Performance Degradation of the Schottky p-gate GaN HEMT Under Power Cycling

This study investigates the reliability and parametric degradation mechanisms of Schottky p-gate GaN high electron mobility transistors (SP-HEMTs) subjected to power cycling test (PCT) . Active thermal accelerated lifetime testing was employed, combined with real-time junction temperature monitoring by the temperature-sensitive electrical parameter (TSEP) method. Devices underwent 320,000 power cycling events under fixed conduction time conditions. A systematic analysis of key electrical parameters was conducted throughout the test. Experimental results revealed a progressive increase in both gate and drain leakage currents with power cycling, while the subthreshold swing exhibited significant degradation after aging. In contrast, the threshold voltage and static on-resistance remained remarkably stable throughout the test duration. Low-frequency noise (LFN) characterization further indicated that the defect density inside the device gate has increased after the power cycling stress. These findings offer a critical basis for evaluating reliability and optimizing processes of GaN power devices and deliver key understanding for developing robust power electronic systems.