Study on Fabrication Process of Single-Flux-Quantum Integrated Circiuts

• Project/Area Number: 18080007
• Research Category: Grant-in-Aid for Scientific Research on Priority Areas
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: Nagoya University
• Principal Investigator: AKIRA Fujimaki (FUJIMAKI Akira) Nagoya University, 大学院・工学研究科, 教授 (20183931)
• Co-Investigator(Kenkyū-buntansha): HIROYUKI Akaike 名古屋大学, 大学院・工学研究科, 助教 (20273287)
• Project Period (FY): 2006 – 2009
• Project Status: Completed (Fiscal Year 2009)
• Budget Amount: ¥56,200,000 (Direct Cost: ¥56,200,000); Fiscal Year 2009: ¥4,200,000 (Direct Cost: ¥4,200,000); Fiscal Year 2008: ¥14,500,000 (Direct Cost: ¥14,500,000); Fiscal Year 2007: ¥12,600,000 (Direct Cost: ¥12,600,000); Fiscal Year 2006: ¥24,900,000 (Direct Cost: ¥24,900,000)
• Keywords: 超伝導 / 単一磁束量子 / 局在電磁波 / ジョセフソン接合 / 窒化ニオブ / RbN / 単一磁束量子回路 / 二硼化マグネシウム / NbN / オーバーダンプ特性 / ジョセフソン結合 / 反応性スパッタリング / 成膜条件 / 反応性イオンエッチング

Research Abstract

We have studied Josephson junctions based on niobium nitride (NbN), which has 1.5 times larger superconducting energy gap than niobium. We have formed tunnel barriers by nitriding aluminum deposited on the base electrodes of NbN. These junctions show excellent reproducibility and controllability in quality parameters such as critical current density and characteristic voltage. We have also demonstrated intrinsically overdamped junctions by inserting normal conducting layers of NbNx. The junctions have high potential for high-speed operation in the single-flux-quantum logic circuit.

Research Products

• [Journal Article] 単一磁束量子回路による超高速信号処理 (2010)
  • Author(s): 藤巻朗
  • Journal Title: まぐね vol.5,No.1 Pages: 19-24
  • NAID: 110003205116
• [Journal Article] 単一磁束量子を用いた情報処理回路 (2010)
  • Author(s): 藤巻朗, 田中雅光
  • Journal Title: 電気学会誌 vol.130,No.3 Pages: 159-162
  • NAID: 10026224343
• [Journal Article] All MgB2 Josephson junctions with amorphous boron barriers (2010)
  • Author(s): N. Mitamura, C. Maruyama, H. Akaike, A. Fujimaki, R. Ishii, Y. Niihara, M. Naito
  • Journal Title: IEICE Trans. Electronics E93-C,No.4 Pages: 468-472
  • Peer Reviewed
• [Journal Article] All MgB_2 Josephson junctions with Amorphous Boron Barriers (2010)
  • Author(s): N MITAMURA, C MARUYAMA, H AKAIKE, A FUJIMAKI, R ISHII, Y NIIHARA, M NAITO
  • Journal Title: IEICE TRANSACTIONS on Electronics Vol.E93-C No.4 Pages: 468-472
  • NAID: 10026825181
  • Peer Reviewed
• [Journal Article] The preparation process of plasma-nitrided barriers in NbN Josephson junctions for digital applications (2009)
  • Author(s): Y. Nagai, H. Akaike, R. Kanada, N. Naito, A. Fujimaki
  • Journal Title: Supercond. Sci. Technol. 22(11),No.114015 Pages: 5-5
  • Peer Reviewed
• [Journal Article] Current Resolution of a Single-Flux-Quantum Readout Circuit Based on Current-to-Time Conversion Toward a Flux Qubit System (2009)
  • Author(s): S. Nakamura, H. Numabe, A. Bozbey, A. Fujimaki
  • Journal Title: IEEE Trans. Appl. Supercond. 19(3) Pages: 973-976
  • Peer Reviewed
