AN ANALYSIS OF GAS-PHASE ETHANOL-WATER CHEMISTRY FOR DIAMOND CVD

Chemical kinetics calculations were carried out on ethanol (EtOH)-wate r mixtures at a range of temperatures, pressures and EtOH-to-H2O ratio s. The results show that the mole fractions of many chemical species d epend very sensitively on the initial EtOH-to-H2O ratio and diverge sh arply after an induction time which depends on both pressure and tempe rature. We explain this divergence primarily in terms of the stability of carbon monoxide and show that the rate-limiting steps that dictate the induction time are the molecular hydrogen dissociation reactions. Our calculations also predict the dependence of the concentrations of potential growth (C, CH3, C2H2) and etching (O, OH, O-2) species for diamond CVD on operating conditions.