Ultrathin amorphous carbon overcoats by filtered cathodic arc deposition

We studied properties of 2- to 25-nm-thick tetrahedral amorphous carbon films produced by filtered cathodic arc deposition. We found that nitrogen doping was effective in controlling film properties. Both the amount of sp/sup 3/ bonding in the film and the hardness decreased with nitrogen incorporation. The adhesion of lubricant to the carbon film was improved by nitrogen doping. Tests of wear and corrosion on a nanometer scale showed the superior tribological and anticorrosion performance of tetrahedral amorphous carbon films over hydrogenated amorphous carbon films.