CS radical formation in the Hot Filament CVD of diamond thin film by the CRDS

In the present study, the CS radical was detected using Cavity Ringdown Spectroscopic (CRDS) during the Hot Filament CVD growth of diamond thin film for the CH$_{4}$ / H$_{2}$ mixture doped with H$_{2}$S. The absolute absorption optical density of the CS radical was obtained, and the concentration of this radical was estimated as function of CH$_{4}$ and H$_{2}$S concentrations. It was found that the yield of the CS radical depends on the presence of the substrate. The experimental results show that the heterogeneous sources of the CS radical are more significant in the presence of the substrate than in experiments without substrate. The relationship between the homogeneous and heterogeneous channels of the CS radical generation was estimated for both cases with and without substrate. The translational (Doppler analysis of the line contour) and rotational (fitting of the rotationally resolved CS spectrum) temperatures were estimated.