First principles study of the initial stages of SiC growth on Si(001)

The initial stages of SiC growth on Si(001) are studied via ab initio molecular dynamics simulations at finite temperature. Several C coverages are considered, at various adsorption sites. At low T, C is adsorbed at the surface, with SI-C bond lengths close to that of bulk SiC. When increasing temperature, C adatoms are incorporated in the substrate subsurface layers, giving rise to the carbonization process. On the contrary, C dimers do not penetrate the substrate and remain stable even at the highest temperatures considered: our results point at radicals with single C atoms as efficient precursors for SIC growth. (C) 2001 American Institute of Physics.