Robustness in short-circuit mode: Benchmarking of 600V GaN HEMTs with power Si and SiC MOSFETs

A short-circuit e.g. in a half-bridge converter is a severe and potentially destructive operation condition for a power transistor and needs to be turned-off quickly and safely. In order to define strategies how to improve the reliability of a power device, it is necessary to understand the failure dynamics during a short-circuit. In this paper, an experimental study focussing on the short-circuit capability of different types of 600V power transistors based on Si, SiC and GaN is presented. Usually, a 10μ8 short-circuit withstand time at 400V is required for 600V power transistors. Measurement results show that the investigated Si and SiC MOSFETs can withstand short-circuit times up to 13μs at 400V and 150°C, while the normally-off and cascode GaN devices demonstrate considerably less withstand capability.