氏名

オオハシ ケイシ

大橋 啓之

職名

上級研究員(研究院教授) (https://researchmap.jp/7000007514/)

所属

(ナノ・ライフ創新研究機構)

連絡先

メールアドレス

メールアドレス
k-ohashi@aoni.waseda.jp

住所・電話番号・fax番号

住所
〒162-0041東京都 新宿区 早稲田鶴巻町513
電話番号
03-5286-8341

URL等

研究者番号
50740560

学歴・学位

学位

博士(工学) 論文 名古屋大学 電子デバイス・電子機器

経歴

1996年08月-1998年05月茨城日本電気株式会社MRヘッド部設計専任部長等
1998年05月-2014年03月日本電気株式会社中央研究所主席研究員等
2014年04月-2015年03月早稲田大学ナノ理工学研究機構上級研究員(研究院教授)
2015年04月-早稲田大学ナノ・ライフ創新研究機構上級研究員(研究院教授)
2004年10月-2006年03月理化学研究所フロンティア研究システム 長波長光調査研究チームチームリーダー
2006年04月-2011年05月株式会社半導体先端テクノロジーズプログラムマネージャ(半導体MIRAIプロジェクト光配線テーマリーダー)

所属学協会

日本磁気学会

電子情報通信学会 システムナノ技術に関する特別研究専門委員会委員

応用物理学会

電気化学会

米国電気電子学会

米国材料学会

米国電気化学会

国際電気化学会

委員歴・役員歴(学外)

1999年04月-2005年03月日本応用磁気学会評議員
2001年04月-2002年03月光産業技術振興協会近接場光研究会委員
2001年04月-2003年03月先端加工機械技術振興協会機能性材料の3次元微細加工調査研究会委員
2002年04月-2007年03月製造科学技術センターナノレベル電子セラミックス技術推進委員会 推進委員
2003年04月-2004年03月理化学研究所フロンティア研究システム 戦略検討委員
2003年04月-2006年03月製造科学技術センターナノレベル電子セラミックス技術プロジェクト 運営委員
2005年04月-2006年03月光産業技術振興協会研究企画調整会議委員
2005年04月-2006年03月つくば半導体コンソーシアムNSI準備委員会LSIチップ光配線主査
2006年08月-2010年07月電子情報通信学会シリコンフォトニクス時限研究専門委員会 副委員長
2006年04月-2012年03月電子情報技術産業協会 半導体部会国際ナノテクノロジー会議 準備委員
2007年11月-2008年03月光産業技術振興協会シリコンフォトニクスブレークスルー技術委員会委員
2008年-2014年The Electrochemical SocietyOrganizer, Integrated Optoelectronics
2009年04月-2011年03月つくば半導体コンソーシアム研究交流推進委員会推進委員
2009年04月-2015年03月科学技術振興機構戦略的創造研究推進事業「プロセスインテグレーションによる次世代ナノシステムの創製」領域アドバイザー
2011年04月-2012年03月新機能素子研究開発協会技術企画委員会委員長
2011年04月-2014年03月電子情報技術産業協会センシング技術専門委員
2011年-2012年Materials Research SocietyLead Organizer, MRS 2012 Spring, Symposium L “Group IV Photonics for Sensing and Imaging”
2016年-2017年The Electrochemical SocietyOrganizer, Contemporary Issues and Case Studies in Electrochemical Innovations

受賞

応用物理学会JJAP論文賞

2006年08月授与機関:応用物理学会

タイトル:Si Nano-Photodiode with a Surface Plasmon Antenna

受賞者(グループ):石勉,藤方潤一,牧田紀久夫,馬場寿夫,大橋啓之

表面技術協会技術賞

2006年03月授与機関:表面技術協会

タイトル:高密度用超小型磁気ヘッドの開発研究と実用化

受賞者(グループ):逢坂哲彌,高井まどか,大橋啓之,齋藤美紀子,溝下義文,越川誉生

Demo Day 最優秀賞

2015年10月授与機関:Waseda-EDGE

タイトル:動物生体バランス

受賞者(グループ):大橋啓之,島岡未来子,丸山祐丞,片岡孝介

その他基本情報

2015年08月

「超EDGE人材」認定、早稲田大学EDGE人材育成プログラム

研究分野

キーワード

センシング技術

科研費分類

総合理工 / ナノ・マイクロ科学 / ナノマイクロシステム

複合領域 / 人間医工学 / リハビリテーション科学・福祉工学

情報学 / 人間情報学 / 知能ロボティクス

工学 / 電気電子工学 / 電子デバイス・電子機器

共同研究希望テーマ

生体センシング

希望連携機関:産学連携、民間を含む他機関等との共同研究等

目的:受託研究

研究シーズ

皮膚に優しいケミカル健康モニタ

シーズ分野:ライフサイエンス

研究テーマ履歴

2016年-2019年芸術のための表示素子

研究テーマのキーワード:エレクトロクロミズム

国内共同研究

2014年-2019年生体センシング

研究テーマのキーワード:FETセンサ, センシングシステム

国内共同研究

2010年-2014年赤外線およびマイクロ波によるイメージセンシング

研究テーマのキーワード:赤外線材料, カーボンナノチューブ, RFID

機関内共同研究

2005年-2010年LSIオンチップ光配線

研究テーマのキーワード:LSI配線, 光電変換, 電気光学効果

国内共同研究

2004年-2006年高分解能テラヘルツ波イメージング

研究テーマのキーワード:テラヘルツ波, 近接場

国内共同研究

2002年-2010年表面プラズモン共鳴デバイスの研究

研究テーマのキーワード:表面プラズモン, ナノセラミクス

機関内共同研究

1992年-2002年高磁気モーメント材料およびその磁気デバイスへの適用

研究テーマのキーワード:磁気記録, 磁性材料

国内共同研究

1979年-1998年薄膜磁気ヘッド

研究テーマのキーワード:マイクロマグネティクス, 電気化学

機関内共同研究

論文

Review of Physiological Balance Sensing in an Unobtrusive Manner

Ohashi, Keishi; Kuroiwa, Shigeki; Hideshima, Sho; Nakanishi, Takuya; Osaka, Tetsuya

Electronics and Communications in Japan100(9)p.50 - 552017年09月-2017年09月 

DOIScopus

詳細

ISSN:19429533

概要:© 2017 Wiley Periodicals, Inc. The concept of unobtrusive physiological balance sensing system implementing biosensors is discussed. Biosensors connected with a data system are expected to play a significant role when we extend the sensing objects from body to mind and spirit. Here, we describe the unobtrusive monitoring system using field effect transistor–type sensors and wireless communication devices. Substances subject to the survey of our research will include small ions, immunoglobulins, and hormones.

Industrialization Trial of a Biosensor Technology

Ohashi, Keishi; Osaka, Tetsuya

ECS Transactions査読有り招待有り75(39)p.1 - 92017年01月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:A biosensing system is commercialized based on a concept of physiological balance for healthcare. The addition of low-cost biochemical sensors to the sensing system would help with scientific prescriptions based on contemporary medicine. As a candidate for a low-cost and robust chemical sensor platform, the ion-sensitive field-effect transistor (ISFET) has long been examined. After reviewing past ISFET research, our two approaches for new business trials are discussed. One approach is based on the progressiveness of technology that relies on a public finance with existing big companies. Another approach is a lean startup based on a customer development model for entrepreneurs.

生体バランス物質のさりげないセンシングに関するレビュー

大橋 啓之;黒岩 繁樹;秀島 翔;中西 卓也;逢坂 哲彌

電気学会論文誌. E, センサ・マイクロマシン部門誌査読有り136(8)p.357 - 3612016年08月-2016年08月 

DOICiNiiScopus

詳細

掲載種別:研究論文(学術雑誌)ISSN:13418939

概要:The concept of unobtrusive physiological balance sensing system implementing biosensors is discussed. Biosensors connected with a data system is expected to play a significant role when we extend the sensing objects from body to mind and spirit. Here, we describe the unobtrusive monitoring system using FET-type sensors and wireless communication devices. Substances subject to the survey of our research will include small ions, immunoglobulins, and hormones.

Tag-antenna-based presence sensing using near-field traveling-wave reader antenna

Hattori, Wataru; Ohashi, Keishi; Fukuda, Hiroshi

2014 International Conference on the Internet of Things, IOT 2014p.103 - 1072014年10月-

DOIScopus

詳細

概要:© 2014 IEEE. We propose tag-antenna-based sensing (TABS) for detecting objects and people using a low-cost near-field traveling-wave reader antenna. This technology is inspired by TABS, which enables the use of ordinary far-field radio-frequency identification (RFID) tags as extremely low-cost proximity presence sensor nodes. This allows the sensor nodes to be pervasively deployed in the Internet of Things (IoT); however, frequent reading errors have been a problem in applying practical usage for detecting objects and people. We introduce a low-cost near-field traveling-wave RFID reader antenna that significantly reduces reading errors. We successfully demonstrated the detection of items and human footprints by adopting this technology.

埋もれた技術と埋もれなかった技術

大橋啓之

まぐね8(6)p.288 - 2912013年12月-

link

詳細

概要:技術開発には様々な人が携わり各人ごとのストーリーがある.私は1970年代末から磁気ヘッドの仕事に携わり貴重な経験をさせていただいた.その一部は,今,研究開発に取り組んでいる人のお役に立つこともあると思い,編集部から与えていただいた機会を利用して,これまであまり書かれなかったようなことを中心にまとめてみた.

A Plastic-Based Bolometer Array Sensor Using Carbon Nanotubes for Low-cost Infrared Imaging Devices

Kaoru Narita, Ryosuke Kuribayashi, Ersin Altintas, Hiroko Someya, Kenichiro Tsuda, Keishi Ohashi, Toru Tabuchi, Shuichi Okubo, Masaharu Imazato, Shigeyuki Komatsubara

Sensors and Actuators A195p.142 - 1472013年06月-

DOI

詳細

概要:We have developed an infrared image sensor based on bolometers on a plastic substrate that is potectially ultra low-cost due to its simple structure consisting of mainly organic materials. The bolometer includes a thermal isolator made of a very low thermal conductive polymer (parylene) and a newly developed, highly sensitive (TCR<-2%/K) carbon nanotube thin film thermister. Experiment results showed that the responsivity of our sensor was 138 V/W (at V_B = 2V) and the estimated noise equivalent temperature difference (NETD) at room temperature was 1.1 K. The row-column type 64-pixel (8 x 8) array sensor was gabricated and evaluated while the image of a heat source was focused on the sensor array by a Ge lens. Utilizing the test readout circuit based on switching modules, we obtained the images of the heat source and confirmed the basic operation of IR imaging.

Infrared Optical and Mechanical Properties of Ceramic Coatings Fabricated by Aerosol Deposition

Hiroki Tsuda, Jun Akedo, Shingo Hirose, Keishi Ohashi

Additional Conferences, Microelectronics Research Portal査読有り2012(CICMT)p.406 - 4102012年09月-

DOI

詳細

掲載種別:研究論文(国際会議プロシーディングス)

概要:The posibility and mechanical improvement of the infrared ceramic coatings fabricated on fluoride substrates at room temperature by aerosol deposition (AD) were investigated aiming to optical components for infrared applications and devices. The yttria coating possibility fabricated on barium fluoride substrate by the AD process was found by adjusting one of the deposition conditions The optical and mechanical properties of the fabricated ceramic coatings, which are important in practical applications, were evaluated by transmittance and hardness measurements respectively. The mechanical hardness of the fabricated yttria single coatings was increased to 4 times higher than that of the barrium fluoride substrates. Furthermore, by an additional layer on a barium fluoride substrate, the mechanical properties of the fabricated multi-coatings including an upper yttria layer were improved from that of the single yttria coating on the barium fluoride substrate, retaining the IR transmittance of the single yttria coating at the wavelength of 10 um.

プラズモンを用いた光検出

大橋啓之

表面科学33(4)p.191 - 1962012年04月-

DOI

詳細

概要:This paper describes the recent trend of the surface-plasmon technology for photo-detectors. Surface plasmons create strong near-field on a metal surface thereby reducing the size of the photodetectors. One of the merits for such small detectors is their extremely small electric capacitance. A possible effect of the small capacitance is to bring about the high efficiency of the photo detector circuit at very high frequency. Small photodiodes for on-chip optical interconnection and data communication are reviewed as an example of such applications. A near-field probe for subwavelength THz imaging is also discussed.

InGaAs Nano-Photodiode Enhanced Using Polarization-Insensitive Surface-Plasmon Antennas

Daisuke Okamoto, Junichi Fujikata, and Keishi Ohashi

Japanese Journal of Applied Physics50(12)p.1202012011年11月-

DOI

詳細

概要:We propose InGaAs nano-photodiodes incorporated with a ring-type polarization-insensitive surface-plasmon (SP) antenna, which consists of gold concentric-ring gratings. This ring antenna induces SP resonance for any polarization of incident light and enhances light absorption in a thin InGaAs layer owing to its symmetric structure. Finite-difference time-domain simulation suggest that the carefully designed ring SP antenna can achieve a quntum efficiency of more than 70% for a wide wavelength range and a maximum efficiency of about 80% A 3 dB bandwidth of 21 GHzand an external responsivity of 0.39 A/W were experimentally demonstrated at a 1.55 um wavelength.

Introduction to the Issue on Photonics Packaging and Integration Technologies

S. M. Garcia-Blanco, M. S. Bakir, K. I. Mattheus, K. Ohashi, and F. Horst

IEEE Journal of Selected Topics in Quantum Electronics17(3)p.495 - 4972011年05月-

DOI

詳細

概要:THE GUEST editors of the IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS (JSTQE) are pleased to introduce this issue on Photonic Packaging and Integration Technologies. The topic of this publication represents an area of increased interest in the photonics community and this publication constitutes an important milestone, putting together the latest developments in this growing field.

表面プラズモンをエレクトロニクスで使う

大橋啓之

応用物理招待有り80(2)p.146 - 1502011年02月-

link

詳細

掲載種別:研究論文(学術雑誌)

概要:表面プラズモンは光素子の小型化や高効率化にとって便利な道具になりうる.しかし導入の仕方を間違えると,単に損失源を追加するだけになってしまう.本稿では特に,光とエレクトロニクスの融合を必要とする受光デバイスと発光デバイスへの表面プラズモン技術の適用について,その意味を理解しやすいように動作機構の解説を行う.

表面プラズモンアンテナを利用したSiナノフォトダイオード

藤方潤一,大橋啓之,最上徹

光学40(2)p.98 - 1032011年02月-

link

詳細

掲載種別:研究論文(学術雑誌)

概要:We studied the surface plasmon (SP) resonance effect on Si nano-photodiode (PD) characteristics for future optical interconnections on LSI chips. We designed an SP antenna which converts input light into SP polaritons and localizes light power on the subwavelength area, and developed a very efficient and very fast Si nano-PD which consists of the SP antenna and a small Si absorption layer. We also developed a waveguide-integrated Si nano-PD with an SP antenna for on-chip optical clock distribution. The interfacial periodic nano-scale metal-semiconductor-metal Schottky electrodes were shown to function as an SP optical antenna and also as an optical coupler between a SiON waveguide and a very thin Siabsorption layer. A very high speed response as well as enhanced photoresponsivity was achieved for a 10-m m coupling length. By using this technology, we fabricated a prototype of a large-scale-integration (LSI) on-chip optical clock system and demonstrated 5 GHz of optical clock circuit operation connected with a 4-branching H-tree structure.

Vertical-Coupling Optical Interface for On-Chip Interconnection

Hirohito Yamada, Michinao Nozawa, Masao Kinoshita, and Keishi Ohashi

Optics Express19(2)p.698 - 7032011年01月-

DOI

詳細

概要:We present a vertical-coupling optical interface with a grating coupler for transmitting and receiving optical signals between single-mode optical fibers and microphotonic waveguides with a view to realize on-chip optical interconnection. The optical interface consisting of a simple grating structure with a reflective mirror and an optical power combiner exhibits high optical coupling efficiency and wide tolerance range for the misalignment of optical fibers. The optical interface exhibits high coupling efficiency even if the optical input is almost vertical to the chip surface.

LSIと光配線の融合

大橋啓之

電子情報通信学会知識ベース 知識の森S2群2編ナノエレクトロニクス(8-2ヘテロインテグレーション)p.5 - 62011年01月-

link

詳細

掲載種別:研究論文(その他学術会議資料等)

シリコンフォトニクス

中村隆宏,中村滋,大橋啓之

工業材料58(3)p.46 - 492010年03月-

CiNii

詳細

概要:情報処理量、通信トラフィックの増大に伴い、コンピュータ、サーバ、ネットワーク機器の消費電力増大の抑制など、さまざまな課題が生じている。それに応える技術として注目、期待されているシリコンフォトニクスについて紹介する。

表面プラズモンアンテナとシリコンナノフォトダイオード

大橋啓之

O plus E32(2)p.165 - 1682010年02月-

CiNii

オンチップ光配線導入の課題検討

大橋啓之,鳥居淳,最上徹

電子情報通信学会誌査読有り招待有り93(11)p.933 - 9372010年11月-

link

詳細

掲載種別:研究論文(学術雑誌)

概要:LSIのグローバル配線における消費電力,シグナルインテグリティ等の課題を解決するために光配線を導入する検討を行った.Siフォトニクス,表面プラズモンなどの光技術により,寸法的にはLSI内の機能ブロック間を光配線で結ぶことができ,また配線遅延が低減することを示すことができる.ここでは,最新の光配線技術に基づき光配線のアーキテクチャについて考察した内容を報告する.

Gigahertz-Rate Optical Modulation on Mach-Zehnder PLZT Electro-Optic Modulators Formed on Silicon Substrates by Aerosol Deposition

Takanori Shimizu, Masafumi Nakada, Hiroki Tsuda, Hiroshi Miyazaki, Jun Akedo, and Keishi Ohashi

IEICE Electronics Express6(23)p.1669 - 16752009年12月-

DOI

詳細

掲載種別:研究論文(国際会議プロシーディングス)

概要:In this paper, we have demonstrated 10-GHz operation. Cross-sectional view of ring-resonator PLZT EO modulator structure of a PLZT EO modulator with a ring resonator formed on a silicon substrate for on-chip optical interconnects.

Lanthanum-Modified Lead Zirconate Titanate Electro-Optic Modulators Fabricated Using Aerosol Deposition for LSI Interconnects

Masafumi Nakada, Takanori Shimizu, Hiroshi Miyazaki, Hiroki Tsuda, Jun Akedo, and Keishi Ohashi

Japanese Journal of Applied Physics査読有り48p.09KA062009年09月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:We developed lanthanum-modified lead zirconate titanate (PLZT), electro-optic modulators using aerosol deposition (AD). AD of complex oxide films on Si substrates is achievable, leading to the possible integration of these modulators into semiconductor integrated circuits. Polarization was measured in PLZT optical waveguides that were 1.8 µm in width, and ferroelectric hysteresis loops were observed. Mach–Zehnder interferometer (MZI) PLZT modulators were demonstrated with 500-µm-length electrodes, and the insertion loss of the MZI modulators changed with applied electric field. Their change in insertion loss exhibited hysteresis loops, which were comparable to their ferroelectric ones. We obtained a 2-GHz optical output signal with a relevant bias voltage.

