Effect of nitrogen concentrations on O, structural and mechanical properties of self-organized a-C:N films

Diamond like Carbon (DLC) or amorphous carbon is having a wide range of applications in automobile industries and surface engineering as low friction (solid lubricant) and hard surface coating. The nitrogenated thin films are playing an important role to improve the surface properties of DLC for the above mentioned applications. Those properties comprise high mechanical strength, chemically inert with atmosphere and biomaterials, low friction and wear resistance. These properties should be achieved in nano-micro scale thickness, because the thickness of the film is limited by its own internal stress above which the film will behaving poor adhesion to the substrate material and will be stripped off. Especially nitrogenated carbon films (a-C:N) have more importance in this area due to the possibility of formation of carbon nitride (C₃N₄) in usual deposition conditions of amorphous carbon films. Where the production of pure carbon nitride need extreme deposition conditions which are difficult and expensive in practice. This work elaborates the deposition of nitrogenated carbon films on silicon and glass substrates using DC and RF-Magnetron Reactive Sputtering in nitrogen atmosphere. The structural analysis of the film was carried by XRD and Raman spectroscopy, Optical by Ellipsometry and Photoluminescence, Compositional by EDAX and XPS and Surface properties by AFM and SEM. The hardness has been measured by means of nano-indentation method and the above results were correlated. The effect of Nitrogen in few properties is compared for both DC and RF sputtered Carbon films. (author)