Study on III-Nitride Based MIS-Transistors with Low-loss and High-breakdown voltage Characteristics

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420328
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Electron device/Electronic equipment
• Research Institution: University of Fukui
• Principal Investigator: Kuzuhara Masaaki 福井大学, 工学(系)研究科(研究院), 教授 (20377469)
• Co-Investigator(Kenkyū-buntansha): TOKUDA HIROKUNI 福井大学, 大学院工学研究科, 特命助教 (10625932)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 窒化物半導体 / HEMT / MOSFET / ゲート絶縁膜 / パッシベーション / 耐圧 / 電流コラプス

Outline of Final Research Achievements

The purpose of this work is to develop AlGaN/GaN MIS HEMTs with a low reverse gate leakage current and a suppressed increase in dynamic on-resistance. It was found that ALD-deposited composite layers of Al2O3 and ZrO2 were effective as an MIS gate insulator.
We then studied surface passivation films, such as SiN, SiON, and SiO2, in terms of improvement in current collapse characteristics. It was found that SiN or SiO2 film was effective to reduce dynamic on-resistance in AlGaN/GaN HEMTs. In addition, we found that more significant reduction in current collapse was achievable by introducing O2 plasma treatment before surface passivation film deposition. The fabricated MIS-HEMT with separately optimized gate insulator and passivation film demonstrated very promising breakdown characteristics of more than 2 kV with a very reduced gate leakage current.

Free Research Field

化合物半導体デバイス