チップ内応用への課題と展望(LSIチップ光配線)

木下雅夫,大橋啓之

エレクトロニクス実装学会誌12(5)p.452 - 4572009年08月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

On-Chip Optical Interconnect

Keishi Ohashi, Kenichi Nishi, Takanori Shimizu, Masafumi Nakada, Junichi Fujikata, Jun Ushida, Sunao Torii, Koichi Nose, Masayuki Mizuno, Hiroaki Yukawa, Masao Kinoshita, Nobuo Suzuki, Akiko Gomyo, Tsutomu Ishi, Daisuke Okamoto, Katsuya Furue, Toshihide Ueno, Tai Tsuchizawa, Toshifumi Watanabe, Koji Yamada, S-I Itabashi, and Jun Akedo

Proceedings of the IEEE査読有り招待有り97(7)p.1186 - 11982009年07月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:We describe a cost-effective and low-power-consumption approach for on-chip optical interconnection. This approach includes an investigation into architectures, devices, and materials. We have proposed and fabricated a bonded structure of an Si-based optical layer on a large-scale integration (LSI) chip. The fabricated optical layer contains Si nanophotodiodes for optical detectors, which are coupled with SiON waveguides using surface-plasmon antennas. Optical signals were introduced to the optical layer and distributed to the Si nanophotodiodes. The output signals from the photodiodes were sent electrically to the transimpedance-amplifier circuitries in the LSI. The signals from the photodiodes triggered of the circuitries at 5 GHz. Since electrooptical modulators consume the most power in on-chip optical interconnect systems and require a large footprint, they are critical to establish on-chip optical interconnection. Two approaches are investigated: 1) an architecture using a fewer number of modulators and 2) high electrooptical coefficient materials.

Photodetector Using Surface-Plasmon Antenna for Optical Interconnect

Keishi Ohashi and Junichi Fujikata

MRS Proceedings1145p.1145 MM01 052009年-

DOI

詳細

掲載種別:研究論文(国際会議プロシーディングス)

概要:We used a surface-plasmon antenna to obtain small photodetectors for LSI on-chip optical interconnection by using near-field light generated by the antenna. Such near-field devices are not constrained by the diffraction limit and they offer an approach to integrated nanoscale photonic devices. A small semiconductor structure is located near the antenna to absorb the nearfield light. This structure can be made as small as the Schottky depletion layer, so the separation between electrodes can be reduced to almost the size of the near-field region. We have demonstrated a “Si nano-photodiode” or plasmon photodiode that uses the near-field localized in a subwavelength region, which is usually relatively large in size because of the long absorption length for Si (~10 μm at a wavelength of ~800 nm). The Si nano-photodiode has a fast impulse response with a full-width at half-maximum of ~20 ps even when the bias voltage is small (~1 V or less). We demonstrated an on-chip optical interconnect chip to operate circuitry in an LSI chip by using waveguide-coupled Si nano-photodiodes.

透明機能性薄膜による超小型高速光素子

中田正文,大橋啓之

セラミックス43(9)p.722 - 7252008年09月-

CiNii

詳細

掲載種別:研究論文(学術雑誌)

概要:本稿ではAD法で形成したPLZT系薄膜の光学特性と電気光学効果を示すとともに,光素子の開発例として,超小型低消費電力型変調器と,ファイバ電界/磁界センサーについて紹介する。

LSI On-Chip Optical Interconnection with Si Nano-Photonics

J. Fujikata, K. Nishi, A. Gomyo, J. Ushida, T. Ishi, H. Yukawa, D. Okamoto, M. Nakada, T. Shimizu, M. Kinoshita, K. Nose, T. Ueno, M. Mizuno, T. Tsuchizawa, T. Watanabe, K. Yamada, S. Itabashi, and K. Ohashi

IEICE Transactions on Electronics査読有り招待有りE91 C(2)p.131 - 1372008年09月-

DOI

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掲載種別:研究論文(学術雑誌)

概要:LSI on-chip optical interconnections are discussed from the viewpoint of a comparison between optical and electrical interconnections. Based on a practical prediction of our optical device development, optical interconnects will have an advantage over electrical interconnects within a chip that has an interconnect length less than about 10mm at the hp32-22nm technology node. Fundamental optical devices and components used in interconnections have also been introduced that are small enough to be placed on top of a Si LSI and that can be fabricated using methods compatible with CMOS processes. A SiON waveguide showed a low propagation loss around 0.3dB/cm at a wavelength of 850nm, and excellent branching characteristics were achieved for MMI (multimode interference) branch structures. A Si nano-photodiode showed highly enhanced speed and efficiency with a surface plasmon antenna. By combining our Si nano-photonic devices with the advanced TIA-less optical clock distribution circuits, clock distribution above 10GHz can be achieved with a small footprint on an LSI chip.

Low-loss Silicon Oxynitride Waveguides and Branches for the 850-nm-Wavelength Region

Tai Tsuchizawa, Toshifumi Watanabe, Koji Yamada, Hiroshi Fukuda, Seiichi Itabashi, Junichi Fujikata, Akiko Gomyo, Jun Ushida, Daisuke Okamoto, Kenichi Nishi, and Keishi Ohashi

Japanese Journal of Applied Physics47(8)p.6739 - 67432008年08月-

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掲載種別:研究論文(学術雑誌)

概要:We developed silicon oxynitride (SiON) waveguides and branches working at around 850 nm wavelength for on-chip optical interconnection. SiON films were deposited by plasma-enhanced chemical vapor deposition (PECVD) and were very transmissive in this wavelength region. The propagation losses of fabricated waveguides were as low as 0.2–0.3 dB/cm. The branches are based on multimode interference (MMI) and exhibited excellent 3 dB characteristics. We also integrated a SiON waveguide with a Si nano-photodiode (PD) with a surface plasmon antenna. A large photocurrent of about 0.1 mA at a coupling length of only 10 µm and a high-speed response of 17 ps were demonstrated for the waveguide-integrated Si nano-PD.

Optical Properties of Pb(Zr,Ti)O3 Films Prepared by Aerosol Deposition

Hiroki Tsuda, Masafumi Nakada, Jun Akedo, and Keishi Ohashi

IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control査読有り55(5)p.97509792008年05月-

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掲載種別:研究論文(学術雑誌)

概要:The optical properties and related band structure of ferroelectric lead zirconate titanate [PZT, Pb(Zr0.6Ti0.4)O3] films prepared on glass substrates at room temperature by aerosol deposition were investigated. The reflectance and transmittance of the PZT films were measured in the wavelength range from UV to near-infrared. The measured optical spectra were analyzed using dielectric function models that describe optical transitions in the band gap region. Optical absorption of the as-deposited PZT films was found to be larger than that of the annealed PZT films in the near-infrared wavelength range. The analyzed results indicated that post-deposition annealing increased the band gap energy of the PZT films, corresponding to a decrease in optical absorption.

Numerical Study of Near-Infrared Photodetectors with Surface-Plasmon Antenna for Optical Communication

Daisuke Okamoto, Junichi Fujikata, Kenichi Nishi, and Keishi Ohashi

Japanese Journal of Applied Physics査読有り47(4)p.2921 - 29232008年04月-

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概要:We propose an InP-based nanoscale metal–semiconductor–metal photodiode with a surface plasmon antenna composed of gold slit arrays for optical communication systems. Resonant modes of the surface plasmon antenna are numerically simulated by the finite-difference time-domain method. The calculation results suggest the advantage of the hybrid mode, which is produced by a Wood–Rayleigh anomaly mode and a vertical cavity mode. The hybrid mode enables a quantum efficiency of more than 50% when using a 250-nm-thick InGaAs absorption layer. A higher efficiency of about 95% can be achieved by combining a surface plasmon antenna with a distributed Bragg reflector consisting of 20 periods of quarter-wave InP/InGaAsP layers.

LSIオンチップ光配線技術

大橋啓之,鈴木信夫,西研一

電子情報通信学会誌査読有り91(3)p.201 - 2062008年03月-

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掲載種別:研究論文(学術雑誌)

概要:光配線は伝送損や遅延が少なくかつ電磁雑音に強いという大きな利点を持つ。しかし,短距離の電気配線を光配線に置き換えるには,電気信号と光信号の変換素子が十分に小さくまたシリコンチップ上に集積可能なプロセスにより製造できるものである必要がある。ここでは,LSI上の光配線を目指して著者らが開発したSiON光導波路と結合したSiナノフォトダイオード,及びナノ結晶粒セラミックスを用いた超小型電気光学変調器を利用したオンチップ光配線について紹介する。

シリコンベース光検出器

大橋啓之,藤方潤一

光学査読有り招待有り37(1)p.21 - 262008年01月-

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掲載種別:研究論文(学術雑誌)

概要:Silicon-based photo-detectors are reviewed with emphasis on silicon photodiodes for on-chip integrated optoelectronics. A variety of device structure have been developed to obtain high-speed and high-efficiency response using silicon with relatively low optical-absorption coefficient. Optical resonators are useful for the high-speed silicon photodiodes to obtain small drift time by reducing the separation between electrodes. Surface-plasmon antenna adds other merits of small electric capacitance and efficient coupling between the waveguide and the active layer of a photodiode. These technologies make silicon photo-detectors operate at high-frequency at more than tens of GHz on a silicon chip.

Waveguide-Integrated Si Nano-Photodiode with Surface-Plasmon Antenna and Its Application to On-Chip Optical Clock Distribution

J. Fujikata, K. Nose, J. Ushida, K. Nishi, M. Kinoshita, T. Shimizu, T. Ueno, D. Okamoto, A. Gomyo, M. Mizuno, T. Tsuchizawa, T. Watanabe, K. Yamada, and K. Ohashi

Applied Physics Express1(2)p.220012008年01月-

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概要:We developed a waveguide-integrated Si nano-photodiode (PD) with a surface plasmon (SP) antenna for on-chip optical clock distribution. The interfacial periodic nano-scale metal–semiconductor–metal Schottky electrodes were shown to function as an SP optical antenna and also as an optical coupler between a SiON waveguide and a very thin Si-absorption layer. Furthermore, a very high speed response of 17 ps as well as enhanced photoresponsivity was achieved for a 10-um coupling length. By using this technology, we fabricated a prototype of a large-scale-integration (LSI) on-chip optical clock system and demonstrated 5GHz of optical clock circuit operation connected with a 4-branching H-tree structure.

A Silicon Photonics Approach for the Nanotechnology Era

K. Ohashi, K. Nishi, T. Shimizu, M. Nakada, J. Fujikata, J. Ushida, A. Gomyo, T. Ishi, K. Nose, M. Mizuno, M. Kinoshita, N. Suzuki, D. Okamoto, H. Yukawa, T. Tsuchizawa, T. Watanabe, K. Yamada, S. Itabashi, and J. Akedo

Technical Digest of IEDM 2007 - IEEE International Electron Device Meeting査読有り招待有りp.787 - 7902007年12月-

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掲載種別:研究論文(国際会議プロシーディングス)

概要:Abstract: With the further scaling of feature size in the nanotechnology era, on-chip optical interconnection will be essential for meeting high-capacity data transmission needs. This paper describes a silicon photonics approach to achieving cost-effective and low-power-consumption on-chip optical interconnects, which includes the use of a small ceramic electro-optical modulator and a Si nano-photodiode coupled with a SiON/SiO2 waveguide, and discusses it in comparison with other approaches.

表面プラズモンを用いたシリコンフォトダイオード

大橋啓之

レーザー研究35(9)p.572 - 5762007年09月-

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掲載種別:研究論文(学術雑誌)

概要:The concept of nano-photodiode, employing surface-plasmon antenna to create sub-wavelength size near-field, is described in relation to silicon photonics. Response time of the prototype silicon nano-photodiode was much shorter (~20 ps) than that of conventional silicon photodiodes (> 1 ns). There are two reasons for the high-speed response: short distance between electrodes (~100 nm) and small electrode area (1 square micrometer). The former is realized by lapping near-field region over depletion region (Schottky barrier) in silicon thereby eliminating time-consuming carrier diffusion process. The latter results in small electrode capacitance and thus reducing response time of the photodiode circuit. This nano-photodiode technology can be applied to other semiconductor materials such as germanium and ternary compound semiconductors.

Ultra Small Magneto-Optic Field Probe Fabricated by Aerosol Deposition

Mizuki Iwanami, Masafumi Nakada, Hiroki Tsuda, Keishi Ohashi, and Jun Akedo

IEICE Electronics Express査読有り4(17)p.542 - 5482007年09月-

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詳細

掲載種別:研究論文(学術雑誌)

概要:The basic performance of a newly developed microscopic magneto-optic probe is described. The probe was fabricated by directly depositing a Bi-substituted yttrium iron garnet [Bi-YIG] film onto the optical fiber edge using aerosol deposition. This fabrication process is inexpensive and simple because there are no complicated procedures such as fine lithography and etching. The film is 125-µm-wide, which is the same as the diameter of a typical single mode fiber, and approximately 10-µm-thick. The 3-dB bandwidth and spatial resolution of the probe were found to be about 3GHz and in the 10-µm order, respectively. Because the developed magneto-optic probe is very tiny and thin, it can be a powerful tool for detailed electrical characterization of densely packaged electronic circuits.

Dielectric Characteristics of PZT Films Prepared by Aerosol Deposition in Millimeter Wave Range

M. Nakada, K. Ohashi, H. Tsuda, E. Kawate and J. Akedo

Proceedings of 16th International Symposium on Application of Ferroelectrics (ISAF 2007), IEEE UFFC査読有りp.528 - 5302007年05月-

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掲載種別:研究論文(国際会議プロシーディングス)

概要:The dielectric properties of lead zirconate titanate [PZT, Pb(Zr0.3Ti0.7)O3] films, prepared by aerosol deposition (AD), were measured in the millimeter wave and THz range. Millimeter wave spectroscopy was applied for measurement in the frequency range from 45 to 80 GHz, and far-infrared Fourier transform measurements from 120 GHz to 20 THz was carried out. Spectroscopic data were analyzed with combination of Debye model with a distribution of Debye relaxation frequencies and harmonic oscillators. We clearly observed that the Debye relaxation took place below several tens GHz for annealed AD films. Combination of millimeter wave and THz spectroscopy was effective measurement technique for dielectric properties of ferroelectric materials at over millimeter wave range.

Optical Properties of Pb(Zr,Ti)O3 Films Prepared by Aerosol Deposition

H. Tsuda, M. Nakada, J. Akedo and K. Ohashi

Proceedings of 16th International Symposium on Application of Ferroelectrics (ISAF 2007), IEEE UFFC査読有りp.829 - 8302007年05月-

DOI

詳細

掲載種別:研究論文(国際会議プロシーディングス)

概要:Optical properties of Ferroelectric lead zirconate titanate [PZT, Pb(Zr,Ti)O3] films prepared on glass substrates at room temperature by aerosol deposition (AD) were investigated. The reflectance and transmittance of PZT films were measured in the wavelength range from ultraviolet to near infrared. Optical absorption of as-deposited films was found to be larger than that of the annealed films in the near infrared wavelength range. The results analyzed using optical models with the measured spectra indicate that the band gap energy of the PZT film increases with annealing.

Optical Characteristics of a PZT Waveguide Fabricated Using Aerosol Deposition for Optical Modulators on LSI Chips

T. Shimizu, M. Nakada, H. Tsuda, J. Akedo, K. Nishi, and K. Ohashi

Proceedings of 16th International Symposium on Application of Ferroelectrics (ISAF 2007), IEEE UFFC査読有りp.831 - 8332007年05月-

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掲載種別:研究論文(国際会議プロシーディングス)

概要:We developed a lead zirconate titanate, Pb(Zr,Ti)O3 (PZT), optical waveguide fabricated using aerosol deposition (AD). The device's optical transmission loss of about 4 dB/mm is comparable with that of AD film. The PZT optical waveguide can meet the requirements of optical modulators for low optical loss.

Ultra Small Fiber-Optic Electric Field Probe Fabricated by Aerosol Deposition

M. Iwanami, M. Nakada, H. Tsuda, K. Ohashi, and J. Akedo

Proceedings of 16th International Symposium on Application of Ferroelectrics (ISAF 2007), IEEE UFFC査読有りp.834 - 8362007年05月-

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掲載種別:研究論文(国際会議プロシーディングス)

概要:We developed a microscopic electro-optic field probe by directly depositing a lead zirconate-titanate [PbZr0.3Ti0.7O3] film onto optical fiber edge using aerosol deposition. Its fabrication process is virtually self-aligning because there are no complicated procedures such as fine lithography and etching. The lateral size of the film pattern is 125 mum, which is the same as the diameter of a typical single mode fiber, and the thickness is approximately 5 mum. An RF electro-optic signal was successfully measured over a microstrip line. The measurable bandwidth of the probe was over 2 GHz. Because it is very tiny and thin, the developed electrooptic probe has great potential for detailed electrical characterization in the microscopic regions of high performance electronic products such as the interconnecting parts between LSI packages and printed circuit boards and spaces among different LSI chips in a package.

Si Nano-Photonics Innovate Next Generation Network Systems and LSI Technologies

Kenichi Nishi, Yutaka Urino, and Keishi Ohashi

NEC Technical Journal2(1)p.67 - 712007年03月-

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掲載種別:研究論文(大学,研究機関紀要)

概要:“Si nanophotonics” controls light by employing a nano-scale structural technology. Featuring state-of-the-art technologies to manufacture LSI chips, Si nanophotonics technology enables impressive miniaturization and achieves low power consumption compared to the conventional optical elements technologies. Optical signal transmission of the LSI chip has not hitherto been realized, however by adopting this Si nanophotonics technology to the elements of an LSI, NEC demonstrated the possibility to significantly improve LSI performance. With this technology NEC is proposing to create new devices to support next generation networks and LSI innovations.

Application of Electronic Devices for Aerosol Deposition Methods

Masafumi Nakada, Toshihiro Kawakami, Mizuki Iwanami, and Keishi Ohashi

NEC Technical Journal2(1)p.76 - 802007年03月-

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掲載種別:研究論文(大学,研究機関紀要)

概要:Oxide materials have superior functional characteristics that are attributed to their versatile structures and chemically stable characteristics. These characteristics are expected to enable their employment as the functional device materials that are required to support the ubiquitous society. The aerosol deposition method is a nanocrystalline film forming method that employs the impact solidification phenomenon of ultra fine particles. This method enables the formation of oxide films onto any type of substrate. NEC and NEC TOKIN are co-developing piezoelectric and optical device products to be used in the aerosol deposition.

Aerosol Deposition on Transparent Electro-Optic Films for Optical Modulators

Masafumi Nakada, Hiroki Tsuda, Keishi Ohashi, and Jun Akedo

IEICE Transactions on Electronics査読有りE90 C(1)p.36 - 402007年01月-

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掲載種別:研究論文(学術雑誌)

概要:Complex thin oxide films with electro-optic (EO) properties are promising for use in advanced optical devices because of their large EO effect. We developed a method of aerosol deposition (AD) for fabricating EO films. The mechanism for AD is based on the solidification by impact of submicron particles onto a substrate. Since particles in AD films preserve their crystalline structure during the formation of film, epitaxial growth is not necessary for exhibiting the EO effect. Highly transparent Pb(Zr, Ti)O3 films, which have acceptable transmittance loss for use as optical devices, were directly deposited on glass substrates by AD. We found the Pb(Zr, Ti)O3 film by AD produced a fairly high EO coefficient (>150 pm/V), approximately 10 times larger than that of LiNbO3. A Fabry-Perot (FP) optical modulator was developed with EO films fabricated by AD. We demonstrated the modulation of optical intensity with an electrical field applied to an EO film made of ferroelectric Pb (Zr, Ti)O3.

Ultra Small Electro-Optic Field Probe Fabricated by Aerosol Deposition

Mizuki Iwanami, Masafumi Nakada, Hiroki Tsuda, Keishi Ohashi, and Jun Akedo

IEICE Electronics Express査読有り4(2)p.26 - 322007年01月-

DOI

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掲載種別:研究論文(学術雑誌)

概要:We developed a microscopic electro-optic field probe by directly depositing a lead zirconate-titanate [PbZr0.3Ti0.7O3] film onto the optical fiber edge using aerosol deposition. Its fabrication process is low-cost and relatively easy because there are no complicated procedures such as fine lithography and etching. The lateral size of the film is 125µm, which is the same as the diameter of a typical single mode fiber, and the thickness is approximately 5µm. An RF electro-optic signal was successfully measured over a microstrip line. The capability for detecting GHz range fields is also shown. Because it is very tiny and thin, the developed electro-optic probe has great potential for detailed electrical characterization in the microscopic regions of high performance electronic products such as the interconnecting parts between LSI packages and printed circuit boards and spaces among different LSI chips in a package.

