Impact of p-GaN gate length on performance of AlGaN/GaN normally-off HEMT devices

Abstract

In this work, we have studied the effect of variation in length of GaN gate with p-type doping concentration on the DC performances of AlGaN/GaN normally-off HEMT using 2D Atlas TCAD simulator. A comprehensive simulation is undertaken on the proposed device to examine different performance parameters such as drain current, transconductance factor, energy band diagram, and surface potential with respect to change in p-type GaN gate lengths. The gate lengths are varied from 60 to 90 nm, and it is noticed from the simulation results that with a decrease in gate length the drain current increases and transconductance increases. A proper optimization of gate length is indispensable to preserve the normally-off mode operation and at the same time enhancing certain performance parameters.