Development of Fundamental Technologies for Fabricating Nitride Semiconductor and Superconductor Hybrid Devices

• Project/Area Number: 21H01827
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 30010:Crystal engineering-related
• Research Institution: Tokyo University of Science (2023); The University of Tokyo (2021-2022)
• Principal Investigator: Kobayashi Atsushi 東京理科大学, 先進工学部マテリアル創成工学科, 准教授 (20470114)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Project Status: Completed (Fiscal Year 2023)
• Budget Amount: ¥17,810,000 (Direct Cost: ¥13,700,000、Indirect Cost: ¥4,110,000); Fiscal Year 2023: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000); Fiscal Year 2022: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2021: ¥11,570,000 (Direct Cost: ¥8,900,000、Indirect Cost: ¥2,670,000)
• Keywords: 窒化物半導体 / 窒化物超伝導体

Outline of Research at the Start

本研究では、超伝導LEDやオンチップ単一光子回路などの窒化物量子デバイスの作製に必要な、窒化物超伝導体と窒化物半導体の高品質ヘテロ界面作製プロセスを開拓する。エピタキシャル成長によって窒化物半導体と超伝導体が接合できれば、単一光子やクーパー対がキャリアとなる新しい窒化物量子デバイスが設計できるようになる。

Outline of Final Research Achievements

In this study, we developed a technology for epitaxial integration of nitride semiconductors and nitride superconductors. We focused on the structural characteristics of the interface between the nitride superconductor and semiconductor fabricated using the sputtering method, and successfully controlled the properties of the heterojunction.The epitaxial growth technology established in this study contributes to the development of novel quantum devices utilizing superconductor/semiconductor heterojunctions.

Academic Significance and Societal Importance of the Research Achievements

窒化物半導体を基板とする薄膜成長法を採用することで、これまでに明らかにされてこなかったNbN薄膜の結晶構造と電気的特性を詳細に理解することできた。今回の研究成果は、窒化物半導体とNbN超伝導体薄膜を均質な状態でエピタキシャルに融合できる可能性を示すものであり、次世代超伝導・半導体融合デバイスの開発に向けた基盤技術となる。

