Comparative Study of Single and Double Quantum Well AlGaN/GaN HEMT Structures for High Power GHz Frequency Application

Abstract

The aim of this work is to simulate and analyze the performance of single and double quantum well AlGaN/GaN HEMT (High Electron Mobility Transistor) structures for high power GHz frequency application with the variation of gate length, spacer layer thickness and doping layer thickness. To study the effect of these variations we use Atlas Tcad-Silvaco numerical simulation software. The drift-diffusion model has been taken for simulating the proposed device. We use sapphire as a substrate for this structure. We have performed the comparative characterization study of 2-DEG (Two Dimensional Electron Gas), threshold voltage (Vth) and transconductance (gm) of the double quantum with single quantum well HEMT structure. As a result of this comparison the double quantum well HEMT structure has been seen to exhibit more sensitive to these parameters. Thus, optimization of the gate length, donor layer thickness and spacer layer thickness of double quantum well HEMT structure is crucial.