光配線

大橋啓之

『超LSI製造・試験装置ハンドブック2007年版』,電子材料別冊p.52 - 562006年12月-

Development of Miniturized Thin-Film Magnetic Field Probes for On-Chip Measurement

N. Ando, N. Masuda, N. Tamaki, T. Kuriyama, M. Saito, S. Saito, K. Kato, K. Ohashi, and M. Yamaguchi

Journal of the Magnetics Society of Japan査読有り30(4)p.429 - 4342006年12月-

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掲載種別:研究論文(学術雑誌)

概要:We developed thin-film magnetic field probes with a high spatial resolution aiming to obtain the absolute value of a high-frequency power current on an LSI chip. The spatial resolution was enhanced by miniaturizing the shielded loop coil, which is the detection part of the probe. The minimum outer size of the new coil is 50 x 22 μm. In taking measurements with the new probe over a 60-μm-wide microstrip line used as a device under test (DUT), we found that the probe output decreases by 6 dB at a distance of 40 μm. This value is less than half that of our previous probe, which was around 100 μm. In taking measurements with the new probe over 5-μm-wide microstrip lines used as a DUT, we found that the new probe achieved 10-μm-class high spatial resolution. This value is comparable to the typical width of global power lines on an LSI chip, which ranges from 10 μm to 100 μm. We estimated the configuration of the lines on an LSI chip that would enable the new probe to achieve a spatial resolution high enough to obtain the absolute value of a high-frequency power current on an LSI chip.

部材・デバイスレベルでの機能集積化とナノ構造制御技術

大橋啓之,中田正文

MATERIAL STAGE5(11)p.29 - 332006年11月-

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概要:電気光学材料をLSI上の素子にするためには,薄膜材料として製膜し加工する必要がある。ところが残念なことに,機能性酸化物薄膜の組成および結晶構造を十分精密に制御することはそれほど容易なことではなく,PLZTの場合もバルクセラミクスと同等の電気光学特性を持つセラミクス膜は得られていない。本稿では,明渡氏により開発されたエアロゾルデポジション(AD)法を用いて作成したナノスケールの粒径を持つPZTおよびPLZTセラミクス膜の光学的および電気光学的特性について説明する。

表面プラズモンアンテナを用いたシリコンナノフォトダイオード

西研一,藤方潤一,石勉,大橋啓之

OPTRONICS25(299)p.131 - 1362006年11月-

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概要:表面プラズモンは,金属微粒子を用いた光(波長)の制御技術として,中世の頃より応用され,例えば美しいステンドグラスの着色などとして応用されてきている。近年では,近接場光と結びついた新しい物理現象や,その応用が注目されている。特に,導体の表面近傍に局在した表面プラズモンのモードは,波長として可視域の光から,テラヘルツ域を含む広い波長範囲の電磁波と結合し,表面プラズモンポラリトンとして光を伝搬することが可能である。この表面プラズモンと光の共鳴的な作用は,近接場光学と融合しつつ,計測から半導体デバイスまで,多くの分野で応用されつつある。

Teraherz-Wave Near-Field Imaging with Subwavelength Resolution Using Surface-Wave-Assisted Bow-Tie Aperture

Kunihiko Ishihara, Keishi Ohashi, Tomofumi Ikari, Hiroaki Minamide, Hiroyuki Yokoyama, Jun-ichi Shikata, and Hiromasa Ito

Applied Physics Letters査読有り89(20)p.2011202006年11月-

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掲載種別:研究論文(学術雑誌)

概要:We demonstrate the terahertz-wave near-field imaging with subwavelength resolution using a bow-tie shaped aperture surrounded by concentric periodic structures in a metal film. A subwavelength aperture with concentric periodic grooves, which are known as a bull’s eye structure, shows extremely large enhanced transmission beyond the diffraction limit caused by the resonant excitation of surface waves. Additionally, a bow-tie aperture exhibits extraordinary field enhancement at the sharp tips of the metal, which enhances the transmission and the subwavelength spatial resolution. We introduced a bow-tie aperture to the bull’s eye structure and achieved high spatial resolution (∼λ∕17) in the near-field region. The terahertz-wave near-field image of the subwavelength metal pattern (pattern width=20μm) was obtained for the wavelength of 207μm.

高密度用超小型磁気ヘッドの開発研究と実用化

逢坂哲彌,高井まどか,大橋啓之,齋藤美紀子,溝下義文,越川誉生

表面技術57(10)p.705 - 7112006年10月-

CiNii

Development and Applications of a Si Nanophotodiode with a Surface Plasmon Antenna

Keishi Ohashi, Junichi Fujikata, Tsutomu Ishi, Daisuke Okamoto, Kikuo Makita, and Kenichi Nishi

Proceedings of SPIE査読有り6352p.63521U 1 - 63521U 92006年09月-

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掲載種別:研究論文(国際会議プロシーディングス)

概要:Optoelectronic and electrooptic elements are integrated on VLSI chips. The junction capacitance of a nano-photodiode is extremely low (<10aF), which permits a high load resistance to be used, resulting in higher output voltage at high frequencies. A ceramic Pb(,ZrTi)O3 film with average crystallite diameter below 20nm has a high electro-optical coefficient (>150pm/V) suitable for on-chip modulators. This paper introduces a new approach for realizing high-speed optical interconnects on silicon chips. This concept uses nano-photodiodes on silicon with extremely low parasitic capacitance (less than 10aF) enabling robust communication at very high frequencies. The results demonstrate 5GHz clocking with the promise of up to 20GHz. The authors will also discuss how the silicon nano-photodiode can be used for wavelength-division multiplexing and low-voltage electro-optic modulators for on-chip and off-chip optical communications.

金属微細構造による光透過率増大と光記録への応用

藤方潤一,石勉,柳沢雅広,大橋啓之

レーザー研究招待有り34(5)p.353 - 3572006年05月-

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掲載種別:研究論文(学術雑誌)

概要:We reviewed on the enhanced photon-tunneling and the near-field enhancement effect for a metallic nanoscale aperture with a concentric surface plasmon resonance structure. About two-orders larger light transmission and an enhanced near-field were achieved by optimizing the grating structures. This enhanced near-field was applied to optical recording, and about 100-nm recorded patterns were successfully made on phase change media. This surface plasmon optics would open up the ultra-high-density recording technology.

Optical Interconnect Technologies for High-Speed VLSI Chips Using Silicon Nanophotonics

Keishi Ohashi, Junichi Fujikata, Masafumi Nakada, Tsutomu Ishi, Kenichi Nishi, Hirohito Yamada, Muneo Fukaishi, Masayuki Mizuno, Koichi Nose, Ichiro Ogura, Yutaka Urino, and Toshio Baba

Digest of Technical Papers ISSCC 2006 - IEEE International Solid-State Circuits Conference査読有り49(23.5)p.426 - 4272006年02月-

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掲載種別:研究論文(国際会議プロシーディングス)

概要:Optoelectronic and electrooptic elements are integrated on VLSI chips. The junction capacitance of a nano-photodiode is extremely low (<10aF), which permits a high load resistance to be used, resulting in higher output voltage at high frequencies. A ceramic Pb(,ZrTi)O3 film with average crystallite diameter below 20nm has a high electro-optical coefficient (>150pm/V) suitable for on-chip modulators. This paper introduces a new approach for realizing high-speed optical interconnects on silicon chips. This concept uses nano-photodiodes on silicon with extremely low parasitic capacitance (less than 10aF) enabling robust communication at very high frequencies. The results demonstrate 5GHz clocking with the promise of up to 20GHz. The authors will also discuss how the silicon nano-photodiode can be used for wavelength-division multiplexing and low-voltage electro-optic modulators for on-chip and off-chip optical communications.

Fabry-Perot Optical Modulator Fabricated by Aerosol Deposition

Masafumi Nakada, Keishi Ohashi, Hiroki Tsuda, and Jun Akedo

Proceedings of SPIE査読有り6050p.6050042005年12月-

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掲載種別:研究論文(国際会議プロシーディングス)

概要:We developed a Fabry-Perot (FP) optical modulator with electro-optic (EO) films fabricated by aerosol deposition (AD). We found the ferroelectric Pb(Zr,Ti)O3 film by AD produced a fairly high EO coefficient (>150 pm/V), approximately 10 times larger than that of LiNbO3. Since thick EO films greater than 5 μm can be deposited on a transparent electrode layer or a metallic mirror layer of the FP optical modulator by AD, the FP optical modulator can achieve low capacitance, resulting in high modulation speed. Transmittance spectra of the FP optical modulator coincided with the optical simulation spectra, which indicated that optical scattering in AD films and at the surface/boundary were very small. We demonstrated an optical intensity modulation with applied electric field to EO film of ferroelectric Pb (Zr, Ti)O3. We obtained a 4-dB modulation with 50 V for the 10-μm-thick modulator with dielectric multilayer mirror on a glass substrate.

プラズモン共鳴を用いた近接場光増強Siナノフォトダイオード

大橋啓之,藤方潤一,石勉,西研一,馬場寿夫

応用物理招待有り74(11)p.1453 - 14572005年11月-

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掲載種別:研究論文(学術雑誌)

概要:GHz台で応答する光電変換素子をSi材料主体のCMOS製造プロセスに適合させるために,筆者らは近接場光を利用したナノフォトダイオードを開発した。これは,素子表面に設けたプラズモン共鳴を生じるための金属製のアンテナとナノスケールの微小な受光部とを組み合わせることで,高速性と高感度特性を両立させた光電変換素子である。これら二つの特性が両立可能な受光素子は,VLSIの配線遅延問題解決に向けたチップ内光配線導入に必要である。ナノフォトダイオードは,高機能なエレクトロニクスと高伝送容量の光配線をつなぐ基本素子として期待される技術である。

Excitonic Molecule in a Quantum Dot: Photoluminescence Lifetime of a Single InAs/GaAs Quantum Dot

Shunsuke Kono, Akihiko Kirihara, Akihisa Tomita, Kazuo Nakamura, Junichi Fujikata, Keishi Ohashi, Hideaki Saito, and Kenichi Nishi

Physical Review B査読有り72p.155307 - 1553112005年10月-

DOI

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掲載種別:研究論文(学術雑誌)

概要:Time dependence of the photoluminescence (PL) attributed to the exciton and biexciton in a single InAs∕GaAs quantum dot is investigated at 4.3K with microscopic spectroscopy. Dynamical behavior of the PL decay and the excitation intensity dependence of the exciton and biexciton PL are analyzed by rate equations assuming a cascading recombination from the biexciton to exciton state. The analysis shows that the biexciton lifetime is longer than the exciton lifetime. The estimated ratio of the biexciton lifetime to the exciton lifetime shows a molecular nature of the biexciton in the large quantum dots compared with the exciton Bohr radius.

銀デンドライトにおける表面増強ラマン散乱

柳沢雅広,齋藤美紀子,和田恭雄,大橋啓之,中山景次

表面科学26(9)p.532 - 5362005年09月-

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概要:We have studied an indirect observation for surface plasmons on a variety of nano-structured surfaces by means of surface-enhanced Raman scattering (SERS). In this report, we find the ultrahigh Raman intensity image of the sputtered carbon film on silver dendrites. In order to estimate Raman enhancement on some topographic features, (A) smooth quartz substrates without silver film, (B) smooth quartz substrates with silver film of 300 nm in thickness, (C) silver protrusions of 50 nm in the tip diameter, and (D) silver dendrites were prepared. The maximum Raman intensity of G-band and D-band for the case (D) is 88,000 times larger than that on the flat glass substrates (case(A)). The relative enhancement is 5 times for the case (B) and 400 times for the case (C). In the case (D), some strong Raman scattering points, so called "hot spots" were observed at around the region of 500 nm in the dendrite structure, where the electric field intensity can be enhanced by local plasmons.

Dielectric Characteristics of Ferroelectric Films Prepared by Aerosol Deposition in THz Range

Masafumi Nakada, Keishi Ohashi, and Jun Akedo

Japanese Journal of Applied Physics査読有り44 part 1(9B)p.6918 - 69222005年09月-

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掲載種別:研究論文(学術雑誌)

概要:The dielectric properties of lead titanate [PbTiO3] and lanthanum-modified lead zirconate titanate [PLZT, Pb0.91La0.09(Zr0.65Ti0.35)O3] films, prepared by aerosol deposition (AD), were measured in the frequency range from 100 GHz to 10 THz and in the kHz range. THz time-domain spectroscopy was applied for measurement in the wavenumber range from 4 cm-1 to 70 cm-1, and far-infrared Fourier transform measurements from 70 cm-1 to 700 cm-1 was carried out. We observed that the dielectric constants change smoothly from kHz to THz ranges for the as-deposited PbTiO3 film, indicating that the as-deposited PbTiO3 film exhibits no dielectric dispersion due to domain wall motions. The value of the real part of the dielectric constants in the kHz range increased with annealing, suggesting the appearance of Debye relaxation by annealing. We found that the real parts of the dielectric constants of the AD-PLZT films in the kHz range were one order of magnitude smaller than those of bulk PLZT ceramics, while the dielectric responses in the THz range, which were determined by phonon modes, were comparable to those of bulk ceramic PLZT. The structure of AD-PLZT film, which consists of grains of about 20 nm in size, may affect the motion of polar nanoregions, resulting in a low dielectric response in the low frequency range.

Electro-Optic Properties of Pb(Zr1-xTix)O3 (x = 0, 0.3, 0.6) Films Prepared by Aerosol Deposition

Masafumi Nakada, Keishi Ohashi, and Jun Akedo

Japanese Journal of Applied Physics査読有り44 part 2(34)p.L1088 - L10902005年08月-

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掲載種別:研究論文(学術雑誌)

概要:We measured annealing temperature and the Zr-to-Ti concentration ratio dependence of the electro-optic (EO) effect for highly transparent Pb(Zr1-xTix)O3 [PZT] films more than 1 µm thick, directly deposited on glass substrates by aerosol deposition (AD). X-ray diffraction patterns show that as-deposited AD films have a large strain and lattice distortions, and these affects can be attenuated by increasing annealing temperature. The dielectric constant of AD-PZT films increased with annealing temperature, which is consistent with the X-ray diffraction measurement. The EO effect was enhanced with increasing Zr concentration, and a linear EO coefficient (rc) of 102 pm/V was obtained for the PbZr0.6T0.4O3 film annealed at 600°C, whose composition is near its morphotropic phase boundary. The rc of PbZr0.6T0.4O3 films increased with annealing temperature, and the film annealed at 850°C showed an rc of 168 pm/V. The EO measurements show that AD is a highly promising film-deposition method for optical devices such as EO modulators and optical switches.

Terahertz Near-Field Imaging Using Enhanced Transmission through a Single Subwavelength Aperture

Kunihiko Ishihara, Tomofumi Ikari, Hiroaki Minamide, Jun-ichi Shikata, Keishi Ohashi, Hiroyuki Yokoyama, and Hiromasa Ito

Japanese Journal of Applied Physics査読有り44 part 2(29)p.L929 - L9312005年07月-

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掲載種別:研究論文(学術雑誌)

概要:We demonstrate terahertz (THz) near-field imaging using resonantly enhanced transmission of THz-wave radiation (λ~200 µm) through a bull's eye structure (a single subwavelength aperture surrounded by concentric periodic grooves in a metal plate). The bull's eye structure shows extremely large enhanced transmission, which has the advantage for a single subwavelength aperture. The spatial resolution for the bull's eye structure (with an aperture diameter d=100 µm) is evaluated in the near-field region, and a resolution of 50 µm (corresponding to λ/4) is achieved. We obtain the THz near-field images of the subwavelength metal pattern with a spatial resolution below the diffraction limit.

Strong Influence of Surface Structures on Enhanced Transmission through Subwavelength Hole Arrays

Kunihiko Ishihara and Keishi Ohashi

Japanese Journal of Applied Physics査読有り44 part 2(30)p.L973 - L9752005年07月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:We analyzed the influence of the surface structure on enhanced transmission through subwavelength hole arrays. The hole arrays show extremely large enhanced transmission, but the transmission rapidly decreases as the hole diameter decreases. To clarify the cause of the transmission decrease, we calculated the dimple arrays and found that the diameter of the dimple strongly influences the efficiency of surface plasmon polaritons (SPPs) excitation. We show that the addition of the optimized surface structure to conventional hole arrays for the efficient SPP excitation leads to strongly enhanced transmission in much smaller diameter holes than the incident light wavelength.

Terahertz Wave Enhanced Transmission through a Single Subwavelength Aperture with Periodic Surface Structures

Kunihiko Ishihara, Gen-ichi Hatakoshi, Tomofumi Ikari, Hiroaki Minamide, Hiromasa Ito, and Keishi Ohashi

Japanese Journal of Applied Physics査読有り44 part 2(32)p.L1005 - L10072005年07月-

DOI

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掲載種別:研究論文(学術雑誌)

概要:We demonstrate resonantly enhanced transmission of terahertz (THz) wave radiation (λ~200 µm) through a bull's eye structure (a single subwavelength aperture surrounded by concentric periodic grooves in a metal plate). The phenomenon is caused by the resonant excitation of surface waves, which are known as surface plasmon polaritons in the optical region, generated by the concentric periodic grooves. Strongly enhanced transmission of THz-wave radiation is observed through the single subwavelength circular aperture (diameter d = 100 µm). We also show that introducing the Bragg reflector to the bull's eye structure results in the further increase of the enhanced transmission.

エアロゾルデポジション法による透明電気光学薄膜

中田正文,大橋啓之

マテリアルインテグレーション18(5)p.53 - 592005年05月-

CiNii

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概要:We develop functional oxide films with a large electro-optic (EO) effect for use in very small, low-power EO conversion devices. We have been applied an aerosol deposition (AD) method to form lead oxide films with a perovskite structure. [(Pb,La)(Zr,Ti)O3] films were deposited and systematically studied in terms of optical and EO properties. Transparent films, which have acceptable transmittance loss level for use as optical devices, with large EO effect were obtained. In this report, we summarize a present progress and future prospects on AD method for optical devices application.

Si Nano-Photodiode with a Surface Plasmon Antenna

Tsutomu Ishi, Junichi Fujikata, Kikuo Makita, Toshio Baba, and Keishi Ohashi

Japanese Journal of Applied Physics査読有り44 part 2(12)p.L364 - L3662005年03月-

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掲載種別:研究論文(学術雑誌)

概要:Nano-photodiodes with a subwavelength active area using the optical near-field enhanced by surface plasmon resonance are proposed. We fabricated a Si Schottky photodiode that consists of an active area of 300 nm in diameter and a surface plasmon antenna to generate the carrier within the active area efficiently. The fabricated photodiode shows an increase of the photocurrent by several tenfold compared to that without a surface plasmon antenna. This result suggests an enhanced photogeneration of carriers in a semiconductor via surface plasmon resonance. Such a Si nano-photodiode is a potential high-speed optical signal detector because the opto-electronic conversion process occurs within a subwavelength scale.

Optical and Electro-Optical Properties of Pb(Zr,Ti)O3 and (Pb,La)(Zr,Ti)O3 Films Prepared by Aerosol Deposition Method

Masafumi Nakada, Keishi Ohashi, and Jun Akedo

Journal of Crystal Growth査読有り275(1 2)p.e1275 - e12802005年02月-

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掲載種別:研究論文(学術雑誌)

概要:We deposited high-transparency, lanthanum-modified lead zirconate titanate [PLZT, Pb0.91La0.09(Zr0.65Ti0.35)O3] films, using an aerosol deposition method. The films showed an acceptable scattering loss level for optical devices. The transmittance of the PLZT films increased with the incident angle increase of the PLZT particle beams, because the concentration and size of the impurities, such as pores and PbO particles, decreased with the incident angle. The extinction coefficient of the highly transparent films decreased with the inverse fourth power of the wavelength, which means that the degradation of the film transmittance was due to Rayleigh scattering. This indicates that the sizes of the scattering centers in the films are at least ten times smaller than the measurement wavelength, which is consistent with the TEM observations of the sizes of the crystal grains and impurities. Lead zirconate titanate [PZT, Pb(Zr0.54Ti0.46)O3] films were also successfully deposited with a high transparency, although the PZT bulk ceramics are opaque due to optical anisotropy. Linear and quadratic electro-optical responses were observed for PZT and PLZT films, consistent with the expected bulk properties. The electro-optical coefficients were comparable to those of films deposited using conventional methods, such as the sol–gel and sputtering methods.

