Theoretical investigation on surface kinetics of the SiC single crystal growth

According to the BCF theory, a simple surface diffusion model of SiC single crystal was established, and the key parameters such as the surface diffusion length, the critical nucleation and growth rate were obtained by theoretical calculation. The results show that surface diffusion length is 460nmat 2400K and it decreases with the rise of temperature. The relationship between the critical nucleation and the temperature was analyzed. For silicon surface, the critical saturation is decreased with the increase of temperature. Compared with silicon surface, the critical saturation of carbon surface is smaller and almost constant with the increase of temperature. That means, under the same saturation, two-dimensional nucleation occurs on the carbon surface. The growth rate of SiC was obtained using the surface diffusion length, the critical saturation and chemical equilibrium constant of reaction system. And the value was in agreement with the experimental results.