Kinetics of the diamond-like film deposition on glass fibers

Abstract

Abstract In order to determine the mechanism of diamond-like film deposition in a r.f. discharge in methane, a tiny glass fiber was spanned along the discharge axis and perpendicular to the parallel-plate electrodes. The discharge was operated in a symmetric and slightly asymmetric regime. The film thickness and its surface topography were analyzed by means of scanning electron microscopy. Across the interelectrode space a non-uniform film thickness distribution on the fiber was observed. The films up to 15 μm were deposited with excellent coverage uniformity and time stability on a 40 μm diameter glass fiber substrate. The film thickness distribution along the fiber is the result of the space-dependent density profile of methyl CH 3 radicals which contribute mostly to the film formation. It was concluded that the diffusion of methyl radicals in the discharge is responsible for the observed film thickness profile along the fiber.