歪みＳｉＧｅスピンＭＯＳＦＥＴの創製

• Project/Area Number: 18J00502
• Research Category: Grant-in-Aid for JSPS Fellows
• Allocation Type: Single-year Grants
• Section: 国内
• Research Field: Applied materials
• Research Institution: Osaka University
• Principal Investigator: 山田 道洋 大阪大学, 基礎工学研究科, 特任助教
• Project Period (FY): 2018-04-25 – 2021-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥11,700,000 (Direct Cost: ¥9,000,000、Indirect Cost: ¥2,700,000); Fiscal Year 2019: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2018: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
• Keywords: シリコン / ゲルマニウム / スピントロニクス / スピン伝導 / ホイスラー合金 / 歪みエンジニアリング / スピン注入 / 原子層制御

Outline of Annual Research Achievements

本研究課題は，IoT社会の実現に向けて大きな問題となっている情報処理にかかるエネルギーの問題を解決すべく，超低消費電力化が期待されるスピンMOSFETの実現を最終目標としている．本年度は，スピン伝導層への歪み印加による不純物誘起谷間スピン反転散乱の抑制と強磁性体/半導体界面の原子層制御による室温磁気抵抗比の二桁増大を達成した．
前年度の結果から，緩和SiGeを形成した際に，高品質な強磁性膜の成長が可能な(111)面上では， 格子定数の大きなGe上にSiGe層を成長した際に欠陥導入が起こりやすく，歪みが緩和してしまうことが明らかになった．そこで，歪みSiGeを形成するために，歪みSiGeの成長条件の探索を行った． 成長条件を最適化した試料のX線回折の結果から歪みSiGeを作製することに成功した．また，Hall効果測定から歪み緩和SiGeと比較して移動度が２倍以上に増大を観測した．歪みSiGeをチャネル層に用いた横型スピンバルブ素子を作製し，スピン緩和時間を測定したところ，低温ではあるが緩和SiGeと比較して3倍程度に増大することが明らかになった．これは低温において支配的な不純物誘起スピン反転散乱が歪み印可によって抑制されているためであると考えられ，歪みによるスピン緩和抑制の効果を実験的に示した初めての結果である．
強磁性体/半導体(Ge)界面では前年度の構造評価からGeが強磁性ホイスラー合金へと拡散することでスピン注入効率が低減していることが明らかにされていた．そこで，室温におけるスピン信号の増大に向けて，強磁性ホイスラー合金/Ge界面にFe原子層を挿入することで取り組んだ．Fe原子層を挿入した場合に界面の構造評価から挿入しなかった場合と比較してGeの拡散を1/3程度に抑制することに成功し，室温の磁気抵抗比は二桁程度増大する結果が得られつつある．

