Deposition of superhard amorphous carbon films by pulsed vacuum arc deposition

The deposition of superhard amorphous carbon films demands high energies of all impinging particles for film formation by subplantation instead of condensation. Such conditions may be realized by vacuum arc discharge. By using pulsed arc currents and laser controlled ignition (Laser-Arc) the usual problems in arc ablation of carbon targets have been overcome. In this way, smooth and very hard films with hardness in the superhard range between 40 and 80 GPa have been prepared with high deposition rates comparable to conventional industrial arc deposition. Due to the high ion energies, low deposition temperatures are possible without reducing the adherence. They are even necessary for the formation of the diamond bonds by avoiding relaxation towards a graphitic structure. Hence, materials besides metals such as steels or aluminum, temperature-sensitive materials such as polymers have been successfully coated with these hard layers.