Flow modification enhancing the growth rate in top seeded solution growth of SiC crystals

In this study, multiphysics simulations were carried out to understand the convection mechanisms of the top seeded solution growth (TSSG) of SiC. Experimental melting tests and crystal growth were conducted to verify the simulation results in the growing temperatures between 1700 and 1900 °C with rf induction heating furnace. From the solidified melt of Si-Cr solution after the melting test, the melt flow in the simulation was successfully verified. In the given experimental conditions, the electromagnetic convection was found to govern the global fluid flow, while other mechanisms including the Marangoni convection, the buoyancy convection and the centrifugal forced convection influence the fluid flow near the crystal. Based on an understanding of the fluid flow obtained with the simulations, a structural flow modifier (FM) was applied to enhance the growth rate of the SiC crystal. The growth rates of SiC with/without FM were successfully estimated from simulations showing good agreements with the experimental values. After the experimental crystal growth using FM, a remarkable enhancement in the growth rate was found in an FM configuration, which suggests a way to improve the growth rate by the TSSG method based on the efficient use of the dissolved C in the melt. Based on the verified multiphysics simulation, a model describing C transport contributing to crystal growth was suggested. Based on the further understanding of C transport, the growth rate was enhanced by adopting a flow modifier in the melt.