Dynamic MC simulation of DLC films synthesis by PBII

Dynamic Monte Carlo simulations have been applied to the synthesis of diamond-like carbon films by plasma-based ion implantation (PBII). The direct chemical incorporation of the radicals, like CH3 reacting with a diamond surface, is too low for the deposition of DLC films, so that the other reaction mechanisms should be responsible. We assumed a surface reaction layer consisted of several radical layers, in which radicals are dissociated by the collisions with energetic ions and some H and C atoms are released out and some H and C atoms are stitched into the subsurface and the stitched C atoms are assumed to form the sp3 states. In the subsurface, it was assumed that sp3 states atoms are released to the sp2 state and H atoms are released out of the surface as a results of collision cascades induced by the energetic ions. The following was obtained by the simulation: the C atom stitching probability, which related with sp3 state formation, has a maximum of near 500 eV independent of the dissociation energy of radicals, number of monolayers in the surface reaction layer, or ion/radical arrival ratio. It agrees with the experimental result. The stitching probability increases with the decrease of the dissociation energy and the increase of number of monolayers in the surface reaction layer and ion/radical ratio. The H concentration shows a maximum of near 300 eV. It also agrees with the experimental result.