Comparative Investigation on the Repetitive Short-Circuit Capability of 100 V Commercial p-GaN Gate Power HEMTs With Different Processing and Structure

Reliability of 100-V p-GaN gate power high-electron-mobility transistors (HEMTs) under repetitive short-circuit (SC) stress is investigated in this work, which is a vital topic nowadays because GaN devices are quickly penetrating the medium- and low-voltage power electronics market. In this work, two devices with different processing and structure are compared. Under the stress condition of <tex-math notation="LaTeX">V DD </tex-math> = 60 V, <tex-math notation="LaTeX">V GS </tex-math> = 5.8 V, and pulsewidth of <tex-math notation="LaTeX">10 μ s </tex-math> , both the devices show a certain level of degradation with positive <tex-math notation="LaTeX">V TH </tex-math> shift and current collapse, but no catastrophic failure even after 1000-cycle stress. Guidelines for understanding the failure mechanism and improving the SC capability are achieved as: 1) the floating field plate is effective to smoothen the peak electric field; 2) the extended p-GaN ledge may weaken the electric field crowding effect, reduce the hot carrier injection, and push the trapping area away from the gate area; and 3) higher gate leakage current is beneficial to suppress the positive <tex-math notation="LaTeX">V TH </tex-math> shift during the SC stress by discharging the negative charges. These guidelines are of paramount significance to promote the SC withstand capability for the p-GaN gate power HEMTs in the future.