Nitrogen and Aluminum Doped Diamond-like Carbon Thin Films by Dc Magnetron Sputtering Deposition

Diamond-like carbon (DLC) thin films used in this study were prepared with DC magnetron sputtering deposition. Silicon (100) wafers were used as the substrates onto which an RF bias was applied during the film deposition. For the nitrogen doped DLC films, a pure graphite target was used as the carbon source and nitrogen gas was introduced into the deposition chamber via a mass flow controller. For the aluminum doped DLC films, the graphite and a pure Al targets were co-sputtered. Nitrogen doping level was monitored by controlling the N2 flow rate from 0 to 12 sccm, while Al doping level was controlled by varying the DC power from 0 to 25 W applied on the Al target. All the DLC films were deposited at room temperature (∼22°C). The DLC films lightly doped with nitrogen and aluminum could maintain the high sp contents in the films indicating good mechanical properties of these films.