Electrical and thermal modeling of AlGaN/GaN HEMTS on diamond silicon substrates

The following work modeled an AlGaN/GaN HEMT on a silicon/polydiamond/polycrystalline silicon substrate to predict the self heating aspects of the FETs current and voltage characteristics. Various thermal conductivity substrate structure combinations were investigated. Simulation and measured data are compared for DC IV curves. The 2D modeling was used to examine self heating in the DC IV by mobility and thermal conductivity parameters. Removal in the simulation of the bottom polysilicon handle was used to predict improved HEMT DC performance. Results are shown that suggest that a 20 ¿m diamond substrate layer improves the DC IV characteristics and lowers channel temperatures.