Research Progress Status

翌年度、交付申請を辞退するため、記入しない。

Strategy for Future Research Activity

翌年度、交付申請を辞退するため、記入しない。

Research Products

• [Int'l Joint Research] University of York(英国)
• [Journal Article] Spin transport in antimony-doped germanium detected using vertical spin-valve structures (2020)
  • Author(s): T. Shiihara, M. Yamada, M. Honda, A. Yamada, S. Yamada, and K. Hamaya
  • Journal Title: Appl. Phys. Express Volume: 13 Issue: 2 Pages: 023001-023001
  • DOI: 10.35848/1882-0786/ab6ca8
  • Peer Reviewed
• [Journal Article] Inverse local magnetoresistance effect up to room temperature in ferromagnet-semiconductor lateral spin-valve devices (2020)
  • Author(s): Naito Takahiro、Yamada Michihiro、Yamada Shinya、Kanashima Takeshi、Sawano Kentarou、Hamaya Kohei
  • Journal Title: Materials Science in Semiconductor Processing Volume: 113 Pages: 105046-105046
  • DOI: 10.1016/j.mssp.2020.105046
  • Peer Reviewed
• [Journal Article] Germanium pn junctions between ferromagnetic CoFe and Fe3Si layers for spintronic applications (2020)
  • Author(s): Mizuki Honda、Takahiro Shiihara、Michihiro Yamada、Shinya Yamada、Kohei Hamaya
  • Journal Title: Materials Science in Semiconductor Processing Volume: 116 Pages: 105066-105066
  • DOI: 10.1016/j.mssp.2020.105066
  • Peer Reviewed
• [Journal Article] Critical thickness of strained Si1-xGex on Ge(111) and Ge-on-Si(111) (2019)
  • Author(s): Alam Md. Mahfuz、Wagatsuma Youya、Okada Kazuya、Hoshi Yusuke、Yamada Michihiro、Hamaya Kohei、Sawano Kentarou
  • Journal Title: Applied Physics Express Volume: 12 Issue: 8 Pages: 081005-081005
  • DOI: 10.7567/1882-0786/ab2db8
  • NAID: 210000156582
  • Peer Reviewed / Open Access
• [Journal Article] Nonmonotonic bias dependence of local spin accumulation signals in ferromagnet/semiconductor lateral spin-valve devices (2019)
  • Author(s): Fujita Y.、Yamada M.、Tsukahara M.、Naito T.、Yamada S.、Sawano K.、Hamaya K.
  • Journal Title: Physical Review B Volume: 100 Issue: 2 Pages: 024431-024431
  • DOI: 10.1103/physrevb.100.024431
  • Peer Reviewed
• [Journal Article] Room-temperature local magnetoresistance effect in n-Ge devices with low-resistive Schottky-tunnel contacts (2019)
  • Author(s): M. Tsukahara, M. Yamada, T. Naito, S. Yamada, K. Sawano, V. K. Lazarov, and K. Hamaya
  • Journal Title: Appl. Phys. Express Volume: 12 Issue: 3 Pages: 033002-033002
  • DOI: 10.7567/1882-0786/ab0252
  • NAID: 210000135621
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Crystal orientation effect on spin injection/detection efficiency in Si lateral spin-valve devices (2019)
  • Author(s): M. Ishikawa, M. Tsukahara, S. Honda, Y. Fujita, M. Yamada, Y. Saito, T. Kimura, H. Itoh, and K. Hamaya
  • Journal Title: J. Phys. D: Appl. Phys. Volume: 52 Issue: 8 Pages: 08510-033002
  • DOI: 10.1088/1361-6463/aaf37c
  • Peer Reviewed
• [Journal Article] Observation of local magnetoresistance signals in a SiGe-based lateral spin-valve device (2018)
  • Author(s): M. Yamada, T. Naito, M. Tsukahara, S. Yamada, K. Sawano, and K. Hamaya
  • Journal Title: Semicond. Sci. Technol. Volume: 33 Issue: 11 Pages: 114009-114009
  • DOI: 10.1088/1361-6641/aae34f
  • Peer Reviewed
• [Journal Article] Correlation between spin transport signal and quality of the Heusler-alloy/semiconductor interface in lateral spin-valve devices (2018)
  • Author(s): B. Kuerbanjiang, Y. Fujita, M. Yamada, S. Yamada, A. M. Sanchez, P. J. Hasnip, A. Ghasemi, D. Kepaptsoglou, G. Bell, K. Sawano, K. Hamaya, and V. K. Lazarov
  • Journal Title: Phys. Rev. B Volume: 98 Issue: 11 Pages: 115304-115304
  • DOI: 10.1103/physrevb.98.115304
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Spin transport and relaxation in germanium (Topical Review) (2018)
  • Author(s): K. Hamaya, Y. Fujita, M. Yamada, M. Kawano, S. Yamada, and K. Sawano
  • Journal Title: J. Phys. D: Appl. Phys. Volume: 51 Issue: 39 Pages: 393001-393001
