The structures and properties of a-C:H films deposited at a wide range of relative hydrogen gas flow rate by RF sputtering

Amorphous hydrogenated carbon (a-C:H) film have been deposited by RF magnetron sputtering system in H2/He plasma. We investigated the effects of the gas pressure (pt) to films deposited in a wide region of relative hydrogen gas flow rate. The growth rate of the films at pt = 53.2 Pa was the highest. The bonding hydrogen concentration (nH) and the optical gap of the film at higher pt were higher. Moreover, the film with high nH had high optical gap. These results indicate that the film with the high optical gap can be deposited at low RH by using high pt.