• [Journal Article] Single-Flux-Quantum Circuit Based Readout System for Detector Arrays by Using Time to Digital Conversion (2009)
  • Author(s): A. Bozbey, S. Miyajima, H. Akaike, A. Fujimaki
  • Journal Title: IEEE Trans. Appl. Supercond. 19(3) Pages: 509-513
  • Peer Reviewed
• [Journal Article] Self-Shunted NbN Junctions With NbNx/AlN Bilayered Barriers for 4 K Operation (2009)
  • Author(s): R. Kanada, Y. Nagai, H. Akaike, A. Fujimaki
  • Journal Title: IEEE Trans. Appl. Supercond. 19(3) Pages: 249-252
  • Peer Reviewed
• [Journal Article] The preparation process of plasma-nitrided barriers in NbN Josephson junctions for digital applications (2009)
  • Author(s): Y Nagai, H Akaike, R Kanada, N Naito, A Fujimaki
  • Journal Title: Supercond.Sci.Technol Vol.22 No.11
  • Peer Reviewed
• [Journal Article] Single-flux-quantum circuit based readout system for detector arrays by using time to digital conversion (2009)
  • Author(s): Ali Bozbey, Sigeyuki Miyajima
  • Journal Title: IEEE Transactions on Applied Superconductivity (印刷中)
  • Peer Reviewed
• [Journal Article] Self-shunted NbN junctions with NbN_x/AIN bilayered barriers for 4 K operation (2009)
  • Author(s): Ryohei Kanada
  • Journal Title: IEEE Transactions on Applied Superconductivity (印刷中)
  • Peer Reviewed
• [Journal Article] Bit-Serial Single Flux Quantum Microprocessor CORE (2008)
  • Author(s): A. Fujimaki, M. Tanaka, T. Yamada, Y. Yamanashi, Heejoung Park, N. Yoshikawa
  • Journal Title: IEICE Trans. Electron. E91-C(3) Pages: 342-349
  • NAID: 10026817119
  • Peer Reviewed
• [Journal Article] Design and implementation of a pipelined 8 bit-serial single-flux-quantum microprocessor with cache memories (2007)
  • Author(s): M. Tanaka, Y. Yamanashi, N. Irie, H. -J. Park, S. Iwasaki, K. Takagi, K. Taketomi, A. Fujimaki, N. Yoshikawa, H. Terai, S. Yorozu
  • Journal Title: Supercond. Sci. Technol. 20(11)
  • Peer Reviewed
• [Journal Article] Quantitative evaluation of delay time in the single-flux-quantum circuit (2007)
  • Author(s): S. Iwasaki, M. Tanaka, N. Irie, A. Fujimaki, N. Yoshikawa, H. Terai, S. Yorozu
  • Journal Title: Physica C 463-465 Pages: 1068-1071
  • Peer Reviewed
• [Journal Article] Effects of surface morphologies of base electrodes on the qualities of Nb/AlOx/Nb Josephson junctions with high critical densities (2007)
  • Author(s): N.J. Mehta, N. Mitamura, R. Kanada, H. Akaike, A. Fujimaki
  • Journal Title: Physica C 463-465 Pages: 975-978
  • Peer Reviewed
• [Journal Article] A New Design Approach for High-Throughput Arithmetic Circuits for Single-Flux-Quantum Microprocessors (2007)
  • Author(s): M. Tanaka, Y. Yamanashi, Y. Kamiya, A. Akimoto, N. Irie, H. -J. Park, A. Fujimaki, N. Yoshikawa, H. Terai, S. Yorozu
  • Journal Title: IEEE Trans. Appl. Supercond. 17(2) Pages: 516-519
  • Peer Reviewed
• [Journal Article] Self-shunted NbN junctions with NbN_x/AlN/NbN_x multilayered barriers for 4 K operation
  • Author(s): R.Kanada, Y.Nagai, H.Akaike, A.Fujimaki
