Analysis of Trap and Recovery Characteristics Based on Low-Frequency Noise for E-Mode GaN HEMTs under Electrostatic Discharge Stress

Abstract

The ESD effects on the E-mode AlGaN/GaN high-electron mobility transistors (HEMTs) with p-GaN gate are investigated under repetitive TLP pulses. Firstly, the degradation and recovery of output, transfer characteristics, gate-leakage characteristics and low-frequency noises (LFN) are analyzed in detail before and after reverse electrostatic discharge (ESD) stress. The experimental results show that the electrical characteristics of the devices gradually degraded as the transmission line pulse (TLP) pules increased. Subsequently, the LFN measurements are performed over the frequency range of 1 Hz-10 KHz by increasing TLP pulses. Finally, the recovery tendency of DC (direct current) characteristics and trap density are studied and discussed after resting the device at room temperature for 1 to 3 months. These results physically confirm that the mechanism of the performance degradation and recovery of the devices 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.