Deposition of hard amorphous carbon coatings by laser and arc methods

The principal deposition conditions for the preparation of hard amorphous c arbon films with hardness values above 50 GPa are now well known: the high energy of the impinging carbon particles and low deposition temperature. Su ch conditions are in good accordance with the widely accepted subplantation concept. Notwithstanding this basic understanding, the influence of specif ic plasma conditions such as electron temperature and ion energy distributi on are rather uncertain. A number of suitable carbon ion sources: ArF and Nd-YAG lasers, laser-contr olled Are (Laser Are) and filtered high-current pulsed Are (phi-HCA) have b een applied. The use of the same investigation methods for all plasma sourc es enables a direct comparison of plasma parameters and film properties. Th e plasma investigation includes electron temperature, ionization state and distribution of kinetic energy, and the film characterization evaluates the mechanical and optical properties. A very productive plasma source is the filtered high current pulsed Are (ph i-HCA), which will be applied in industrial coating machines. A general ins ight into the necessary plasma conditions allows us to improve the phi-HCA and develop new plasma sources. (C) 1999 Elsevier Science S.A. All rights r eserved.