Methods and apparatus for simultaneous multi-sided coating of optical

Abstract

The present invention is directed to methods and apparatus for depositing optical thin film coatings simultaneously onto both sides of at least one substrate in a dual-frequency plasma-enhanced chemical vapor deposition vacuum reaction chamber utilizing microwave and radio frequency energies. The substrate can be a continuous substrate, such as a flexible polymer web, or it can be one or more discrete substrates, such as rigid plastic, glass, or glass/polymer composite substrates. The substrate can be processed in a stationary or an in-line processing mode. In addition, the coatings deposited simultaneously onto both sides of the substrate can be identical, i.e. symmetrical, or different, i.e., non-symmetrical. The plasma attributes and reaction conditions on either side of the substrate can be independently controlled to provide either identical or different coating compositions and properties on the two sides of the substrate. Multiple plasmas can also be generated, in either an overlapping or isolated manner, to form multiple independently-controlled CVD reaction zones for simultaneous deposition of either identical or different coatings onto the sides of the substrate within the different zones.