First stages of the oxidation of the Si-rich 3C–SiC(001) surface

Systematic studies of O adsorption on clean and H-saturated Si-rich 3C–SiC(0 0 1) 3 × 2 surfaces within density functional theory are presented. We investigate the O binding energy for a variety of possible adsorption sites on the surface and in subsurface regions for both substrates. We find that the on-surface adsorption sites are preferred over deep adsorption for both substrates and that O is more strongly bound on the hydrogenated surface. We explore the dependence between the energy of the adsorption site and the surface relaxation accompanying it.