Large Optical Transmission through a Single Subwavelength Hole Associated with a Sharp-Apex Grating,

Tsutomu Ishi, Junichi Fujikata, and Keishi Ohashi

Japanese Journal of Applied Physics査読有り44 part 2(4)p.L170 - L1722005年01月-

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掲載種別:研究論文(学術雑誌)

概要:The effect of grating shapes on optical transmission in a bull's eye structure (a single subwavelength hole surrounded by a concentric grating in a metal) is discussed. Finite-difference time-domain calculations predict that a sharp-apex shape gives as high a reflective structure to the propagating surface plasmon polaritons (SPPs) as does a rectangular shape. Fabricated samples with a sharp-apex grating actually show large optical transmission (a factor of 400 greater than that of samples with a single hole) even when the number of corrugations is three. This result indicates that a sharp-apex grating acts as an effective SPP reflector to confine the energy around the hole, resulting in high optical throughput.

Surface Plasmon Enhancement Effect and Its Application to Near-Field Optical Recording

J. Fujikata, T. Ishi, H. Yokota, K. Kato, M. Yanagisawa, M. Nakada, K. Ishihara, K. Ohashi, T. Thio, and R. A. Linke

Transactions of the Magnetics Society of Japan査読有り4(4 2)p.255 - 2592004年11月-

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掲載種別:研究論文(学術雑誌)

概要:We studied on enhanced photon-tunneling and the near-field enhancement effect for a nano-scale aperture with a concentric surface plasmon resonance structure. About two-orders larger light transmission and an enhanced near-field were achieved by optimizing the grating structures. This enhanced near -field was applied to optical recording, and about 100 -nm recorded patterns were successfully made on phase change media. This surface plasmon optics would open up the ultra-high-density recording technology.

Miniaturized thin-film magnetic field probe with high spatial resolution for LSI chip measurement

Ando, Noriaki; Masuda, Norio; Tamaki, Naoya; Kuriyama, Toshihide; Kato, Kunio; Saito, Mikiko; Saito, Shinsaku; Ohashi, Keishi; Yamaguchi, Masahiro

IEEE International Symposium on Electromagnetic Compatibility2p.357 - 3622004年10月-2004年10月 

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ISSN:10774076

概要:It is important to obtain the absolute value of current flowing through each power line on a chip of large-scale integrated (LSI) circuits by measurement because this current on an LSI chip is regarded as conductive noise. We have developed a thin-film magnetic field probe that has spatial resolution high enough to obtain the absolute value of high-frequency power current on an LSI chip. Spatial resolution was enhanced by miniaturizing the shielded loop coil, the detection part of the probe. The outer size of the new coil is 50 × 22 μm. In taking measurements with the new probe over a 60-μm-wide microstrip line used as a device under test (DUT), we obtained a 6-dB decrease point of 40 μm, which indicates the spatial resolution of the probe. This value is comparable to the typical width of power lines on an LSI chip, around 50 μm and is less than half that of our conventional probes, around 90 μm. In measurements with the new probe over an LSI chip, we obtained such a fine magnetic near-field distribution that the magnetic fields generated from the lines on the chip were separated. On-chip decoupling was also confirmed by using the new probe. The new probe enables direct verification of a circuit design for suppressing electromagnetic interference (EMI), while conventional coarse mapping of the magnetic near-field cannot be used to evaluate such conductive noise.

Electro-Optical Properties and Structures of PLZT and PT Films Prepared Using Aerosol Deposition Method

Masafumi Nakada, Keishi Ohashi, and Jun Akedo

Japanese Journal of Applied Physics査読有り43 part 1(9B)p.6543 - 65482004年09月-

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掲載種別:研究論文(学術雑誌)

概要:The electro-optical (EO) properties, film structures and far-infrared spectra were measured for lanthanum-modified lead zirconate titanate [PLZT, Pb0.91La0.09(Zr0.65Ti0.35)O3] and lead titanate [PT, PbTiO3] films, prepared by the aerosol deposition (AD) method. The EO response appeared for AD films annealed at over 500°C, and increased as the annealing temperature increased. Downward shifts of the diffraction peaks, compared with diffraction peak positions of the corresponding to powders, were observed for as-deposited PLZT films in X-ray diffraction patterns of θ-2θ scans. The (200) peaks shifted to higher angles with increasing X-ray incidence angle to the film surface, indicating that the peak shifts were caused by lattice distortion induced by in-plane compressive stress. The (200) peaks shifted to the powder position when annealed at 600°C, which means that the annealing can relax the residual stress. Far-infrared spectroscopy measurements of reflectivity and transmittance were carried out on the PLZT and the PT powders and films, and the IR spectra of PT films were analyzed using the classical damped harmonic oscillator models to determine the oscillation parameters. We observed LO mode degradation and the broadening of the dielectric function peaks on the AD films. The frequencies of the E (1TO) soft-phonon mode of the annealed PT films were shown to have downward shifts of over 20 cm-1, compared with those of bulk ceramics and single crystals, suggesting that the AD may have induced a microscopic lattice degradation in the PT films, which may be responsible for the small EO response.

表面プラズモン共鳴による近接場光の増強

大橋啓之,藤方潤一,石勉,石原邦彦,柳沢雅広,中田正文,横田均

日本応用磁気学会誌査読有り28(6)p.774 - 7802004年06月-

CiNii

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掲載種別:研究論文(学術雑誌)

概要:This paper discusses a technology for enhancing near-field light by controlling surface plasmons. Near-field light is effective for creating a very small heat spot, since it is localized at surface of a material. The resonance of surface plasmons at a metalsurface can control the distribution of the intensity of the nearfield. A concentric ring structure on a silver metal film was investigated as a plasmon-enhancement structure for high-density recording devices. Far-field measurements showed that the transmitted light was enhanced by a factor of 125. A hard-disk-drive-type head with a ring-type surface plasmon ebhancement structure and a hole 100 nm in diameter was fabricated. The head generated near-field light at least a hundred times as strong as that generated by a simple hole 100 nm in diameter.

情報ストレージ高密度化および高速化のための薄膜磁気ヘッドに関する研究

大橋啓之

名古屋大学学位論文2004年06月-

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掲載種別:学位論文(博士)

Electro-Optical Properties of (Pb, La)(Zr, Ti)O3 Films Prepared by Aerosol Deposition Method

Masafumi Nakada, Keishi Ohashi, Maxim Lebedev, and Jun Akedo

Japanese Journal of Applied Physics査読有り42 part 1(9B)p.5960 - 59622003年09月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:The electro-optical (EO) properties, film structures and far-infrared spectra were measured for lanthanum-modified lead zirconate titanate [PLZT, Pb0.91La0.09(Zr0.65Ti0.35)O3] and lead titanate [PT, PbTiO3] films, prepared by the aerosol deposition (AD) method. The EO response appeared for AD films annealed at over 500°C, and increased as the annealing temperature increased. Downward shifts of the diffraction peaks, compared with diffraction peak positions of the corresponding to powders, were observed for as-deposited PLZT films in X-ray diffraction patterns of θ-2θ scans. The (200) peaks shifted to higher angles with increasing X-ray incidence angle to the film surface, indicating that the peak shifts were caused by lattice distortion induced by in-plane compressive stress. The (200) peaks shifted to the powder position when annealed at 600°C, which means that the annealing can relax the residual stress. Far-infrared spectroscopy measurements of reflectivity and transmittance were carried out on the PLZT and the PT powders and films, and the IR spectra of PT films were analyzed using the classical damped harmonic oscillator models to determine the oscillation parameters. We observed LO mode degradation and the broadening of the dielectric function peaks on the AD films. The frequencies of the E (1TO) soft-phonon mode of the annealed PT films were shown to have downward shifts of over 20 cm-1, compared with those of bulk ceramics and single crystals, suggesting that the AD may have induced a microscopic lattice degradation in the PT films, which may be responsible for the small EO response.

Enhanced Nonlinear Optical Conversion from a Periodically Nano-Structured Metal Film

Ajay Nahata, Richard A Linke, Tsutomu Ishi, and Keishi Ohashi

Optics Letters査読有り28(6)p.423 - 4252003年03月-

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掲載種別:研究論文(学術雑誌)

概要:We demonstrate an ∼10^4 increase in conversion efficiency for optical second-harmonic generation (SHG) from a periodically nanostructured metal structure consisting of a single subwavelength aperture in a thin silver film surrounded by a set of concentric surface grooves. The forward-transmitted second-harmonic radiation from this structure is measured relative to that from an identical aperture with no surrounding surface periodicity. We explain the observed SHG enhancement quantitatively in terms of a measured 120× increase in the strength of the fundamental radiation in the vicinity of the aperture resulting from the periodic nanostructuring.

The Electrodeposition Conditions of CoNiFe Films, Crystal Structure, and Evaluation of Magnetic Moments

M. Saito and K. Ohashi

ECS Proceedings; Magnetic Materials, Processes, and Devices VIIPV 2002-27p.241 - 2532003年-

Influence of Carbon Inclusion on Properties of Electrodeposited CoNiFeMo Thin Films

Tokihiko Yokoshima, Asako Kawashima, Takuya Nakanishi, Tetsuya Osaka, Mikiko Saito, and Keishi Ohashi

ECS Proceedings; Magnetic Materials, Processes, and Devices VIIPV 2002-27p.365 - 3752003年-

Evaluation of the Crystal Structure, Film Properties, and Bs of Electroplated CoNiFe Films

M. Saito, N. Ishiwata, and K. Ohashi

Journal of the Electrochemical Society査読有り149(12)p.C642 - C6472002年12月-

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掲載種別:研究論文(学術雑誌)

概要:The factors which affect the saturation magnetic flux density (Bs) of electroplated CoNiFe films were investigated and the results are reported. The Fe composition, the ratio of body-centered cubic (110) to face-centered cubic (111) peak intensity (Rb), and the density were found to affect the Bs of the films. The Bs increased when the Rb, Fe composition, and the density were increased; we found that a larger grain size and fewer impurities produced a higher density film. It was determined that the suppression of the impurities and the increased grain size led to the high film density and high Bs.

ナノストレージ技術とめっき:Co-Fe-Niの巨大な磁気モーメント

大橋啓之

電気化学および工業物理化学査読有り招待有り70(11)p.884 - 8872002年11月-

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掲載種別:研究論文(学術雑誌)

概要:HDD 用ヘッドの磁気コア材料には長い間パーマロイ(Ni-Fe)めっき膜が使われてきた.最近著者らが開発したCo-Fe-Ni めっき膜は,パーマロイの2倍の飽和磁化を 持つ新しい材料として最先端のHDD に使われ始めている.ここでは,このCo-Fe-Ni を中心として,ソフト磁性材料のめっき条件と磁気モーメントなどの磁気物性との関係についての最近の研究結果を紹介する.

TMRヘッド

大橋啓之

計測と制御40(6)p.4652002年06月-

CiNii

Read/Write Characteristics of Focused-Ion-Beam-Etched Heads for Perpendicular Magnetic Recording Media

S. Tsuboi, H. Matsutera, T. Ishi, N. Ishiwata, and K. Ohashi

Journal of Magnetism and Magnetic Materials査読有り235(1 3)p.375 - 3812001年10月-

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掲載種別:研究論文(学術雑誌)

概要:The read/write characteristics for perpendicular magnetic recording media of focused-ion-beam (FIB)-etched recording heads were investigated. It was found that the trailing edge of an FIB-etched head produces a higher gradient in the magnetic field perpendicular to the medium than a head which has not been etched. The signal-to-noise ratio of the medium increased with the FIB-etched write gap. A high-Bs and thin pole increased the magnetic field's gradient in the perpendicular direction, resulting in excellent read/write characteristics.

Read Performance of Tunneling Magneto-Resistive Heads

K. Ishihara, M. Nakada, E. Fukami, K. Nagahara, H. Honjo, and K. Ohashi

IEEE Transactions on Magnetics査読有り37(4)p.1687 - 16902001年07月-

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掲載種別:研究論文(学術雑誌)

概要:We discuss the read performance, including the off-track performance and noise characteristics, of TMR heads. A vortex-like sense current field in TMR heads creates insensitive zones in the free layer and affects the output voltage and effective read width. The 1/f noise in the MHz-order frequency range was observed. To achieve a low-noise TMR head for high-density recording with small junction area, a high-quality thin barrier is a key to obtaining low 1/f noise, as well as small R/spl middot/A products to reduce the shot noise.

Structural and Magnetic Properties of High Saturation Induction CoNiFe Electroplated Films

N. Ohshima, M. Saito, K. Ohashi, H. Yamamoto, and K. Mibu

IEEE Transactions on Magnetics査読有り37(4)p.1767 - 17692001年07月-

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掲載種別:研究論文(学術雑誌)

概要:The structure and saturation induction (Bs) of Co90-xNi10Fex (8<=x<=40) electroplated films have been studied with a view to their use as high-density write-core materials. The Bs of the films were slightly larger than those of CoNiFe powders and were increased into the 1.8 to 2.1 T range by controlling the Fe composition and the amount of bcc phase. The latter was achieved by controlling the plating conditions, i.e., the current density and bath temperature. The hyperfine field of the films was about 34 T, slightly larger than that of the powders (33 T), suggesting that their magnetic moments were slightly larger than those of equivalent bulk alloys. The Bs values were increased by increases of the amount of bcc phase relative to the equilibrium phase with increasing the magnetic moments. A band calculation showed that the bcc phase had a larger magnetization than the fcc phase although the difference between the total energies of the two phases was fairly small. This confirmed our results.

Thermal Asperity of TMR Heads for Removable Disk Drives

Keishi Ohashi, Akinobu Sato, Kunihiko Ishihara, Takao Matsubara, Tsutomu Mitsuzuka, Hisanao Tsuge, and Nobuyuki Ishiwata

IEEE Transactions on Magnetics査読有り37(4)p.1919 - 19212001年07月-

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詳細

掲載種別:研究論文(学術雑誌)

概要:The thermal asperity of the tunneling magnetoresistive (TMR) head was studied using Zip-type flexible media, and compared with that of the anisotropic magnetoresistive (AMR) head. The examined head had a shielded structure with the TMR element close to the air bearing surface. Nevertheless, it generated relatively small thermal asperity even when the mechanical spacing between the head and medium was less than 20 nm, at which large and frequent thermal asperity was observed when the AMR head was used. Such relatively small thermal asperity of the TMR head Is attributed mainly to the small low-temperature coefficient of the electrical resistivity of the TMR element.

高速・大容量磁気ヘッド技術

石綿延行,本庄弘明,藤方潤一,石勉,中田正文,大橋啓之

NEC技報54(6)p.41 - 442001年06月-

詳細

掲載種別:研究論文(大学,研究機関紀要)

概要:ネットワーク社会を前進させる上で,データセンタに代表される高速で大容量なストレージシステムは,ますますその重要性を増し市場を拡大させています。これを実現するためのストレージデバイスとして,ハイエンド高速HDDは中心的な役割を果たしてきています。HDDは近年,ディスク回転数の高速化と,GMRヘッドというコア技術により,データ転送速度においては年率40%,記憶容量としては実に年100%の勢いで性能を向上させてきました。この性能を今後も継続的に向上させるために,NECでは世界に先駆けて,高速高密度磁気記録再生を実現するコア技術として,超小型CoNiFe記録,TMR再生による磁気ヘッド技術を開発しました。

超小型コアヘッドによる高周波磁気記録

大橋啓之,石綿延行,本庄弘明,石勉,野中義弘,鳥羽環,斉藤信作

日本応用磁気学会誌査読有り25(6)p.1316 - 13212001年06月-

CiNii

詳細

掲載種別:研究論文(学術雑誌)

概要:Magnetic recording heads with a high-moment Co-Ni-Fe core are examined. Saturation flux density Bs of the core is 2.0 T. Good high-frequency write performance up to 500 MHz is obtained by reducing the core length to less than 10 um. Excellent write performance of narrow (0.55 um) pole tip head is also confirmed with high coercivity of a 480 kA/m (6000 Oe) medium. Finally, simulation results for higher-density and higher-speed magnetic recording are discussed.

Low Resistance Magnetic Tunneling Junctions and Their Interface Structures

J. Fujikata, T. Ishi, S. Mori, K. Matsuda, K. Mori, H. Yokota, K. Hayashi, M. Nakada, A. Kamijo, and K. Ohashi

Journal of Applied Physics査読有り89(11)p.7558 - 75602001年06月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:Effects of interface structure and oxidation state were studied in stacked magnetic tunnel junction (MTJ) structures with top and bottom antiferromagnetic layers to obtain optimum resistance and high tunneling magnetoresistance (TMR) ratios for read heads. The roughness of the NiFe surface and the Al coverage were significantly improved by introduction of O2 surfactant gas on the Ta-seed-layer surface, which increased TMR ratios of the MTJ with low resistance area (RA) products of less than 10 Ω μm2. Furthermore, it was found that avoidance of Ni oxidation and Co oxidation at the tunnel barrier interface is essential to obtaining high TMR ratios, and that a good Al coverage and Fe–oxide formation may enhance TMR ratios when Fe-rich magnetic materials are used. For the top-type and bottom-type structures, a TMR ratio of 12%–17% with RA products of 6–7 Ω μm2 was obtained, which provides sufficient performance for read heads.

NETs連載講座 超高記録密度HDDの実現技術;100Gビット/(インチ)2超のHDDを実現するヘッド技術

大橋啓之

日経エレクトロニクス(791)p.215 - 2272001年03月-

CiNii

詳細

概要:面記録密度100Gビット/(インチ)2以上の実現に向けた新しいヘッド技術を紹介する。次世代ヘッドとして注目を集める飽和磁束密度の高い磁性材料を用いた記録ヘッドとTMRヘッドの試作結果を開発者自らが解説する。垂直記録方式への応用やTMRヘッドの次を担う要素技術にも言及する。

The Effect of Preparation Conditions on The Magnetic Properties of Electroplated High-Bs CoNiFe Films

M. Saito, N. Ishiwata, and K. Ohashi

ECS Proceeding; Magnetic Materials, Processes, and Devices VI査読有りPV 2000-29p.185 - 1962001年-

詳細

掲載種別:研究論文(国際会議プロシーディングス)

概要:We have developed a high-speed, high-density recording head by using an electroplated CoNiFe film having a saturation induction (Bs) of 2 T. The film has a bcc-fcc mixed crystallographic phase, which provides it with good soft magnetic properties. We investigated the relationship between the properties of CoNiFe films and the consitions of their electrodeposition, and we found that a low coercivity (Hc) of less than 0.16 kA/m (2 Oe) and a low magnetostriction were obtained when the bcc ratio in the films was decreased. We also found that Bs increased with an increase in the bcc/fcc phase ratio in the filoms. Electroplating at a bath temperature of less than 20 degree C and with a high current density (15 mA/cm2) was effective in increasing the bcc/fcc phase ratio in the film.

Co-Ni-Fe Write Heads with a 10-μm Yoke Length for High-Speed Recording

Y. Nonaka, H. Honjo, T. Toba, S. Saito, T. Ishi, M. Saito, N. Ishiwata, and K. Ohashi

IEEE Transactions on Magnetics査読有り36(5)p.2514 - 25162000年09月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:We have developed a Co-Ni-Fe write head with a short yoke length for high-speed recording. By reducing the yoke length to 9.5 um, the eddy currents induced in a yoke with a relatively low resistivity (0.2 micro Ohms/m) were reduced. The head of this short yoke had good write performance for a medium with a coercivity of 400 kA/m (5000 Oe) at frequencies up to 250 MHz (the overwrite less than -30 dB, and nonlinear transition shift less than 7%.

