Coated article with improved barrier layer structure and method of making the same

#This invention relates to a coated article including a metal or metal nitride layer provided between an IR reflecting layer (e.g., Ag layer) and an oxide barrier layer (e.g,. NiCrOx), and a method of making the same.

#Coated articles provided for solar control purposes are known in the art. For example, see U.S. Pat. No. 5,344,718, which discloses a layer stack of: glass/Si3N4/NiCr/Ag/NiCr/Si3N4. In coatings such as this, NiCr barrier layers are commonly used to protect the Ag (silver) in low-E type coatings.

#Unfortunately, metallic NiCr is characterized by high absorption which reduces transmittance of the final coated article. Due to this high absorption problem, those in the art desiring products with high visible transmission have been forced to use very thin NiCr barrier layers. For example, the NiCr layers in the aforesaid '718 patent are “less than about 7 Å” thick, in order to obtain the desired visible transmission. The thinner such layers are, the less barrier functionality and protection they provide. Consequently, those skilled in the art have been seeking to increase barrier layer transmission by introducing oxygen and/or nitrogen to NiCr barrier layers (e.g., see U.S. Pat. No. 6,014,872 at col. 4, lines 40-50).

#FIG. 1 is a cross sectional view of a coated article according to an embodiment of this invention.

#FIG. 2 is a cross sectional view of a coated article according to another embodiment of this invention.

#FIG. 3 is a cross sectional view of a coated article according to yet another embodiment of this invention.

#Referring now more particularly to the accompanying drawings in which like reference numerals indicate like parts throughout the several views.

#Coated articles according to different embodiments of this invention may be used in the context of architectural windows (e.g., IG units), automotive windows, or any other suitable application. Coated articles herein may or may not be heat treated (e.g., thermally tempered, heat bent, or the like) in different embodiments of this invention.

#FIG. 1 is a side cross sectional view of a coated article according to an embodiment of this invention. The coated article includes substrate 1 (e.g., clear, green, bronze, or blue-green glass substrate from about 1.0 to 10.0 mm thick, more preferably from about 1.8 mm to 4 mm thick), first dielectric layer 3, lower barrier layer 5, lower barrier contact layer 7 (which contacts IR reflecting layer 9), first conductive metallic infrared (IR) reflecting layer 9, upper barrier contact layer 11 (which contacts IR reflecting layer 9), upper barrier layer 13, and upper dielectric layer 15. The “contact” layers 7 and 11 each contact IR reflecting layer 9. Example non-limiting materials for layers 3-15 are illustrated in FIG. 1. The aforesaid layers 3-15 make up a solar control coating (e.g., a low-E or low emissivity type coating) which may be provided on glass or plastic substrates 1. The layer stack 3-15 illustrated in FIG. 1 may, in certain alternative embodiments of this invention, be repeated on substrate 1 one or more times (e.g., another layer stack 3-15 may be provided on top of the stack shown in FIG. 1 on the same substrate—this applies to any and all embodiments herein).