Thermal analysis of AlN/GaN/AlGaN HEMTs grown on Si and SiC substrate through TCAD simulations and measurements

In this paper, a comprehensive evaluation of thermal behaviour of the AlN/GaN/AlGaN high electron mobility transistors (HEMT) grown on Si and SiC substrates have been carried out through simulations and measurements. Three dimensional (3D) thermal TCAD simulations are performed to obtain steady-state variations of the junction temperature and to extract the thermal resistance (Rth) for different device geometries. On-wafer pulsed IV measurements are carried out at different dissipated power (Pdiss) and chuck temperature (Tchuck). The thermal resistance extracted from measurements has been verified using the TCAD results and found to be in excellent agreement for various device geometries.