Theoretical model of transport characteristics of AlGaN/GaN high electron mobility transistors

Abstract

A quasi-two-dimensional AlGaN/GaN high electron mobility transistor model has been developed that is capable of accurately predicting the drain-source current as well as small-signal parameters such as drain conductance and device transconductance. Salient features of the model are the incorporation of fully and partially occupied sub-bands in the interface quantum well, combined with a self-consistent solution of the Schrodinger and Poisson equations. In addition, nonlinear polarization effects, self-heating, voltage drops in the ungated regions of the device are also taken into account. The model incorporates accurate models for both the two-dimensional electron gas mobility and the electron drift velocity. The calculated model results are in very good agreement with existing experimental data for AlxGa1–xN/GaN HEMT devices with Al mole fraction within the range from 0.15 to 0.50, especially in the linear regime. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)