Unclamped-Inductive-Switching Behaviors of p-GaN HEMTs at Cryogenic Temperature
Chi Zhang, Sheng Li, Weihao Lu, Siyang Liu, Yanfeng Ma, Jingwen Huang, Jiaxing Wei, Long Zhang, Weifeng Sun
Abstract
In this letter, the unclamped-inductive-switching (UIS) behaviors of GaN-based high-electron-mobility transistors with p-type GaN gate (p-GaN HEMTs) at cryogenic temperature (CT) are first revealed. Unlike the temperature-dependent avalanche-induced failure for SiC devices during UIS process, the withstanding behaviors and final critical breakdown voltage of p-GaN HEMT during UIS process at CT are completely consistent with the results at room temperature. As proved, the resonant circuit formed by device output capacitance and load inductor is the key factor influencing UIS waveforms, and such state is temperature insensitive. Furthermore, the inverse-piezoelectric effect induced by high electric field during UIS process is demonstrated to be the original cause that makes this temperature-independent failure phenomenon. In conclusion, the UIS withstanding capability of p-GaN HEMT will not be degraded in such an extremely low temperature scene, indicating a superiority of p-GaN HEMT for special applications compared with traditional devices.