Mechanism analysis of dynamic on-state resistance degradation for a commercial gan hemt using double pulse test

The dynamic on-resistance (R_ON) behavior of one commercial GaN HEMT device with p-GaN gate is investigated under hard-switching conditions. The non-monotonic performance of dynamic R_ON with off-state voltage ranging from 50 to 400 V is ascribed to the “leaky dielectric” model. The highest normalized R_ON value of 1.22 appears at 150 and 200 V. The gradual increase and following maximum of dynamic R_ON are found when the device is exposed to a stress voltage for an extended stress time under 100 and 200 V, which is due to a much longer trapping time compared to detrapping time related to deep acceptors and donors. No obvious R_ON degradation, thanks to the suppressed trapping effect, is observed at higher V_DS . From the multi-pulse test, the dynamic R_ON is seen to be insensitive to the frequency. It is demonstrated that the leakage, especially under source and drain contact, is a key issue in the dynamic resistance degradation.