Degradation Behavior and Mechanisms of E-Mode GaN HEMTs With p-GaN Gate Under Reverse Electrostatic Discharge Stress

The degradation behavior and its mechanisms of E-mode GaN high electron mobility transistors (HEMTs) with p-GaN gate under electrostatic discharge (ESD) stress were investigated. Reverse short-pulse stress was generated by a transmission line pulse (TLP) tester in order to simulate the static electricity. The experiment results show that the reverse short-pulse stress leads to the characteristic degradation of the E-mode GaN HEMTs with p-GaN gate. The values of the threshold voltage and ON-resistance increase, and the gate capacitance curve shifts positively. The low-frequency noises (LFNs) were obtained for the E-mode GaN HEMTs with p-GaN gate before and after the reverse short-pulse stress. The concentration of traps was extracted, and it has doubled after 700 cycles. The degradation mechanism could be attributed to the generation of traps at p-GaN/AlGaN heterointerface, AlGaN barrier, and GaN/AlGaN interface. Such an investigation can be a significant reference in the design and application of E-mode GaN power devices.