ナノ機能化ゲルマニウム系チャネル

2007 Fiscal Year Annual Research Report

• Project/Area Number: 18063005
• Research Institution: The University of Tokyo
• Principal Investigator: 高木 信一 The University of Tokyo, 大学院・工学系研究科, 教授 (30372402)
• Co-Investigator(Kenkyū-buntansha): 菅原 聡 東京工業大学, 理工学研究科附属像情報工学研究施設, 准教授 (40282842) ; 竹中 充 東京大学, 大学院・工学系研究科, 准教授 (20451792)
• Keywords: ゲルマニウム / MOSFET / GOI / 移動度 / 面方位 / スピン / 強磁性

Research Abstract

微細化に適合した高性能GeチャネルMOS構造である、極薄Ge層を用いたSi/Ge/Si-On-Insulator構造メタルソース・ドレインMOSFETの課題の一つが、ソース・ドレイン間の大きなリーク電流であるが、その低減に原子状水素アニールが極めて有効であることを見出した。このリーク低減の起源は、Geチャネル中の何らかの欠陥準位を水素が終端することによるものと考えられる。また、GeチャネルpMOSFETの更なる高移動度化に有効な(110)面をもつMOSFETの実現のため、酸化濃縮法による極薄膜(110)面GOI(Ge-On-Insulator)基板を用いてMOSFETを試作し、プレーナ構造では世界で初めて(110)面GOI pMOSFETのデバイス動作に成功した。(100)面のSi pMOSFETのユニバーサル移動度に対し、約1.5倍程度の移動度向上が確認された。更に、酸化濃縮GOI MOSFETの最大の問題点であるリーク電流の低減に、原子状水素アニールが有効であることを見出した。450℃の原子状水素アニールにより4桁程度のオンオフ電流比が得られた。このリーク低減には水素が関与しており、活性な水素による欠陥準位の終端がリーク電流低減の起源と考えられる。
また、GOIチャネルに強磁性ハーフメタルソース/ドレインを形成したスピンMOSFET基盤技術に関し、非常に薄いSOI上にGeの低温MBE成長を行って形成した擬似GOI基板を用いて、L21型フルホイスラー合金の
CoFeGeの形成を試みた。薄層化したSOI(100)上に単結晶Geを成長した後、CoとFeを連続堆積した後、急速熱アニールを施してジャーマナイド化行うことにより、規則度の高いL21構造のCo2FeGe膜が形成でき、磁気円二色性の測定から、磁気的に均一なホイスラー合金が実現できることを明らかにした。

