Experimental and simulation analysis of single event effects on lateral depletion-mode β-Ga2O3 MOSFETs

Abstract

This paper investigates the single-event effects (SEEs) in β-Ga2O3 lateral double-diffused metal–oxide–semiconductor field-effect transistors (MOSFETs) under heavy-ion irradiation. Through a combination of heavy-ion experiments, Technology Computer-Aided Design simulations, and analysis based on established atomic-scale models, we elucidate the underlying physical mechanisms leading to device degradation. Experimental results reveal two distinct transient phenomena upon ion impact: a step-like increase in gate leakage current to the compliance limit, indicative of localized dielectric damage, and a recoverable transient spike in the off-state drain current. Post-irradiation, the device exhibited significant permanent degradation, including a negative threshold voltage shift and an increase in off-state leakage. Our analysis demonstrates that the transient effects are triggered by the formation of a dense electron–hole plasma track along the heavy ion's trajectory. We attribute the permanent degradation to a combined mechanism of hole trapping at preexisting oxygen vacancies within the bulk of the Al2O3 gate dielectric and irradiation-induced interface trap generation. These findings provide a comprehensive understanding of SEE-induced degradation in β-Ga2O3 MOSFETs and underscore the critical role of the gate dielectric's defect properties in determining device reliability in radiation-prone environments.