Low-Resistance Tunnel Magnetoresistive Head

K. Ohashi, K. Hayashi, K. Nagahara, K. Ishihara, E. Fukami, J. Fujikata, S. Mori, M. Nakada, T. Mitsuzuka, K. Matsuda, H. Mori, A. Kamijo, and H. Tsuge

IEEE Transactions on Magnetics査読有り36(5)p.2549 - 25532000年09月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:A tunnel magnetoresistive (TMR) head with a low resistance of about 30 Ohms and effective track width of 1.4 um was fabricated using an in situ natural oxidation (ISNO) technique. Its read-output was almost the same as that expected from test elements at the wafer level. We found no large difference in noise voltages between TMR head and GMR head when their resistance was about 30 Ohms. A very low-resistivity TMR element with a resistance-area product of 14 Ohms um2 and a fairly high Delta R/R of 14% was also developed using ISNO. A signal-to-noise ratio consideration suggests that such low resistance is a key to TMR heads for high recording densities.

高Bs記録ヘッドによる高保磁力媒体への記録特性

野中義弘,鳥羽環,斉藤信作,本庄弘明,石勉,石綿延行,大橋啓之

日本応用磁気学会誌査読有り24(4 2)p.355 - 3582000年04月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:A magnetic recording head with a Co-Ni-Fe/Ni-Fe composite write pole was designed. The saturation induction Bs of Co-Ni-Fe is 2 T. In a computer simulation of a 3D static magnetic field, a recording head with Co-Ni-Fe films on both sides of a write gap generated a longitudinal write field of 9.9 kOe at a magnetic spacing of 40 nm from the write gap. The write characteristics of the recording head with the dual high-Bs structure designed above was tested for media with high coercivities of 4.5 to 7 kOe. The overwrite performance is over 30 dB for a medium with high coercivity of 7 kOe. Straight patterns of magnetic transitions written on the medium with a coercivity of 7 kOe were observed by using a magnetic force microscope (MFM). On the other hand, bends were found in the track-edges of magnetic transitions written on a medium with a coercivity of 4.5 kOe. This indicates that the recording head generated too large a write field for the medium with a coercivity of 4.5 kOe.

Mo共析による高Bs高r CoNiFe系電析薄膜の作成

曽川禎道,川島麻子,横島時彦,中西卓也,南孝昇,逢坂哲彌,大橋啓之

日本応用磁気学会誌査読有り24(4 2)p.699 - 7022000年04月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:Addition of a complexing agent and/or Na2MoO4 to the bath was investigated with a view to increasing the resistivity of CoNiFe soft magnetic thin films. Results showed that the electrical resistivity of CoNiFe thin films was increased by addition of a complexing agent such as sodium tartrate and sodium citrate. These films contained a small amount of carbon of 1 to 2 at%. The addition of Na2MoO4 also resulted in an increase in resistivity of CoNiFe thin films. This Co59Ni12Fe26Mo1C2 thin film had the following properties: Bs = 1.8 T, Hc = 1.6 Oe, ρ = 129 μΩcm.

Ultra-High-Density Magnetic Information Storage Technologies

K. Ohashi, N. Ishiwata, M. Yanagisawa, A. Sato, S. Tsuboi, and H. Hokkyo

NEC Research & Development41(2)p.160 - 1652000年02月-

詳細

掲載種別:研究論文(大学,研究機関紀要)

概要:Three approaches used to acheve ultra-high-density recording of 100 Gbit/in2 are discussed. In order to overcome the thermal fluctuation problem of recorded patterns, a write head with Co-Ni-Fe pole has been developed. The Co-Ni-Fe pole generates the strongest write field. The head wrote well in media with a coercivity of 7 kOe, which is sufficiently large for ultra-high-density recording. A narrow gap Co-Ni-Fe head for perpendicular recording has also been developed. The experimental results on contact recording and a double-layer perpendicular medium are also discussed.

Purity of Films and Performance of Recording Heads

Keishi Ohashi, Mikiko Saito, Hiroaki Honjo, Tamaki Toba, Yoshihiro Nonaka, and Nobuyuki Ishiwata

ECS Proceedings; Electrochemical Technology Applications in Electronics III査読有りPV 99-34p.241 - 2492000年-

詳細

掲載種別:研究論文(国際会議プロシーディングス)

概要:The effect of impurities in CoNiFe films and the performance of CoNiFe pole heads were investigated. Electrodeposition of CoNiFe from a bath containing no sulfur-containing additives (SCAs) produced a pole material with excellent magnetic properties. CoNiFe pole heads generated a strong field of about 10 kOe in a recording medium. These heads did not experience large write instability because of the near-zero magnetostriction of the CoNiFe films. Besides producing good magnetic properties, removal of SCAs from the bath improved corrosion resistance. Moreover, annealing after deposition played an important role in controlling magnetic properties and corrosion resistance. Corrosion resistance was inferior if the film was deposited at a relatively low current density, even when a non-SCA bath was used. However, corrosion resistance of that film was improved by annealing. This improved corrosion resistance suggests that the imperfections associated with adsorption and evolution of hydrogen may play important roles in the corrosion mechanism.

Write Performance of Heads with a 2.1-Tesla CoNiFe Pole

Keishi Ohashi, Noboru Morita, Tadaaki Tsuda, and Yoshihiko Nonaka

IEEE Transactions on Magnetics査読有り35(5)p.2538 - 25401999年09月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:We examined the write performance of heads with a CoNiFe/NiFe composite write pole. The saturation induction Bs of the CoNiFe film was 2.1 T (21 kG). The CoNiFe layer thickness was typically 0.5-0.6 um, and the rest of the write pole was composed of Ni80Fe20. The dual high Bs layer structure with the CoNiFe films on both sides of the write gap gave excellent overwrite performance. It was over 30 dB for a medium that had a high coercivity of 560 kA/m (7.0 kOe).

Corrosion properties of electroplated CoNiFe films

Saito, M.; Yamada, K.; Ohashi, K.; Yasue, Y.; Sogawa, Y.; Osaka, T.

Journal of the Electrochemical Society146(8)p.2845 - 28481999年08月-1999年08月 

DOIScopus

詳細

ISSN:00134651

概要:Electroplated CoNiFe films with a saturation flux density as high as 2.1 T are potentially useful in high-density magnetic recording heads. We found that films electroplated at a high current density (15 mA/cm2) from a bath without saccharin have a sufficient anodic pitting-corrosion potential (-65 mV). We also found that the pitting-corrosion potential of films electroplated under a low current density (5 mA/cm2) from saccharin-free baths have anodic pitting-corrosion potentials of less than -300 mV. However, the corrosion resistance improved after annealing at temperatures above 100°C. The crystal-grain boundaries in the as-plated film that electroplated under a low current density from saccharin-free baths are not clear (i.e., that the phase is amorphous). But the crystal grain boundaries in the annealed film are clear. Films electroplated from baths containing saccharin also have anodic pitting-corrosion potentials of less than -300 mV. Their corrosion resistance did not improve when they were annealed at 250°C. The deterioration of the corrosion resistance is attributed to the defects that increase the face-centered cubic (111) lattice constant. One of the most important characteristics of a highly corrosion-resistant CoNiFe film is fine crystal structure with very few defects.

Influence of crystalline structure and sulfur inclusion on corrosion properties of electrodeposited CoNiFe soft magnetic films

Osaka, Tetsuya; Takai, Madoka; Sogawa, Yoshimichi; Momma, Toshiyuki; Ohashi, Keishi; Saito, Mikiko; Yamada, Kazuhiko

Journal of the Electrochemical Society146(6)p.2092 - 20961999年06月-1999年06月 

DOIScopus

詳細

ISSN:00134651

概要:The corrosion resistance of soft magnetic films is an important property to be considered in the manufacture of magnetic devices. We investigated the corrosion behavior of the electrodeposited CoNiFe film with desired soft magnetic properties by varying the crystalline structure and the amount of included sulfur. The corrosion property in 2.5% NaCl solution depends largely on the sulfur content and also on the structure of the film. Although the CoNiFe film contains more than 13 atom % Fe, the film of face-centered to body-centered cubic mixed crystals exhibits a high anticorrosion property because of very small grain size with essentially no sulfur inclusion (<0.1 atom %).

高Bs-CoNiFe電析膜の軟磁気特性に及ぼす成膜条件の影響

曽川禎道,水谷聡,門間聰之,逢坂哲彌,齋藤美紀子,大橋啓之,山田一彦

日本応用磁気学会誌査読有り23(4 part 2)p.1405 - 14081999年04月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:Electrodeposited CoNiFe soft magnetic films with high Bs were investigated for use as head core materials. It was found that a film consisting of an fcc phase structure with low Fe content has low magnetostriction of +2∼+6 × 10-6. When the film composition was fixed at Co62Ni12Fe26, the operating conditions fElectrodeposited CoNiFe soft magnetic films with high Bs were investigated for use as head core materials. It was found that a film consisting of an fcc phase structure with low Fe content has low magnetostriction of +2∼+6 × 10-6. When the film composition was fixed at Co62Ni12Fe26, the operating conditions for obtaining soft magnetic properties were optimized It was found that soft magnetic thin films composed of fine crystals 10-15 nm in diameter were obtained in conditions of low pH (< 3.0) and low current density (< 40 mAcm-2). In these operating conditions, a current efficiency of less than 80% with hydrogen evolution during the CoNiFe deposition was confirmed to be one of key factors for obtaining soft magnetic CoNiFe films with a suitably high Bs value. A typical Co62Ni12Fe26 film had the following properties. Bs=2.0 T, Hc=1.7 Oe, and λs=+4.9×10-6. or obtaining soft magnetic properties were optimized It was found that soft magnetic thin films composed of fine crystals 10-15 nm in diameter were obtained in conditions of low pH (< 3.0) and low current density (< 40 mAcm-2). In these operating conditions, a current efficiency of less than 80% with hydrogen evolution during the CoNiFe deposition was confirmed to be one of key factors for obtaining soft magnetic CoNiFe films with a suitably high Bs value. A typical Co62Ni12Fe26 film had the following properties. Bs=2.0 T, Hc=1.7 Oe, and λs=+4.9×10-6.

超高密度記録磁気ヘッドコア用新磁性体を開発

大橋啓之, 逢坂哲彌

エレクトロニクス(10)p.102 - 1041998年10月-

詳細

概要:最近のハードディスク装置(HDD)の記録密度は3G(ギガ)ビット/in2を超え始めており,西暦2000年には10Gビット/in2が実現されようとしています。このように高い記録密度を実現するためには、低ノイズでありかつ磁化データが熱ゆらぎに強い高保磁力媒体に書き込むことのできる磁気ヘッドが必要です。ここでは、書込み用ヘッドの動向および高い飽和磁束密度(Bs)を持つ磁気コア材料の必要性について解説します。また、世界最高のBsを持つ磁気コア材料であるCoNiFe膜についてその開発の経緯の一端に触れます。

電気めっき法による高飽和磁束密度ソフト材料の開発とMRヘッドへの応用

逢坂哲彌,高井まどか,大橋啓之

日本応用磁気学会誌22(7)p.1182 - 11881998年08月-

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New Soft Magnetic CoNiFe Plated Films with High Bs = 2.0-2.1 T

Tetsuya Osaka, Madoka Takai, Katsuyoshi Hayashi, Yoshimichi Sogawa, Keishi Ohashi, Yoshihiko Yasue, Mikiko Saito, and Kazuhiko Yamada

IEEE Transactions on Magnetics査読有り34(4)p.1432 - 14341998年07月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:A CoNiFe film with saturation magnetic flux density (Bs) greater than 2.0 tesla (T) has been prepared for the first time as a soft magnetic film; the coercivity (Hc) of the film is less than 160 A/m (2.0 Oe). This success was achieved by formulating a new plating bath and operating conditions to form fine grains. The film has a low Hc of less than 160 A/m, a low saturation magnetostriction (ls) of approximately 10-6, and a high Bs of 2.0-2.1 T. The present invention is expected to contribute to accelerating the development of not only the technology of high-density magnetic recording but also the field of magnetic materials in general.

A soft magnetic CoNiFe film with high saturation magnetic flux density and low coercivity

Osaka, Tetsuya; Takai, Madoka; Hayashi, Katsuyoshi; Ohashi, Keishi; Saito, Mikiko; Yamada, Kazuhiko

Nature392(6678)p.796 - 7981998年04月-1998年04月 

DOIScopus

詳細

ISSN:00280836

概要:Magnetic materials are classed as 'soft' if they have a low coercivity (the critical field strength H(c) required to flip the direction of magnetization). Soft magnetic materials are a central component of electromagnetic devices such as step motors, magnetic sensors, transformers and magnetic recording heads. Miniaturization of these devices requires materials that can develop higher saturation flux density, B3, so that the necessary flux densities can be preserved on reducing device dimensions, while simultaneously achieving a low coercivity. Common high-B3 soft magnetic films currently in use are electroplated CoFe-based alloys, electroplated CoNiFe alloys, and sputtered Fe-based nanocrystalline and FeN films. Sputtering is not suitable, however, for fabricating the thick films needed in some applications, for which electrochemical methods are preferred. Here we report the electrochemical preparation of a CoNiFe film with a very high value of B(s) (2.0-2.1 T) and a low coercivity. The favourable properties are achieved by avoiding the need for organic additives in the deposition process, which are typically used to reduce internal stresses. Our films also undergo very small magnetostriction, which is essential to ensure that they are not stressed when an external magnetic field is applied (or conversely, that external stresses do not disrupt the magnetic properties). Our material should find applications in miniaturization of electromechanical devices and in high-density magnetic data storage.

An Advanced Magneto-Resistive Head with A Newly Developed Electroplated High-Bs Write Pole

Hiroshi Gokan, Kaoru Toki, Keishi Ohashi, Takao Maruyama, Mitsuo Abe, and Susumu Mizuno

NEC Research & Development39(3)p.309 - 3161998年03月-

詳細

掲載種別:研究論文(大学,研究機関紀要)

概要:A Magneto-Resistive (MR) head with a newly developed electroplated high-Bs CoNiFe write pole has been developed for use in Hard Disk Drives (HDDs). The electroplated film has the leading high saturation magnetization (Bs) of 2.1 T to provide a soft magnetic film suitable for the write element in MR heads. Introducing high-Bs films for the write-pole improves overwrite performance in 2,950 Oe high-Hc media by 17.7 dB. For the read element, a large exchange coupling NiMn film has been developed. This film provides an excellent biasing scheme for maximum asymmetry change during repeated read/write operations is improved by optimizing the write-core design and the magnetostriction of the magnetic layers as well as by optimizing the biasing scheme. Altitude sensitivity, which is defined as the change in flying height when atmospheric pressure is reduced from 1.0 to 0.7 atm, is supressed from 11 to 5 nm by modifying the ABS (Air-Bearing Surface) design to increase the negative pressure induced. Typical read/write characteristics of MR heads with high-Bs write pole designed for 2.6 Gb/in^2 areal-density recording are described. An output-signal voltage of 400 uV/um with excellent signal stability has been obtained.

MR素子における出力安定性のMR縦バイアス接合形状依存性に関する検討

苅屋田英嗣,倉科晴次,池澤延幸,森田昇,小田淳,嶋林清孝,大橋啓之,土岐薫,浦井治雄

日本応用磁気学会誌査読有り21(4 part 2)p.253 - 2561997年04月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:Hysteresis and baseline shift are studied in soft-adjacent-layer-biased MR sensors with abutted quasi-permanent magnetic bias. The magnet consists of NiFe/NiMn exchange-coupling films, which apply longitudinal bias field to an MR sensor. Abutted bias-magnet structures with various taper angles fabricated, and the overlap lengths were measured as the length of the MR flat active region covered by the longitudinal bias films. The hysteresis measured from the transfer curve decreases with decreasing overlap length. The repeatable baseline shift in the readback signal was also improved by decreasing the overlap length in the MR sensor.

高密度化を支えるMRヘッド技術

後閑博史,浦井治雄,土岐薫,大橋啓之

NEC技報49(6)p.23 - 281996年06月-

詳細

掲載種別:研究論文(大学,研究機関紀要)

熱硬化フォトレジスト膜の電気、機械特性評価

齋藤美紀子,大橋啓之,山田一彦,清宮健司,小澤隆

日本応用磁気学会誌査読有り19(2)p.141 - 1441995年-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:The surface structure of a thermally cured photoresist (PR) layer used as a thin-film-head insulation layer greatly affects that layer's insulation resistance (IR) and internal stress. As the carbonyl peak ratio in the PR increases, the IR decreases. In air heat treatment, compressive stress is induced in the PR. These phenomena are explained as follow. Many carbonyl and aromatic ketone groups, which are typical of the hydrophilic group, exist in the PR. Consequently, moisture sorption is induced in the surface of the PR, resulting in swelling of the PR. This stress change is related to the changes in the upper NiFe magnetic domain. It is concluded that supressing change in the PR surface structure improves the head reliability.

Magnetization Dynamics in Thin Film Heads

Keishi Ohashi

Journal of Magnetism and Magnetic Materials査読有り134(2 and 3)p.262 - 2671994年06月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:The relationship between domain wall motion and magnetization rotation is investigated. A wall motion mechanism previously proposed by the author is examined. The model gives the novel concept that the energy difference between transition state (magnetization curling) and final state (after wall motion) accelerates the wall motion. The magnetic moments in the region coupled with 90° walls rotate more slowly than those moments in the non-coupled region, hence the magnetic flux change is confined to a narrower portion of central domains at higher frequencies.

Preparation of Electrodeposited FeP Films and Their Soft Magnetic Properties

Tetsuya Osaka, Madoka Takai, Akiyoshi Nakamura, Fujio Asa, Keishi Ohashi, and Hiroaki Tachibana

Journal of the Magnetics Society of Japan査読有り18(S1)p.187 - 1901994年-

DOI

詳細

掲載種別:研究論文(大学,研究機関紀要)

概要:Electrodeposited FeP alloy films were formed, and the most suitable FeP alloy film exhibits a minimum coercivity, 0.2 Oe, and high saturation magnetic flux density, 1.4 T, at the composition of 27at%P. In order to improve the magnetic properties, in particular, the permeability, the magnetic field heat treatment was adopted, and the permeability increased until 1400. The most suitable FeP film was found to be a hyper-fine crystalline structure. The thermal stability of the FeP film was also confirmed to be until 300 degree C annealing without magnetic field in vacuum.

薄膜ヘッドにおける磁化の動特性

大橋啓之

日本応用磁気学会誌査読有り16(S1)p.81 - 841992年-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:This paper gives an overview of magnetization dynamics in thin film heads. The relationship between domain wall motion and magnetization rotation is essential in both impedance noise and Barkhausen noise. A model which describes coupled wall motion with magnetization rotation proposed by the author is compared with other models.

Effect of Plated NiFe Composition on Domain Configuration

K. Ohashi, M. Ito, and T. Maruyama

ECS Proceedings; Magnetic Materials, Processes, and Devices査読有りPV 90-08p.247 - 2581990年-

詳細

掲載種別:研究論文(国際会議プロシーディングス)

概要:This paper describes changes in magnetic domain which vary with the magnetostriction coefficient (a parameter closely related to film composition) in the production of thin film heads. Domain configuration and direction of domain walls are affected by annealing and machining. There are two different mechanisms which change the domain configuration during annealing: deformation of a magnetic film near its edges and deformation of polymer structures under magnetic films. Domain configuration change during machining is connected with the stress of over coat film.