  • Journal Title: IEEE Trans.Appl.Supercond. (in press)
  • Peer Reviewed
• [Journal Article] Single-flux-quantum circuit based readout system for detector arrays by using time to digital conversion
  • Author(s): A.Bozbey, S.Miyajima, H.Akaike, A.Fujimaki
  • Journal Title: IEEE Trans.Appl.Supercond. (in press)
  • Peer Reviewed
• [Presentation] NbN Josephson junctions for SFQ LSIs (2010)
  • Author(s): A. Fujimaki, Y. Nagai, N. Naito, H. Akaike
  • Organizer: The 3rd Superconducting SFQ VLSI Workshop (SSV 2010) A01-1
  • Place of Presentation: Yokohama, Japan
  • Year and Date: 2010-01-13
• [Presentation] Fabrication of NbN Josephson Junctions with Plasma- Nitrided AlN Barriers Formed by RF Substrate Biasing (2010)
  • Author(s): Y. Nagai, N. Naito, H. Akaike, A. Fujimaki
  • Organizer: The 3rd Superconducting SFQ VLSI Workshop (SSV 2010) P15
  • Place of Presentation: Yokohama, Japan
  • Year and Date: 2010-01-13
• [Presentation] Experimental analysis of gray zones in quasi-one-junction SQUIDs (2010)
  • Author(s): S Miyajima
  • Organizer: The 3^<rd> Superconducting SFQ VLSI Workshop
  • Place of Presentation: Yokohama横浜国立大学
  • Year and Date: 2010-01-13
• [Presentation] Fabrication of NbN Josephson Junctions with Plasma-Nitrided AlN Barriers Formed by RF Substrate Biasing (2010)
  • Author(s): Y Nagai
  • Organizer: The 3^<rd> Superconducting SFQ VLSI Workshop
  • Place of Presentation: Yokohama横浜国立大学
  • Year and Date: 2010-01-13
• [Presentation] 磁束トラップ低減へ向けた窒化ニオブグランドプレーンの有効性評価 (2010)
  • Author(s): 御田村直樹
  • Organizer: 第57回応用物理学関係連合講演会
  • Place of Presentation: 平塚市東海大学
• [Presentation] 4KにおけるQOS比較器の感度の評価 (2009)
  • Author(s): 宮嶋茂之
  • Organizer: 第56回応用物理学会関係連合講演会
  • Place of Presentation: 筑波大学
  • Year and Date: 2009-03-31
• [Presentation] イベント駆動型セレクタを組み込んだ超伝導アナログーデジタル変換機の開発 (2009)
  • Author(s): 東陽介
  • Organizer: 第56回応用物理学会関係連合講演会
  • Place of Presentation: 筑波大学
  • Year and Date: 2009-03-31
• [Presentation] 小型中性子回折システムに向けたSFQ信号処理回路 (2009)
  • Author(s): 中西功
  • Organizer: 第56回応用物理学会関係連合講演会
  • Place of Presentation: 筑波大学
  • Year and Date: 2009-03-31
• [Presentation] イベント駆動型セレクタを組み込んだ超伝導アナログ-デジタル変換器の開発 (2009)
  • Author(s): 東陽介,宮嶋茂之,藤巻朗
  • Organizer: 2009年春季第56回応用物理学関係連合講演会
  • Place of Presentation: 筑波大学
  • Year and Date: 2009-03-30
• [Presentation] 4KにおけるQOS比較器の感度の評価 (2009)
  • Author(s): 宮嶋茂之,東陽介,藤巻朗
  • Organizer: 2009年春季第56回応用物理学関係連合講演会
  • Place of Presentation: 筑波大学
  • Year and Date: 2009-03-30
• [Presentation] Development of Single-Flux-Quantum Circuits for a Compact Neutron Diffractometer (2009)
  • Author(s): A. Fujimaki, I. Nakanishi, S. Miyajima, T. Ishida
  • Organizer: The 5th East Asia Symposium on Superconductor Electronics (EASSE2009) M2-2
  • Place of Presentation: Nanjing, China
• [Presentation] RSFQ Circuit Design for Detector Applications (2009)
  • Author(s): A. Fujimaki
  • Organizer: 6th FLUXONICS RSFQ design workshop
  • Place of Presentation: Ilmenau, Germany
• [Presentation] Preparation Process of Plasma-Nitrided Barriers in NbN Josephson Junctions for Digital Applications (2009)
