Normally-off p-GaN/AlGaN/GaN high-electron-mobility transistors using oxygen plasma treatment

• Published in: Applied physics express Vol. 12; no. 5; pp. 51001 - 51005
• Main Authors: Sun, Chi, Hao, Ronghui, Xu, Ning, He, Tao, Shi, Fengfeng, Yu, Guohao, Song, Liang, Huang, Zengli, Huang, Rong, Zhao, Yanfei, Wang, Rongxin, Cai, Yong, Zhang, Baoshun
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.05.2019
• Subjects: GaN; HEMT; normally-off; oxygen plasma treatment
• ISSN: 1882-0778; 1882-0786
• DOI: 10.7567/1882-0786/ab0b78

We propose a method of oxygen plasma treatment to realize normally-off p-GaN/AlGaN/GaN high-electron-mobility transistors. The fabricated device features an oxide surface passivation layer and a high-resistivity GaN cap layer at the access region, both transformed from p-GaN by the oxygen plasma treatment technique. With optimized treatment conditions, a low sheet resistance of 682 / has been successfully obtained and the fabricated device shows high performance with a positive threshold voltage of +1.02 V, a maximum drain current of 301 mA mm−1, a high on/off ratio of ∼108, a breakdown voltage of 660 V, and low current collapse.