Effects of coil frequency on the carbon transport in the top-seeded solution growth of SiC single crystal

Abstract

The flow pattern and carbon transport in the solution for the solution growth of silicon carbide (SiC) in an induction-heating system can be effectively controlled by adjusting the coil frequency to obtain a relatively uniform distribution of growth rate. In this paper, a global heat and mass transfer model was first verified by the SiC crystal growth experiment results at the coil frequency of 8 kHz. Then, the influence of coil frequency on the fluid flow, carbon concentration, and growth rate for the growth of SiC crystals was numerically investigated. The results indicated that electromagnetic convection (at low frequencies) greatly enhances the upward convection beneath the crystal and weakens the adverse effects of Marangoni convection, resulting in a uniform distribution of radial temperature along the growth interface. Consequently, the carbon transport from the crucible wall to the crystal center is strengthened, leading to a uniform region of high carbon supersaturation with a lower coil frequency. The optimal radial uniformity of the growth rate along the growth interface is achieved at the coil frequency of 3 kHz.