  • Author(s): Y. Nagai, R. Kanada, H. Akaike, A. Fujimaki
  • Organizer: 12th Int. Superconductive Electronics Conf. (ISEC2009) TD-O6 Extended Abstracts of the 12th International Superconductive Electronics Conference TD-O6
  • Place of Presentation: Fukuoka, Japan
• [Presentation] Preparation of MgB2/B/MgB2 Josephson Junctions (2009)
  • Author(s): N. Mitamura, C. Maruyama, H. Akaike, A. Fujimaki, R. Inoue, Y. Niihara, M. Naito
  • Organizer: 12th Int. Superconductive Electronics Conf. (ISEC2009) TD-P14Extended Abstracts of the 12th International Superconductive Electronics Conference TD-P14
  • Place of Presentation: Fukuoka, Japan
• [Presentation] Demonstration of 2x3 Reconfigurable-Data-Path Processors with 14000 Josephson Junctions (2009)
  • Author(s): A. Fujimaki, R. Kasagi, K. Takagi, I. Kataeva, H. Akaike, M. Tanaka, N. Takagi, N. Yoshikawa, K. Murakami
  • Organizer: 12th Int. Superconductive Electronics Conf. (ISEC2009) (SSV Session) SP-O4Extended Abstracts of the 12th International Superconductive Electronics Conference SP-O4
  • Place of Presentation: Fukuoka, Japan
• [Presentation] Electrical Properties of All MgB2 Josephson Junctions with Different Tunnel Barriers (2009)
  • Author(s): N. Mitamura, C. Maruyama, H. Akaike, A. Fujimaki, R. Ishii, Y. Niihara, M. Naito
  • Organizer: The 2nd Superconducting SFQ VLSI Workshop (SSV2009) O10
  • Place of Presentation: Fukuoka, Japan
• [Presentation] Recent Progress in Superconducting Digital Electronics (2009)
  • Author(s): A. Fujimaki
  • Organizer: Joint JSPS-ESF International Conference on Nanoscience and Engineering in Superconductivity
  • Place of Presentation: Tsukuba, Japan
• [Presentation] Investigation of the Bias Current Dependence of Gray Zone in Quasi-One-Junctions SQUID Comparator (2009)
  • Author(s): S Miyajima
  • Organizer: The 2^<nd> Superconducting SFQ VLSI Workshop
  • Place of Presentation: Fukuoka九州大学
• [Presentation] Delta Analog-to-digital Converters with Event-driven Decimation Filters for a Detector Array (2009)
  • Author(s): Y Higashi
  • Organizer: 12^<th> Int. Superconductive Electronics Conf.
  • Place of Presentation: Fukuoka九州大学
• [Presentation] The preparation process of plasma-nitrided barriers in NbN Josephson junctions for digital applications (2009)
  • Author(s): Y Nagai
  • Organizer: 12^<th> Int. Superconductive Electronics Conf.
  • Place of Presentation: Fukuoka九州大学
• [Presentation] アモルファス半導体障壁層を用いたMgB_2ジョセブソン接合の評価 (2009)
  • Author(s): 御田村直樹
  • Organizer: 第70回応用物理学会学術講演会
  • Place of Presentation: 富山大学
• [Presentation] プラズマ窒化AlN障壁を用いたNbNジョセフソン接合の作製 (2009)
  • Author(s): 長井友樹
  • Organizer: 第70回応用物理学会学術講演会
  • Place of Presentation: 富山大学
• [Presentation] 超伝導検出器のアレイ化に向けたイベント駆動型セレクタ回路の開発 (2008)
  • Author(s): 東陽介
  • Organizer: 電子情報通信学会2008年ソサイエティ大会
  • Place of Presentation: 明治大学
  • Year and Date: 2008-09-19
• [Presentation] TESアレーに向けた読出し回路と実装方法の検討 (2008)
  • Author(s): Ali Bozbey, 赤池宏之, 藤巻朗
  • Organizer: 2008年秋季第69回応用物理学学術講演会
