Growth kinetics and thermal stress in the sublimation growth of silicon carbide

The productivity and quality of SiC bulk crystal grown from vapor phase depend strongly on the temperature distribution in a SiC growth chamber. An analytical formulation is proposed to correlate the growth rate with process parameters such as pressure, temperature, and temperature gradient. A growth kinetic model is also developed to predict the growth rate and examine the transport effects on the growth rate and dislocation formation. Simulation and analytical results show that the growth rate increases when the growth temperature increases, argon pressure decreases, and/or the temperature gradient between the source and seed increases. An anisotropic thermoelastic stress model is proposed to study the influence of thermal stress on dislocation density. The method to attach the seed is observed to play an important role in stress distribution in an as-grown silicon carbide ingot.