Creation of high performance and highly reliable GaN MOS devices based on interface engineering

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H00767
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Medium-sized Section 21:Electrical and electronic engineering and related fields
• Research Institution: Osaka University
• Principal Investigator: WATANABE Heiji 大阪大学, 大学院工学研究科, 教授 (90379115)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 窒化ガリウム / パワーデバイス / MOS構造 / 界面反応制御

Outline of Final Research Achievements

The quality of insulator/GaN interface, which is the key component of GaN-based metal-oxide-semiconductor (MOS) power devices, was successfully improved by means of interface engineering. Although insertion of ultrathin GaOx layer at the insulator/GaN interface significantly reduces the defect density near the conduction band edge of GaN, the GaOx interlayer was found to be vulnerable to the post annealing in a reducing atmosphere, leading to generation of electrical defects in GaN MOS structures. In this study, we investigated electrical properties of the insulator/GaN interface and achieved high quality and highly reliable GaN MOS devices through thorough design of post annealing conditions and deposition method of insulating films.

Free Research Field

薄膜工学

Academic Significance and Societal Importance of the Research Achievements

MOS構造は電子デバイスの基本構造であり、Si半導体においては界面欠陥の物理的な起源や欠陥終端技術が確立されているのに対して、GaN半導体では界面欠陥の起源やMOS構造の高品質化に向けた指針が確立されていない。GaN MOS構造の界面電子物性の理解は、学術的な観点からも極めて興味深い研究対象であると同時に、物性解析を通じた高品質GaN MOS構造の実現によりGaNパワーデバイスの社会実装が進めば、電気エネルギーの有効活用や、高周波用途への利用拡大を通じて高度情報化社会の構築に大きく貢献する。