Numerical Modeling of the Cellular Structure Formation Process in SiC Solution Growth for Suppression of Solvent Inclusions

For the solution growth of silicon carbide, solvent inclusions are significant technological issues, and methods to suppress the formation of solvent inclusions are investigated in this study. Experimental observations show that solvent inclusions are formed behind the cellular structures. A phase field model is used to reproduce the formation process of cellular structures and solvent inclusions. Simulation results indicate that slight perturbations of the step front can convert into cellular structures in the case of insufficient supply of carbon, and the overdeveloped cellular structures consequently result in solvent inclusions. Accordingly, several schemes can be suggested by the simulation model to suppress the formation of cellular structures by enhancing the carbon supply. By increasing the carbon diffusion coefficient, cellular structures can be suppressed. Moreover, the step height and the solution flow direction also play an important role in suppressing the cellular structures. This study provides a comprehensive understanding of the formation process of cellular structures and solvent inclusions. A growth process with a high diffusion coefficient and opposite solution flow to the step flow direction was proposed to suppress the formation of cellular structures. The proposed numerical model could be applied in other solution crystal growth methods.