Two Dimensional Inorganic/Organic Hetero Interface for Normally Off MoS2 FET

• Project/Area Number: 17K14662
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Electron device/Electronic equipment
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Kawanago Takamasa 東京工業大学, 科学技術創成研究院, 助教 (30726633)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Project Status: Discontinued (Fiscal Year 2020)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2020: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2019: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
• Keywords: TMDC / FET / 自己組織化 / 先端機能デバイス / マイクロ・ナノデバイス / 表面・界面物性 / ナノ材料

Outline of Final Research Achievements

Object of this study is to demonstrate the control of threshold voltage (Vth) by engineering a gate metal electrode in molybdenum disulfide (MoS2) field-effect transistors (FETs). The fabrication process for gate stacks involves the deposition of aluminum oxides (AlOx) on a high-work-function metal and the subsequent formation of a self-assembled monolayer (SAM) by an immersion method. A positive Vth of 0.15V was demonstrated using a platinum (Pt) metal as a gate electrode accompanied by a low density of traps at the interface owing to the close-packed SAM. The Pt gate electrode exhibits a Vth shift of about 1V in the positive direction compared with the aluminum (Al) gate electrode. This Vth shift is consistent with the difference in the work function of Pt and Al gate metal electrodes.

Academic Significance and Societal Importance of the Research Achievements

2次元半導体材料の二硫化モリブデン（MoS2）は移動度が高く、未結合手が無いため化学的、電気的に安定な材料である事から次世代低消費電力エレクトロニクスに向けたFETのチャネル材料として期待されている。本研究によって素子特性で最も重要な閾値電圧制御をMoS2 FETで確立し、正の閾値電圧を実証できた事は次世代低消費電力エレクトロニクスに向けた大きな一歩となり2次元半導体材料の可能性を示す事ができた考えている。

