INFLUENCE OF DEPOSITION PARAMETERS ON DIAMOND THERMAL PLASMA CHEMICAL-VAPOR-DEPOSITION WITH LIQUID FEEDSTOCK INJECTION

A global three-dimensional two-phase model for thermal plasma chemical vapor deposition with liquid feedstock injection developed in our gro up [1,2] has been used for a simulation of diamond production from ace tone, ethanol and methane in argon-hydrogen plasmas. In this study, th e influence of precursor type, gas and liquid flow rates, atomizing pr obe location and characteristics, and catalytic reactor chamber is dis cussed. The main finding is that deposition utilizing liquid precursor s offers a distinct new deposition mechanism-liquid droplet penetratio n of the substrate boundary layer followed by a rapid droplet evaporat ion and a local increase in the surface deposition rates. Although the overall deposition rate does not exceed that of gasphase precursors, it is believed that further optimization mill lead to a deposition rat e increase. (C) 1998 Elsevier Science S.A.