Influence of the aluminum incorporation on the structure of sputtered ZrNx films deposited at low temperatures

We have studied the influence of the Al incorporation in the crystalline structure of ZrN thin films deposited by dc magnetron sputtering processes at low temperature. The incorporation of the aluminum in the films depends directly on the Ar/N2 ratio in the gas mixture and the power applied to the aluminum cathode during the deposition. The chemical composition and the crystalline structure of the films were analyzed by Energy Dispersive X-ray (EDX) spectroscopy and X-ray Diffraction (XRD), respectively. When Al atoms are incorporated into the ZrN coatings, the strong ZrN (200) preferred orientation is modified to a combination of phases related to (111) ZrN with a contribution of cubic (111) AlN and possibly (211) Zr3N4, which are detected by XRD for high aluminum concentrations. Fourier Transform Infrared (FTIR)spectroscopy allowed us to complete the identification of the nitrides and oxides incorporated into the deposited films. The effect of a bias voltage applied to the substrate has also been investigated and related to the changes in the microstructure and in the nanohardness values of the ZrAlN films.