Ab initio study of nucleation on the diamond (1Â 0Â 0) surface during chemical vapor deposition with methyl and H radicals

Ab initio calculations have been performed to investigate the initial stage of the CVD growth of the diamond (1 0 0) surface with CH3 and H radicals. The reaction and the activation energies were calculated for nucleation on a flat terrace, the so-called dimer mechanism. CH2 insertion is found to be the rate-determining step of the dimer mechanism. CVD growth via the dimer mechanism is thermodynamically favorable, however, it is expected to be slow due to the high activation barrier.