SILICON OXYNITRIDE PROTECTIVE COATINGS

摘要

A layer for protecting an underlying functional coating stack for example a single silver layer or double silver layer Low-E coating stack includes silicon oxynitride or silicon aluminum oxynitride layer. The protective film may have a uniform composition throughout its thickness i.e. homogeneous protective layer, a constantly increasing or decreasing index of infraction throughout its thickness i.e. a graded protective layer, or a combination of all or some of the foregoing i.e. a non-homogeneous protective layer. The graded and non-homogeneous layers may have an outer surface of silicon nitride, silicon aluminum nitride, silicon dioxide, silicon oxynitride or silicon aluminum oxynitride. The protective layer of the invention may be the last layer deposited on the functional coating stack or may have a film deposited thereon.