超低損失パワーデバイス実現に向けた窒化ガリウムのアバランシェ破壊特性の解明

• Project/Area Number: 18J20080
• Research Category: Grant-in-Aid for JSPS Fellows
• Allocation Type: Single-year Grants
• Section: 国内
• Research Field: Electronic materials/Electric materials
• Research Institution: Kyoto University
• Principal Investigator: 前田 拓也 京都大学, 工学研究科, 特別研究員(PD)
• Project Period (FY): 2018-04-25 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥3,100,000 (Direct Cost: ¥3,100,000); Fiscal Year 2020: ¥1,000,000 (Direct Cost: ¥1,000,000); Fiscal Year 2019: ¥1,000,000 (Direct Cost: ¥1,000,000); Fiscal Year 2018: ¥1,100,000 (Direct Cost: ¥1,100,000)
• Keywords: 窒化ガリウム(GaN) / アバランシェ破壊 / 衝突イオン化係数 / 絶縁破壊電界 / p-n接合 / Franz-Keldysh効果 / 光電流 / パワーデバイス / 半導体 / 窒化ガリウム / 電子デバイス / p-n接合ダイオード / 絶縁破壊

Outline of Annual Research Achievements

本年度は，窒化ガリウム(GaN)半導体のアバランシェ破壊特性の解明を目指し，衝突イオン化係数およびその温度依存性の測定に取り組んだ．p-n接合界面から主にp層側へ空乏層が拡がるGaN p-/n+接合ダイオードを作製し，基礎吸収端(~365nm)より短波長/長波長の光照射下における光誘起電流の測定・解析を行うことで，電子注入・正孔注入時のアバランシェ増倍係数を求めた．得られた増倍係数を解析することでGaNの電子・正孔の衝突イオン化係数を223-373K温度範囲で抽出することに成功した．得られた衝突イオン化係数を経験式を用いてモデル化し，得られた衝突イオン化係数の式(パラメータ)を用いてGaNの理想的な絶縁破壊特性をシミュレーションした．様々なドーピング密度のGaN p-n接合に対して絶縁破壊電圧をシミュレーションしたところ，過去に報告されているGaNパワーデバイスの絶縁破壊特性をよく再現した．得られた絶縁破壊電圧より絶縁破壊電界のドーピング密度依存性を経験式を用いてモデル化した．また，絶縁破壊特性の温度依存性，耐圧維持層の極性依存性，膜厚依存性についてもシミュレーションを行い，詳細に議論した．これらの結果は，J. Appl. Phys.に投稿・採択された．

Research Progress Status

令和2年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和2年度が最終年度であるため、記入しない。

Research Products

• [Journal Article] Impact Ionization Coefficients and Critical Electric Field in GaN (2021)
  • Author(s): Takuya Maeda, Tetsuo Narita, Shinji Yamada, Tetsu Kachi, Tsunenobu Kimoto, Masahiro Horita, Jun Suda
  • Journal Title: Journal of Applied Physics Volume: 129 Issue: 18
  • DOI: 10.1063/5.0050793
  • Peer Reviewed
• [Journal Article] Defect-insensitive current-voltage characteristics of Schottky barrier diode formed on heteroepitaxial α-Ga2O3 grown by mist chemical vapor deposition (2020)
  • Author(s): Takuya Maeda, Mitsuru Okigawa, Yuji Kato, Isao Takahashi, Takashi Shinohe
  • Journal Title: AIP Advances Volume: 10 Issue: 12
  • DOI: 10.1063/5.0028985
  • Peer Reviewed / Open Access
• [Journal Article] Forward thermionic field emission transport and significant image force lowering caused by high electric field at metal/heavily-doped SiC Schottky interfaces (2020)
  • Author(s): M. Hara, S. Asada, T. Maeda, and T. Kimoto
  • Journal Title: Applied Physics Express Volume: 13 Issue: 4 Pages: 041001-041001
  • DOI: 10.35848/1882-0786/ab7bcd
  • Peer Reviewed
• [Journal Article] Design and Fabrication of GaN p-n Junction Diodes with Negative Beveled-Mesa Termination (2019)
  • Author(s): T. Maeda, T. Narita, H. Ueda, M. Kanechika, T. Uesugi, T. Kachi, T. Kimoto, M. Horita and J. Suda
