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(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.