conference on Solid-State Devices andMaterials (SSDM2007), Tsukuba.
35. M. Tajima, J. Kotani, A. Basile, T. Hashizume, "Effects of surface modification and oxide layer
formationon DC characteristics and operating stability of AlGaN/GaN HEMTs", 2007
International Meeting for Future of Electron Devices, Kansai (IMFEDK), Oosaka, April 24 - 25,
2007.
36. T. Kimura and T. Hashizume, " Carbon diffusion into GaN using SiNx/CNx bilayer structure
prepared by ECR-CVD", 2007 International Meeting for Future of Electron Devices, Kansai(IMFEDK), Oosaka, April 24 - 25, 2007.
37. C. Mizue, J. Kotani, M. Miczek, T. Hashizume, "Interface state characterization of insulating
gates on AlGaN layers and AlGaN/GaN heterostructures", 2007 International Meeting for Futureof Electron Devices, Kansai (IMFEDK), Oosaka, April 24 - 25, 2007.
38. J. Kotani, M. Tjima, S. Kasai and T. Hashizume, "Analysis of lateral surface leakage in thevicinity of Schottky gates in AlGaN/GaN HEMTs", 65th Annual Device Research Conference(DRC-65), University of Notre Dame, South Bend, IN on June 18-20, 2007.
39. N. Shiozaki and T. Hashizume, "Characterization of thin native-oxide layer formed on GaN
by photoelectrochemical process in glycol solution", 17th International Vacuum Congress(IVC-17), 13th International Conference on Surface Science (ICSS-13), International
Conference on Nano Science and Technology (ICN+T 2007), Jul. 2-6, 2007, Stockholm,
Sweden.
40. J. Kotani and T. Hahsizume, "Characterization of deep levels in MOVPE-grown AlGaN bycapacitance transient spectroscopy", 17th International Vacuum Congress (IVC-17), 13th
International Conference on Surface Science (ICSS-13), International Conference on Nano
Science and Technology (ICN+T 2007), Jul. 2-6, 2007, Stockholm, Sweden.
41. C. Mizue, T. Matsuyama, J. Kotani, M. Miczek and T. Hashizume, "AlON insulated-gatestructure on AlGaN prepared by ECR-CVD using an aluminum-ethoxide source", 17th
International Vacuum Congress (IVC-17), 13th International Conference on Surface Science(ICSS-13), International Conference on Nano Science and Technology (ICN+T 2007), Jul. 2-6,
2007, Stockholm, Sweden.