原子レベル平坦界面トランジスタのゲート絶縁膜リーク電流の高精度統計的解析

2014 Fiscal Year Annual Research Report

• Project/Area Number: 24360129
• Research Institution: Tohoku University
• Principal Investigator: 須川 成利 東北大学, 工学(系)研究科(研究院), 教授 (70321974)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 電子デバイス・機器 / 電子デバイス・集積回路 / MOSFET / シリコン / リーク電流

Outline of Annual Research Achievements

ゲート絶縁膜／Si界面の原子レベル平坦化技術を大規模集積回路製造工程に導入した。具体的には、シャロートレンチアイソレーション（STI）素子分離を用いた微細プロセステクノロジーにおいて、ゲート絶縁膜形成直前のプロセスステップにおいて、850℃以下で原子レベル平坦化処理を行うプロセス技術を開発した。ここで、Si表面と素子分離用のSiO2とが共存するウェハを処理を行う必要があるが、SiO2から放出される可能性がある酸化種とSiとの反応が起こると、Siのマイグレーションに基づく原子レベル平坦化を阻害する揮発性SiOの発生によるエッチング反応が起こってしまう。そこで、素子分離用SiO2からの酸化種の放出を抑制しつつ、原子レベル平坦化を両立するためには、処理中の酸素、水分濃度を30ppb以下に抑制した原子レベル平坦化処理装置を導入して処理雰囲気の酸化種を低減するとともに、850℃以下の温度で処理を行い素子分離用SiO2からの酸化種の放出を抑制すれば行えば良いことを明らかにし、直径200mmのウェハ全面におけるSi領域の原子レベル平坦化を達成した。
本開発技術を導入して大規模アレイテスト回路を試作し、膜厚5.6nmのゲート絶縁膜を有する6万個を超えるMOSFETのゲート電流を測定したところ、従来のプロセス技術で試作したゲート絶縁膜/Si界面に約1nmのラフネスが存在するMOSFETと比べて、ゲート電流が大きい素子の発生割合が一桁以上低減できたことを測定結果によって明らかにした。