磁気ヘッド技術

伊藤勝,山田忠治,大橋啓之,嶋林清孝,堀内真人

NEC技報41(15)p.41 - 441988年12月-

詳細

掲載種別:研究論文(大学,研究機関紀要)

概要:磁気記録の進歩の推進力となっている磁気ヘッド技術について解説します。特に磁気ディスク装置の信頼性の観点から、高密度記録用ヘッドを開発するにあたり必要となったトライボロジと薄膜ヘッド技術について解説します。

Application of Electroplating to Thin Film Head

K. Ohashi, M. Ito, and M. Watanabe

ECS Proceedings; Electrochemical Technology in Electronics査読有り招待有りPV 88-23p.525 - 5421988年-

詳細

掲載種別:研究論文(国際会議プロシーディングス)

概要:Electroplating is a crucial step in the production of thin film heads to be used for magnetic disk drives. Anomalous codeposition of NiFe film must be accurately controlled for a stable read/write head operation. Plated NiFe film offers 20% higher voltage output than sputter-depositted film. Research on plating of high saturation magnetization material, which promises improved recording density, has been also performed. Copper film is preffered as a low resistivity conductor for coil windings. It is deposited through micron-size photoresist patterns to provide a high aspect ratio cross section. This paper provides: a review of electroplating in thin film head applications and results of some experiments conducted by the authors.

磁気ヘッド技術

渡辺真,大橋啓之

NEC技報39(9)p.56 - 601986年09月-

CiNii

詳細

掲載種別:研究論文(大学,研究機関紀要)

概要:ハードディスク装置のキーコンポーネントである浮動ヘッドについて高記録密度化のための設計上の留意点について述べ,ウィンチェスタ,フェライトヘッドの改善,薄膜ヘッドの材料技術,信頼性について触れ,それぞれの特長を明らかにして将来の展望を示しました。

Mechanism of 90° Wall Motion in Thin Film Heads

Keishi Ohashi

IEEE Transactions on Magnetics査読有り21(5)p.1581 - 15831985年09月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:The interaction between the rotational motion of magnetization and wall movement are investigated for an infinite strip of magnetic film with closure domains. When an external field is applied, the direction of magnetization is assumed to curl parabollicaly near the 90° walls. The 90° wall will move to decrease the energy associated with this curling. This movement can be described by the equation of rotational motion for the wall. The switching time relating to a 90° wall is fairly short (6 - 18 nsec) calculated by solving the equation of motion. It is due to the acceleration of the wall movement by the magnetization rotation.

Magnetic After-Effect in Amorphous Tb-Fe Films

Keishi Ohashi, Hisao Tsuji, Shigeru Tsunashima, and Susumu Uchiyama

Japanese Journal of Applied Physics査読有り19(7)p.1333 - 13381980年07月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:Magnetic after-effect in sputter deposited TbxFe1-x (x×0.17~0.24) films is studied. The after-effect is directly observed using polar Kerr magneto-optic effect as a slow propagation of domain walls. The velocity of the domain growth (10-4~10-1 cm/s) changes exponentially with the applied field. The viscosity coefficient Sv≡dM/d ln tcenterdotχ-1 (χ: irreversible susceptibility), which was used in describing Jordan type after-effect, is applied to characterize the after-effect. The value of Sv (22~110 Oe) is inversely proportional to the saturation magnetization at room temperature and decreases with rising temperature. The origin of the slow wall motion is inferred to be the random anisotropy of Tb ion rather than the oxidation of the film surface.

Magnetic Aftereffect Due to Domain Wall Motion in Amorphous TbFe Sputtered Films

K. Ohashi, H. Takagi, S. Tsunashima, S. Uchiyama, and T. Fujii

Journal of Applied Physics査読有り50(B3)p.1611 - 16131979年03月-

DOI

詳細

掲載種別:研究論文(学術雑誌)

概要:A very large aftereffect is observed in sputtered amorphous Tb‐Fe films with uniaxial anisotropy perpendicular to the film plane. In the present experiment, the film is first saturated to −Ms by a premagnetizing field Hp (<0), where Ms is the saturation magnetization. Then the applied field is suddenly changed from Hp (<0) to Ha (?0) which is close to the coercive field. With proper choice of the film composition, temperature, Ha and so on, the magnetization changes from −Ms to almost +Ms with the passage of time while Ha is kept constant. The dependences of the aftereffect on the applied field and on the temperature are shown. The domain observation by means of polar Kerr effect reveals that the aftereffect is associated with the slow dendritic growth of the magnetic domains. It is also found that the density of reversed domain nuclei depends on the premagnetizing field Hp.

書籍等出版物

'Thin-film Head and the Innovator's Dilemma' in "Electrochemical Engineering: From Discovery to Product" edited by R. C. Alkire et al., Chap. 5.

Keishi Ohashi(分担執筆)

Wiley-VCH2019年 01月-2019年 01月

詳細

単行本(学術書)総ページ数:344担当ページ数:129-158ISBN:978-3527342068ASIN:3527342060

『入力革命』 1-3 「センシングシートで優しく見守る」

大橋啓之、服部渉(分担執筆)

日経BP社2014年 10月-

詳細

ISBN:978-4822276409

『ディスプレイ技術年鑑 2015』 3-3「センシングシートで優しく見守る」

大橋啓之、服部渉(分担執筆)

日経BP社2014年 10月-

詳細

ISBN:978-4822276324

『化学便覧応用化学編 第7版』 第19.7.2項「光配線」

大橋啓之(分担執筆)

丸善2014年 01月-

詳細

事典・辞書ISBN:978-4621087596

Group IV Photonics for Sensing and Imaging

K. Ohashi, R. A. Soref, G. Roelkins, H. Minamide, and Y. Ishikawa, editors(編著)

Cambridge University Press2013年 06月-

詳細

単行本(学術書)ISBN:978-1627482417

『プラズモン基礎理解の徹底と応用展開』 第8章「受光用デバイス用途光(情報伝送、センシング、イメージング)」

大橋啓之(分担執筆)

情報機構2011年 03月-

詳細

単行本(学術書)ISBN:978-4904080733

'Optical Devices ' in "Silicon-Germanium Nanostructures" edited by Y. Shiraki and N. Usami, Chap. 21.

Keishi Ohashi(分担執筆)

Woodhead Publishing2011年 02月-

詳細

単行本(学術書)ISBN:978-1845696894

三上修監修『光配線実装技術ハンドブック』 第2部4章「LSIオンチップ光配線」

大橋啓之(分担執筆)

オプトロニクス社2008年 09月-

詳細

単行本(学術書)ISBN:978-4902312300

明渡純監修『エアロゾルデポジション法の基礎から応用まで』 第5章2節「電気光学薄膜による超小型高速光素子」

中田正文、大橋啓之(分担執筆)

シーエムシー出版2008年 06月-

詳細

単行本(学術書)ISBN:978-4781300177

『ナノテクノロジーハンドブックIII編』第3章「情報ストレージ」 「ヘッド・機構」

大橋啓之(分担執筆)

オーム社2003年 05月-

詳細

単行本(学術書)ISBN:978-4274024986

日本化学会編『電気化学 光化学 無機固体 環境ケミカルサイエンス』 第1編第5章「磁気記録デバイスプロセス」

大橋啓之(分担執筆)

丸善2003年 03月-

詳細

単行本(学術書)ISBN:978-4621071571

日経エレクトロニクス編『21世紀を支えるディジタル記録技術最前線』 「高密度記録を支える磁気ヘッド技術」

大橋啓之(分担執筆)

日経BP社2001年 07月-

詳細

単行本(一般書)ISBN:978-4822202361

逢坂哲彌編『湿式法を利用したエレクトロニクス高機能薄膜作成法』 第1章「薄膜ヘッド軟磁性めっき」

大橋啓之(分担執筆)

広信社1992年 10月-

詳細

単行本(学術書)ISBN:978-4905969013

日本化学会編『めっきとハイテク』 第5章「髪の毛より細かいめっき」

大橋啓之(分担執筆)

大日本図書1992年 09月-

LINK

詳細

単行本(一般書)ISBN:978-4477002132

講演・口頭発表等

データストレージデバイスとイノベーションのジレンマ

大橋啓之

第86回研究会電気化学デバイスとビジネス(静岡県東部精密技術研究会)招待有り2019年10月02日

詳細

国内会議公開講演開催地:静岡県沼津市

概要: クリステンセン教授の「イノベーションのジレンマ」は優良な巨大企業が新興企業に負けてしまう場合があることを破壊的イノベーションという概念で説明する名著である。ここでは、その中で破壊的イノベーションではなかった例として取り上げられている「薄膜ヘッド」について、従来の経営的見方だけでなく、予期することの難しいいくつもの画期的な技術革新がデータストレージビジネスにおいていかに重要だったかという、より長期にわたる製造技術の歴史に基づく別の見方を示す。

ストレスマーカーの低侵襲測定に向けたアプタマー固定化電界効果トランジスタセンサの作製

遠山良,林宏樹,黒岩繁樹,秀島翔,大橋啓之,門間聰之,逢坂哲彌

電気化学秋季大会(電気化学会)2019年09月06日

詳細

国内会議口頭発表(一般)

Trial of Realization of Electrochemical Nanotechnology to Advanced Manufacturing

Keishi Ohashi, Tetsuya Osaka, Daikichi Mukoyama

The 70th Annual Meeting of the International Society of Electrochemistry(International Society of Electrochemistry)招待有り2019年08月08日

詳細

国際会議口頭発表(基調)開催地:ダーバン

概要: The transfer of the new technologies from our university to industries will be introduced, in particular, sensing systems on biosensors and batteries. A biosensing system is commercialized based on a concept of physiological balance for healthcare. The addition of low-cost biochemical sensors to the sensing system would help with scientific prescriptions based on contemporary medicine. As a candidate for a low-cost and robust chemical sensor platform, the ion-sensitive field-effect transistor (ISFET) has long been examined. Besides, we introduced an approach related to battery evaluation by Electrochemical impedance spectroscopy (EIS). After reviewing past our research, our two approaches for new business trials are discussed. One approach is based on the progressiveness of technology that relies on public finance with existing big companies. Another approach is a lean startup based on a customer development model for entrepreneurs.

芸術と量子とナノテクノロジー ~イントロダクション

大橋啓之

システムナノ技術に関する特別研究専門委員会 第2回研究会(電子情報通信学会 システムナノ技術に関する特別研究専門委員会)2019年06月14日

詳細

国内会議公開講演開催地:東京

センサビジネススタートアップと市場規模

大橋啓之

石油学会第62回年会(石油学会)招待有り2019年05月29日

詳細

国内会議口頭発表(招待・特別)開催地:東京

概要: 物理センサの機械学習等によるデータ活用の次の技術として期待される,生体の化学的なセンシングをビジネスとして成立させる条件につき,情報と通貨の流動性の観点から議論する。

IoTと生体物質センシング

大橋啓之

第6回分科会ワークショップ「こころとからだの健康と医療」(早稲田大学ナノテクノロジーフォーラム)2019年03月13日

詳細

国内会議公開講演開催地:東京

センサ情報とその流動性

大橋啓之

製造業のサービス化コンソーシアム(産業技術総合研究所)招待有り2019年02月20日

詳細

国内会議口頭発表(招待・特別)開催地:東京

センサーデータとブロックチェーン

大橋啓之

人間機械協奏技術コンソーシアム第6回公開シンポジウム(人間機械協奏技術コンソーシアム)2019年01月08日

詳細

国内会議公開講演開催地:東京

バイオチップの応用

大橋啓之

関東学院大学 材料・表面工学研究所講演会(関東学院大学 材料・表面工学研究所)招待有り2018年11月09日

詳細

国内会議開催地:小田原市

Detection of four kinds of Stress Biomarkers by Aptamer-Immobilized Field Effect Transistor Biosensor

R. Toyama, S. Kuroiwa, S. Hideshima, N. Kaneko, H. Horii, H. Minagawa, K. Ohashi, T. Momma, T. Osaka

International Symposium on Biological Material Science for Agriculture and Engineering(Tokyo University of Agriculture and Technology)2018年06月27日

詳細

国際会議ポスター発表開催地:東京

Gradient tint smart window using metallo-supramolecular polymer

Masayoshi Higuchi, Yuki Seino, Keishi Ohashi

第67回高分子学会年次大会(高分子学会)2018年05月24日

詳細

国内会議口頭発表(一般)開催地:名古屋

概要: Metallo-supramolecular polymer is a new type polymer composed of metal ions and multitopic organic ligands. The polymer is expected to show unique electrochemical and/or optical properties due to the electronic interaction between the metals and ligands through the polymer chain. We found electrochromic properties of polymer and the other functions so far. In this presentation we report gradient tint smart window using the metallo-supramolecular polymer.

Detection of Mental Stress Biomarker by Aptamer-Immobilized FieldEffect Transistor Sensor

Shigeki Kuroiwa, Sho Hideshima, Katsunori Horii, Naoto, Kaneko, Hirotaka Minagawa, Toshiyuki Momma, Takuya Nakanishi, Keishi Ohashi, Tetsuya Osaka, Ryota Takibuchi, Iwao Waga

22nd Topical Meeting of the International Society of Electrochemistry(The International Society of Electrochemistry)2018年04月17日

詳細

国際会議ポスター発表開催地:東京

概要: We detected α-amylase, sIgA, CgA, and cortisol in phosphate buffer using each biosensor.  Increases in the magnitude of response were observed with increases of the biomarkers’ concentration in the range between 1 nmol/dm3 and 100 nmol/dm3, 3 pmol/dm3 and 3 nmol/dm3, 2 nmol/dm3 and 200 nmol/dm3, 1 μmol/dm3 and 1 mmol/dm3, for α-amylase, sIgA, CgA, and cortisol, respectively. FET sensor responded as a gate voltage shift to the change in charge on the gate insulator surface. The observed responses suggested to be the binding of negatively charged α-amylase (isoelectric point (pI) = 6.34), sIgA (pI = 4.8-6.5), CgA (pI = 4.6-4.9) to the corresponding aptamers. Though cortisol is an electrically neutral molecule, a similar behavior toward the increase of negative charge or the decrease of positive charge was observed.

使う側に感謝される要素技術研究 ~シーズとニーズの協奏 

大橋啓之

人間機械協奏技術コンソーシアム 第4回シンポジウム招待有り2018年03月17日

詳細

国内会議シンポジウム・ワークショップ パネル(指名)開催地:愛知県

ストレスマーカーモニタリング技術の開発

大橋啓之

COI東北拠点シンポジウム「202X年の健康幸福社会を実現するデータ・インテグレーション」(東北大学 革新的イノベーション研究プロジェクト)2018年02月07日

詳細

国内会議シンポジウム・ワークショップ パネル(指名)開催地:東京

Fabrication of Aptamer-Immobilized Field-Effect Transistor Biosensor for Detecing Stress Biomakers

R. Takibuchi, S. Kuroiwa, S. Hideshima, T. Nakanishi, K. Ohashi, T. Momma, T. Osaka

5th DGIST-Waseda Workshop on Electrochemistry2017年12月12日

詳細

国内会議ポスター発表開催地:東京

QoW評価のための疲労センシング

大橋啓之

人間機械協奏技術コンソーシアム第3回公開シンポジウム招待有り2017年11月06日

詳細

国内会議シンポジウム・ワークショップ パネル(指名)開催地:東京都江東区

Fabrication of Aptamer-Immobilized Multi-Target Field-Effect Transistor Biosensor for Sensing Mental Stress

Shigeki Kuroiwa, Ryota Takibuchi, Akane Matsuzaka, Sho Hideshima, Naoto Kaneko, Hirotaka Minagawa, Katsunori Horii, Iwao Waga, Takuya Nakanishi, Keishi Ohashi, Toshiyuki Momma, Tetsuya Osaka

232nd ECS Meeting(The Electrochemical Society)2017年10月01日

詳細

国際会議ポスター発表開催地:Maryland

概要: The sensing of biomarkers in the body is very effective for diagnosis of disease and monitoring of human health condition. However, blood sampling of mental stress markers is stressful for those who do not feel serious health concerns when they want to check only their own stress level. We need to measure stress markers noninvasively in our daily lives. Saliva is an ideal biological sample to be taken noninvasively. α-amylase and cortisol are known as stress markers in saliva. Since individual differences in stress response are large, it is important to simultaneously detect multiple markers and evaluate the stress level. In this study, we attempted to fabricate two field effect transistor (FET) biosensors using aptamers against α-amylase and cortisol as indexes of stress. Our purpose was to investigate the characteristics of sensing two types of biomarkers, a protein and a steroid molecule, using aptamer-immobilized FET biosensors. The aptamer against α-amylase and the one against cortisol were obtained after eight rounds of selection by SELEX method from an initial DNA library. The gate insulator (SiO2) of FET was modified with 3-aminopropyltriethoxysilane, followed by addition of glutaraldehyde. Each of two aptamers, which are terminated with amino group, was immobilized on the thus-prepared surface of insulator. We detected α-amylase and cortisol in phosphate buffer using the aptamer against α-amylase and the one against cortisol respectively. An increase in the magnitude of response was observed with an increase of α-amylase concentration in the range between 1 nmol/dm3 and 100 nmol/dm3. FET sensor responded as a gate voltage shift to the change in charge on the gate insulator surface. The observed response was suggested the binding of negatively charged α-amylase (isoelectric point = 6.34) to the aptamer. Though cortisol is an electrically neutral molecule, an increase in the magnitude of response was observed with an increase of cortisol concentration in the range between 1 μmol/dm3 and 1 mmol/dm3. It was a similar behavior toward the increase of negative charge or the decrease of positive charge. The phosphate groups of DNA aptamers and their counter ions have an electrical charge on the gate insulator. This suggests that the cortisol aptamer contracted and its negative charge penetrated Debye length or that the counter ion bound to the aptamer beforehand was removed after the association of cortisol. The concentration of α-amylase in saliva is 1 - 3 μmol/dm3. The sensitivity of this α-amylase sensor is at a practical level. The concentration of cortisol in saliva is 3 - 11 nmol/dm3. This cortisol FET sensor requires optimization of aptamer and refinement of the device for practical application. The quantitative detection of α-amylase and cortisol using aptamer-immobilized FET sensor was achieved. This sensor can be sensitive to a structural change of aptamer induced by the target binding. It was demonstrated that the detection of the neutral target molecule is possible.

Nanoscale Application of Surface Plasmon Resonance

Keishi Ohashi

3rd International Workshop on Chromogenic Materials and Devices(National Institute for Materials Science (NIMS))招待有り2017年09月27日

詳細

国際会議口頭発表(招待・特別)開催地:Tokyo

大きなテーマと小さなテーマ-イノベーションを生む研究-

大橋啓之

企業若手人材 交流・勉強会(早稲田大学ナノテクノロジーフォーラム)2017年07月12日

詳細

国内会議講習開催地:東京

概要: 多くの先端産業でロードマップが必要とされ、そのロードマップに振り回されています。ロードマップは誰のために作られているのか? 破壊的イノベーションはロードマップから生まれるのか? ここでは、講演者がビジネスおよび研究開発に直接携わったハードディスク装置、光通信、半導体デバイス、および人体センシングを例に多くの失敗と一時的な成功とを振り返ることで、これからイノベーションに取り組む人たちに何が本質なのか考える材料を提起したいと思います。

NFC給電のみで動作可能なpH測定デバイスの提案

宮林駿, 隼田大輝, 岩瀬英治, 藤枝俊宣, 武岡真司, 大橋啓之, 佐藤慎, 黒岩繁樹, 門間聰之, 逢坂哲彌, 多和田雅師, 戸川望, 片岡孝介, 朝日透, 岩田浩康

ロボティクス・メカトロニクス講演会(日本機械学会)2017年05月11日

詳細

国内会議口頭発表(一般)開催地:福島県郡山市

概要: Skin-attachable devices are essential to the realization of personalized skin health through continuously monitoring individual's skin surface pH. This paper describes an approach to measure the skin surface pH no matter when or where, just holding a NFC enable phone over the pH-sensor device capable of operating only with NFC energy harvesting. Since NFC can generate the power and batteries are replaced, the proposed device becomes smaller, lighter and thinner. Therefore, it could be attached on the skin by using the ultrathin polymer film called nanosheet. Moreover, the low-power circuit is proposed which implements the constant current circuit and the function of wireless communication.

