F2 REACTION DYNAMICS WITH DEFECTIVE SI(100) - DEFECT-INSENSITIVE SURFACE-CHEMISTRY

We have investigated the influence of a variety of dimer vacancy defects on the reactivity of F-2 molecules with the clean Si(100)-2 X 1 reconstructed surface via molecular dynamics using an ab-initio-derived Stillinger-Weber-type many-body potential. Our simulations of a wide variety of defective surfaces indicate that vacancy defects have a negligible effect on the reactivity of F-2 molecules toward the Si surface. These simulations suggest that the density of accessible Si dangling bonds (i.e., the number of reactive surface sites) is the sole critical factor in determining the reactivity for this highly exothermic surface reaction. Thus, defective Si(100) exhibits essentially the same reactivity toward F-2 as a perfect Si(100)-2 X 1 surface.