ON THE SUBLIMATION GROWTH OF SIC BULK CRYSTALS - DEVELOPMENT OF A NUMERICAL PROCESS MODEL

The development of a numerical process model to simulate the sublimation growth of SiC bulk crystals is discussed. Radiation, conduction and convection are considered as heat transfer mechanisms. Mass transport by diffusion and convection is taken into account. First results on the simulation of heat and mass transfer in a 2 inch SiC growth set-up show a negligible effect of convection on process conditions. Chemical reactions in the SiC-graphite system have also been implemented into our model. Preliminary analysis on the dependence of concentration fields and growth velocity on possible chemical reaction mechanisms, e.g. graphitization, reveal that the incorporation of chemical processes into modelling is very important for an accurate description of SiC sublimation growth.