Study on GaN-based vertical transistors using ScAlMgO4 substrates

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K13963
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Electron device/Electronic equipment
• Research Institution: Tohoku University
• Principal Investigator: Suemitsu Tetsuya 東北大学, 国際集積エレクトロニクス研究開発センター, 教授 (90447186)
• Co-Investigator(Kenkyū-buntansha): 松岡 隆志 東北大学, 金属材料研究所, 教授 (40393730)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 窒化物半導体 / パワーデバイス / トランジスタ / SCAM基板

Outline of Final Research Achievements

GaN HEMT heterostructures are grown on cleaved ScAlMgO4 (SCAM) substrates. By using small off-cut SCAM, HEMT structures with flat surface comparable to those grown on conventional sapphire substrates are confirmed. As a part of the GaN HEMT process, neutral beam etching is applied to the GaN material systems for the first time. By means of this advanced etching, significant reduction of current collapse in GaN HEMTs are observed. The cleaving of thin SCAM layers off from bulk SCAM substrates is also a key technology to achieve GaN vertical transistors. It has been confirmed that thick GaN layers are automatically cleaved off from SCAM substrates during cooling down after growth by means of the stain induced by thermal expansion.

Free Research Field

半導体デバイス工学