Electrothermal power cycling of GaN and SiC cascode devices

Abstract

This study investigates the power cycling tests of the GaN and SiC cascode devices to enable analysis of the alteration of their properties, such as case temperature, transfer characteristics, threshold voltage and leakage current once cycles complete. The highest increase in case temperature is seen in GaN cascode devices and more pronounced changes are seen in the drain current of these devices than that of the SiC devices as well. This is also the case in threshold voltage instability which is seen in the transfer characteristics of GaN devices whereas there is no change in their leakage currents. With respect to SiC cascode devices, the case temperature rise in the devices is around 25 °C and there is little increase in the leakage current after increasing the cycles, although there is a decreasing trend in their threshold voltages that can be linked to the temperature rise of the device while their transfer characteristics are invariant with increasing power cycles.