Research Progress Status

26年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

26年度が最終年度であるため、記入しない。

Causes of Carryover

26年度が最終年度であるため、記入しない。

Expenditure Plan for Carryover Budget

26年度が最終年度であるため、記入しない。

Research Products

• [Journal Article] Atomically Flattening of Si Surface of Silicon on Insulator and Isolation-Patterned Wafers (2015)
  • Author(s): Tetsuya Goto, Rihito Kuroda, Naoya Akagawa, Tomoyuki Suwa, Akinobu Teramoto, Xiang Li, Toshiki Obara, Daiki Kimoto, Shigetoshi Sugawa, Tadahiro Ohmi, Yutaka Kamata, Yuki Kumagai, and Katsuhiro Shibusawa
  • Journal Title: Japanese Journal of Applied Physics Volume: 54 Pages: 04DA04-1-7
  • DOI: 10.7567/JJAP.54.04DA04
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Analysis of breakdown voltage of area surrounded by multiple trench gaps in 4 kV monolithic isolator for communication network interface (2015)
  • Author(s): Yusuke Takeuchi, Rihito Kuroda and Shigetoshi Sugawa
  • Journal Title: Japanese Journal of Applied Physics Volume: 54 Pages: 04DB01-1-5
  • DOI: 10.7567/JJAP.54.04DB01
  • Peer Reviewed
• [Journal Article] [REVIEW PAPER] Si image sensors with wide spectral response and high robustness to ultraviolet light exposure (2014)
  • Author(s): Rihito Kuroda and Shigetoshi Sugawa
  • Journal Title: IEICE Electronics Express Volume: 11 Pages: 20142004-1-16
  • DOI: http://dx.doi.org/10.1587/elex.11.20142004
  • Peer Reviewed
• [Journal Article] High Selectivity in Dry Etching of Silicon Nitride over Si Using a Novel Hydrofluorocarbon Etch Gas in a Microwave Excited Plasma for FinFET (2014)
  • Author(s): Y. Nakao, T. Matsuo, A. Teramoto, H. Utsumi, K. Hashimoto, R. Kuroda, Y. Shirai, S. Sugawa, and T. Ohmi
  • Journal Title: ECS Transactions Volume: 61 Pages: 29-37
  • DOI: 10.1149/06103.0029ecst
  • Peer Reviewed
• [Journal Article] Flattening Technique of (551) Silicon Surface Using Xe/H2 Plasma (2014)
  • Author(s): Tomoyuki Suwa, Akinobu Teramoto, Shigetoshi Sugawa, and Tadahiro Ohmi
  • Journal Title: ECS Transactions Volume: 61 Pages: 401-407
  • DOI: 10.1149/06102.0401ecst
  • Peer Reviewed
• [Journal Article] Amorphous InGaZnO Thin-Film Transistors Prepared by Magnetron Sputtering Using Kr and Xe Instead of Ar (2014)
  • Author(s): Tetsuya Goto, Shigetoshi Sugawa and Tadahiro Ohmi
  • Journal Title: Journal of the Society for Information Volume: 21 Pages: 517-523
  • DOI: 10.1002/jsid.210
  • Peer Reviewed
• [Presentation] Analysis of Pixel Gain and Linearity of CMOS Image Sensor using Floating Capacitor Load Readout Operation (2015)
  • Author(s): S. Wakashima, F. Kusuhara, R. Kuroda, S. Sugawa
  • Organizer: IS&T/SPIE Electronic Imaging
  • Place of Presentation: San Francisco, USA
  • Year and Date: 2015-02-08 – 2015-02-12
• [Presentation] Wide spectral response and highly robust Si image sensor technology (2014)
  • Author(s): Rihito Kuroda and Shigetoshi Sugawa
  • Organizer: 2nd Asian Image Sensor and Imaging System Symposium
  • Place of Presentation: 東京工業大学キャンパス・イノベーションセンター（東京都・港区）
  • Year and Date: 2014-12-01 – 2014-12-02
  • Invited
• [Presentation] Atomically Flattening of Si Surface of SOI and Isolation-patterned Wafers (2014)
  • Author(s): T. Goto, R. Kuroda, N. Akagawa, T. Suwa, A. Teramoto, X. Li, S. Sugawa, T. Ohmi, Y. Kumagai, Y. Kamata, and T. Shibusawa
  • Organizer: 2014 International Conference on Solid State Devices and Materials
  • Place of Presentation: つくば国際会議場（茨城県・つくば市）
  • Year and Date: 2014-09-08 – 2014-09-11
• [Presentation] Analysis of the breakdown voltage of an area surrounded by the multi-trench gaps in a 4kV monolithic isolator for a communication network interface (2014)
  • Author(s): Yusuke Takeuchi, Rihito Kuroda and Shigetoshi Sugawa
  • Organizer: 2014 International Conference on Solid State Devices and Materials
  • Place of Presentation: つくば国際会議場（茨城県・つくば市）
  • Year and Date: 2014-09-08 – 2014-09-11
• [Presentation] A Novel Analysis of Oxide Breakdown based on Dynamic Observation using Ultra-High Speed Video Capturing Up to 10,000,000 Frames Per Second (2014)
  • Author(s): Rihito Kuroda, Fan Shao, Daiki Kimoto, Kiichi Furukawa, Hidetake Sugo, Tohru Takeda, Ken Miyauchi, Yasuhisa Tochigi, Akinobu Teramoto and Shigetoshi Sugawa
  • Organizer: 2014 IEEE International Reliability Physics Symposium
  • Place of Presentation: Waikoloa, USA
  • Year and Date: 2014-06-03 – 2014-06-05
• [Presentation] Demonstrating Individual Leakage Path from Random Telegraph Signal of Stress Induced Leakage Current (2014)
  • Author(s): A. Teramoto, T. Inatsuka, T. Obara, N. Akagawa, R. Kuroda, S. Sugawa and T. Ohmi
  • Organizer: 2014 IEEE International Reliability Physics Symposium
  • Place of Presentation: Waikoloa, USA
  • Year and Date: 2014-06-03 – 2014-06-05
• [Presentation] Analyzing Correlation between Multiple Traps in RTN Characteristics (2014)
  • Author(s): Toshiki Obara, Akinobu Teramoto, Akihiro Yonezawa, Rihito Kuroda, Shigetoshi Sugawa, and Tadahiro Ohmi
  • Organizer: Toshiki Obara, Akinobu Teramoto, Akihiro Yonezawa, Rihito Kuroda, Shigetoshi Sugawa, and Tadahiro Ohmi
  • Place of Presentation: Waikoloa, USA
  • Year and Date: 2014-06-03 – 2014-06-05
• [Presentation] Application of Rotation Magnet Sputtering Technology to a-IGZO Film Depositions (2014)
  • Author(s): Tetsuya Goto, Shigetoshi Sugawa, Tadahiro Ohmi
  • Organizer: Society for Information Display, SID International Symposium 2014
  • Place of Presentation: San Diego, USA
  • Year and Date: 2014-06-01 – 2014-06-06
  • Invited
• [Presentation] High Selectivity in a Dry Etching of Silicon Nitride over Si Using a Novel Hydrofluorocarbon Etch Gas in a Microwave Excited Plasma for FinFET (2014)
  • Author(s): Yukihisa Nakao, Takatoshi Matsuo, Akinobu Teramoto, Hidetoshi Utsumi, Keiichi Hashimoto, Rihito Kuroda, Yasuyuki Shirai, Shigetoshi Sugawa, and Tadahiro Ohmi
  • Organizer: 225th Meeting of The Electrochemical Society
  • Place of Presentation: Orlando, USA
  • Year and Date: 2014-05-11 – 2014-05-15
• [Presentation] Flattening Technique of (551) Silicon Surface Using Xe/H2 Plasma (2014)
  • Author(s): Tomoyuki Suwa, Akinobu Teramoto, Shigetoshi Sugawa, and Tadahiro Ohmi
  • Organizer: 225th Meeting of The Electrochemical Society
  • Place of Presentation: Orlando, USA
  • Year and Date: 2014-05-11 – 2014-05-15
• [Presentation] Effect of Composition Ratio on Erbium Silicide Work Function on Different Morphology of Si(100) Surface Changed by Alkaline Etching (2014)
  • Author(s): Hiroaki Tanaka, Tomoyuki Suwa, Akinobu Teramoto, Tsukasa Motoya, Shigetoshi Sugawa, and Tadahiro Ohmi
  • Organizer: 225th Meeting of The Electrochemical Society
  • Place of Presentation: Orlando, USA
  • Year and Date: 2014-05-11 – 2014-05-15