Industrial Trial of a Biosensor Technology

Keishi Ohashi and Tetsuya Osaka

Pacific Rim Meeting on Electrochemical and Solid-State Science 2016(The Electrochemical Society)招待有り2016年10月04日

詳細

国際会議口頭発表(招待・特別)開催地:ハワイ、ホノルル

概要: Sensor network systems using mobile phones with several physical sensors can collect big data related to human health. The addition of low-cost chemical sensors to the sensor system increases the scientific prescription based on contemporary medicine. The authors examine the commercialization of a system based on the concept of physiological balance sensing. Individuals and animals possess biological barrier systems against various stressors. This study offers a system that constantly monitors biological barrier functions on the epithelial layers by using an ion sensitive field-effect transistor (ISFET) sensor and feedback recommendations and precipitations through a smart phone.

生体物質をさりげなくセンシングするシステム

大橋啓之

Conference for BioSignal and Medicine 2016招待有り2016年09月29日

詳細

国内会議口頭発表(招待・特別)開催地:大分県日田市

概要: 様々な物理センサがモバイル通信システムに採用されて人の動作等をモニタすることが可能になってきた。しかし健康状態を直接検出できる化学センサは比較的高価で使い勝手が悪いため未だにスマートフォンレベルへの搭載は行われていない。ここではイオン感応性電界効果トランジスタを主要デバイスとしたシステムを例としてとりあげ,IoT時代に向けての人および動物に対するさりげないセンシングへの試みを紹介する。

Aptamer-Based Biosensors for Rapid Detection of Stress Markers

Naoto Kaneko, Hirotaka Minagawa, Joe Akitomi, Keishi Ohashi, Shigeki Kuroiwa, Shofarul Wustoni, Sho Hideshima, Tetsuya Osaka, Katsunori Horii, and Iwao Waga

The 43rd International Symposium on Nucleic Acids Chemistry2016年09月28日

詳細

国際会議ポスター発表開催地:Kumamoto

概要: Cortisol has been recognized as one of the stress biomarker in evaluating stress related disorders. However, it is difficult to develop the simple test since cortisol is small molecules. In this study, we developed aptamer-based biosensor, constructed with anti-cortisol aptamer and DNAzyme, to detect cortisol by fluorescence detection, colorimetric detection, fluorescence polarization (FP) detection and electrical detection such as field effect transistor (FET) sensor.

Monitoring Biomolecules and Ions with an FET Sensor for Physiological Balance

Keishi Ohashi, Shigeru Kuroiwa, Sho Hideshima, Takuya Nakanishi, Tetsuya Osaka

26th Anniversary World Congress on Biosensors(Elsevier)2016年05月27日

詳細

国際会議ポスター発表開催地:ヨーテボリ

概要: A concept of physiological balance sensing using a multi-target field-effect transistor (FET) sensor is proposed. Today’s smart phones equip various physical sensors, which has been accelerating the accumulation of human health data. However, more scientific prescription based on contemporary medicine is expected to be pulled out from data bases if low-cost chemical sensors are added to the system. People and animals have inherited biological barrier systems against various stressors. The barriers at the interface between body and external environment, such as skin, gut, and oral cavity, are especially important in the protection of body from external factors. Our plan is to develop a system which constantly monitors the biological barrier functions by using FET sensors. The size of the sensor element is about one millimeter, and is therefore suitable for integration with silicon electronics connecting to the Internet. We already reported a two-target FET sensor chip which detects two different tumor markers. A multiple-target sensor system constructed as the extension of this chip technology is under development. The immune system plays a main role in biological barriers. We have developed an FET immunoglobulin E (IgE) sensor for the examination of egg allergy. Some key molecules for the balance sensing have little or no polarization. Aptamers, which deform to change charge distributions within the Debye length, are under investigation for the detection of such small-molecule hormones. pH is a useful indicator for the physiological balance. A wireless FET sensor system has been developed to monitor skin pH. The system is controlled from a smartphone, and the monitored data is stored in the phone and sent to Cloud. A simple and quick skin pH measurement method was developed to apply to both people and dog. The difference of skin pHs between various sites of a dog will also be presented.

未病状態を化学的に把握する

大橋啓之

TOBIRA第5回研究交流フォーラム(東京バイオマーカー・イノベーション技術研究組合)2016年05月23日

詳細

国内会議開催地:東京

概要: 通信と入出力だけでなく制御・演算機能も備えたスマートフォンが普及したことで,モバイルセンサシステムを容易かつ安価に組むことが可能になった。その結果,位置,加速度,角速度,温度,気圧など,さまざまな種類のセンサがカメラや全地球測位システムと共にスマートフォンに採用され,望む人はそこから得られた自分に関するデータを容易に活用できる環境が整ってきた。特に,センシングされた生データの加工技術および大規模データ集合のデータ処理技術の進歩は,人々に有用な情報を提供し始めている。しかし,これまで導入されているセンサの多くは加速度センサや光センサなどの物理センサであり,化学種を直接検出する化学センサではなかった。化学センサをスマートフォンレベルで容易に使うことができるようになれば,近年急激に発展している分子生物学に基づく医学上の知見によるさまざまな判断を,家庭など日常の場で行えるようになることが期待される。そのようなさりげない生体センシングが実現されれば,高齢化社会における未病予防に向けた体と心の健康のために大いに役立つことになると考えられる。本講演では,さりげないセンシングを実現するために我々が取り組んでいるFET型バイオセンサをベースとした生体バランス物質センシングについて紹介する。

ストレスセンサー

大橋啓之

COI感性ワークショップ(JST)2016年03月25日

詳細

国内会議シンポジウム・ワークショップ パネル(指名)開催地:東京

基礎研究から発想の転換でビジネス化に挑戦

大橋啓之

第16回 表界研勉強会(表面界面研究会)招待有り2016年02月03日

詳細

国内会議口頭発表(招待・特別)開催地:東京

Physiological Balance Sensing Using an FET Sensor System

Keishi Ohashi, Tetsuya Osaka

3rd DGIST-WASEDA Workshop on Electrochemistry2015年12月10日

詳細

国際会議口頭発表(招待・特別)開催地:東京

Physiological Balance Sensing in an Unobtrusive Manner

Keishi Ohashi

The Catholic University of Korea & Waseda University 2nd Joint Symposium2015年11月27日

詳細

国際会議口頭発表(招待・特別)開催地:Tokyo

生体バランス物質のさりげないセンシング

大橋啓之,黒岩繁樹,秀島翔,逢坂哲彌

第32回「センサ・マイクロマシンと応用システム」シンポジウム(電気学会)2015年10月30日

詳細

国内会議口頭発表(招待・特別)開催地:新潟

Unobtrusive and Wireless Physiological Balance Sensing

Keishi Ohashi, Shigeru Kuroiwa, Sho Hideshima, Takuya Nakanishi, Akane Matsuzaka, Tetsuya Osaka

The 6th Annual Conference on RFID Technology and Application(IEEE)2015年09月18日

詳細

国際会議ポスター発表開催地:東京

True Nano, True Business

Keishi Ohashi

The 6th International Symposium on Advanced Materials Development and Integration of Novel Structural Metallic and Inorganic Materials招待有り2015年06月09日

詳細

国際会議口頭発表(基調)開催地:東京

皮膚接触型センサ

大橋啓之

COIプログラム センサワークショップ(JST)2015年04月28日

詳細

口頭発表(一般)

ナノテクノロジーの発展動向と新時代のビジネス

大橋啓之

第70回マテリアルズ・テーラリング研究会招待有り2015年04月18日

詳細

国内会議口頭発表(招待・特別)

What is Innovation?

大橋啓之

Introduction to Innovation,最先端光科学講義(東京大学ALPS)2014年11月28日

詳細

国内会議講義等

ボトムアップテクノロジーとスケーリング

大橋啓之

第27回秋季シンポジウム(セラミックス協会)招待有り2014年09月10日

詳細

国内会議口頭発表(招待・特別)

コンピュータ用光配線が目指すもの

大橋啓之

コンピューティクス研究会招待有り2014年05月23日

詳細

国内会議セミナー開催地:東京大学

センサーシートで優しく見守る

大橋啓之

FPD International 2014,第1回「クルマや医療・介護を変える『入力革命』」(日経BP)招待有り2014年03月20日

詳細

国内会議セミナー

トライボロジーに纏わるビジネス経験から

大橋啓之

東北発素材技術先導プロジェクト超低摩擦領域講演会(東北大学)2014年02月04日

詳細

国内会議講義等

ファウンドリ時代の材料・デバイス開発

大橋啓之

第50回秋期講演大会(日本電子材料技術協会)招待有り2013年11月08日

詳細

国内会議口頭発表(招待・特別)

イノベーションと科学

大橋啓之

フォトンサイエンス・リーディング大学院(ALPS)第2回交流会(東京大学ALPS)招待有り2013年10月01日

詳細

国内会議講義等

シリコンフォトニクス分野における電気光学セラミックス

大橋啓之

フューチャー・フェロエレクトリックス 第5回誘電体若手夏の学校(日本物理学会誘電体分科)招待有り2013年09月29日

詳細

国内会議口頭発表(招待・特別)

基礎研究とビジネスの距離を小さくする

大橋啓之

東北発素材技術先導プロジェクト超低摩擦領域&GRENE事業グリーントライボ・イノベーション・ネットワーク連携シンポジウム(東北大学)招待有り2012年10月29日

詳細

国内会議セミナー

The Final Push to Mainstream; Can Integrated Optics Learn From Integrated Magnetics?

Keishi Ohashi

Evening Discussion Session, International Solid-State Circuits Conference 2012(IEEE)招待有り2012年02月20日

詳細

国際会議シンポジウム・ワークショップ パネル(指名)開催地:San Francisco

概要: The electronic industry introduced photolithography for fabricating printed circuit boards in the 1930s and semiconductor integrated circuits in the late 1950s. The success stimulated both the optics and magnetics industries. In optics, various micro-optical components have been proposed since the 1960s, and a large assortment of elemental devices using CMOS photonics has been developed. The final push to create a profitable market may be guided by the lessons learned from the hard disk drives (HDDs) in the 1990s. In magnetics, simple replacement of bulk ferrite heads with small integrated thin-film heads using photolithography was not enough to establish a new market. A key technology that enabled small HDDs was the magneto-resistive head, since its read voltage does not depend on the disk velocity. Such enabling technologies for creating a new market in integrated optics will be discussed with the merits produced by the devices operating under different mechanisms.

LSIと光の結合

大橋啓之

ソサイエティ大会,依頼シンポジウム「接合技術を用いた新規集積デバイス」(電子情報通信学会)招待有り2011年09月15日

詳細

国内会議口頭発表(招待・特別)

フォトニックデバイスの現状と今後の展望〜磁気デバイスとの比較〜

大橋啓之

分科会シリコンテクノロジー,No.140 「グリーン・ナノデバイスの新たな展開」(応用物理学会)招待有り2011年08月05日

詳細

国内会議口頭発表(招待・特別)

シリコンフォトニクス:技術と経済学

大橋啓之

次世代電子デバイス教育研究開発拠点ミニセミナー(大阪大学)招待有り2011年07月15日

詳細

国内会議講義等

表面プラズモンデバイス

大橋啓之

次世代ナノ研究専門委員会研究会「シリコンフォトニクスからプラズモニクス−通信応用からセンシング、イメージング」(電子情報通信学会)招待有り2011年06月30日

詳細

国内会議口頭発表(招待・特別)

LSIと光

大橋啓之

戦略的研究基盤形成支援事業「次世代LSIに向けた新機能シリコン系ナノ電子・光・スピンデバイスの創出」第2回シンポジウム(東京都市大学)招待有り2011年06月30日

詳細

国内会議口頭発表(招待・特別)

LSIチップ光配線開発の現状と課題

大橋啓之,最上徹

デザインガイア2010(電子情報通信学会)招待有り2010年11月29日

詳細

口頭発表(一般)

パッケージング技術

大橋啓之

PECST研究会議(東京大学先端科学研究所)2010年11月05日

詳細

口頭発表(一般)

シリコンフォトニクスとナノフォトニクス

大橋啓之

つくばナノテク産学独連携人材育成プログラム・シンポジウム招待有り2010年08月06日

詳細

国内会議口頭発表(一般)

MIRAIにおけるSiフォトニクス研究開発について

大橋啓之,最上徹

第145委員会「結晶加工と評価技術」研究会(日本学術振興会)招待有り2010年07月23日

詳細

国内会議口頭発表(招待・特別)

表面プラズモンアンテナとフォトディテクション

大橋啓之

第82回研究会「ナノフォトニクス・プラズモニクスの展開」(有機デバイス研究会)招待有り2010年07月16日

詳細

国内会議口頭発表(招待・特別)

On-chip Optical Interconnect to Replace Global Electric Interconnect

Keishi Ohashi, Tohru Mogami

OptoElectronics and Communications Conference 2010招待有り2010年07月05日

詳細

国際会議口頭発表(一般)

オンチップ光配線によるグローバル配線の低消費電力化

大橋啓之

Selete Symposium 2010(半導体先端テクノロジーズ)2010年05月11日

詳細

国内会議口頭発表(一般)

半導体MIRAIプロジェクト:LSIオンチップ光配線

大橋啓之

第3回シリコンフォトニクス技術フォーラム(光産業技術振興協会)2010年03月10日

詳細

国内会議口頭発表(一般)

LSIチップ上プラズモンフォトダイオード

大橋啓之,藤方潤一,板橋聖一

未踏・ナノデバイステクノロジー第151委員会,平成21年度第4回研究会(日本学術振興会)招待有り2010年01月29日

詳細

国内会議口頭発表(一般)

Siフォトニクス:光通信とエレクトロニクスの融合

大橋啓之,中村滋,石坂政茂

H21年度第4回フォトニックデバイス・応用技術研究会(光産業技術振興協会)招待有り2010年01月21日

詳細

国内会議口頭発表(一般)

LSIチップ光配線技術

大橋啓之

半導体MIRAIプロジェクト成果報告会(半導体先端テクノロジーズ)2009年12月16日

詳細

国内会議公開講演

Siフォトニクスにおける光と電気の融合

大橋啓之

NEアカデミー:機器設計に革命を起こすSiフォトニクス(日経BP)招待有り2009年11月24日

詳細

国内会議セミナー

光インターコネクションニーズ再考

大橋啓之

第12回シリコン・フォトニクス研究会(電子情報通信学会)招待有り2009年11月18日

詳細

国内会議口頭発表(一般)

光のときめき(力)が半導体設計に革命を起こす!〜光配線技術が秘める大きな可能性

大橋啓之

第40回NMSセミナー(NECマイクロシステムズ)招待有り2009年10月19日

詳細

国内会議セミナー

Bonded Photonic Structure Incorporated into a Chip

K. Ohashi, M. Nakada, T. Nakamura

35th European Conference Optical Communication 2009招待有り2009年09月20日

詳細

国際会議シンポジウム・ワークショップ パネル(指名)

光配線によるエレクトロニクスのグリーン化

大橋啓之

ソサイエティ大会,通信ソサイエティ特別企画:フォトニック技術によるグリーンIT実現に向けて(電子情報通信学会)招待有り2009年09月16日

詳細

国内会議口頭発表(招待・特別)

光配線はどこまでエレクトロニクスに入り込めるか

大橋啓之

秋季第70回学術講演会,フォトニックICT研究会企画:フォトニックICTを取り巻く課題と技術(応用物理学会)招待有り2009年09月08日

詳細

国内会議口頭発表(招待・特別)

Surface Plasmon Antenna for Photo Detection

K. Ohashi, J. Fujikata, T. Ishi, K. Ishihara, D. Okamoto,

Applied Plasmonics Workshop, 4th International Conference on Surface Plasmon Photonics(PLEAS)招待有り2009年06月22日

詳細

国際会議シンポジウム・ワークショップ パネル(指名)

Electro-Optical Ceramic Film for On-Chip Optical Interconnect

K. Ohashi, M. Nakada, T. Shimizu, J. Akedo, H. Tsuda, J. Park

8th Pacific Rim Conference Ceramic and Glass Technology(ACS)招待有り2009年05月31日

詳細

国際会議口頭発表(招待・特別)

オンチップ光波長多重基盤技術の開発

大橋啓之

Selete Symposium 2009(半導体先端テクノロジーズ)2009年05月27日

詳細

国内会議公開講演

オンチップ光配線のためのシリコンフォトニクス/プラズモニクス

大橋啓之

第112回研究会(微小光学研究会)招待有り2009年05月19日

詳細

国内会議口頭発表(招待・特別)

光配線: チップ間からチップ上,チップ内へ

大橋啓之

総合大会,エレクトロニクスソサイエティ依頼シンポジウム:シリコンフォトニクス(電子情報通信学会)招待有り2009年03月17日

詳細

国内会議口頭発表(招待・特別)

Silicon Photonics and Plasmonics for On-Chip Interconnection

K. Ohashi

2009 International Seminar on Advanced Semiconductor Materials & Devices(Hokkaido University)招待有り2009年03月02日

詳細

国際会議口頭発表(招待・特別)

LSIチップ光配線

大橋啓之

講演会『シリコンフォトニクスの現状と今後の展開』(応用物理学会関西支部)招待有り2009年01月30日

詳細

国内会議セミナー

Plasmonic Coupling for Photonic Device Shrink

K. Ohashi

Microphotonics Center Fall Meeting(MIT)招待有り2008年12月21日

詳細

国際会議シンポジウム・ワークショップ パネル(指名)

オンチップ光配線開発の動向

大橋啓之

光エレクトロニクス研究会(電子情報通信学会)招待有り2008年12月19日

詳細

国内会議口頭発表(招待・特別)

LSIチップ光配線

大橋啓之

半導体MIRAIプロジェクト成果報告会(半導体先端テクノロジーズ)2008年12月10日

詳細

国内会議公開講演

Photodetector Using Surface-Plasmon Antenna for Optical Interconnect

K. Ohashi, J. Fujikata

2008 Materials Research Society Fall Meeting(MRS)招待有り2008年12月01日

詳細

口頭発表(一般)

シリコンナノフォトダイオード

大橋啓之

光エレクトロニクス第130委員会,第263回研究会(日本学術振興会)招待有り2008年11月10日

詳細

国内会議口頭発表(招待・特別)

GFP2008/ECOC2008会議報告

大橋啓之

新技術探索分科会#3 学会・展示会調査報告(新機能素子研究開発協会)招待有り2008年10月28日

詳細

国内会議セミナー

AD法の応用事例 ナノフォトニクス応用

大橋啓之

オープンラボ(産業技術総合研究所)招待有り2008年10月21日

詳細

国内会議公開講演

チップレベル光配線の動向

大橋啓之

Advanced Metallization Conference 2008(応用物理学会)招待有り2008年10月08日

詳細

チュートリアル

Waveguide-Integrated Si Nano-Photodiode with Surface-Plasmon Antenna and Its Application to On-Chip Optical Clock Signal Distribution

J. Fujikata, K. Nose, J. Ushida, K. Nishi, M. Kinoshita, T. Shimizu, T. Ueno, D. Okamoto, A. Gomyo, M. Mizuno, T. Tsuchizawa, T. Watanabe, K. Yamada, S. Itabashi, K. Ohashi,

5th International Conference on Group IV Photonics 2008(IEEE)招待有り2008年09月17日

詳細

口頭発表(招待・特別)

Silicon Photonics and Plasmonics for Electronics

K. Ohashi

14th International Symposium on the Physics of Semiconductors and Applications招待有り2008年08月26日

詳細

国際会議口頭発表(招待・特別)

Silicon Photonic Devices and Their Integration

K. Ohashi

International Nano-Optoelectronics Workshop 2008招待有り2008年08月10日

詳細

国際会議口頭発表(招待・特別)

海外のシリコンフォトニクスプロジェクト

大橋啓之

第9回シリコン・フォトニクス研究会(電子情報通信学会)招待有り2008年07月18日

詳細

国内会議口頭発表(一般)

シリコンCMOSコンパチブルプロセスを用いる光クロック基盤技術の開発

大橋啓之

Selete Symposium 2008(半導体先端テクノロジーズ)2008年05月26日

詳細

国内会議公開講演

オンチップ光配線技術

大橋啓之

統合研究院ワークショップ/精密工学研究所シンポジウム 次世代インターコネクト技術(東京工業大学)2008年05月22日

詳細

口頭発表(一般)