  • Place of Presentation: 中部大学
  • Year and Date: 2008-09-05
• [Presentation] NbNセルフオーバーダンプ接合へ向けたMgO基板前処理の検討 (2008)
  • Author(s): 長井友樹, 金田亮平, 赤池宏之, 藤巻朗
  • Organizer: 2008年秋季第69回応用物理学会学術講演会
  • Place of Presentation: 中部大学
  • Year and Date: 2008-09-05
• [Presentation] NbNセルフオーバーダンプ接合に向けたMgo基板前処理の検討 (2008)
  • Author(s): 長井友樹
  • Organizer: 第69回応用物理学会学術講演会
  • Place of Presentation: 中部大学
  • Year and Date: 2008-09-04
• [Presentation] Design of Single-flux-quantum circuit based read-out electronics for X-Ray sensitive TES arrays (2008)
  • Author(s): A.Bozbey, S.Miyajima, H.Akaike, A.Fujimaki
  • Organizer: International Conference on Superconductivity and Magnetism (ICSM2008)
  • Place of Presentation: Antalya
  • Year and Date: 2008-08-31
• [Presentation] Design of single-flux-quantum circuit based read-out electronics for X-ray sensitive small-pixel TES arrays (2008)
  • Author(s): A.Bozbey, S.Miyajima, H.Akaike, A.Fujimaki
  • Organizer: Eighth Int'l Workshop on Low Temperature Electronics (WOLTE2008)
  • Place of Presentation: Jena
  • Year and Date: 2008-06-24
• [Presentation] NbN/AlN/NbN_x/NbNオーバーダンプ接合に向けたAlN障壁層の特性評価 (2008)
  • Author(s): 金田亮平, 長井友樹, 赤池宏之,藤巻朗
  • Organizer: 第55回応用物理学関係連合講演会
  • Place of Presentation: 日本大学
  • Year and Date: 2008-03-28
• [Presentation] NbN/AlN/NbNx/NbNオーバーダンプ接合に向けたAIN障壁層の特性評価 (2008)
  • Author(s): 金田亮平, 長井友樹, 赤池宏之, 藤巻朗
  • Organizer: 第55回応用物理学関係連合講演会
  • Place of Presentation: 日本大学(船橋)
  • Year and Date: 2008-03-28
• [Presentation] Fabrication and measurement of high quality and high critical current density Nb/AlOx/Nb Josephson junction (2008)
  • Author(s): N. Mitamura, H. Akaike, A. Fujimaki
  • Organizer: Superconducting SFQ VLSI Workshop (SSV2008) P1-3
  • Place of Presentation: Yokohama, Japan
  • Year and Date: 2008-03-17
• [Presentation] Self-shunted NbN Josephson Junctions with AlN/NbNx Barriers (2008)
  • Author(s): A. Fujimaki, R. Kanada, Y. Nagai, H. Akaike
  • Organizer: Superconducting SFQ VLSI Workshop (SSV2008) A1-2
  • Place of Presentation: Yokohama, Japan
  • Year and Date: 2008-03-17
• [Presentation] Self-shunted NbN Josephson Junctions with AlN/NbN_x Barriers (2008)
  • Author(s): A.Fujimaki, R.Kanada, Y.Nagai, H.Akaike
  • Organizer: 2008 Superconducting SFQ VLSI Workshop
  • Place of Presentation: Yokohama
  • Year and Date: 2008-03-17
• [Presentation] Self-shunted NbN Josephson Junctions with AIN/NbNx Barriers (2008)
  • Author(s): A. Fujimaki, R. Kanada, Y. Nagai, H. Akaike
  • Organizer: 2008 Superconducting SFQ VLSI Workshop
  • Place of Presentation: 横浜国立大学(横浜)
  • Year and Date: 2008-03-17
• [Presentation] 窒化ニオブ電極を用いたオーバーダンプ型ジョセフソン接合の開発 (2008)
  • Author(s): 赤池宏之, 金田亮平, 長井友樹, 藤巻朗
  • Organizer: 電子情報通信学会超伝導エレクトロニクス研究会SCE
  • Place of Presentation: 機会振興会館
  • Year and Date: 2008-01-25
• [Presentation] 窒化ニオブ電極を用いたオーバーダンプ型ジョセフソン接合の開発 (2008)
  • Author(s): 赤池宏之, 金田亮平, 長井友樹, 藤巻朗
  • Organizer: 電子情報通信学会超伝導エレクトロニクス研究会
  • Place of Presentation: 機会振興会館(東京)
  • Year and Date: 2008-01-25
