Estimation of supersaturation at steps during chemical vapor deposition of 4H-SiC ( 0001¯ ) from reported growth rate and cross-sectional profile of spiral hillock

Abstract

Abstract Based on the Burton–Cabrera–Frank (BCF) and Cabrera–Levine theories, supersaturation at steps (σ step) during chemical vapor deposition of 4H-SiC (0001̄) at 1570 °C under the condition of C/Si ratio of unity was estimated from the reported growth rate and cross-sectional profile of a spiral hillock, as a function of surface diffusion length of C2H2 molecules (λC2H2). The previously assumed zero σ step in the BCF theory was found to be a possible source of error in the case λC2H2 > 0.63 μm because of the estimated ratio of σ step to the surface supersaturation exceeding 0.1.