Modeling of highly anisotropic microstructures for electro-thermal simulations of power semiconductor devices

When performing electro-thermal simulations of power semiconductors, usually the FEM model of the device does not include small geometrical features in order to limit the computational effort. In this paper we propose a method to replace the detailed elementary cell structure of a power Trench MOSFET by thermally equivalent homogenous layers with averaged anisotropic material properties. The impact of equivalent material models on the device behavior is evaluated and compared to an isotropic model by means of electro-thermal simulations