INFLUENCE OF ANISOTROPIC THERMAL CONDUCTIVITY IN THE APPARATUS INSULATION FOR SUBLIMATION GROWTH OF SIC: NUMERICAL INVESTIGATION OF HEAT TRANSFER By

Using a mathematical heat transfer model including anisotropic heat conduction, radiation, and RF heating, we use our software WIAS-HiTNIHS 1 to perform numerical computations of the temperature field in axisymmetric growth apparatus during sublimation growth of silicon carbide (SiC) bulk single crystals by physical vapor transport (PVT) (modified Lely method). As it is not unusual for the thermal insulation of PVT growth apparatus to possess an anisotropic thermal conductivity, we numerically study the influence that this anisotropic thermal conductivity has on the temperature field in the growth chamber. Moreover, we also study the influence of the thickness of the insulation. Our results show that, depending on the insulation’s orientation, even a moderate anisotropy in the insulation can result in temperature variations of more than 100 K at the growing crystal’s surface, which should be taken into account when designing PVT growth apparatus.