Calculated energies of adsorption of non-hydrocarbon species on diamond H/C(1 1 1) surface and the abstraction energies of these species abstracted by hydrogen atoms using ab initio calculation

The energetics of adsorption of non-hydrocarbon radical species on H/C(1 1 1) diamond surface and the abstraction energies of these species abstracted by hydrogen atoms, which are in excess in gas phase in the diamond thin film growth using the chemical vapor deposition (CVD) method, were examined using ab initio calculation method. Based on the calculated results for the examined species, which include H, F, OH, NH₂, Cl, CH_mX_n (X = F or Cl) radicals, the tendency of incorporation of F, O, N, H and Cl atoms in the diamond thin film is discussed. The high adsorption energy and the high abstraction energy abstracted by excess gas-phase H atoms for F radicals suggest that F atom has the highest tendency to stay in the diamond thin film among the examined non-carbon atoms. In contrast, the comparable adsorption energy of Cl atom with other examined radicals except F radical, and its low abstraction energy, indicate that CI atom possesses the least tendency to be incorporated in the diamond thin film. For O, N and H atoms, their calculated abstraction energy values suggest that the overall order of tendency of incorporation in diamond thin film is F>O>N>H>Cl. In addition, the energetically comparable adsorption energy for the CH₂Cl radical, compared with the other examined CH_mX_n species, and the low abstraction energy of CI atom support that CH₂Cl is a good growth species in diamond CVD thin film growth.