HYDROCARBON ADSORPTION ON A DIAMOND (100) STEPPED SURFACE

We present theoretical studies of various hydrocarbon radicals and mol ecules on the (100) surface of diamond. We use molecular dynamics and a dynamical quenching algorithm to calculate the energetics of differe nt adsorption configurations, allowing for full relaxation of the unde rlying lattice. We use a parametrized many-body potential function tha t has been used for energetics calculations with a great deal of succe ss [D. Brenner, Phys. Rev. B 42, 9458 (1990)]. Our calculations show t hat adsorption of hydrocarbons on either the flat terraces or near dif ferent types of step edges give small variations of binding energies a nd equilibrium configurations. This reflects the strong covalent bondi ng pervasive in the carbon systems, which forces the strain fields and bonding energetics to be determined to a great extent by the local en vironments. We analyze the consequences of these results for the dynam ics of growth under typical conditions.