Modeling GaN HEMTs using thermal particle-based device simulator

This paper presents a Monte Carlo device simulator developed to investigate the electronic transport properties in AlGaN/AlN/GaN high electron mobility transistors (HEMTs). Two different polarization models are considered to introduce electromechanical coupling and changes in the piezoelectric polarization charge at the interface and their effect on the device characteristics is compared. The influence of the gate-voltage dependence of the polarization charge on the electron sheet charge density in the channel is determined. Results reveal that a 10% increase in the polarization charge is needed to match the experimental data when the gate voltage dependence of the polarization charge is included in the theoretical model.