Electrical Performances and Physics Based Analysis of 650V E-mode GaN Devices at High Temperatures

High temperature performances of commercial cascode GaN FET and p-GaN HEMT are investigated and compared in this paper. The differences of device structures lead to quite different high temperatures performances. The p-GaN device shows smaller shifts in threshold voltage but larger increase in gate leakage current at high temperatures than cascode device. Moreover, high temperatures also lead to different variations in dynamic electrical parameters. By using analytical models, it is found that the decrease of electron mobility dominates the variations in switching parameters for p-GaN device, however, the decrease of Vth dominates the variations for cascode device.