Analysis of trap and recovery characteristics based on low-frequency noise for E-mode GaN HEMTs with p-GaN gate under repetitive short-circuit stress

In this letter, the degradation and recovery characteristics of E-mode AlGaN/GaN high-electron mobility transistors (HEMTs) were investigated under repetitive short-circuit (SC) stress. Output, transfer, transconductance and gate-leakage characteristics were analyzed in detail before and after repetitive SC stress. After stress, the electrical characteristics of the devices gradually degraded as the SC pules increased. Low-frequency noise measurements are performed over the frequency range of 1 Hz-10 KHz by increasing SC pulses. Furthermore, the recovery tendency of DC characteristics and trap density is observed between repetitive SC measurements, and this physically confirms that the mechanism of the performance degradation could be attributed to the trapping and releasing processes of electrons in the p-GaN layer and AlGaN barrier layer of AlGaN/GaN HEMTs, which change the electric field distribution under the gate.