Synthesis and characterization of tungsten oxynitride films deposited by reactive magnetron sputtering

Tungsten nitride and tungsten oxynitride films were produced by a planar type reactive sputtering system using an atmosphere of argon and reactive gas mixture of nitrogen and oxygen. Tungsten and nitrogen content of the films decreased and oxygen content of the films increased on increasing O2/N2 ratio. The as-deposited tungsten nitride film contains face center cubic W2N phase with (1 1 1) orientation. However, with incorporation of oxygen in the film the formation of a broad peak occurred, suggesting that a part of the structure becomes amorphous. Plastic hardness and Young's modulus of tungsten oxynitride films were lower than tungsten nitride film. The potentiodynamic polarization measurements in 0.05 M H2SO4 solution indicated that amorphous-like tungsten oxynitride film shows better corrosion resistance than tungsten nitride film.