Mechanism of Replicating 4H-SiC Polytype during Solution Growth on Concave Surface

To determine the mechanism of 4H-SiC replication during solution growth on a concave surface, SiC growth on a 2-in.-diameter 4H-SiC (0001̅) seed and on 0.5-in. square seeds of different planes was carried out at 2273 K using Si–40 mol % Cr-based solvent with and without Al addition. Grown crystal that replicated 4H-SiC possessed (11̅02̅) facets at the periphery of the growth interface, with its growth tips located at both edges of the facet. Al addition to the solvent enlarged such facets on the growth interface and increased the probability of 4H-SiC replication. Furthermore, Al addition to the solvent improved the stability of crystal grown on the (11̅02̅) seed, as evaluated from surface roughness analysis. According to the surface stability, we propose a mechanism for 4H-SiC replication and the effect of Al addition into the solvent during solution growth on a concave surface.