Modeling of a mask for improving thickness uniformity of thin films and vacuum coatings

Abstract

A new approach has been used to improve thickness uniformity of thin films and coatings deposited on plane moving substrates of large area such as polymer films, paper or steel strips. It consists of mathematical modeling a special mask designed for controllable partial screening of the vapor stream. A precise procedure is proposed to optimize a profile of the mask so as to obtain the best thickness uniformity of either the thin film or the vacuum coating at any evaporator - substrate geometry. Experimental results confirm the high efficiency of the proposed modeling that can be used not only at newly designed plants, but also at already working systems. The method is applicable not only for physical vapor deposition processes, but also for sputtering and ion plating.