The application of the cathodic arc to plasma assisted chemical vapor deposition of carbon

This article reports on the properties of hydrogenated carbon films deposited using a cathodic arc decomposition process with a graphite cathode used in a plasma assisted chemical vapor deposition mode. In this application of the cathodic arc, acetylene is broken down into radicals to form hydrogenated amorphous carbon films. Some results are also reported using hydrogen gas. The density in terms of plasmon energy or sp3 fraction of the films has been found to decrease with increasing acetylene or hydrogen flow rate, approaching the value for glow discharge deposited polymer-like hydrogenated amorphous carbon. When substrate bias is used, the hydrogen content is reduced and graphite microcrystals appear, together with cauliflower-like growths. In the range between 100 and 500 V, negative substrate bias increases the density of the films. Overall, the hydrogen content decreases with the density of the films.