Methods and apparatus for producing silver based low emissivity coatings without the use of metal primer layers and articles produced thereby

• US 6,398,925 B1
• Filed: 12/18/1998
• Issued: 06/04/2002
• Est. Priority Date: 12/18/1998
• Status: Expired due to Term

• Current Assignee: Vitro Flat Glass LLC (Compagnie De Saint-Gobain)
• Original Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Inventors: Finley, James J., Arbab, Mehran
• Primary Examiner(s): VerSteeg, Steven H.
• Application Number:
  US09/215,560
• Time in Patent Office: 1,264 Days
• Field of Search: 204/192.15, 204/192.16, 204/192.22, 204/192.25, 427/404, 427/419.3, 427/419.4
• US Class Current: 204/192.22
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3605 Coatings of the type glass/metal/inorganic compound
• CPC Class Codes: C03C 17/3615 Coatings of the type glass/metal/other inorganic layers, at least one layer being non-metallic
• CPC Class Codes: C03C 17/3618 Coatings of type glass/inorganic compound/other inorganic layers, at least one layer being metallic
• CPC Class Codes: C03C 17/3639 Multilayers containing at least two functional metal layers
• CPC Class Codes: C03C 17/3642 the multilayer coating containing a metal layer
• CPC Class Codes: C03C 17/3644 the metal being silver
• CPC Class Codes: C03C 17/366 Low-emissivity or solar control coatings
• CPC Class Codes: C23C 14/086 of zinc, germanium, cadmium, indium, tin, thallium or bismuth

Abstract

Methods are presented for depositing an infrared reflective, e.g., silver, containing multi-layer coating onto a substrate to form a coated article. One or more ceramic cathodes are used to deposit a protective layer over the silver layer. The use of the ceramic cathodes eliminates the need for the metal primer layers common in the prior art. Both the infrared reflective layer and a ceramic layer can be deposited in the same coating zone, this coating zone containing sufficient oxygen to provide a substantially oxidized ceramic coating layer without adversely impacting upon the properties of the infrared reflective layer.

Claims

1. A method of forming a coated article, comprising the steps of:

sputter depositing a metal layer over a substrate, and

sputtering a conductive ceramic cathode in a controlled atmosphere to deposit a metal doped metal oxide layer defined as a ceramic layer over the metal layer.

2. The method as claimed in claim 1, wherein the metal layer is selected from the group consisting of silver, gold, aluminum and copper.

3. The method as claimed in claim 1, wherein the ceramic layer is selected from the group consisting of indium doped tin oxide, zinc doped tin oxide, antimony doped tin oxide, cadmium doped tin oxide, tin doped indium oxide and indium doped zinc oxide.

4. The method as claimed in claim 1, wherein the ceramic layer is an aluminum doped zinc oxide layer.

5. The method as claimed in claim 1, including heating the coated article to bend, temper or heat strengthen the coated article.

6. The method as claimed in claim 1, including:

sputter depositing a first zinc stannate layer over the substrate;

sputter depositing a first zinc oxide layer over the first zinc stannate layer;

practicing the step of sputter depositing a metal layer to deposit the metal layer over the first zinc oxide layer;

practicing the step of sputtering a ceramic target to deposit the ceramic layer over the metal layer;

sputter depositing a second zinc stannate layer over the ceramic layer;

sputter depositing a second zinc oxide layer over the second zinc stannate layer;

sputter depositing a second metal layer over the second zinc oxide layer;

sputter depositing a second ceramic layer over the second metal layer;

sputter depositing a third zinc stannate layer over the second ceramic layer; and

sputter depositing a protective overcoat over the third zinc stannate layer.

7. The method as claimed in claim 1, including:

sputter depositing a first zinc stannate layer on the substrate;

sputter depositing a ceramic layer defined as a first ceramic layer on the first zinc stannate layer;

practicing the step of sputter depositing a metal layer to deposit the metal layer on the first ceramic layer;

practicing the step of sputtering a ceramic target to deposit the ceramic layer defined as a second ceramic layer over the metal layer;

sputter depositing a second zinc stannate layer on the second ceramic layer;

sputter depositing a third ceramic layer on the second zinc stannate layer;

sputter depositing a second metal layer on the third ceramic layer;

sputter depositing a fourth ceramic layer on the second metal layer;

sputter depositing a third zinc stannate layer on the fourth ceramic layer; and

sputter depositing a protective overcoat on the third zinc stannate layer.

8. The method as claimed in claim 1, including sputter depositing an antireflective layer over the ceramic layer.

9. The method as claimed in claim 1, wherein the ceramic layer is a first ceramic layer and the method includes sputter depositing a second ceramic layer over the substrate and sputter depositing the metal layer over the second ceramic layer.

10. The method as claimed in claim 1, including sputter depositing an antireflective layer over the substrate and depositing the metal layer over the antireflective layer.

11. The method as claimed in claim 10, wherein the antireflective layer is selected from the group consisting of zinc stannate, indium tin oxide, titanium oxide, tin oxide, indium oxide, zinc oxide, silicon nitride and bismuth oxide.

12. The method as claimed in claim 1, wherein the step of depositing the metal layer includes depositing an infrared reflective metal layer.

13. The method as claimed in claim 12, wherein the ceramic layer is a first ceramic layer, the method including the steps of:

sputter depositing a second ceramic layer over the substrate;

sputter depositing the infrared reflective metal layer over the second ceramic layer, and

practicing the step of sputtering a ceramic target to deposit the first ceramic layer over the infrared reflective metal layer.

14. The method as claimed in claim 12, including:

sputter depositing a first antireflective layer over the substrate;

sputter depositing the infrared reflective layer over the first antireflective layer;

practicing the step of sputtering a ceramic target to deposit the ceramic layer over the infrared reflective layer; and

sputter depositing a second antireflective layer over the ceramic layer.

15. The method as claimed in claim 14, wherein the steps of depositing the infrared reflective layer and depositing the ceramic layer are practiced in the same coating zone.

16. The method as claimed in claim 1, wherein the steps of depositing the metal layer and the ceramic layer are practiced in the same coating zone and the method further includes the step of adding sufficient oxygen to the coating zone to substantially fully oxidize the ceramic layer during the practice of at least one of the depositing steps.

17. The method as claimed in claim 16, including controlling the oxygen content in the coating zone such that the oxygen content is about 0-20 vol. %.

18. The method as claimed in claim 16, wherein the metal layer is a silver layer and the method includes controlling the oxygen in the coating zone such that the conductivity of the silver layer is not reduced below 50% of that for a silver layer sputtered in an argon atmosphere.