Evaluation of the Thermal Resistance in GaN-Diodes by means of Electro-Thermal Monte Carlo Simulations

Abstract

In this paper we use an electro-thermal method [solver of the heat-flux equation coupled with an ensemble Monte Carlo (MC) simulator] to extract the value of the thermal resistance, Rth, in diodes consisting in un-gated Al0.27Ga0.73N/GaN heterostructures. Different substrates (polycrystalline diamond - PCD, diamond, silicon and sapphire), and die dimensions will be analysed. When a temperatureindependent thermal conductivity is considered, the obtained values of Rth depend on the geometry and substrate material, and are constant with the dissipated power (Pdiss). When a temperaturedependent thermal conductivity is needed to correctly reproduce the thermal behaviour of the device, Rth exhibits a strong dependence on Pdiss.