Study on GaN-based vertical transistors using ScAlMgO4 substrates

• Project/Area Number: 15K13963
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Electron device/Electronic equipment
• Research Institution: Tohoku University
• Principal Investigator: Suemitsu Tetsuya 東北大学, 国際集積エレクトロニクス研究開発センター, 教授 (90447186)
• Co-Investigator(Kenkyū-buntansha): 松岡 隆志 東北大学, 金属材料研究所, 教授 (40393730)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2016: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000); Fiscal Year 2015: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 窒化物半導体 / パワーデバイス / トランジスタ / SCAM基板

Outline of Final Research Achievements

GaN HEMT heterostructures are grown on cleaved ScAlMgO4 (SCAM) substrates. By using small off-cut SCAM, HEMT structures with flat surface comparable to those grown on conventional sapphire substrates are confirmed. As a part of the GaN HEMT process, neutral beam etching is applied to the GaN material systems for the first time. By means of this advanced etching, significant reduction of current collapse in GaN HEMTs are observed. The cleaving of thin SCAM layers off from bulk SCAM substrates is also a key technology to achieve GaN vertical transistors. It has been confirmed that thick GaN layers are automatically cleaved off from SCAM substrates during cooling down after growth by means of the stain induced by thermal expansion.

Research Products

• [Int'l Joint Research] MIT(米国)
• [Int'l Joint Research] MIT(米国)
• [Journal Article] Halide vapor phase epitaxy of thick GaN films on ScAlMgO4 substrates and their self-separation for fabricating freestanding wafers (2017)
  • Author(s): Ohnishi Kazuki、Kanoh Masaya、Tanikawa Tomoyuki、Kuboya Shigeyuki、Mukai Takashi、Matsuoka Takashi
  • Journal Title: Applied Physics Express Volume: 10 Issue: 10 Pages: 101001-101001
  • DOI: 10.7567/apex.10.101001
  • Peer Reviewed
• [Journal Article] Neutral beam process in AlGaN/GaN HEMTs: Impact on current collapse (2017)
  • Author(s): Hemmi Fuyumi、Thomas Cedric、Lai Yi-Chun、Higo Akio、Watamura Yoh、Samukawa Seiji、Otsuji Taiichi、Suemitsu Tetsuya
  • Journal Title: Solid-State Electronics Volume: 137 Pages: 1-5
  • DOI: 10.1016/j.sse.2017.07.015
  • Peer Reviewed
• [Journal Article] Neutral beam etching for device isolation in AlGaN/GaN HEMTs (2017)
  • Author(s): F. Hemmi, C. Thomas, Y. C. Lai, A. Higo, A. Guo, S. Warnock, J. A. del Alamo, S. Samukawa, T. Otsuji, T. Suemitsu
  • Journal Title: Physica Status Solidi A Volume: 214 Issue: 3
  • DOI: 10.1002/pssa.201600617
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] A new process approach for slant field plates in GaN-based high-electron-mobility transistors (2016)
  • Author(s): T. Suemitsu, K. Kobayashi, S. Hatakeyama, N. Yasukawa, T. Yoshida, T. Otsuji, D. Piedra, and T. Palacios
  • Journal Title: Japanese Journal of Applied Physics Volume: 55 Issue: 1S Pages: 01AD02-01AD02
  • DOI: 10.7567/jjap.55.01ad02
  • NAID: 210000145958
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] InP and GaN high electron mobility transistors for millimeter-wave applications (2015)
  • Author(s): Tetsuya Suemitsu
  • Journal Title: IEICE Electronics Express Volume: 12 Issue: 13 Pages: 20152005-20152005
  • DOI: 10.1587/elex.12.20152005
  • NAID: 130005087552
  • ISSN: 1349-2543
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] AlGaN/GaN HEMTのゲートリセス構造形成における中性粒子ビームエッチング適用効果 (2017)
  • Author(s): 渡村遥、邉見ふゆみ、C.トーマス、Y.C.ライ、肥後昭男、寒川誠二、尾辻泰一、末光哲也
  • Organizer: 第64回応用物理学会春季学術講演会
  • Place of Presentation: 横浜
  • Year and Date: 2017-03-14
• [Presentation] Neutral beam process in AlGaN/GaN HEMTs: Impact on current collapse (2016)
  • Author(s): F. Hemmi, C. Thomas, Y. C. Lai, A. Higo, S. Samukawa, T. Otsuji, T. Suemitsu
  • Organizer: International Semiconductor Device Research Symposium
  • Place of Presentation: Washington DC, USA
  • Year and Date: 2016-12-07
  • Int'l Joint Research
• [Presentation] Impact of neutral beam etching on isolation leakage current and breakdown voltage in AlGaN/GaN HEMTs (2016)
  • Author(s): F. Hemmi, C. Thomas, Y. C. Lai, A. Higo, A. Guo, S. Warnock, J. A. del Alamo, S. Samukawa, T. Otsuji, T. Suemitsu
  • Organizer: 第77回応用物理学会秋季学術講演会
  • Place of Presentation: 新潟
  • Year and Date: 2016-09-13
• [Presentation] The effect of neutral beam etching on device isolation in AlGaN/GaN HEMTs (2016)
  • Author(s): F. Hemmi, C. Thomas, Y. C. Lai, A. Higo, A. Guo, S. Warnock, J. A. del Alamo, S. Samukawa, T. Otsuji, T. Suemitsu
  • Organizer: 43rd International Symposium on Compound Semiconductors
  • Place of Presentation: Toyama, Japan
  • Year and Date: 2016-06-26
  • Int'l Joint Research
• [Presentation] Suppression of isolation leakage current in AlGaN/GaN HEMTs by neutral-beam etching (2016)
  • Author(s): F. Hemmi, C. Thomas, Y.-C. Lai, A. Higo, A. Guo, S. Warnock, J. A. del Alamo, S. Samukawa, T. Otsuji, and T. Suemitsu
  • Organizer: 第63回応用物理学会春季学術講演会
  • Place of Presentation: 東京都目黒区
  • Year and Date: 2016-03-19
• [Presentation] Drain depletion length in InAlN/GaN MIS-HEMTs with slant field plates (2015)
  • Author(s): N. Yasukawa, S. Hatakeyama, T. Yoshida, T. Kimura, T. Matsuoka, T. Otsuji, and T. Suemitsu
  • Organizer: 42nd International Symposium on Compound Semiconductors
  • Place of Presentation: Santa Barbara, USA
  • Year and Date: 2015-06-28
  • Int'l Joint Research