Influence of interfacial energy on the growth of SiC single crystals from high temperature solutions

We report the results of long-time (80 h) growth of 4-inch SiC single crystals from solutions of C–Si–Cr–Ce with and without Al addition (5 at%) by a top seeded solution growth (TSSG) method aiming at clarifying the role of interfacial energy between SiC and liquid solution. The Al addition smooths the growth surface by suppressing step bunching and two-dimensional (2D) nucleation, improves the crystalline quality, stabilizes the 4H polytype, and changes the ingot shape. Importantly, the growth rate is more than two factors enhanced by adding Al to the solution in comparison with the solution free of Al. The substantial curbs of step bunching and 2D nucleation on the advancing surface of SiC are responsible for the enhancement of the growth rate. The interfacial energy of SiC/solution is found to decrease upon Al addition based on the in situ contact angle measurements of solution droplets on SiC (000) at 1750 °C and 1850 °C for the first time. Our results clearly verify the effect of Al on the SiC growth from solutions and highlight the importance of solid/liquid interfacial energy anisotropy on the growth of SiC by TSSG.