  • Journal Title: IEEE Electron Device Letters Volume: 40 Issue: 6 Pages: 941-944
  • DOI: 10.1109/led.2019.2912395
  • Peer Reviewed
• [Journal Article] Shockley-Read-Hall Lifetime in Homoepitaxial p-GaN Extracted from Recombination Current in GaN p-n+ Junction Diodes (2019)
  • Author(s): T. Maeda, T. Narita, H. Ueda, M. Kanechika, T. Uesugi, T. Kachi, T. Kimoto, M. Horita and J. Suda
  • Journal Title: Japanese Journal of Applied Physics Volume: 58 Issue: SC Pages: SCCB14-SCCB14
  • DOI: 10.7567/1347-4065/ab07ad
  • Peer Reviewed / Open Access
• [Journal Article] Estimation of Impact Ionization Coefficient in GaN by Photomultiplication Measurements Utilizing Franz-Keldysh Effect (2019)
  • Author(s): T. Maeda, T. Narita, H. Ueda, M. Kanechika, T. Uesugi, T. Kachi, T. Kimoto, M. Horita and J. Suda
  • Journal Title: Proceedings of the 31st IEEE International Symposium on Power Semiconductor Devices and ICs (ISPSD) Volume: - Pages: 59-62
  • DOI: 10.1109/ispsd.2019.8757676
  • Peer Reviewed
• [Journal Article] Franz-Keldysh effect in 4H-SiC p-n junction diode under high electric field along the <11-20> direction (2019)
  • Author(s): T. Maeda, X. Chi, H. Tanaka, M. Horita, J. Suda and T. Kimoto
  • Journal Title: Japanese Journal of Applied Physics Volume: 58 Issue: 9 Pages: 091007-091007
  • DOI: 10.7567/1347-4065/ab3873
  • Peer Reviewed
• [Journal Article] Measurement of avalanche multiplication utilizing Franz-Keldysh effect in GaN p-n junction diodes with double-side-depleted shallow bevel termination (2019)
  • Author(s): T. Maeda, T. Narita, H. Ueda, M. Kanechika, T. Uesugi, T. Kachi, T. Kimoto, M. Horita and J. Suda
  • Journal Title: Applied Physics Letters Volume: 115 Issue: 14 Pages: 142101-142101
  • DOI: 10.1063/1.5114844
  • Peer Reviewed
• [Journal Article] Impact Ionization Coefficients in GaN Measured by Above- and Sub-Eg Illuminations for p－/n+ junction (2019)
  • Author(s): T. Maeda, T. Narita, S. Yamada, T. Kachi, T. Kimoto, M. Horita and J. Suda
  • Journal Title: IEDM Technical Digest Volume: - Pages: 70-73
  • DOI: 10.1109/iedm19573.2019.8993438
  • Peer Reviewed
• [Journal Article] Phonon-assisted optical absorption due to Franz-Keldysh effect in 4H-SiC p-n junction diode under high reverse bias voltage (2018)
  • Author(s): Takuya Maeda, Xilun Chi, Masahiro Horita, Jun Suda and Tsunenobu Kimoto
  • Journal Title: Applied Physics Express Volume: 11 Issue: 9 Pages: 091302-091302
  • DOI: 10.7567/apex.11.091302
  • Peer Reviewed
• [Journal Article] Parallel-Plane Breakdown Fields of 2.8-3.5 MV/cm in GaN-on-GaN p-n Junction Diodes with Double-Side-Depleted Shallow Bevel Termination (2018)
  • Author(s): Takuya Maeda, Narita Tetsuo, Hiroyuki Ueda, Masakazu Kanechika, Tsutomu Uesugi, Tetsu Kachi, Tsunenobu Kimoto, Masahiro Horita and Jun Suda