Research Products

• [Journal Article] Transfer printing of Al2O3 gate dielectric for fabrication of top-gate MoS2 FET (2019)
  • Author(s): Takamasa Kawanago, Tomoaki Oba, Shunri Oda
  • Journal Title: Applied Physics Express Volume: 12 Issue: 2 Pages: 026501-026501
  • DOI: 10.7567/1882-0786/aaf995
  • NAID: 210000135571
  • Peer Reviewed
• [Journal Article] Control of threshold voltage by gate metal electrode in molybdenum disulfide field-effect transistors (2017)
  • Author(s): Kawanago Takamasa、Oda Shunri
  • Journal Title: Applied Physics Letters Volume: 110 Issue: 13 Pages: 133507-133507
  • DOI: 10.1063/1.4979610
  • Peer Reviewed
• [Journal Article] Fabrication of hybrid self-assembled monolayer/hafnium oxide gate dielectric by radical oxidation for molybdenum disulfide field-effect transistors (2017)
  • Author(s): Kawanago Takamasa、Ikoma Ryo、Oba Tomoaki、Takagi Hiroyuki
  • Journal Title: Applied Physics Letters Volume: 111 Issue: 20 Pages: 202904-202904
  • DOI: 10.1063/1.4998313
  • Peer Reviewed
• [Presentation] ゲート絶縁膜転写とPVAドーピングによるトップゲートMoS2 FET の作製 (2020)
  • Author(s): 川那子高暢，松﨑貴広，小田俊理
  • Organizer: 第67回応用物理学会春季学術講演会
• [Presentation] Fabrication of top-gate MoS2 FET with transferred Al2O3 gate dielectric (2019)
  • Author(s): Takamasa Kawanago, Tomoaki Oba, Shunri Oda
  • Organizer: ECS 2019
  • Int'l Joint Research
• [Presentation] PVA によるMoS2 FET へのキャリアドーピングと電気特性への影響 (2019)
  • Author(s): 松﨑貴広, 大場智明，川那子高暢，小田俊理
  • Organizer: 第80回応用物理学会秋季学術講演会
• [Presentation] Al2O3ゲート絶縁膜転写法を用いたトップゲートMoS2 FETの作製 (2019)
  • Author(s): 川那子高暢，大場智明，小田俊理
  • Organizer: 第66回応用物理学会春季学術講演会
• [Presentation] MoS2 FET fabricated by adhesion lithography (2018)
  • Author(s): Takamasa Kawanago
  • Organizer: International Symposium 3RD Japan-EU Flagship Workshop on Graphene and Related 2D Materials 2018
  • Int'l Joint Research / Invited
• [Presentation] Two-dimensional inorganic/organic hetero interface for field-effect transistor applications (2018)
  • Author(s): Takamasa Kawanago
  • Organizer: Recent Progress Graphene Research (RPGR) 2018
  • Int'l Joint Research / Invited
• [Presentation] Two-dimensional inorganic/organic interface for field-effect transistor application (2018)
  • Author(s): Takamasa Kawanago
  • Organizer: 1st Workshop on Novel 2D Device & Materials Physics (2DMaP)
  • Invited
• [Presentation] Gated Four-Probe Method to Evaluate the Impact of SAM Gate Dielectric on Mobility in MoS2 FET (2018)
  • Author(s): Takamasa Kawanago, Tomoaki Oba, Ryo Ikoma, Hiroyuki Takagi, Shunri Oda
  • Organizer: ESSDERC 2018
  • Int'l Joint Research
• [Presentation] SAMゲート絶縁膜を用いたMoS2 FETのチャネル移動度への影響 (2018)
  • Author(s): 川那子高暢，大場智明，小田俊理
  • Organizer: 第79回応用物理学会秋季学術講演
• [Presentation] Gated Four-Probe Method for Evaluation of Electrical Characteristics in MoS2 Field-Effect Transistors (2018)
  • Author(s): Tomoaki Oba, Takamasa Kawanago, Shunri Oda
  • Organizer: Recent Progress Graphene Research (RPGR) 2018
  • Int'l Joint Research
• [Presentation] Polarity Control in WSe2 Field-Effect Transistors using Dual Gate Architecture (2018)
  • Author(s): Hiroyuki Takagi, Ryo Ikoma, Tomoaki Oba, Takamasa Kawanago
  • Organizer: 2nd Electron Devices Technology and Manufacturing (EDTM) Conference 2018
  • Int'l Joint Research
• [Presentation] 積層SAM/HfOxゲート絶縁膜を用いたMoS2 FETの作製 (2018)
  • Author(s): 川那子高暢, 居駒遼, 大場智昭, 高木寛之
  • Organizer: 第65回応用物理学会春季学術講演会
• [Presentation] 基板バイアス構造を用いたキャリア注入制御とWSe2FETの作製 (2018)
  • Author(s): 川那子高暢, 高木寛之, 居駒遼, 大場智昭
  • Organizer: 第65回応用物理学会春季学術講演会
• [Presentation] Radical Oxidation Process for Hybrid SAM/HfOx Gate Dielectrics in MoS2 FETs (2017)
  • Author(s): Takamasa Kawanago, Ryo Ikoma, Tomoaki Oba, Hiroyuki Takagi
  • Organizer: 47th European Solid-State Device Research Conference
  • Int'l Joint Research
• [Presentation] Transfer printing of nanostructured membrane with elastomeric stamp and its application to TMDC-based field-effect transistors (2017)
  • Author(s): Takamasa Kawanago, Wanjing Du, Ryo Ikoma, Tomoaki Oba, Hiroyuki Takagi and Shunri Oda
  • Organizer: 17th International Workshop on Junction Technology
  • Int'l Joint Research / Invited
• [Presentation] Heavily-doped SOI Substrate and Transfer Printing for Charge Injection into (2017)
  • Author(s): Ryo Ikoma, Takamasa Kawanago
  • Organizer: 17th International Workshop on Junction Technology
  • Int'l Joint Research
• [Presentation] 高濃度SOI基板と転写法によるTMDC FETsの作製 (2017)
  • Author(s): 川那子 高暢、居駒 遼、高木 寛之、小田 俊理
  • Organizer: SDM(シリコン材料・デバイス)研究会
• [Presentation] Heavily-doped SOI with SAM-Based Gate Dielectrics in Application to TMDC FET (2017)
  • Author(s): Ryo Ikoma, Takamasa Kawanago, Yukio Kawano
  • Organizer: 232nd ECS MEETING
  • Int'l Joint Research
• [Presentation] 剥離転写法による高濃度ドープSOI基板を用いたTMDC-FETの作製 (2017)
  • Author(s): 居駒遼, 川那子高暢, 河野行雄
  • Organizer: 第７８回応用物理学会秋季学術講演
• [Presentation] 濃度SOI基板をゲート電極に用いたWSe2pFETの作製 (2017)
  • Author(s): 高木寛之, 居駒遼, 大場智昭, 川那子高暢
  • Organizer: 第７８回応用物理学会秋季学術講演
• [Presentation] 積層SAM/HfOxゲート絶縁膜を用いたMoS2 FETの作製 (2017)
  • Author(s): 大場智昭, 居駒遼, 川那子高暢
  • Organizer: 第７８回応用物理学会秋季学術講演
• [Book] グラフェンから広がる二次元物質の新技術と応用 (2020)
  • Author(s): 川那子高暢(分担執筆)
  • Total Pages: 479
  • Publisher: エヌ・ティー・エス出版
  • ISBN: 9784860436636
• [Book] 自己組織化有機単分子膜を用いた界面制御とゲート絶縁膜技術 (2018)
  • Author(s): 川那子 高暢
  • Total Pages: 5
  • Publisher: 応用物理 第87巻 第7号 511