Synthesis of amorphous carbon nitride by ion implantation

N2+ were implanted into diamondlike carbon (DLC) films in an attempt to synthesize amorphous carbon nitride. The DLC films were previously deposited on steel substrate by using an ion beam sputtering deposition (IBSD) where a single Kaufman type ion gun with argon source was used to sputter a graphite target and simultaneously bombard the growing film. Parallel to the ion implantation route, amorphous carbon nitride films were also synthesized by directly using the reactive ion beam sputtering deposition (RIBSD) with nitrogen source to incorporate nitrogen into the film. The structure and properties of the films were determined by using Raman spectroscopy, XPS and nano-indentation. The implantation of N2+ into a-C films offers a higher hardness than that directly synthesized by RIBSD, probably through an increase in sp3/sp2 ratio and in the proportion of nitrogen atoms chemically bonding to carbon atoms. The results show that although there are differences in film composition, structure and properties between these two processes, both methods can be used for synthesis of nitrogen-containing amorphous DLC thin films which significantly modify the substrate surface.