Deposition and properties of ZrNx films produced by radio frequency reactive magnetron sputtering

Thin ZrNx films have been prepared by reactive radio frequency magnetron sputtering. The radio frequency power has been chosen as a sputtering parameter and the effect on the compositional and optical properties of the films was systematically studied. The films have been analyzed by X-ray photoelectron spectroscopy. The reflectance and transmittance of the samples have been recorded by a spectrophotometer in the UV–Vis–IR range. The effects of the different powers (in the range 100–400 W) on the stoichiometry of ZrNx films have been studied. The components revealed on N 1s photoelectron peaks were correlated with different bounding states for the zirconium nitride. The threshold power value between N-rich ZrNx films and Zr-rich ZrNx ones is 270 W. A correlation has been observed between the optical properties and the stoichiometry of the films. In fact, the samples catalogued as N-rich by X-ray photoelectron spectroscopy analyses are optically insulating and the Zr-rich ones show a metallic behaviour. A simple growth model has been set up in order to explain the different chemical states detected from the compositional measurements.