Self-heating effects in GaN/AlGaN heterostructure field-effect transistors and device structure optimization

Gallium nitride and related compounds have established themselves as extremely important for next generation of high-power density devices for microwave communications and radar applications. GaN/AlGaN heterostructure field-effect transistors (HFET) demonstrated high frequency and low-noise operation. At the same time, performance of these devices has been limited by self-heating and other problems associated with the large defect densities. In this paper we present results of our simulation of temperature rise in GaN/AlGaN HFETs characterized by different 'geometry, layered structure, doping density and substrate type. In these simulations, we use the materials specific model for GaN thermal conductivity recently developed in our group.