Transport phenomena in sublimation growth of SiC bulk crystals

Sublimation growth of SIC bulk crystals in the atmosphere of concentrated multi-component vapor is studied using a specially developed model of transport processes coupled with heterogeneous reactions at the source and the seed surfaces. The convective and multi-component diffusion mechanisms of the gas phase transport, dependence of the pressure level inside the growth chamber on the growth conditions, and kinetic jumps of the species partial pressures at the Knudsen layers on the reactive surfaces are taken into account in the model. The latter effect is described by introduction of novel boundary conditions representing extension of the Hertz-Knudsen relationship for the case of multicomponent vapor. The results of calculations are shown to be in a good agreement with the available experimental data. (C) 1999 Elsevier Science S.A. All rights reserved.