Growth and characterization of cathodic arc evaporated CrN, (TiAl)N and (TiZr)N films

Abstract

Nitride films have been grown using newly developed chromium, titanium-aluminum and titanium-zirconium targets by the cathodic arc evaporation process. Special alloy processing produced cathodes that overcame conventional problems associated with evaporation of multicomponent cathodes. Single and multilayer films of the various nitride compositions were analysed using X-ray photoelectron spectroscopy (XPS) and their electrochemical polarization behaviour was tested using polarization corrosion methods. From the XPS data, it was determined that the atomic ratio of the metallic constituents in the alloy cathodes was unity and the ratio of the cations to the anions in the nitride films was also unity. The Ti 2p, Al 2p and Zr 3d binding energies from the nitride films were 0.8–1.0 eV higher than in the corresponding target material. The XPS results strongly suggest that the (TiAl)N films are made up of distinct TiN and AlN phases and the (TiZr)N films of similarly distinct TiN and ZrN phases. In addition, electrochemical studies showed that the rest potential and polarization behaviour of the nitride films were influenced by the composition and integrity of the surface film.