Corrosion resistance and biocompatibility of zirconium oxynitride thin film growth by rf sputtering

Abstract

Thin films of zirconium oxynitride were grown on common glass, silicon (100) and stainless steel 316 L substrates using the reactive rf magnetron sputtering technique. The films were analyzed through structural, morphological, and biocompatibility studies. The structural analysis was carried out using X-ray diffraction (XRD), and the morphological analysis was carried out using scanning electron microscopy (SEM) and atomic force microscopy (AFM). These studies were done as a function of growth parameters, such as power applied to the target, substrate temperature, and flow ratios. The corrosion resistance studies were made on samples of stainless steel 316 L coated and uncoated with Zr$_{\text{x}}$N$_{\text{y}}$O films, through of polarization curves. The studies of biocompatibility were carried out on zirconium oxynitride films deposited on stainless steel 316L through proliferation and cellular adhesion. The XRD analysis shows that films deposited at 623 K, with a flow ratio $\Phi$N2/$\Phi$O$_{2}$ of 1.25 and a total deposit time of 30 minutes grew preferentially oriented along the (111) plane of the zirconium oxyitride monoclinic phase. The SEM analyses showed that the films grew homogenously, and the AFM studies indicated that the average rugosity of the film was 5.9 nm and the average particle size was 150 nm. The analysis of the corrosion resistant, shows that the stainless steel coated with the film was increased a factor 10. Finally; through the analysis of the biocompatibility we established that the films have a better surface than the substrate (stainless steel 316 L) in terms of the adhesion and proliferation of bone cells.