Physical Models of Temperature-dependent Resitivity and Hall Coefficient in Heavily Al-doped 4H-SiC

• Project/Area Number: 20K04565
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21050:Electric and electronic materials-related
• Research Institution: Osaka Electro-Communication University
• Principal Investigator: Matsuura Hideharu 大阪電気通信大学, 工学部, 教授 (60278588)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2022: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2021: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2020: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
• Keywords: p型4H-SiC / IGBT / 高濃度Al添加4H-SiC / NNH伝導 / VRH伝導 / Hall係数 / Hall係数の符号反転 / XRD分析 / Al添加4H-SiC / SiC / 電気伝導機構 / 4H-SiC / Alドープ / ホール係数 / 電気伝導 / 抵抗率

Outline of Research at the Start

本研究の概要は、脱炭素化を目指して、超低損失パワー半導体デバイス実現のために、次世代半導体であるSiCを用いたnチャネル絶縁ゲート型バイポーラトランジスタ (IGBT) の基礎研究を行うことである。特に、IGBTのコレクタとなるp型4H-SiC基板の低抵抗率化を目指し、アクセプタであるAl濃度と電気特性（特に抵抗率とHall係数）との関係を明らかにし、超高濃度Al添加4H-SiCの伝導機構の解明を行う研究である。

Outline of Final Research Achievements

In order to reduce the resistivity of the p-type 4H-SiC substrate (collector) of SiC n-channel IGBT, we investigated the conduction mechanism in highly Al doping. Although Al-doped 4H-SiC is a p-type semiconductor, it has been experimentally found that the Hall coefficient becomes negative (i.e., n-type semiconductors) in hopping conduction such as NNH conduction and VRH conduction in the low-temperature region. Therefore, we have proposed a physical model for the sign of the Hall coefficient in hopping conduction. Furthermore, we have proposed a physical model that elucidates that the activation energies of the resistivity and Hall coefficient in the NNH conduction region are almost equal.

Academic Significance and Societal Importance of the Research Achievements

アモルファス半導体においては、伝導型（p型またはn型）とは反対のホール係数の符号（負または正）が現れることが知られていて、理論的検討が行われている。
一方、結晶半導体では高濃度p型半導体でのホッピング伝導領域では、ホール係数が負になるとの報告はほとんど無く、さらに理論的検討は行われていない。したがって、今回提案した物理モデルには学術的意義がある。さらに、ホッピング伝導領域での抵抗率の活性化エネルギーとホール効果の活性化エネルギーがほぼ等しくなることは、我々の報告だけである。したがって、その物理モデルを提案できたことは学術的意義がある。

Research Products

• [Journal Article] Electrical Properties of Heavily Al-Doped 4H-SiC (2023)
  • Author(s): Hideharu Matsuura, Akinobu Takeshita, Rinya Nishihata, Yuuki Kondo, and Atsuki Hidaka
  • Journal Title: Materials Science Forum Volume: -
  • Peer Reviewed / Open Access
• [Journal Article] Sign and Activation Energy of Hall Coefficient for Hopping Conduction in Heavily Al-Doped 4H-SiC (2022)
  • Author(s): Hideharu Matsuura, Rinya Nishihata, and Atsuki Hidaka
  • Journal Title: Journal of Physics and Chemistry Research Volume: 4 Issue: 1 Pages: 1-8
  • DOI: 10.36266/jpcr/145
  • Peer Reviewed / Open Access
• [Journal Article] Simple physical model for the sign of the Hall coefficient in variable-range hopping conduction in heavily Al-doped p-type 4H-SiC (2021)
  • Author(s): Matsuura Hideharu、Kondo Yuki、Iida Kosuke、Hidaka Atsuki、Ji Shiyang、Eto Kazuma、Kojima Kazutoshi、Kato Tomohisa、Yoshida Sadafumi、Okumura Hajime
  • Journal Title: Japanese Journal of Applied Physics Volume: 60 Issue: 3 Pages: 031008-031008
  • DOI: 10.35848/1347-4065/abe645
  • Peer Reviewed / Open Access
• [Journal Article] Anomalous Temperature Dependence of the Hall Coefficient of Heavily Al-Doped 4H-SiC Epilayers in the Band Conduction Region (2020)
  • Author(s): Matsuura Hideharu、Nishihata Rinya、Takeshita Akinobu、Ogawa Kohei、Imamura Tatsuya、Takano Kota、Okuda Kazuya、Hidaka Atsuki、Ji Shi Yang、Eto Kazuma、Kojima Kazutoshi、Kato Tomohisa、Yoshida Sadafumi、Okumura Hajime
  • Journal Title: Materials Science Forum Volume: 1004 Pages: 215-223
  • DOI: 10.4028/www.scientific.net/msf.1004.215
  • Peer Reviewed
• [Journal Article] Anomalous Conduction between the Band and Nearest-Neighbor Hopping Conduction Regions in Heavily Al-Doped p-Type 4H-SiC (2020)
  • Author(s): Hidaka Atsuki、Takeshita Akinobu、Ogawa Kohei、Imamura Tatsuya、Takano Kota、Okuda Kazuya、Matsuura Hideharu、Ji Shi Yang、Eto Kazuma、Mitani Takeshi、Kojima Kazutoshi、Kato Tomohisa、Yoshida Sadafumi、Okumura Hajime
  • Journal Title: Materials Science Forum Volume: 1004 Pages: 224-230
  • DOI: 10.4028/www.scientific.net/msf.1004.224
  • Peer Reviewed
• [Journal Article] Sign of Hall coefficient in nearest-neighbor hopping conduction in heavily Al-doped p-type 4H-SiC (2020)
  • Author(s): Matsuura Hideharu、Takeshita Akinobu、Hidaka Atsuki、Ji Shiyang、Eto Kazuma、Mitani Takeshi、Kojima Kazutoshi、Kato Tomohisa、Yoshida Sadafumi、Okumura Hajime
  • Journal Title: Japanese Journal of Applied Physics Volume: 59 Issue: 5 Pages: 051004-051004
  • DOI: 10.35848/1347-4065/ab8701
  • Peer Reviewed / Open Access
• [Presentation] Electrical Properties of Heavily Al-Doped 4H-SiC (2022)
  • Author(s): Hideharu Matsuura, Akinobu Takeshita, Rinya Nishihata, Yuuki Kondo, and Atsuki Hidaka
  • Organizer: 3rd Asia-Pacific Conference on Silicon Carbide and Related Materials
  • Int'l Joint Research / Invited
• [Presentation] Al濃度1E20 cm^-3台前半でのp型4H-SiC CVDエピ膜の結晶性と電気特性との関係 (2022)
  • Author(s): 近藤 佑樹, 日高 淳輝, 松浦 秀治, 紀 世陽, 江藤 数馬, 児島 一聡, 加藤 智久, 吉田 貞史, 奥村 元
  • Organizer: 第64回応用物理学会春季学術講演会
• [Presentation] Al濃度10^20 cm^-3台前半でのp型4H-SiCエピ膜の電気抵抗率の温度依存性とAl濃度との関係 (2020)
  • Author(s): 近藤 佑樹, 竹下 明伸, 今村 辰哉, 高野 晃大, 奥田 和也, 日高 淳輝, 松浦 秀治, 紀 世陽, 江藤 数馬, 児島 一聡, 加藤 智久, 吉田 貞史, 奥村 元
  • Organizer: 第81回応用物理学会秋季学術講演会