P-GaN栅增强型HEMT器件的电学性能受AlGaN势垒层厚度大小影响的仿真研究OA

In order to explore the effects of AlGaN barrier layer thickness on the electrical properties of P-GaN gate enhancement-mode(E-mode)power devices,modeling and simulation of P-GaN gate E-mode HEMT devices are carried out using the Atlas module of Silvaco-TCAD software,and the reasons are further analyzed from the perspective of conduction band energy structure chart.According to the results,when the AlGaN barrier layer gets thicker,the threshold voltage of HEMTs devices is decreased,the maximum drain current in the saturation region is increased,and the peak transconductance of HEMT devices is decreased.In the off-state(zero gate bias),a deeper AlGaN/GaN potential well is formed as the the AlGaN barrier layer becomes thicker.The P-GaN/AlGaN potential well is shallowed to deplete the two-dimensional electron gas(2DEG)in the GaN layer,and the 2DEG concentration in the P-GaN layer decreased,resulting in a lowered threshold voltage.In the on-state(the gate voltage is 5 V),a deeper AlGaN/GaN potential well is formed,the and the 2DEG concentration in the P-GaN layer is increased,leading to an increased maximum saturated output drain current.After optimized calculation,the best comprehensive electrical properties of HEMT devices is achieved when the AlGaN barrier layer thickness is set to 15 nm.The simulation result obtained are proved to provide certain guidance for the practical preparation of the E-mode HEMTs with a P-GaN gate.