NANOTRIBOLOGICAL CHARACTERIZATION OF HYDROGENATED CARBON-FILMS BY SCANNING PROBE MICROSCOPY

Mechanical and tribological properties of hydrogenated carbon films we re evaluated using three newly developed nanotribological characteriza tion techniques based on scanning probe microscopy, including nano-har dness tests and nano-wear tests using a point contact microscope and n ano-friction tests using a friction force microscope. It was found tha t the nanoindentation hardness decreases with increase of hydrogen con tent in the films, and the substrate influence on the hardness values is not significant for indentation depths less than a quarter of the t hickness of the carbon films. The critical load for wear on the fricti on force versus loading force curve also decreases with hydrogen conce ntration, whereas the nano-wear depth and the nano-friction coefficien t increase. Our results show that the three characterization methods a re very effective in determining mechanical or tribological properties of ultrathin films and optimizing the fabrication process parameters.