Degradation Behavior and Mechanisms of E-Mode GaN HEMTs With p-GaN Gate Under Reverse Electrostatic Discharge Stress
Yiqiang Chen, Jingtai Feng, J. L. Wang, Xinbing Xu, Zhiyuan He, G. Y. Li, Dengyun Lei, Yuan Chen, Yun Huang
Abstract
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.