The laser-arc: A new industrial technology for effective deposition of hard amorphous carbon films

The laser-arc evaporation process has been developed to an industrial high-rate deposition technology for amorphous carbon films of diamond-like nature. Deposition rates above 3 nm s(-1) have been realized on substrates larger than 100 cm(2) with the quality being comparable with magnetically filtered are techniques characterized by a much lower efficiency. The basic process consists of a pulsed cathodic vacuum are ignited by focused laser pulses. By limiting the are pulse duration between 20 and 100 mu s the are spot erodes only a definite region surrounding its ignition point, the laser focus. Thus, the local overheating of the cathode material and the emission of microparticles, the inherent drawback of the conventional are process, are essentially reduced. The are spot position is controlled by the displacement (scanning) of the laser focus on the rotating cylindrical cathode, allowing its systematic erosion. With cathodes composed of different materials, multilayered film structures can be realized with easily changed variations. Owing to the low deposition temperature, below 150 degrees C, the method is especially suitable for temperature-sensitive substrate materials. Examples for the application of laser-arc coatings in different fields are presented.