A physics based compact model of gate capacitance in AlGaN/GaN HEMT devices

Abstract

In this paper we present a physics-based analytical model for the gate capacitance Cg in AlGaN/GaN HEMT devices. A continuous and analytical expression for the 2-DEG charge density ns is developed from the consistent solution of Schrodinger's and Poisson's equation in a quantum well with triangular potential profile. The developed ns expression is used to derive the model for Cg. The proposed model is valid in all regions of device operation and has no empirical parameters. The model is in excellent agreement with experimental data.