Virtual-Body p-GaN Gate HEMT With Enhanced Ruggedness Against Hot-Electron-Induced Degradation

GaN power devices exhibit deteriorated dynamic RON after hot electron stress (HES) as new defects/traps are generated at surface or in buffer layer. In this work, we propose a virtual-body p-GaN gate HEMT (VB-HEMT) to improve the ruggedness against hot-electron induced degradation. In the ON-state, the holes injected from p-GaN gate reach the interface between the GaN channel layer and the buried AlGaN layer, forming a hole channel that serves as a "virtual body". The virtual body screens the hot-electron induced buffer trapping. Additionally, the surface trapping effect is also alleviated in the VB-HEMT, which is likely caused by the spillover of holes from virtual body to the surface or by the hole/electron recombination that emits photons to accelerate the recovery of surface trapping. The suppression of hot-electron induced dynamic RON degradation is verified by HES test with various stressing time, stressing voltage, and stressing current.