  • Journal Title: IEDM Technical Digest Volume: - Pages: 687-690
  • DOI: 10.1109/iedm.2018.8614669
  • Peer Reviewed
• [Journal Article] Franz-Keldysh effect in GaN p-n junction diode under high reverse bias voltage (2018)
  • Author(s): Takuya Maeda, Narita Tetsuo, Masakazu Kanechika, Tsutomu Uesugi, Tetsu Kachi, Tsunenobu Kimoto, Masahiro Horita and Jun Suda
  • Journal Title: Applied Physics Letters Volume: 112 Issue: 25
  • DOI: 10.1063/1.5031215
  • Peer Reviewed
• [Presentation] GaNの電子・正孔の衝突イオン化係数の温度依存性 (2021)
  • Author(s): 前田拓也，成田哲生，山田真嗣，加地徹，木本恒暢，堀田昌宏，須田淳
  • Organizer: 第68回応用物理学会春季学術講演会
• [Presentation] サファイア基板上Mist-CVD成長α-Ga2O3ショットキーバリアダイオードにおけるほぼ理想的な熱電子放出および熱電子電界放出 (2021)
  • Author(s): 前田拓也，沖川満，加藤勇次，高橋勲，四戸孝
  • Organizer: 第68回応用物理学会春季学術講演会
• [Presentation] Impact Ionization Coefficients in GaN Measured by Above- and Sub-Eg Illuminations for p-/n+ Junction (2020)
  • Author(s): 前田拓也，成田哲生，山田真嗣，加地徹，木本恒暢，堀田昌宏，須田淳
  • Organizer: IEEE関西コロキアム電子デバイスワークショップ
  • Invited
• [Presentation] GaNの電子・正孔の衝突イオン化係数の測定 (2020)
  • Author(s): 前田拓也，成田哲生，山田真嗣，加地徹，木本恒暢，堀田昌宏，須田淳
  • Organizer: 第67回応用物理学会春季学術講演会
• [Presentation] <11-20>方向に電界印加した4H-SiC p-n接合ダイオードにおけるFranz-Keldysh効果に起因したフォノンアシスト光吸収 (2019)
  • Author(s): 前田拓也，遅熙倫，田中一，堀田昌宏，須田淳，木本恒暢
  • Organizer: 第80回応用物理学会秋季学術講演会
• [Presentation] Temperature dependence of barrier height in Ni/n-GaN Schottky barrier diode (2019)
  • Author(s): T. Maeda, M. Okada, M. Ueno, Y. Yamamoto, T. Kimoto, M. Horita and J. Suda
  • Organizer: 第80回応用物理学会秋季学術講演会
  • Invited
• [Presentation] Parallel-Plane Breakdown Fields of 2.8-3.5 MV/cm in GaN-on-GaN p-n Junction Diodes with Double-Side-Depleted Shallow Bevel Termination (2019)
  • Author(s): 前田拓也，成田哲生，上田博之，兼近将一，上杉勉，加地徹，木本恒暢，堀田昌宏，須田淳
  • Organizer: IEEE関西コロキウム・電子デバイスワークショップ
  • Invited
• [Presentation] Record Breakdown Fields of 2.8-3.5 MV/cm in GaN p-n Junction Diodes (2019)
  • Author(s): T. Maeda, T. Narita, H. Ueda, M. Kanechika, T. Uesugi, T. Kachi, T. Kimoto, M. Horita and J. Suda
  • Organizer: The 38th Electronic Materials Symposium (EMS),
• [Presentation] Estimation of Impact Ionization Coefficient in GaN by Photomultiplication Measurements Utilizing Franz-Keldysh Effect (2019)
  • Author(s): T. Maeda, T. Narita, H. Ueda, M. Kanechika, T. Uesugi, T. Kachi, T. Kimoto, M. Horita and J. Suda
  • Organizer: The 31st IEEE International Symposium on Power Semiconductor Devices and ICs (ISPSD2019)
  • Int'l Joint Research
• [Presentation] Estimation of Impact Ionization Coefficient in GaN and its Temperature Dependence by Photomultiplication Measurements Utilizing Franz-Keldysh Effect (2019)
  • Author(s): T. Maeda, T. Narita, H. Ueda, M. Kanechika, T. Uesugi, T. Kachi, T. Kimoto, M. Horita and J. Suda