Research Products

• [Journal Article] Carrier-transport-enhanced channel CMOS for improved power consumption and performance (lnvited Paper) (2008)
  • Author(s): S. Takagi, T. lrisawa, T. Tezuka, T.Numata, S. Nakaharai, N. Hirashita, Y. Moriyama, K. Usuda, E. Toyoda, S. Dissanayake, M. Shichijo, R. Nakane, S. Sugahara, M. Takenaka and N. Sugiyama
  • Journal Title: IEEE Transaction on Electron Devices 55 Pages: 21-39
  • Peer Reviewed
• [Journal Article] Ultrathin Ge-On-lnsulator Metal Source/Drain p-Channel MOSFETs Fabricated By Low Temperature Molecular Beam Epitaxy (2007)
  • Author(s): T. Uehara, H. Matsubara, S. Sugahara and S. Takagi
  • Journal Title: Japanese Journal of Applied Physics 46 Pages: 2117-2121
  • Peer Reviewed
• [Journal Article] Mobility-Enhanced Device Technologies Using SiGe/Ge MOS Channels (2007)
  • Author(s): S. Takagi, T. Irisawa, T. Tezuka, S. Nakaharai, T. Numata, N. Hirashita, Y. Moriyama, K. Usuda, S. Dissanayake, M. Tekenaka, S. Sugahara and N. Sugiyama
  • Journal Title: ECS Transaction 11 Pages: 61-74
• [Journal Article] Gate Dielectric Formation and MIS interface Characterization on Ge (2007)
  • Author(s): S. Takagi, T. Maeda, N. Taoka, M. Nishizawa, Y. Morita, K lkeda, Y. Yamashita, M. Nishikawa, H. Kumagai, R. Nakane, S. Sugahara and N. Sugiyama
  • Journal Title: Microelectronic Engineering 84 Pages: 2314-2319
  • Peer Reviewed
• [Presentation] Fabrication of(110)GOI Layers by Ge Condensation of SiGe/(110)SOI Structure and Application to pMOSFET Devices (2007)
  • Author(s): S. Dissanayake, S. Sugahara, M. Takenaka and S. Takagi
  • Organizer: 2nd International Conference on Industrial and Information Systems(ICIIS 2007)
  • Place of Presentation: University of Peradeniya, Sri Lanka
  • Year and Date: 20070808-11
• [Presentation] Carrier-Transport-Enhanced CMOS using New Channel Materials and Structures (invited) (2007)
  • Author(s): S. Takagi, T. Irisawa, T. Tezuka, S. Nakaharai, K. Usuda, N. Hirashita, M. Takenaka and N. Sugiyama
  • Organizer: International Semiconductor Device Research Symposium (ISDRS)
  • Place of Presentation: Maryland, USA
  • Year and Date: 2007-12-13
• [Presentation] Effect of Annealing on (100) and (110) Oriented pseudo-GOI pMOSFETs Fabricated by Ge Condensation Method (2007)
  • Author(s): S. Dissanayake, S. Tanabe, S. Sugahara, M. Takenaka and S. Takagi
  • Organizer: 5th International Symposium on Control of Semiconductor Interfaces-for Next Generation ULSI Process Integrations- (ISCSI-V)
  • Place of Presentation: Tokyo, Japan
  • Year and Date: 2007-11-14
• [Presentation] Superior MOS Interface Properties of GeO2/Ge Structures Fabricated by Ozone Oxidation (2007)
  • Author(s): S. Takagi, H. Matsubara, M. Nishikawa, T. Sasada, R. Nakane, S. Sugahara and M. Takenaka
  • Organizer: 5th International Symposium on Control of Semiconductor Interfaces-for Next Generation ULSI Process Integrations- (ISCSI-V)
  • Place of Presentation: Tokyo, Japan
  • Year and Date: 2007-11-13
• [Presentation] High Performance CMOS Device Technologies using New Channel Materials(invited) (2007)
  • Author(s): S. Takagi
  • Organizer: International Workshop on Advanced Silicon-based Nano-devices
  • Place of Presentation: Tokyo, Japan
  • Year and Date: 2007-11-09
• [Presentation] Effects of Atomic Hydrogen Annealing on Reduction of Leakage Current in Ultrathin Si/Ge/Si-On-Insulator Metal Source/Drain p-Channel MOSFETs (2007)
  • Author(s): S. Takagi, T. Uehara, S. Tanabe, H. Matsubara, R. Nakane, M. Takenaka and S. Sugahara
  • Organizer: 34th International Symposium on Compound Semiconductors (ISCS2007)
  • Place of Presentation: Kyoto, Japan
  • Year and Date: 2007-10-16
• [Presentation] Mobility-Enhanced Device Technologies Using SiGe/Ge MOS Channels (invited) (2007)
  • Author(s): S. Takagi, T. Irisawa, T. Tezuka, T. Numata, N. Hirashita, K. Usuda and N. Sugiyama
  • Organizer: ULSI Process Integration Symposium, 212thElectrochemical Society Meeting
  • Place of Presentation: Washington, DC., USA
  • Year and Date: 2007-10-09
• [Presentation] Understanding and Control of Ge MIS Interface Properties (invited) (2007)
  • Author(s): S. Takagi, T. Maeda, N. Taoka, M. Nishizawa, Y. Morita, K. Ikeda, Y. Yamashita, M. Harada, T. Yamamoto, N. Sugiyama, M. Nishikawa, H. Kumagai, H. Matsubara, R. Nakane, M. Takenaka and S. Sugahara
  • Organizer: 4th International Symposium on Advanced Gate Stack Technology
  • Place of Presentation: Dallas, USA
  • Year and Date: 2007-09-27
• [Presentation] Evaluation of SiO2/GeO2/Ge MlS Interface Properties by Low Temperature Conductance Method (2007)
  • Author(s): H. Matsubara, H. Kumagai, S. Sugahara and M. Takenaka and S. Takagi
  • Organizer: International Conference on Solid State Devices and Materials(SSDM)
  • Place of Presentation: Tsukuba, Japan
  • Year and Date: 2007-09-19
• [Presentation] Gate Dielectric Formation and MIS interface Characteriation on Ge(invited) (2007)
  • Author(s): S. Takagi, T. Maeda, N. Taoka, M. Nishizawa, Y. Morita, K. lkeda, Y. Yamashita, M. Nishikawa, H. Kumagai, R. Nakane, S. Sugahara and N. Sugiyama
  • Organizer: 15th lnsulating Films on Semiconductors(INFOS2007)
  • Place of Presentation: Athens, Greece
  • Year and Date: 2007-06-23
• [Presentation] Mobility-Enhanced MOS Device Technologies in Nano-CMOS era (plenary talk) (2007)
  • Author(s): S. Takagi
  • Organizer: Device Research Conference(DRC)
  • Place of Presentation: South Bend, USA
  • Year and Date: 2007-06-20
• [Presentation] (110)Ultra-thin GOI p-MOSFETs Fabricated by Ge Condensation Method (2007)
  • Author(s): S. Dissanayake, H. Kumagai, T. Uehara, Y. Shuto, S. Sugahara and S. Takagi
  • Organizer: 5th international Conference on SiGe(C)Epitaxy and Heterostructures
  • Place of Presentation: Marseille, France
  • Year and Date: 2007-05-22