Analytical Model for the Channel Maximum Temperature in Ga2O3 MOSFETs.

In this work, we proposed an accurate analytical model for the estimation of the channel maximum temperature of Ga2O3 MOSFETs with native or high-thermal-conductivity substrates. The thermal conductivity of Ga2O3 is anisotropic and decreases significantly with increasing temperature, which both are important for the thermal behavior of Ga2O3 MOSFETs and thus considered in the model. Numerical simulations are performed via COMSOL Multiphysics to investigate the dependence of channel maximum temperature on power density by varying device geometric parameters and ambient temperature, which shows good agreements with analytical model, providing the validity of this model. The new model is instructive in effective thermal management of Ga2O3 MOSFETs.