Research Products

• [Journal Article] Epitaxial Junction of Inversion Symmetry Breaking AlN and Centrosymmetric NbN: A Polarity Control of Wide-Bandgap AlN (2023)
  • Author(s): Kobayashi Atsushi、Kihira Shunya、Akiyama Toru、Kawamura Takahiro、Maeda Takuya、Ueno Kohei、Fujioka Hiroshi
  • Journal Title: ACS Applied Electronic Materials Volume: 5 Issue: 1 Pages: 240-246
  • DOI: 10.1021/acsaelm.2c01288
  • Peer Reviewed
• [Journal Article] Crystal‐Phase Controlled Epitaxial Growth of NbNx Superconductors on Wide‐Bandgap AlN Semiconductors (2022)
  • Author(s): Kobayashi Atsushi、Kihira Shunya、Takeda Takahito、Kobayashi Masaki、Harada Takayuki、Ueno Kohei、Fujioka Hiroshi
  • Journal Title: Advanced Materials Interfaces Volume: 9 Issue: 31 Pages: 2201244-2201244
  • DOI: 10.1002/admi.202201244
  • Peer Reviewed
• [Journal Article] Epitaxial growth of superconducting NbN on wide-bandgap AlN (2022)
  • Author(s): Atsushi Kobayashi, Kohei Ueno, Hiroshi Fujioka
  • Journal Title: JSAP Review Volume: 2022 Issue: 0 Pages: n/a
  • DOI: 10.11470/jsaprev.220408
  • ISSN: 2437-0061
  • Peer Reviewed / Open Access
• [Journal Article] Reduction of Twin Boundary in NbN Films Grown on Annealed AlN (2022)
  • Author(s): Kihira Shunya、Kobayashi Atsushi、Ueno Kohei、Fujioka Hiroshi
  • Journal Title: Crystal Growth & Design Volume: 22 Issue: 3 Pages: 1720-1723
  • DOI: 10.1021/acs.cgd.1c01287
  • Peer Reviewed
• [Journal Article] Ultrathin rock-salt type NbN films grown on atomically flat AlN/sapphire substrates (2021)
  • Author(s): Kobayashi Atsushi、Ueno Kohei、Fujioka Hiroshi
  • Journal Title: Journal of Crystal Growth Volume: 572 Pages: 126269-126269
  • DOI: 10.1016/j.jcrysgro.2021.126269
  • Peer Reviewed
• [Presentation] 窒化物半導体・超伝導体・強誘電体のエピタキシャル融合 (2023)
  • Author(s): 小林 篤
  • Organizer: 第4回半導体ナノフォトニクス研究会
  • Invited
• [Presentation] Study on 2DEG Density in ScAlN/GaN and AlGaN/GaN Heterostructures Based on Simulation and Analytical Modeling (2023)
  • Author(s): Yusuke Wakamoto,Atsushi Kobayashi,Yoshiaki Nakano,Takuya Maeda
  • Organizer: 14th International Conference on Nitride Semiconductors (ICNS-14)
  • Int'l Joint Research
• [Presentation] Structural Properties of Epitaxial ScAlN Films Grown by Sputtering: Experimental and Machine Learning Approaches (2023)
  • Author(s): Atsushi Kobayashi,Yoshio Honda,Takuya Maeda,Kohei Ueno,Hiroshi Fujioka
  • Organizer: 14th International Conference on Nitride Semiconductors (ICNS-14)
  • Int'l Joint Research
• [Presentation] Electronic States at the Interface of β-Nb2N/AlN Superlattices (2023)
  • Author(s): Takahiro Kawamura,Toru Akiyama,Atsushi Kobayashi
  • Organizer: 14th International Conference on Nitride Semiconductors (ICNS-14)
  • Int'l Joint Research
• [Presentation] Selectively regrown heavily Si-doped degenerate GaN contact to AlN/AlGaN HEMTs prepared via pulsed sputtering (2023)
  • Author(s): Ryota Maeda,Takao Kozaka,Kohei Ueno,Atsushi Kobayashi,Hiroshi Fujioka
  • Organizer: 14th International Conference on Nitride Semiconductors (ICNS-14)
  • Int'l Joint Research
