Investigation of impact of Heavy-Ion Irradiation on GaN HEMTs

This study investigates the Single-Event-Burnout characteristics of p-GaN HEMTs through combined heavy-ion irradiation experiments and numerical simulations. Experimental results reveal distinct responses: the 100V-rated device exhibited a progressive rise in leakage current, indicating severe degradation yet successfully avoiding catastrophic burnout up to a fluence of 1×107 ions/cm2. In contrast, the 200V-rated device exhibited SEB failure at a drain bias of approximately 100V, which corresponds to half of its rated voltage. To elucidate the underlying physics, TCAD simulations were performed. The analysis suggests that the failure is driven by a positive feedback loop involving radiation-induced hole accumulation. Specifically, holes generated by high-LET particles accumulate at the buffer interface, causing severe electric field distortion that triggers avalanche multiplication and subsequent thermal destruction. These findings highlight the critical role of electric field management and offer guidance for optimizing radiation-hardening strategies in next-generation GaN power devices.