Effects of the Trap Level in the Unintentionally Doped GaN Buffer Layer on Optimized p-GaN Gate AlGaN/GaN HEMTs

摘要

This research investigates the impacts of the AlGaN barrier layer thickness and the Al mole fraction on p-GaN gate AlGaN/GaN HEMTs and presents an optimized structure. Based on 2-D drift-diffusion simulation, the effects of the trap level in the UID GaN buffer layer on the transfer and output characteristics of the optimized device are described. The energies of the trap levels are set at 0.28, 0.33, 0.4, 0.58, and 0.9 eV below the conduction band minimum, respectively. The depth of the trap level is found to influence the off-state leakage current and on-state I_(D,max). The Shockley-Read-Hall recombination model for a single trap level is used to analyze the impact of different trap levels in the UID GaN buffer on p-GaN gate AlGaN/GaN HEMTs.