Development of low-loss inversion channel diamond MOSFET using nitrogen doping

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K15042
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 21060:Electron device and electronic equipment-related
• Research Institution: Kanazawa University
• Principal Investigator: Matsumoto Tsubasa 金沢大学, ナノマテリアル研究所, 准教授 (00739568)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: ダイヤモンド / MOSFET / パワーデバイス

Outline of Final Research Achievements

Diamond has excellent physical properties. However, the device applications have not progressed because many physics that cannot be understood remain. In this study, we investigated the effects of impurity concentration and surface roughness in diamond on device characteristics to understand the interface states and carrier scattering that cause low field-effect mobility in the inversion channel MOSFET, which was realized for the first time in the world. As a result, we have achieved 50 cm^2/Vs, which is about twice as good as the conventional mobility, although there is still an issue in reducing the nitrogen concentration in body of MOSFETs. In addition, by reducing the surface roughness of the boron-doped p-type diamond, a low interface state density of less than 10^12 cm^-2eV^-1 was achieved in the MOS capacitors.

Free Research Field

電子工学

Academic Significance and Societal Importance of the Research Achievements

本研究によって確立しつつある窒素ドーピング技術は、本研究対象とするMOSFET以外のパワーデバイスにおけるドリフト層や素子分離層の形成技術にとどまらず、量子デバイス応用が期待される窒素と空孔との複合欠陥であるNVセンタの精密形成のコア技術となると考えられる。今後も継続して研究していくことにより、SiCやGaNで実現できない高いチャネル移動度を達成するだけではなく、すべてのダイヤモンドデバイスの性能向上に寄与したい。