  • DOI: 10.1088/1361-6463/aad542
  • Peer Reviewed
• [Journal Article] Pure spin current transport in a SiGe alloy (2018)
  • Author(s): T. Naito, M. Yamada, M.Tsukahara, S. Yamada, K. Sawano, and K. Hamaya
  • Journal Title: Applied Physics Express Volume: 11 Issue: 5 Pages: 0530061-5
  • DOI: 10.7567/apex.11.053006
  • NAID: 210000136197
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Local Magnetoresistance at Room Temperature in Si<100> Devices (2018)
  • Author(s): Ishikawa Mizue、Tsukahara Makoto、Yamada Michihiro、Saito Yoshiaki、Hamaya Kohei
  • Journal Title: IEEE Transactions on Magnetics Volume: 54 Issue: 11 Pages: 1-4
  • DOI: 10.1109/tmag.2018.2849753
  • Peer Reviewed
• [Presentation] "Enhancement of room-temperature spin signals in Ge lateral spin devices by improving the quality of Heusler/Ge interfaces (2019)
  • Author(s): M. Yamada, M. Tsukahara, F. Kuroda, S. Yamada, T. Fukushima, K. Sawano, T. Oguchi, K. Hamaya
  • Organizer: 第80回応用物理学会秋季学術講演大会
• [Presentation] 強磁性体/半導体スピン素子の性能と界面磁性の相関 (2019)
  • Author(s): 山田道洋，白土優，塚原誠人，神部広翔，工藤康平，山田晋也，澤野憲太郎，中谷亮一，浜屋宏平
  • Organizer: 第43回日本磁気学会学術講演大会
• [Presentation] Improvement of nonmonotonic bias-dependent local spin signals in Co2FeAl0.5Si0.5/Ge lateral spin-valve devices (2019)
  • Author(s): M. Yamada, S. Honda, Y, Fujita, S. Yamada, K. Sawano, and K. Hamaya
  • Organizer: The 24th Symposium on the Physics and Applications of Spin-related Phenomena in Semiconductors
• [Presentation] Enhancement in room-temperature magnetoresistance ratio in p-Ge based vertical spin-valve devices with a Co2FeSi layer (2019)
  • Author(s): A. Yamada, T. Shiihara, M. Yamada, M. Honda, S. Yamada, and K. Hamaya
  • Organizer: 8th International Symposium on Control of Semiconductor Interfaces(ISCSI-8)
  • Int'l Joint Research
• [Presentation] Inverse local magnetoresistance effect up to room temperature in ferromagnet-semiconductor lateral spin-valve devices (2019)
  • Author(s): T. Naito, M. Yamada, S. Yamada, K. Sawano, K. Hamaya
  • Organizer: 8th International Symposium on Control of Semiconductor Interfaces(ISCSI-8)
  • Int'l Joint Research
• [Presentation] Germanium PN junctions between ferromagnetic CoFe and Fe3Si layers for spintronic applications (2019)
  • Author(s): M. Honda, T. Shiihara, M. Yamada, S. Yamada, K. Hamaya
  • Organizer: 8th International Symposium on Control of Semiconductor Interfaces(ISCSI-8)
  • Int'l Joint Research
• [Presentation] Room-temperature spin-dependent transport through Sb-doped Ge in vertical spin-valve devices (2019)
  • Author(s): T. Shiihara , M. Yamada , M. Honda , S. Yamada, K. Hamaya
  • Organizer: 64th Annual Conference on Magnetism and Magnetic Materials (MMM) 2019
  • Int'l Joint Research
• [Presentation] 強磁性Fe3Si上へのゲルマニウムPN接合の作製 (2019)
  • Author(s): 本田瑞葵, 椎原貴洋, 山田晋也, 山田道洋, 浜屋宏平
  • Organizer: 第80回応用物理学会秋季学術講演大会
• [Presentation] Spin transport in a strained SiGe alloy (2019)
  • Author(s): T. Naito, M. Yamada, M. Tsukahara, S. Yamada, K. Sawano, and K. Hamaya
  • Organizer: 第80回応用物理学会秋季学術講演大会
• [Presentation] Spin-dependent transport through n-Ge in vertical spin valve devices (2019)
  • Author(s): T. Shiihara, M. Yamada, M.Honda, S. Yamada, K. Hamaya
  • Organizer: 第80回応用物理学会秋季学術講演大会
• [Presentation] Ge-on-Si(111) 及びGe(111) 基板上の歪みSi1-xGexの臨界膜厚 (2019)
  • Author(s): 我妻 勇哉、Md. Mahfuz Alam、岡田 和也、星 裕介、山田 道洋、浜屋 宏平、澤野 憲太郎
  • Organizer: 第80回応用物理学会秋季学術講演大会
• [Presentation] Influence of the interface quality on the estimation of the spin-to-charge conversion efficiency in spin pumping experiments on Co2FeAl0.5Si0.5/n-Ge (2019)
  • Author(s): Shingo Kaneta, Shoma Arai, Le Duc Anh, Michihiro Yamada, Kohei Hamaya, and Shinobu Ohya
  • Organizer: 第80回応用物理学会秋季学術講演大会
• [Presentation] 強磁性体/半導体スピン素子におけるスピン蓄積信号の 非線形バイアス依存性 (2019)
  • Author(s): 藤田裕一，山田道洋，塚原誠人，内藤貴大，山田晋也，澤野憲太郎，浜屋宏平
  • Organizer: 第43回日本磁気学会学術講演大会
• [Presentation] Ge-on-Si(111) 及びGe(111) 基板上の歪みSi1-xGexの表面形状と臨界膜厚 (2019)