  • Organizer: The 13th International Conference on Nitride Semiconductors (ICNS13)
  • Int'l Joint Research
• [Presentation] Growth of P-Type GaN Layers with Low Mg Concentrations by Using MOVPE and the Application to Vertical Power Devices (2019)
  • Author(s): T. Narita, K. Tomita, Y. Tokuda, T. Kogiso, T. Maeda, M. Horita, M. Kanechika, H. Ueda, T. Kachi and J. Suda
  • Organizer: The 13th International Conference on Nitride Semiconductors (ICNS13)
  • Int'l Joint Research / Invited
• [Presentation] High Avalanche Capability in GaN p-n Junction Diodes Realized by Shallow Beveled-Mesa Structure Combined with Lightly Mg-Doped p-Layers (2019)
  • Author(s): T. Maeda, T. Narita, H. Ueda, M. Kanechika, T. Uesugi, T. Kachi, T. Kimoto, M. Horita and J. Suda
  • Organizer: The 51st International Conference on Solid-State Devices and Materials (SSDM2019)
  • Int'l Joint Research
• [Presentation] Temperature Dependence of Impact Ionization Coefficients in 4H-SiC along <11-20> Direction (2019)
  • Author(s): D. Stefanakis, X. Chi, T. Maeda, M. Kaneko and T. Kimoto
  • Organizer: The 18th International Conference on Silicon Carbide & Related Materials (ICSCRM2019)
  • Int'l Joint Research
• [Presentation] Forward Thermionic Field Emission Current and Barrier Height Lowering in Heavily-Doped 4H-SiC Schottky Barrier Diodes (2019)
  • Author(s): M. Hara, S. Asada, T. Maeda and T. Kimoto
  • Organizer: The 18th International Conference on Silicon Carbide & Related Materials (ICSCRM2019)
  • Int'l Joint Research
• [Presentation] Photocurrent induced by Franz-Keldysh effect in 4H-SiC p-n junction diodes under high electric field along <11-20> direction (2019)
  • Author(s): T. Maeda, X. Chi, H. Tanaka, M. Horita, J. Suda and T. Kimoto
  • Organizer: The 18th International Conference on Silicon Carbide & Related Materials (ICSCRM2019)
  • Int'l Joint Research
• [Presentation] Significant Image Force Lowering at Metal/Heavily-Doped SiC Interfaces (2019)
  • Author(s): M. Hara, S. Asada, T. Maeda and T. Kimoto
  • Organizer: The 9th Asia-Pacific Workshop on Widegap Semiconductors (APWS2019)
  • Int'l Joint Research
• [Presentation] Impact Ionization Coefficients for 4H-SiC on a-face (11-20) and their Temperature Variations (2019)
  • Author(s): D. Stefanakis, X. Chi, T. Maeda, M. Kaneko and T. Kimoto
  • Organizer: The 9th Asia-Pacific Workshop on Widegap Semiconductors (APWS2019)
  • Int'l Joint Research
• [Presentation] Impact Ionization Coefficients in GaN Measured by Above- and Sub-Eg Illuminations for p－/n+ junction (2019)
  • Author(s): T. Maeda, T. Narita, S. Yamada, T. Kachi, T. Kimoto, M. Horita and J. Suda
  • Organizer: The 65th International Electron Devices Meeting (IEDM2019)
  • Int'l Joint Research
