Reactive laser ablation deposition of C-N films

We report a study of the characteristics of thin films deposited at room temperature on Si and KBr substrates by XeCl laser ablation of graphite in low pressure (0.25-2.5 mbar) nitrogen and ammonia atmospheres. Very hard films, with a very high electrical resistivity were obtained. The deposition rates decrease with increasing ambient pressure. N/C atomic ratios up to 0.6 were calculated from backscattering measurements. Different diagnostic techniques (XPS, IR absorption spectroscopy, etc.) demonstrate the formation of carbon nitride with a prevalent graphite-like structure. Films deposited in NH3 are thinner and present a lower quantity of N atoms bound to C atoms than films deposited in N2 at the same ambient pressure.