一种带有背电极的高耐压AlGaN/GaN RESURF HEMT

A High Breakdown Voltage AlGaN/GaN RESURF HEMT with Back Electrode

针对常规AlGaN/GaN RESURF高电子迁移率晶体管(HEMT)中由于沟道电场分布不均匀而导致击穿电压过低的问题,提出一种带背电极的新型AlGaN/GaN RESURF HEMT结构。该背电极通过感应诱生负电荷调制器件沟道处的电力线分布,使栅漏之间的沟道横向电场分布更加均匀,从而提升器件击穿电压。仿真结果表明,对于栅漏间距为6μm的器件,背电极的引入使器件击穿电压得到显著提升(从1 118V增至1 670V),同时对器件导通电阻几乎没有影响(从0.87mΩ·cm2增至0.88mΩ·cm2)。研究结果为高耐压大功率AlGaN/GaN HEMT设计提供了一种新思路。

A novel high breakdown voltage AIGaN/GaN reduced surface field high electron mobility transistor （RESURF HEMT） with back electrode was proposed. The back electrode, which attracted electric field lines from positive charge at AIGaN/GaN interface, led to a more uniform electric field distribution along the channel, hence a significant improvement of breakdown voltage, with negligible negative impact on on-resistance. Numerical simulation results indicated that, for the proposed device with a gate-drain spacing of 6μm, a breakdown voltage of 1 670 V and on-resistance of 0. 88 mΩ . c㎡ were achieved, compared with 1 118 V breakdown voltage and 0.87 mΩ . c㎡ on-resistance for conventional A1GaN/GaN RESURF HEMT. The high breakdown voltage, coupled with low on-resistance, makes the proposed device a promising candidate for high-voltage / high-power applications.