Evaluation of critical supersaturation ratios during epitaxial growth of hexagonal SiC {0001} under carbon- and hydrogen-rich conditions

Abstract

Abstract Critical supersaturation ratios α crit during epitaxial growth on 6H-SiC (0001) and (000 1 ‾ ) under carbon- and hydrogen-rich conditions were formerly estimated by assuming disc-shaped critical nuclei whose side surfaces were terminated with silicon and carbon atoms, respectively. Since this assumption contradicts the atomic configurations of possible hexagonal-prism-shaped critical nuclei, we evaluated α crit by using the reported surface free energies for hydrogen-passivated 3C-SiC surfaces. To account for the observed α crit being much larger on 6H-SiC (0001) than on 6H-SiC (000 1 ‾ ), we considered that silicon atoms on the side surfaces of hexagonal-prism-shaped critical nuclei be terminated not by carbon but by hydrogen atoms.