  • Author(s): 我妻 勇哉、Md. Mahfuz Alam、岡田 和也、星 裕介、 山田 道洋、浜屋 宏平、澤野 憲太郎
  • Organizer: 第2回結晶工学ⅹISYSE 合同研究会
• [Presentation] Observation of lateral spin transport in non-degenerate n-Ge (2019)
  • Author(s): T. Ueno, M. Yamada, T. Matsuoka, T. Naito, S. Yamada, K. Sawano, and K. Hamaya
  • Organizer: The 24th Symposium on the Physics and Applications of Spin-related Phenomena in Semiconductors
• [Presentation] 全エピタキシャルCoFe/Sb-doped Ge/Fe3Si縦型構造における室温スピン伝導の観測 (2019)
  • Author(s): 椎原貴洋, 山田道洋, 本田瑞葵, 山田晋也, 浜屋宏平
  • Organizer: Spin Research Network of Japan (Spin-RNJ) 2019年度年次報告会
• [Presentation] n-SiGe横型スピンバルブ素子における負の局所スピン信号 (2019)
  • Author(s): 内藤貴大, 山田道洋, 山田晋也, 澤野憲太郎, 浜屋宏平
  • Organizer: Spin Research Network of Japan (Spin-RNJ) 2019年度年次報告会
• [Presentation] 非縮退n-Ge中のスピン伝導特性 (2019)
  • Author(s): 上野登希生, 山田道洋, 松岡哲平, 内藤貴大, 山田晋也, 澤野憲太郎, 浜屋宏平
  • Organizer: Spin Research Network of Japan (Spin-RNJ) 2019年度年次報告会
• [Presentation] Spin transport in Ge and SiGe (2018)
  • Author(s): M. Yamada, M. Tukahara, Y. Fujita, T. Naito, S. Yamada, K. Sawano, and K. Hamaya
  • Organizer: CSRN-Osaka Annual Workshop 2018
  • Int'l Joint Research / Invited
• [Presentation] Local magnetoresistance effect at room temperature in Co2FeAlxSi1-x/n-Ge lateral spin-valve devices (2018)
  • Author(s): M. Yamada, M. Tukahara, T. Naito, Y. Fujita, S. Yamada, K. Sawano, and K. Hamaya
  • Organizer: One-Day Symposium on Spintronics Properties of Graphene and Related 2D Materials
  • Int'l Joint Research
• [Presentation] Electrical spin injection and transport in a SiGe alloy (2018)
  • Author(s): M. Yamada, T. Naito, M. Tsukahara, S. Yamada, K. Sawano, and K. Hamaya
  • Organizer: The 9th International SiGe Technology and Device Meeting (ISTDM)
  • Int'l Joint Research
• [Presentation] Spin transport through Sb-doped n-Ge in vertical spin-valve devices (2018)
  • Author(s): T. Shiihara , M. Yamada, S. Sakai , M. Ikawa, S. Yamada, and K. Hamaya
  • Organizer: One-Day Symposium on Spintronics Properties of Graphene and Related 2D Materials
  • Int'l Joint Research
• [Presentation] Low-resistance ferromagnet/germanium Schottky-tunnel contacts for spintronic applications (2018)
  • Author(s): K. Hamaya, T. Naito, M. Tsukahara, M. Yamada, and K. Sawano
  • Organizer: The Electrochemical Society, 2018 SiGe Symposium
  • Int'l Joint Research
• [Presentation] Spin transport in a Ge-rich SiGe alloy (2018)
  • Author(s): T. Naito, M. Yamada, M. Tsukahara, K. Sawano, and K. Hamaya
  • Organizer: 2018 European Materials Research Society (E-MRS 2018)
  • Int'l Joint Research
• [Presentation] Large local magnetoresistance in Si<100> devices at room temperature (2018)
  • Author(s): M. Ishikawa, M. Tsukahara, M. Yamada, Y. Saito, and K. Hamaya
  • Organizer: INTERMAG 2018
  • Int'l Joint Research
• [Presentation] Observation of local spin signals at room temperature in germanium lateral devices (2018)
  • Author(s): M. Tsukahara, M. Yamada, T. Naito, Y. Fujita, S. Yamada, K. Sawano, and K. Hamaya
  • Organizer: INTERMAG 2018
  • Int'l Joint Research
• [Presentation] Room-temperature spin transport in n-Ge probed by four-terminal nonlocal measurements (2018)
  • Author(s): M. Yamada, M. Tsukahara, Y. Fujita, T. Naito, S. Yamada, K. Sawano, and K. Hamaya
  • Organizer: 第79回 応用物理学会秋季学術講演会
  • Invited
• [Presentation] Inverse local magnetoresistance in Heusler/SiGe lateral spin valve devices (2018)
  • Author(s): T. Naito, M. Yamada, M. Tsukahara, S. Yamada, K. Sawano, and K. Hamaya
  • Organizer: 平成30年度スピン変換年次報告会
• [Presentation] Room-temperature local magnetoresistance effect in n-Ge lateral devices (2018)
  • Author(s): M. Tsukahara, M. Yamada, T. Naito, S. Yamada, K. Sawano, and K. Hamaya
  • Organizer: 平成30年度スピン変換年次報告会
• [Presentation] 反平行磁化配置が不安定なゲルマニウム横型スピンバルブ素子における非局所スピン伝導 (2018)
  • Author(s): 沖宗一郎 ，山田道洋，山田晋也，澤野憲太郎 ，浜屋宏平
  • Organizer: 第42回日本磁気学会学術講演大会