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 molec ular dynamics simulations at finite temperature. Several C coverages are co nsidered, at various adsorption sites. At low T, C is adsorbed at the surfa ce, with SI-C bond lengths close to that of bulk SiC. When increasing tempe rature, C adatoms are incorporated in the substrate subsurface layers, givi ng rise to the carbonization process. On the contrary, C dimers do not pene trate the substrate and remain stable even at the highest temperatures cons idered: our results point at radicals with single C atoms as efficient prec ursors for SIC growth. (C) 2001 American Institute of Physics.