Computational Analysis of Joule Heating Effect in Triple Material Gate AlGaN/GaN High Electron Mobility Transistor

Abstract

A two-dimensional electro-thermal model has been developed to investigate the Joule heating effect in triple material gate (TMG) aluminum gallium nitride (AlGaN) / gallium nitride (GaN) high electron mobility transistor (HEMT) using the software COMSOL. The current continuity and heat transport equations are solved self-consistently to obtain the temperature distribution profile in various layers of the device. By comparing with dual material gate and single material gate HEMTs, it has been found that, besides providing better current carrying capability, TMG HEMT shows optimum thermal performance. Effects of several device parameters like total channel length, spontaneous and piezoelectric polarization induced charges and ratio of lengths of control and screen gates, on the thermal efficiency have been explored. Bias voltage and underlying substrate material dependence of the device operation have also been investigated.