<title>Three-dimensional distributions of methyl density in a hot-filament CVD reactor: comparison with cavity ring-down spectroscopy measurements</title>

Abstract

Developed 3D model of a hot-filament chemical vapor deposition reactor is used to reconstruct the methyl density spatial distributions and to describe reactor parameters dependencies of CH3 which have been measured, by others, using a line-of-sight optical technique called cavity ring- down spectroscopy (CRDS). In the model full set of transport equations taking into account the detailed gas-phase reaction mechanisms, molecular diffusion and thermodiffusion, catalytic hydrogen dissociation at the filament and surface kinetics at the substrate is numerically solved. The results of 3D and 2D model calculations are compared with the high sensitivity measurements of methyl radical absorbance at 231.9 nm by CRDS. Good quantitative agreement of experimental data and 3D model results, in contrast to 2D model calculations, was obtained. An importance of 3D effects for the species densities and gas temperature distributions is revealed.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.