Dehydrogenation of nitrogen-containing carbon films by high-energy He2+ irradiation

It is well known that amorphous carbon and related films consist of nano-si zed carbon clusters. With the incorporation of hydrogen into these films, t he hydrogen termination limits the cluster size and decreases the bond stre ngth among clusters. In this study, dehydrogenation from amorphous hydrogen ated carbon nitride films was accomplished using 3.75 MeV-He2+ irradiation. The hydrogen atoms forming methyl and ethylene groups were mainly removed from the film during the irradiation procedure. With the progress of dehydr ogenation from methyl and ethylene groups, the degree of order of the atomi c configuration became large, resulting in an increase of the cluster size. The mechanical properties of amorphous films were improved due to cluster growth.