• [Presentation] Franz-Keldysh effect in GaN Schottky barrier diodes and p-n junction diodes under high reverse bias voltage (2018)
  • Author(s): Takuya Maeda, Masaya Okada, Masaki Ueno, Yoshiyuki Yamamoto, Tetsuo Narita, Masakazu Kanechika, Tsutomu Uesugi, Tetsu Kachi, Tsunenobu Kimoto, Masahiro Horita and Jun Suda
  • Organizer: 60th Electronic Materials Conference (EMC60)
  • Int'l Joint Research
• [Presentation] Temperature dependence of Schottky barrier height of Ni/n-GaN consistently obtained by C-V, I-V, and IPE measurements (2018)
  • Author(s): Takuya Maeda, Masaya Okada, Masaki Ueno, Yoshiyuki Yamamoto, Tsunenobu Kimoto, Masahiro Horita and Jun Suda
  • Organizer: 2018 Asia-Pacific Workshop on Fundamentals and Applications of Advanced Semiconductor Devices (AWAD2018)
  • Int'l Joint Research
• [Presentation] Photocurrent induced by Franz-Keldysh effect in a 4H-SiC p-n junction diode under high reverse bias voltage (2018)
  • Author(s): Takuya Maeda, Xilun Chi, Masahiro Horita, Jun Suda and Tsunenobu Kimoto
  • Organizer: European Conference on Silicon Carbide and Related Materials 2018 (ECSCRM2018)
  • Int'l Joint Research
• [Presentation] Measurement of Avalanche Multiplication Factor in GaN p-n Junction Diode Using Sub-bandgap Light Absorption Due to Franz-Keldysh Effect (2018)
  • Author(s): Takuya Maeda, Narita Tetsuo, Hiroyuki Ueda, Masakazu Kanechika, Tsutomu Uesugi, Tetsu Kachi, Tsunenobu Kimoto, Masahiro Horita and Jun Suda
  • Organizer: 50th International Conference on Solid-State Devices and Materials (SSDM2018)
  • Int'l Joint Research
• [Presentation] Temperature Dependence of Avalanche Multiplication in GaN PN Diodes Measured by Light Absorption Due to Franz-Keldysh Effect (2018)
  • Author(s): Takuya Maeda, Narita Tetsuo, Hiroyuki Ueda, Masakazu Kanechika, Tsutomu Uesugi, Tetsu Kachi, Tsunenobu Kimoto, Masahiro Horita and Jun Suda
  • Organizer: International Workshop on Nitride Semiconductors 2018 (IWN2018)
  • Int'l Joint Research
• [Presentation] Shockley-Read-Hall Lifetime in Homoepitaxial p-GaN Extracted from the Recombination Current in GaN p-n Junction Diodes (2018)
  • Author(s): Takuya Maeda, Narita Tetsuo, Hiroyuki Ueda, Masakazu Kanechika, Tsutomu Uesugi, Tetsu Kachi, Tsunenobu Kimoto, Masahiro Horita and Jun Suda
  • Organizer: International Workshop on Nitride Semiconductors 2018 (IWN2018)
  • Int'l Joint Research
• [Presentation] Parallel-Plane Breakdown Fields of 2.8-3.5 MV/cm in GaN-on-GaN p-n Junction Diodes with Double-Side-Depleted Shallow Bevel Termination (2018)
  • Author(s): Takuya Maeda, Narita Tetsuo, Hiroyuki Ueda, Masakazu Kanechika, Tsutomu Uesugi, Tetsu Kachi, Tsunenobu Kimoto, Masahiro Horita and Jun Suda
  • Organizer: 64th International Electron Devices Meeting (IEDM2018)
  • Int'l Joint Research