Effects of the Temperature Gradient Near the Crystal‐Melt Interface in Top Seeded Solution Growth of SiC Crystal

The top seeded solution growth (TSSG) method is a promising technique for fabricating high‐quality silicon carbide (SiC) single crystals. The carbon required to grow SiC is provided by dissolving the graphite crucible in the silicon melt, and the carbon distribution in the silicon melt is governed by various factors. In this study, two hot zone structures are evaluated using the finite element analysis (FEA) simulation, especially for the temperature distribution, the velocity field, and the carbon concentration in the silicon melt. The results of the simulations revealed significant differences between the two hot zone structures in terms of temperature and carbon concentrations, especially near the interface between the crystal and the melt. SiC crystals are experimentally grown to verify the simulation results with the two hot zone structures. The grown crystals are evaluated to study their surface morphology, crystal quality, polytype stability, and dislocation density by using optical microscopy, high‐resolution X‐ray diffraction, micro‐Raman spectroscopy, and chemical etching, respectively. The simulations and experiments suggests that the hot zone structure with a small temperature gradient especially near the interface between the crystal and the melt promotes stable conditions for growing SiC crystals via the TSSG method. Through simulations and experiments on the top seeded solution growth of SiC, the effect of temperature gradient near the crystal‐melt interface is evaluated considering the surface morphology, the crystal quality, the polytype stability, and the dislocation density. A small temperature gradient near the crystal is found to make stable conditions for growing SiC crystals.