Characterization of diamond-like films using electron probe microanalysis

Amorphous carbon films were deposited onto Si, SiC, and Ti alloys by implanting low-energy C⁺ ions, laser ablation, or double ion beam sputtering (DIBS). Their soft x-ray emission spectra were recorded by means of an electron probe microanalyzer (EPMA). Comparison of the energy position of peaks with characteristic spectra of various standards has shown that the short range order in films formed by 2 keV C⁺ implantation or laser ablation was about the same as in diamond. On the contrary, DIBS films and implantation films formed at lower energies were rather graphite-like. The former were constituted of true diamond-like carbon, since other analysis indicated that they were free of H and O contamination and that a carbide of the substrate species did not grow. It is concluded that EPMA is a valuable method for characterizing the bonding in carbon films.