NANOTRIBOLOGICAL CHARACTERIZATION OF HYDROGENATED CARBON-FILMS BY SCANNING PROBE MICROSCOPY

Mechanical and tribological properties of hydrogenated carbon films were evaluated using three newly developed nanotribological characterization techniques based on scanning probe microscopy, including nano-hardness tests and nano-wear tests using a point contact microscope and nano-friction tests using a friction force microscope. It was found that the nanoindentation hardness decreases with increase of hydrogen content in the films, and the substrate influence on the hardness values is not significant for indentation depths less than a quarter of the thickness of the carbon films. The critical load for wear on the friction force versus loading force curve also decreases with hydrogen concentration, whereas the nano-wear depth and the nano-friction coefficient increase. Our results show that the three characterization methods are very effective in determining mechanical or tribological properties of ultrathin films and optimizing the fabrication process parameters.