MODELING ANALYSIS FOR THE OPTIMIZATION OF DIAMOND DEPOSITION IN A STAGNATION-FLOW FLAME REACTOR

The successful utilization of premixed oxygen/acetylene flames in the chemical vapor deposition of diamond has led to an interest in scaleab le configurations, realized in this work using a stagnation-flow react or. Through a computational model that incorporates detailed gas-phase kinetics, molecular transport, and surface chemistry, the roles of pr ocess variables such as flame stoichiometry, rate of strain, and the u se of flow diluents are explored. For parameterization, we have charac terized diamond deposition using the surface fluxes of atomic hydrogen and methyl radical, and have correlated the modeling results with exp erimental data from a scaled-up stagnation-flow reactor. Flame tempera ture, stoichiometry, and diluent addition were found to have a strong effect on diamond deposition, enabling optimization of the diamond dep osition rates with a constraint on diamond film quality. Modeling resu lts are presented, and the utility of the flame model in conjuction wi th an experimental diamond deposition study is demonstrated.