Deposition of hard amorphous carbon coatings by laser and arc methods

The principal deposition conditions for the preparation of hard amorphous carbon films with hardness values above 50 GPa are now well known: high energy of the impinging carbon particles and low deposition temperature. Such conditions are in good accordance with the widely accepted subplantation concept. Notwithstanding this basic understanding, the influence of the specific plasma conditions such as electron temperature and ion energy distribution are rather uncertain.A number of suitable carbon ion sources: ArF and Nd-YAG lasers, laser controlled Arc (Laser Arc) and filtered high current pulsed Arc (f-HCA) have been applied. Using the same investigation methods for all plasma sources enables a direct comparison of plasma parameters and film properties. The plasma investigation includes electron temperature, ionization state and distribution of the kinetic energy, the film characterization evaluates the mechanical and optical properties.A very productive plasma source is the filtered high current pulsed Arc(f-HCA), which will be applied in industrial coating machines. A general insight in the necessary plasma conditions allows us to improve the f-HCAand develop new plasma sources