Surface diffusion lengths of adatoms on 6H-SiC{0001} faces in chemical vapor deposition of SiC

Abstract

Surface kinetics on 6H-SiC{0001} faces in chemical vapor deposition of SiC at 1200–1600 °C were studied. Based on a simple diffusion model, surface diffusion lengths were estimated from the lateral growth rates of macrosteps. No significant difference in surface diffusion lengths was observed on Si and C faces. The diffusion length decreased with the reduction of growth temperature. This decrease can be ascribed to the suppressed surface diffusion and to the enhanced incorporation of migrating species into growth nuclei, of which number significantly increased at low temperatures. The effects of gas flow rates on the surface diffusion is also discussed.