CH5 PRECURSOR MECHANISM FOR DIAMOND GROWTH

Deposition rates of polycrystalline diamond films are investigated as a function of concentration of water vapor in a microwave chemical vap or deposition (CVD) apparatus. For CH4:H-2 = 2%: 98% gas composition t he measured deposition rates are compared with mass spectroscopic data published in the literature and predictions suggested by the widely a ccepted methyl radical (CH3) diamond growth model. Our results do not confirm the CH3 model, but a good correlation is found between the con centration of CH5+ radicals and the deposition rates of diamond. The m ain reaction paths leading to diamond deposition from CH5+ are also pr esented.