Comparison of Total Ionizing Dose Effects in GaN HEMTs with p-GaN Gate Structure and Cascode Configuration

This study examines the total ionizing dose (TID) effects on two types of enhancement-mode GaN HEMT devices with p-GaN gate structure and cascode configuration. These devices were exposed to γ-ray, followed by room-temperature annealing and high-temperature aging treatments, to evaluate their radiation tolerance. The results reveal variations in threshold voltage, leakage current, and interface states. Additionally, irradiation induces trapped charges in p-GaN and Cascode HEMTs that cannot be fully recovered via room-temperature annealing or high-temperature aging. Compared to Cascode HEMTs, p-GaN HEMTs exhibit significantly smaller changes in electrical properties after radiation exposure, highlighting their superior radiation tolerance.