A comparative study between pure and Al-containing amorphous carbon films prepared by FCVA technique together with high substrate pulse biasing

Intrinsic stress in the amorphous carbon films prepared by the filtered cathodic vacuum arc technique is relatively high and limits the thickness of the film. Effective stress reduction is obtained by depositing the film in conjunction with high substrate pulse biasing. Stress reduction is also attained, by incorporating a small percentage of metal ions in the films. In the present study, the properties of amorphous carbon films prepared with and without aluminium incorporation (a-C and a-C:Al) under substrate pulse biasing conditions at different frequencies are compared. The a-C:Al films exhibit deposition rates and intrinsic stress lower than pure a-C films. A stress reduction of approximately 85% can easily be obtained, for a-C films at higher pulse frequencies. The stress is further lowered by Al incorporation, but by sacrificing the smoothness, hardness and wear resistance.