Development of novel fabrication process of amorphous oxide semiconductor using field effect

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K13990
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 26020:Inorganic materials and properties-related
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Keisuke Ide 東京工業大学, 科学技術創成研究院, 助教 (70752799)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: アモルファス酸化物半導体

Outline of Final Research Achievements

Amorphous oxide semiconductor (AOS) represented by amorphous In-Ga-Zn-O has been widely applied for various practical displays. To develop further future display, high-mobility and large-band gap AOS is necessary. However, it is known that the controlling defect formation of high-performance AOS is difficult.
In this study, we developed a novel process of AOS using hydrogen doping. Amorphous gallium oxide (a-GaO) has ultra wide-bandgap larger than 4 eV and is suitable for transparent devices. However, it is difficult to enhance the carrier density of a-GaO; the ever-reported carrier density was only 10^14 cm-3. We succeed to enhance the carrier density of a-GaO up to 5x10^15 cm-3 and improve the operation voltage of a-GaO transistors by using our process.

Free Research Field

半導体

Academic Significance and Societal Importance of the Research Achievements

本研究は、新規作製プロセスの開発にとどまらず、さらに発展してAOS中の欠陥の起源解明、環境フレンドリーな水素を使った手法への展開、さらには実デバイスの実証を行ったものである。特に今回着目したアモルファス酸化ガリウムは、室温で作製できる唯一の超ワイドバンドギャップ半導体であり、その一番の課題であるキャリアドーピングの課題を解決しうるものである。今後のフレキシブルパワーエレクトロニクス発展へ寄与できる結果であると考えられる。