Impact of Proton Irradiation-Induced Bulk Defects on Gate-Lag in GaN HEMTs

The relationship between proton-induced defects and gate-lag in GaN high-electron mobility transistors (HEMTs) is examined using simulations and experiments. Surface traps are primarily responsible for the pre-irradiation gate-lag. Experimental data and detailed two-dimensional device simulations demonstrate that bulk traps increase the amount of observed gate-lag after irradiation to high-proton fluences.