Densification of thin a-C: H films grown from low-kinetic energy hydrocarbon radicals under the influence of H and C particle fluxes : a molecular dynamics study

Mol. dynamics simulations have been performed to investigate the role of H- and C-fluxes on the structure and growth of thin a-C: H films. A first series of simulations was carried out using exptl. obsd. hydrocarbon radicals and addnl. H-fluxes to grow the films. The selected conditions correspond to the exptl. deposition using remote plasma sources without substrate bias. A second series of simulations was performed to investigate the influence of a fixed addnl. C particle flux towards the substrate. It is found that H-incorporation into the film considerably changes its microstructure. The mass d. of the films increases as the H-flux towards the film surface increases. A max. in the mass d. is found at H-flux of 20%. A decrease in mass d. is found when using higher H-fluxes. The addnl. C-flux further increases the mass d. The results are explained in terms of the role of the H-atoms in the film and the deposition behavior of the hydrocarbon radicals. These results provide information regarding the deposition and structure of thin a-C: H films grown from low-kinetic energy hydrocarbons, suggesting that densification and hence hardening of the films is possible, even without addnl. ion bombardment, by applying an addnl. H-flux and/or C-flux towards the substrate. [on SciFinder (R)]