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

In this paper we present a physics-based analytical model for the gate capacitance C
_g
in AlGaN/GaN HEMT devices. A continuous and analytical expression for the 2-DEG charge density n
_s
is developed from the consistent solution of Schrodinger's and Poisson's equation in a quantum well with triangular potential profile. The developed n
_s
expression is used to derive the model for C
_g
. 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.