RF-deposited a-C:H films from hydrogen-rich methane mixtures: relationships among plasma characteristics, deposition rates, and material properties

Abstract a-C:H films were prepared by RF glow-discharge decomposition of diluted methane-hydrogen mixtures. RF power, bias voltage and methane percentage were systematically varied, and plasma characteristics, growth rates, and properties of the resulting films were studied by optical emission, photothermal deflection, IR, visible, Raman spectroscopy, and mass density measurements. The results found indicate a role of hydrogen in affecting the deposition mechanism by etching the growing films, but with no major effect on their structure with respect to other hydrocarbon feedstocks.