Single-Event Leakage Current and Single-Event Burnout in High-Voltage GaN and SiC PiN Diodes: A Comparative Analysis

Abstract

Recent developments in GaN power devices challenge the long-standing success of SiC due to GaN’s more advantageous material properties. Models, such as the critical-energy storage and release model, have been developed to explain and predict observed Single-Event Leakage Current (SELC) and Single-Event Burnout (SEB) thresholds for SiC technologies. However, GaN devices have not been tested and compared in the same high-voltage range as SiC. In this work, high-voltage GaN and SiC vertical PiN diodes were tested for SELC/SEB at similar voltages for a wide LET range. The experimental comparison shows a lower SELC/SEB tolerance in GaN, both in terms of raw voltage and critical stored energy (U_SEE). Defect measurements in GaN devices after SELC show a strong E_c - 0.6 eV trap presence that is attributed to SELC-generated N interstitials. The lower SEE tolerance of GaN is attributed to lower defect multiplication activation energies, marking a limitation in GaN as a material, not simply an underdeveloped technology.