オンチップ光配線技術

大橋啓之

集積光デバイス技術時限研究専門委員会 第3回研究会(電子情報通信学会)招待有り2008年05月15日

詳細

国内会議口頭発表(招待・特別)

シリコンフォトニクスというアプローチ

大橋啓之

シリコンフォトニクス技術フォーラム(光産業技術振興協会)招待有り2008年03月10日

詳細

国内会議シンポジウム・ワークショップ パネル(指名)

シリコンフォトニクス

大橋啓之

第11回光技術シンポジウム(産業技術総合研究所)招待有り2008年03月04日

詳細

国内会議口頭発表(招待・特別)

シリコンチップ光配線

大橋啓之

分科会,シリコンテクノロジー第99回研究集会「多層配線」(応用物理学会)招待有り2008年02月08日

詳細

国内会議口頭発表(招待・特別)

大きく動き始めたシリコンフォトニクスの技術動向

大橋啓之

第8回ファイバーオプティクスEXPO,専門セミナー招待有り2008年01月17日

詳細

国内会議セミナー

LSIチップ光配線

大橋啓之

半導体MIRAIプロジェクト成果報告会(半導体先端テクノロジーズ)2007年12月18日

詳細

国内会議公開講演

Nano-Optics for LSI On-Chip Interconnect

K. Ohashi

International Symposium on Advanced Nanodevice and Nanotechnology 2007(日本学術振興会)招待有り2007年12月03日

詳細

国際会議口頭発表(招待・特別)

MIRAI-pjにおけるシリコンフォトニクスの開発現状

大橋啓之

結晶加工と評価技術第145委員会,第112回研究会(日本学術振興会)招待有り2007年11月19日

詳細

国内会議口頭発表(招待・特別)

Optical Interconnect Technology for Computer Systems

K. Ohashi, T. Nakata

Asia-Pacific Optical Communications 2007(SPIE)招待有り2007年11月01日

詳細

国際会議口頭発表(招待・特別)

MIRAI’s LSI Chip Optical Interconnect Project

K. Ohashi

4th International Conference on Group IV Photonics 2007(IEEE)招待有り2007年09月18日

詳細

国際会議口頭発表(基調)

Achieving Convergence between Electronics and Photonics

K. Ohashi

7th International Workshop on Future Information Processing Technologies招待有り2007年09月04日

詳細

国際会議口頭発表(招待・特別)

新たな配線技術〜光配線技術

大橋啓之

フロンティアプロセス2007(産業技術総合研究所)招待有り2007年08月17日

詳細

国内会議口頭発表(招待・特別)

プラズモン共鳴を利用したSiナノフォトダイオード

大橋啓之

第18回若手技術者と学生のためのレーザー応用セミナー「ナノフォトニクスの新しい潮流:ナノプラズモニクスからバイオナノフォトニクスまで」(レーザー学会東京支部)招待有り2007年07月06日

詳細

国内会議チュートリアル

Nanophotonics for Networks: from Telecom to LSI

K. Ohashi

2007 Japan-Italy Bilateral Workshop on Photonics for Communication招待有り2007年07月05日

詳細

国際会議口頭発表(招待・特別)

Optical Interconnect Technologies for High-Speed VLSI Chips Using Silicon Nano-Photonics

K. Ohashi

Silicon Nanoelectronics Workshop 2007(JSAP, IEEE)招待有り2007年06月11日

詳細

口頭発表(一般)

表面プラズモンのオプトエレクトロニクスへの応用

第5回大会(ナノ学会)招待有り2007年05月22日

詳細

口頭発表(一般)

LSI On-Chip Optical Interconnects

K. Ohashi, K Nishi, T. Baba

3rd International Nanotechnology Conference on Communication and Cooperation招待有り2007年04月18日

詳細

国際会議ポスター発表開催地:Belgium

Silicon Photonics for Long-Range and Short-Range Communication

Keishi Ohashi

3rd International Nanotechnology Conference on Communication and Cooperation招待有り2007年04月16日

詳細

国際会議口頭発表(招待・特別)

最先端光配線技術

大橋啓之

第54回応用物理学関係連合講演会,半導体Aシリコン分科内総合講演「LSI多層配線に関するプロセス・信頼性メカニズムと最先端技術」(応用物理学会)招待有り2007年03月28日

詳細

口頭発表(一般)

LSIデバイスの新探求配線の動き−光配線技術と平坦化

大橋啓之

プラナリゼーションCMPとその応用技術専門委員会(精密工学会)2007年02月16日

詳細

口頭発表(一般)

シリコンナノフォトニックデバイス

大橋啓之

薄膜第131委員会 第234回研究会(日本学術振興会)2007年02月02日

詳細

口頭発表(一般)

シリコンナノフォトダイオード

大橋啓之

量子エレクトロニクス研究会「シリコンフォトニクス」(応用物理学会)2007年01月17日

詳細

口頭発表(一般)

シリコンナノフォトニクスの最近の動向

大橋啓之

ナノスケールデバイス技術専門委員会(電子情報技術産業協会)2006年12月22日

詳細

口頭発表(一般)

LSIチップ光配線

大橋啓之

半導体MIRAIプロジェクト成果報告会(半導体先端テクノロジーズ)2006年12月22日

詳細

口頭発表(一般)

シリコンフォトニクスとナノフォトダイオード

大橋啓之

中部支部研究会(表面科学会)2006年12月15日

詳細

口頭発表(一般)

LSI上光配線

大橋啓之

第4回フォトニックデバイス・応用技術研究会(光産業技術振興協会)2006年11月28日

詳細

口頭発表(一般)

シリコンフォトニクス

大橋啓之

フォトニクス・イノベーションシンポジウム,光産業技術振興協会2006年11月24日

詳細

口頭発表(一般)

表面プラズモンとシリコンナノフォトニクス

大橋啓之

光ネットワークシステム技術第171委員会,第24回研究会(日本学術振興会)2006年11月21日

詳細

口頭発表(一般)

Post Cu/Low-k Wiring

大橋啓之

Advanced Metallization Conference 2006(応用物理学会)2006年09月25日

詳細

口頭発表(一般)

チップ上光配線へ向けたシリコン・フォトニクスデバイス

大橋啓之

電子情報通信学会ソサイエティ大会,エレクトロニクスシンポジウム:シリコン・フォトニクス技術の最新動向(電子情報通信学会ソサイエティ大会,エレクトロニクスシンポジウム:シリコン・フォトニクス技術の最新動向)招待有り2006年09月21日

詳細

国内会議口頭発表(招待・特別)

シリコンフォトニクスとナノフォトダイオード

大橋啓之

第37回NCRCプロジェクト研究推進会議研究討論会,東京大学ナノエレクトロニクス連携研究センター(東京大学ナノエレクトロニクス連携研究センター)2006年09月19日

詳細

口頭発表(一般)

Silicon Nanophotodiode

K. Ohashi, J. Fujikata, T. Ishi, K. Nishi, K. Ishihara, M. Mizuno, K. Nose, T. Baba

3rd International Conference on Group IV Photonics 2006(IEEE)招待有り2006年09月13日

詳細

国際会議口頭発表(一般)

Development and Applications of a Si Nano-Photodiode with a Surface Plasmon Antenna

K. Ohashi, J. Fujikata, D. Okamoto, T. Ishi, K. Makita, K. Nishi

Asia-Pacific Optical Communications 2006(SPIE)招待有り2006年09月03日

詳細

国際会議口頭発表(招待・特別)

Siフォトニクス〜企業での取り組みと期待

大橋啓之

ユビキタスネットワーク社会の光技術・産業懇談会第2回討論会(光産業技術振興協会)招待有り2006年08月01日

詳細

国内会議口頭発表(招待・特別)

表面プラズモン受光器

大橋啓之,西研一,藤方潤一,石勉

結晶加工と評価技術第145委員会 第107回研究会(日本学術振興会)招待有り2006年07月07日

詳細

国内会議口頭発表(招待・特別)

LSI上光配線のための要素技術

大橋啓之,西研一,藤方潤一,石勉,中田正文,山田博仁,馬場寿夫

第3回シリコン・フォトニクス研究会(電子情報通信学会)招待有り2006年05月12日

詳細

口頭発表(一般)

表面プラズモンとそのエレクトロニクスへの応用

大橋啓之

NFM研究会(早稲田大学)2005年09月30日

詳細

口頭発表(一般)

産学連携推進方策の大学比較論

大橋啓之

第1回オープンフォーラム,名古屋大学先端技術共同研究センター(名古屋大学)2005年09月13日

詳細

口頭発表(一般)

エレクトロニクスの限界を打破するSiナノフォトニクス

大橋啓之

第20回HPC研究会(NEC)2005年07月12日

詳細

口頭発表(一般)

高密度記録とナノ加工技術

大橋啓之

平成15年度第6回光ディスク懇談会(光産業技術振興協会)2004年03月05日

詳細

口頭発表(一般)

表面プラズモンのストレージ技術への適用

大橋啓之,藤方潤一,石勉

第127回研究会「光と磁気の最近の話題」(日本応用磁気学会)2003年01月17日

詳細

口頭発表(一般)

エレクトロデバイスにおけるキーテクノロジー

大橋啓之

第81回春季年会(日本化学会)招待有り2002年03月26日

詳細

口頭発表(一般)

高密度磁気記録と最先端のめっき技術

大橋啓之,齋藤美紀子

技術講演会(表面技術協会中部支部)2002年03月06日

詳細

口頭発表(一般)

TMRヘッドの低TA特性

大橋啓之

第3回会合(ファイル記憶のトライボロジー研究会)2002年01月26日

詳細

口頭発表(一般)

部材・デバイスレベルでの機能集積化とナノ構造制御技術

大橋啓之

ワークショップ ナノテクノロジープログラム〜ナノ加工・計測技術(NEDO)2002年01月21日

詳細

口頭発表(一般)

高速度記録用Co-Ni-Feヘッドの特性

大橋啓之

ファインプレーティング研究部会第64回例会(表面技術協会)2001年12月19日

詳細

口頭発表(一般)

メゾスコピック記録デバイス開発技術 トンネリングを中心として

大橋啓之

メゾテクノロジーフォーラム(産業技術総合研究所)2001年12月18日

詳細

口頭発表(一般)

最近の高密度記録磁気ヘッド技術と3次元微細加工

大橋啓之

機能性材料の3次元微細加工技術研究会 平成13年度第2回研究会(先端加工機械技術振興協会)招待有り2001年12月

詳細

国内会議口頭発表(招待・特別)

Nanotechnology for Storage Devices

K. Ohashi

8th Annual International Conference on Composites Engineering招待有り2001年08月05日

詳細

国際会議口頭発表(招待・特別)

Magnetic Nanotechnology

Keishi Ohashi

Workshop on Magnetism and Electrochemistry(Trinity College Dublin)2001年05月23日

詳細

国際会議シンポジウム・ワークショップ パネル(指名)

Electroplating for Magnetic Head

K. Ohashi

Workshop on Magnetism and Electrochemistry(Trinity College, Dublin)招待有り2001年05月20日

詳細

国際会議口頭発表(招待・特別)

Thermal Asperity of TMR Heads for Removable Disk Drives

K. Ohashi, A. Sato, K. Ishihara, T. Matsubara, T. Mitsuzuka, H. Tsuge, N. Ishiwata

8th Joint Magnetsm & Magnetic Materials / International Magnetics Conference(IEEE, American Physical Society)2001年01月08日

詳細

国際会議口頭発表(一般)

これからの超高密度磁気記録は?

大橋啓之

日本化学会産業懇談会技術開発フォーラム(日本化学会)2000年11月17日

詳細

口頭発表(一般)

磁気ヘッド製造プロセス技術と界面設計

大橋啓之

未来開拓学術研究推進事業公開シンポジウム 超高密度磁気記録技術の新展開(日本学術振興会)2000年10月31日

詳細

口頭発表(一般)

Purity of Films and Performance of Recording Heads

K. Ohashi, M. Saito, H. Honjo, T. Toba, Y. Nonaka, N. Ishiwata

196th Meeting of Electrochemical Society(ECS)招待有り2000年10月17日

詳細

口頭発表(一般)

A Read Head Structure for Magnetic Tunneling Junction

K. Hayashi, E. Fukami, K. Nagahara, M. Nakada, K. Ohashi, K. Matsuda, A. Kamijo, T. Mitsuzuka, and H. Tsuge

International Magnetics Conference 2000(IEEE)招待有り2000年04月09日

詳細

口頭発表(一般)

高純度CoNiFeめっき膜およびその磁気ヘッドへの応用

大橋啓之

共同プロジェクト研究新機能性スピニクス材料の基礎と応用に関する研究(東北大学電気通信研究所)1999年12月16日

詳細

口頭発表(一般)

高純度CoNiFe磁極ヘッド

大橋啓之,石綿延行,齋藤美紀子,石勉,本庄弘明

第65回マイクロ磁区専門研究会(日本応用磁気学会)1999年09月10日

詳細

口頭発表(一般)

Write Performance of Heads with a 2.1-Tesla CoNiFe Pole

K. Ohashi, N. Morita, T. Tsuda, Y. Nonaka

International Magnetics Conference 1999(IEEE)1999年05月18日

詳細

口頭発表(一般)

記録ヘッド用材料

大橋啓之

第52回合同例会(電気化学会情報機能材料研究会・表面技術協会電子材料表面処理技術部会・表面技術協会ファインプレーティング部会)1998年12月17日

詳細

口頭発表(一般)

Microprocessing for Magnetoresistive Heads

K. Ohashi

2nd International Symposium on Electrochemical Microsystem Technology(ISE)招待有り1998年09月08日

詳細

国際会議口頭発表(招待・特別)

Newly Developed Inductive Write Head with Electroplated CoNiFe Film

K. Ohashi, Y. Yasue, M. Saito, K. Yamada, T. Osaka, M. Takai, K. Hayashi

7th Joint Magnetism & Magnetic Materials / International Magnetics Conference(IEEE, American Physical Society)1998年06月06日

詳細

国際会議口頭発表(一般)

ヘッド用新高Bsめっき材料

大橋啓之,高井まどか,逢坂哲彌

第103回研究会(日本応用磁気学会)1998年01月29日

詳細

口頭発表(一般)

電子部品用パーマロイめっき

大橋啓之

第19回NiDIセミナー(ニッケル開発協会)招待有り1997年08月05日

詳細

国内会議口頭発表(招待・特別)

薄膜ヘッドにおける磁歪の制御

大橋啓之

第89回研究会 メゾスコピックな技術磁化制御の将来への展望(日本応用磁気学会)1995年03月07日

詳細

口頭発表(一般)

ヘッド材料とプロセス

大橋啓之

表面技術協会(表面技術協会第87回講演大会)招待有り1993年03月17日

詳細

口頭発表(一般)

薄膜磁気ヘッドの動特性--磁壁移動と磁化回転

大橋啓之

スピニクス研究会(東北大学)1992年11月18日

詳細

口頭発表(一般)

薄膜ヘッドにおける磁化の動特性

大橋啓之

第2回垂直磁気記録シンポジウム1992年10月12日

詳細

口頭発表(一般)

めっき軟磁性膜の現状

大橋啓之

磁性材料研究会第59回講演会(電気化学協会)招待有り1991年11月12日

詳細

口頭発表(一般)

湿式法による新しい軟磁性薄膜材料

大橋啓之

電気化学協会秋期大会(電気化学協会)招待有り1990年09月29日

詳細

口頭発表(一般)

Effect of Plated NiFe Composition on Domain Configuration

K. Ohashi, M. Ito, T. Maruyama

176th Meeting of Electrochemical Society(ECS)1989年10月15日

詳細

口頭発表(一般)

薄膜ヘッドとめっき技術

大橋啓之,伊藤勝,渡辺真

第19回境界領域における電気化学協会セミナー(電気化学協会)1988年10月28日

詳細

国内会議口頭発表(招待・特別)

Application of Electroplating to Thin Film Head

K. Ohashi, M. Ito, M. Watanabe

172nd Meeting of Electrochemical Society(ECS)招待有り1987年10月18日

詳細

口頭発表(一般)

薄膜ヘッドの動的磁化過程

大橋啓之,伊藤勝,渡辺真,丸山隆男

研究会(日本応用磁気学会)1986年11月26日

詳細

口頭発表(一般)

薄膜ヘッドの動的磁化過程

大橋啓之,伊藤勝,渡辺真

テレビジョン学会1985年06月

詳細

口頭発表(一般)

Mechanism of 90-degree Wall Motion in Thin Film Head

K. Ohashi

International Magnetics Conference 1985(IEEE)1985年04月29日

詳細

口頭発表(一般)

薄膜ヘッドにおける磁壁移動による雑音

大橋啓之, 伊藤勝, 渡辺真

総合全国大会(電子通信学会)1985年03月

詳細

口頭発表(一般)

磁気ディスク用薄膜ヘッドの特性

大橋啓之,山田忠治,丸山隆男,伊藤勝,渡辺真

磁気記録研究会(電子通信学会)1982年11月22日

詳細

国内会議口頭発表(一般)

TbFeアモルファス膜の磁気余効

大橋啓之, 綱島滋, 内山晋

磁性材料研究会(電気学会)1979年01月31日

詳細

口頭発表(一般)

Tb-Feスパッタ膜の磁気余効

大橋啓之, 綱島滋, 内山晋, 藤井壽崇

薄膜第131委員会, 第94回研究会(日本学術振興会)1978年12月08日

詳細

口頭発表(一般)

Tb-Fe非晶質薄膜における磁気余効

大橋啓之,高木博嗣,綱島滋,内山晋,藤井壽崇

第2回学術講演会(日本応用磁気学会)1978年09月20日

詳細

口頭発表(一般)

簡便なストレスマーカー検出のための半導体センサ界面の構築とバイオセンシングシステム

林宏樹,秀島翔,黒岩繁樹,大橋啓之,門間聰之,逢坂哲彌

第2回COI学会(科学技術振興機構)2019年09月19日

詳細

国内会議口頭発表(一般)開催地:東京

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超高速・超低電力・超大面積エレクトロクロミズム2015年10月-2021年03月

分担

提供機関:科学技術振興機構制度名:研究成果最適展開支援プログラム A-STEP

人工核酸によるバイオマーカー簡易検出センサの技術開発2015年12月-2017年11月

分担

提供機関:科学技術振興機構制度名:大学発新産業創出プログラム

皮膚健康モニタリング超薄膜2016年09月-2017年03月

代表

現在担当している科目

科目名開講学部・研究科開講年度学期
総合ナノ理工学特論大学院基幹理工学研究科2019春学期
総合ナノ理工学特論大学院創造理工学研究科2019春学期
総合ナノ理工学特論大学院先進理工学研究科2019春学期
総合ナノ理工学特論大学院先進理工学研究科2019春学期
総合ナノ理工学特論大学院先進理工学研究科2019春学期
Seminar on Nano-Electrochemistry A大学院先進理工学研究科2019春学期
ナノ電気化学演習A大学院先進理工学研究科2019春学期
Seminar on Nano-Electrochemistry B大学院先進理工学研究科2019秋学期
ナノ電気化学演習B大学院先進理工学研究科2019秋学期
Seminar on Nano-Electrochemistry C大学院先進理工学研究科2019春学期
ナノ電気化学演習C大学院先進理工学研究科2019春学期
Seminar on Nano-Electrochemistry D大学院先進理工学研究科2019秋学期
ナノ電気化学演習D大学院先進理工学研究科2019秋学期

作成した教科書・教材・参考書

山内薫、五神真編『先端光科学入門2』の第7章「表面プラズモンからメタマテリアルへ」

2011年03月

詳細

概要:東京大学大学院授業先端レーザー科学教育研究コンソーシアム(CORAL)参考テキスト。波長以下の領域における光の操作を可能にする表面プラズモン共鳴をエレクトロニクスに応用した例、およびその概念を拡張してテラヘルツ波などでの人工材料であるメタマテリアルに用いる試みなどを説明。

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