Experiment and Simulation Study of Single-Event Burnout in GaN Event-Triggering HEMTs

In this study, the single-ion irradiation tolerance of GaN HEMTs with event-triggering HEMT protection structure (ET-HEMTs) was evaluated through both heavy ion experiments and TCAD simulations in comparison with conventional GaN HEMTs with source field plates (SFP-HEMTs). Results revealed that the measured single-event burnout voltage VSEB of 690 V in ET-HEMT was 68 % higher than 410 V in SFP-HEMTs, indicating a superior tolerance to single-ion irradiation. The underlying mechanisms were investigated using Sentaurus TCAD simulations and EMMI-FIB failure analysis. During the single-ion irradiation, GaN HEMTs experience gate voltage oscillations. The event-triggering protection structure in ET-HEMTs significantly suppresses the oscillations. Additionally, the impact ionization for the electrons around the drain and the p-GaN gate in ET-HEMTs was substantially lower than that in SFP-HEMTs. The suppressed voltage oscillations and reduced impact ionization collectively contribute to the superior single-particle irradiation tolerance of ET-HEMTs.