• [Presentation] Self-shunted NbN junctions with NbNx/AlN/NbNx multilayered barriers for 4 K operation (2008)
  • Author(s): R. Kanada, Y. Nagai, H. Akaike, A. Fujimaki
  • Organizer: 2008 Appl. Supercond. Conf. (ASC2008) 2EPH01
  • Place of Presentation: Chicago, Illinois, USA
• [Presentation] Single-flux-quantum circuit based readout system for detector arrays by using time to digital conversion (2008)
  • Author(s): 宮嶋茂之
  • Organizer: Applied Superconductivity Conference 2008
  • Place of Presentation: Hyatt Regency Chicago, USA
• [Presentation] Self-shunted NbN junctions with NbN_x/AIN bilayered barriers for 4 K operation (2008)
  • Author(s): 金田亮平
  • Organizer: Applied Superconductivity Conference 2008
  • Place of Presentation: Hyatt Regency Chicago, USA
• [Presentation] Single-Flux-Quantum-Based Readout System for an Array of Transition Edge Sensors (2008)
  • Author(s): 宮嶋茂之
  • Organizer: 21 th International Symposium on Superconductivity
  • Place of Presentation: エポカル筑波
• [Presentation] NbN/NbN_x/AlN/NbN_x/NbNオーバーダンプ接合に向けた常伝導NbN_x層の特性評価 (2007)
  • Author(s): 金田亮平, 長井友樹, 赤池宏之, 藤巻朗
  • Organizer: 第68回応用物理学学術講演会
  • Place of Presentation: 北海道工業大学
  • Year and Date: 2007-09-04
• [Presentation] NbN/NbNx/AlN/NbNx/NbNオーバーダンプ接合に向けた常伝導NbNx層の特性評価 (2007)
  • Author(s): 金田亮平, 長井友樹, 赤池宏之, 藤巻朗
  • Organizer: 第68回応用物理学会学術講演会
  • Place of Presentation: 北海道工業大学(札幌)
  • Year and Date: 2007-09-04
• [Presentation] Superconducting Elecronics in Japan (2007)
  • Author(s): A. Fujimaki
  • Organizer: The 15th Biennial Workshop on Superconductive Electronics: Devices, Circuits and Systems
  • Place of Presentation: Lakeville, Connecticut, USA
• [Presentation] Recent Progress in SFQ LSI Technology (2007)
  • Author(s): A. Fujimaki
  • Organizer: 8th European Conf. on Applied Superconductivity (EUCAS2007)
  • Place of Presentation: Brussels, Belgium
• [Presentation] Development of High-Speed Single-Flux-Quantum Microprocessors (2006)
  • Author(s): A. Fujimaki, M. Tanaka, N. Irie, S. Iwasaki, T. Yamada, N. Takagi, H. Park, Y. Yamanashi, N. Yoshikawa, H. Terai, S. Yorozu, Y. Takai
  • Organizer: 19th Int. Symposium on Superconductivity (ISS2006) FD-22-INV
  • Place of Presentation: Nagoya, Japan
• [Presentation] High resolution analog-to-digital converter toward a multiple detectors system (2006)
  • Author(s): A. Fujimaki, A. Sekiya, Y. Nishido, T. Yamazaki, H. Sato, H.M. Shimizu
  • Organizer: 2006 Appl. Supercond. Conf. (ASC2006) 2EX06
  • Place of Presentation: Seattle, Washington, USA
• [Presentation] Recent Progress in Rapid-single-flux-quantum Circuits (2006)
  • Author(s): A. Fujimaki
  • Organizer: 11th Int. Conferences on Modern Materials and Technologies (CIMTEC2006) (11th Int. Ceramics Congress and 4th Forum on New Materials) IC-II. 5: SL04
  • Place of Presentation: Sicily, Italy
• [Book] 第24章SFQ回路とその情報通信機器応用"超電導の応用最新技術 (2008)
  • Author(s): 藤巻朗, 日高睦夫
  • Publisher: シーエムシー出版
• [Book] "第6章3超伝導集積回路"テラヘルツ技術総覧(廣本宣久) (2007)
  • Author(s): 藤巻朗
  • Publisher: 有限会社エヌジーティー