Analysis of surface diffusion of carbon- and nitrogen-containing molecules during homoepitaxial growth of 4H-SiC (0001) under silicon-rich conditions

Abstract

Abstract Reported experimental results on homoepitaxial 4H-SiC grown by chemical vapor deposition on 1°- and 4°-off (0001) surfaces under silicon-rich conditions in a SiH4−C3H8−N2−H2 system are quantitatively analyzed according to surface diffusion theory dealing with step dynamics. The surface-diffusion lengths of carbon- and nitrogen-containing molecules are, respectively, estimated to be λ C = 25 nm and λ N ≥ λ C at 1773 K. This magnitude relationship agrees with the reported assumption made for the variation in nitrogen concentration on (000 1 – ) facets of 4H-SiC grown by physical vapor transport.