Thermal modeling of wide bandgap materials for power MOSFETs
This paper investigates the thermal performance of different wide bandgap (WBG) materials for their applicability as
semiconductor material in power electronic devices. In particular, Silicon Carbide (SiC) and Gallium Nitride (GaN) are
modeled for this purpose. These WBG materials have been known to show superior intrinsic material properties as
compared to Silicon (Si), such as higher carrier mobility, lower electrical and thermal resistance. These unique properties
have allowed for them to be used in power devices that can operate at higher voltages, temperatures and switching
speeds with higher efficiencies. Digital prototyping of power devices have facilitated inexpensive and flexible methods
for faster device development. The commercial simulation software COMSOL Multiphysics was used to simulate a 2-D
model of MOSFETs of these WBG materials to observe their thermal performance under different voltage and current
operating conditions. COMSOL is a simulation software that can be used to simulate temperature changes due to Joule
heating in the case of power MOSFETs. COMSOL uses Finite Element/Volume Analysis methods to solve for variables
in complex geometries where multiple material properties and physics are involved. The Semiconductor and Heat
Transfer with Solids modules of COMSOL were used to study the thermal performance of the MOSFETs in steady state
conditions. The results of the simulations for each of the two WBG materials were compared with that of Silicon to
determine relative stability and merit of each material.