Mechanism of improving forward and reverse blocking voltages in AIGaN/GaN HEMTs by using Schottky drain

• Published in: 中国物理B：英文版 2014 (10), p.472-476
• Main Author: 赵胜雷 宓珉瀚 侯斌 罗俊 王毅 戴杨 张进成 马晓华 郝跃
• Format: Article
• Language: English
• Subjects: AlGaN; HEMT器件; 反向偏压; 机理; 肖特基接触; 软件仿真; 阻断电压; 高电子迁移率晶体管
• ISSN: 1674-1056; 2058-3834

In this paper, we demonstrate that a Schottky drain can improve the forward and reverse blocking voltages （BVs） simultaneously in A1GaN/GaN high-electron mobility transistors （HEMTs）. The mechanism of improving the two BVs is investigated by analysing the leakage current components and by software simulation. The forward BV increases from 72 V to 149 V due to the good Schottky contact morphology. During the reverse bias, the buffer leakage in the Ohmic- drain HEMT increases significantly with the increase of the negative drain bias. For the Schottky-drain HEMT, the buffer leakage is suppressed effectively by the formation of the depletion region at the drain terminal. As a result, the reverse BV is enhanced from -5 V to -49 V by using a Schottky drain. Experiments and the simulation indicate that a Schottky drain is desirable for power electronic applications.