Effect of growth parameters on the heteroepitaxy of 3C-SiC on 6H-SiC substrate by chemical vapor deposition

Epitaxial 3C-SiC(1 1 1) films were grown on 6H-SiC(0 0 0 1) Si face on axis substrates by chemical vapor deposition under H2, SiH4 and C3H8 in a cold wall vertical reactor. Two temperatures were studied (1450 and 1700 °C) with various C/Si ratio and deposition time. It was found that under conditions giving high lateral growth (low C/Si and/or high temperature), homoepitaxial growth occurred even at temperatures as low as 1450 °C. For other conditions, the 3C-SiC polytype was detected and always together with the formation of double positioning boundaries whose density was found to depend on the growth conditions but not on the initial surface reconstruction. Single domain enlargement was observed when growth was performed at 1700 °C over a nucleation layer grown at 1450 °C.