Impact of rounded electrode corners on breakdown characteristics of AlGaN/GaN high-electron mobility transistors

Abstract

We investigated the impact of rounded electrode corners on the breakdown characteristics of AlGaN/GaN high-electron mobility transistors. For standard reference devices, catastrophic breakdown occurred predominantly near the sharp electrode corners. By introducing a rounded-electrode architecture, premature breakdown at the corners was mitigated. Moreover, the rate of breakdown voltage (VBR) degradation with an increasing gate width (WG) was significantly lower for devices with rounded corners. When WG was increased from 100 µm to 10 mm, the VBR of the reference device dropped drastically, from 1,200 to 300 V, whereas that of the rounded-electrode device only decreased to a respectable value of 730 V.