Dual FCVA–PECVD deposition for DLC films

It is now well known that the filtered cathodic vacuum arc (FCVA) process produces ta-C films with good mechanical properties such as very high hardness. On the other hand, PECVD films are often hydrogenated, with good mechanical properties but with low hardness (soft DLC). However, the internal stress of materials, produced by both techniques, is high and restricts the DLC film thickness.Acombination of these types of deposition is expected to enlarge the range of mechanical properties of DLC films by producing intermediate sp3/sp2 ratios and hardness. In this paper, we demonstrate the incorporation of hydrogen in ta-C films synthesised by mixing FCVA and PECVD. The hydrogen incorporation is realised by introducing a CH4 flow during the FCVA process. We present in this paper a comparison between ta-C and ta- C:H in terms of average mass density and hardness of the films in order to study the hydrogen influence on structure and properties.