Zirconium nitride/nickel nanocomposite structures

Nanocomposite films that consist of nanocrystalline zirconium nitride embedded in an amorphous nickel matrix were deposited by unbalanced magnetron sputtering on silicon substrates at room temperature with bias voltages in the −45 to −160 V range. The other variable parameter in this study was the nickel content regulated by controlling target power. The power to the Zr target and the nitrogen flow rate were fixed. The films were analyzed by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), spectroscopic ellipsometry, and nanoindentation. The grain size was deduced from the width of the XRD peaks using the Scherer formula and was found to decrease with the increase in nickel content. The chemical and phase composition was determined from XPS measurements. The optical constants were measured using spectroscopic ellipsometry. A correlation between film structure/composition and optical constants was established. The mechanical properties of the coatings were evaluated using nanohardness testing and were found to depend on composition and deposition parameters.