• [Presentation] Sputtering Epitaxial Integration of AlN and NbN for Polarity Control and Crystal Phase Manipulation (2023)
  • Author(s): Atsushi Kobayashi,Shunya Kihira,Takahito Takeda,Masaki Kobayashi,Takuya Maeda,Takayuki Harada,Toru Akiyama,Takahiro Kawamura,Kohei Ueno,Hiroshi Fujioka
  • Organizer: 14th International Conference on Nitride Semiconductors (ICNS-14)
  • Int'l Joint Research
• [Presentation] Characterization of Optical Properties and Bandgaps of ScxAl1-xN Epitaxially Grown on GaN Bulk Substrate by Sputtering Method (2023)
  • Author(s): Takuya Maeda,Yusuke Wakamoto,Shota Kaneki,Hajime Fujikura,Atsushi Kobayashi
  • Organizer: 14th International Conference on Nitride Semiconductors (ICNS-14)
  • Int'l Joint Research
• [Presentation] ScAlN/GaNとAlGaN/GaNに対する数値計算・解析式による2DEGモデリング (2023)
  • Author(s): Y. Wakamoto,A. Kobayashi,Y. Nakano,T. Maeda
  • Organizer: 第42回電子材料シンポジウム(EMS-42)
• [Presentation] GaN基板上にスパッタ成長したScAlN薄膜の構造・光学物性の評価 (2023)
  • Author(s): T. Maeda,Y. Wakamoto,S. Kaneki,H. Fujikura,A. Kobayashi
  • Organizer: 第42回電子材料シンポジウム(EMS-42)
• [Presentation] ScAlN/GaNおよびAlGaN/GaNの二次元電子ガス濃度の数値計算と解析モデルの提案 (2023)
  • Author(s): 若本裕介,小林篤,中野義昭,前田拓也
  • Organizer: 第84回応用物理学会秋季学術講演会
• [Presentation] 分光エリプソメトリーによるScAlN/GaNの光学物性評価 (2023)
  • Author(s): 前田 拓也,若本 裕介,金木 奨太,藤倉 序章,小林 篤
  • Organizer: 第84回応用物理学会秋季学術講演会
• [Presentation] β-Nb2N/AlN超格子構造における界面の電子状態の解析 (2023)
  • Author(s): 河村 貴宏,秋山 亨,小林 篤
  • Organizer: 第84回応用物理学会秋季学術講演会
• [Presentation] ScAlN/GaNヘテロ接合界面における二次元電子ガス濃度の数値計算 (2023)
  • Author(s): 若本裕介,小林篤,中野義昭,前田拓也
  • Organizer: 第15回ナノ構造・エピタキシャル成長講演会
• [Presentation] β-Nb2N/AlN超格子の電子構造解析 (2023)
  • Author(s): 河村貴宏,秋山亨,小林篤
  • Organizer: 第15回ナノ構造・エピタキシャル成長講演会
• [Presentation] NbN/AlNヘテロ構造の作製とAlN極性反転技術への応用 (2023)
  • Author(s): 小林篤, 上野耕平, 藤岡洋
  • Organizer: 日本学術振興会 第R032産業イノベーションのための結晶成長委員会 第10回研究会
  • Invited
• [Presentation] Epitaxial growth of NbN superconductors on lattice-matched AlN wide-bandgap semiconductors (Invited Paper) (2023)
  • Author(s): Atsushi Kobayashi,Shunya Kihira,Kohei Ueno,Hiroshi Fujioka
  • Organizer: SPIE Photonics West 2023 - Gallium Nitride Materials and Devices XVIII
  • Int'l Joint Research / Invited
• [Presentation] AlNに格子整合する六方晶Nb2N超伝導体のエピタキシャル成長 (2022)
  • Author(s): 小林 篤, 紀平 俊矢, 武田 崇仁, 小林 正起, 秋山 亨, 河村 貴宏, 原田 尚之, 上野 耕平, 藤岡 洋
  • Organizer: 第83回応用物理学会秋季学術講演会
• [Presentation] NbNを利用したAl極性AlN上へのN極性AlNエピタキシャル成長 (2022)
  • Author(s): 紀平俊矢,小林篤,上野耕平,藤岡洋
  • Organizer: 第69回応用物理学会春季学術講演会
• [Presentation] Epitaxial integration of NbN superconductors with AlN (2022)
  • Author(s): Atsushi Kobayashi,Shunya Kihira,Kohei Ueno,Hiroshi Fujioka
  • Organizer: IWSingularity 2022
  • Int'l Joint Research / Invited
• [Presentation] 格子整合AlN上へのNbN低温エピタキシャル成長 (2021)
  • Author(s): 趙康,紀平俊矢,小林篤,上野耕平,藤岡洋
  • Organizer: 第13回ナノ構造・エピタキシャル成長講演会
• [Presentation] 表面平坦化処理を施したAlN上へのNbNエピタキシャル成長 (2021)
  • Author(s): 紀平俊矢,前田亮太,小林篤,上野耕平,藤岡洋
  • Organizer: 第82回 応用物理学会 秋季学術講演会
• [Presentation] 窒化物半導体と超伝導体の融合をめざして (2021)
  • Author(s): 小林篤
  • Organizer: 応用物理学会中国四国支部・若手半導体研究会
  • Invited