Tetrahedral Amorphous Carbon Films By Filtered Cathodic Vacuum-Arc Deposition For Air-Bearing-Surface Overcoat

Measures were taken to reduce the generation of particles during the fabrication of tetrahedral amorphous carbon (ta-C) film by the double-bend filtered cathodic vacuum-arc (FCVA) method. Specifically, the use of physical and electrical filters in the plasma path reduced the number of micron-order particles that arrive at the substrate to about 1/100 the usual value. In addition, an experiment was performed to evaluate the density of pinholes of both the ta-C film fabricated by FCVA method with these filters and a hydrogenerated amorphous carbon (a-C:H) film fabricated by chemical vapor deposition (CVD) method. The results of this experiment revealed that the density of pinholes generated for a film thickness of about 3 nm was 2×103/cm2 for the ta-C film compared to 8×103/cm2 for the a-C:H film, indicating that ta-C film is much denser than a-C:H film. Furthermore, an environmental test under high-temperature and high-humidity conditions showed that ta-C film is superior to a-C:H film in terms of corrosion resistance.