Deposition of amorphous hydrogenated silicon carbide thin films by ion beam sputtering

Abstract

Amorphous hydrogenated silicon carbide thin films have been investigated as an adjustable refractive-index material for visible and infrared optical coatings. The films were deposited by the ion beam sputtering of a silicon target with an argon-methane ion beam from a Kaufman-type ion source. Adjusting the argon-to-methane ratio in the ion beam allows the film stoichiometry and optical constants to be varied over a wide range. Rutherford backscattering spectrometry and nuclear reaction analysis were used to determine stoichiometries, and spectroscopic ellipsometry provides information on the optical constants over the visible and near-infrared spectral region. Infrared absorption bands also provide information on the amorphous networking in the films.