FEM SIMULATION OF TEMPERATURE DISTRIBUTION IN THE GROWTH OF SILICON CARBIDE CRYSTALS BY SUBLIMATION GROWTH METHOD

Abstract

Finite element method simulation of temperature distribution during sublimation growth of SiC single crystals by sublimation method. We consider the evolution of temperatures at the SiC source and at the SiC seed crystal, which are highly relevant to the quality of the grown crystals, but inaccessible to direct measurements. The simulations are based on a transient mathematical model for the heat transport, including heat conduction, radiation, and induction heating. Varying the position of the induction coil as well as the heating power, it is shown that the measurable temperature distribution between the bottom and the top of the growth apparatus can usually not be used as a simple indicator for the respective temperature distribution between SiC source and seed. Moreover, it is shown that the one dimensional symmetry is easily broken by the geometry or the temperature distribution. it is observed that SiC seed is unstable because variations in the geometry may give rise to a positive feedback in the growth and etch rates .