2. Relevance of the Vacuum Technology for Thin Film Coatings

Vacuum coating processes are characterized by a number of advantages. These include variability of the coating materials, reproducibility of the film properties, and adjustment of the film properties by changing the coating parameters, and the great purity of the coatings. Despite the influence of residual gases in the recipient, and that of the coating material and the condensation rate, the entrapping residual gas molecules into the film can be kept arbitrarily small, if only the residual gas pressure in the recipient is kept accordingly low. Therefore, the conception of the vacuum system during the design and technical execution of vacuum coating plants for Physical Vapor Deposition (PVD) procedures is especially important.