Method of making coated article by sputtering cast target to form zinc oxide inclusive layer(s)

• US 20060144697A1
• Filed: 01/06/2005
• Published: 07/06/2006
• Est. Priority Date: 01/06/2005
• Status: Abandoned Application

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Centre Luxembourgeois de Recherches pour le Verre et la Ceramique SA
• Inventors: Bobrowski, Sebastian
• Application Number:
  US11/029,655
• Publication Number:
  US 20060144697A1
• Time in Patent Office: Days
• US Class Current: 204/192.150
• CPC Class Codes: C03C 17/002 for flat glass, e.g. float glass
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• 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 17/3644 the metal being silver
• CPC Class Codes: C03C 17/3652 the coating stack containing at least one sacrificial layer to protect the metal from oxidation
• CPC Class Codes: C03C 17/366 Low-emissivity or solar control coatings
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy

Abstract

A coated article includes a coating which has a zinc oxide inclusive layer provided as a contact layer under and directly contacting an infrared (IR) reflecting layer of a material such as silver. It has been found that the emissivity (or emittance) of the coated article can be reduced by sputtering a cast target(s) to form the zinc oxide inclusive contact layer—as opposed to sputtering a target formed by plasma spraying or the like. Thus, it has unexpectedly been found that the emissivity and/or resistivity of an IR reflecting layer can be improved (i.e., lowered) by using a cast target to sputter-form the contact layer located immediately under the IR reflecting layer.

Claims

1. A method of making a coated article including a coating supported by a glass substrate, the method comprising:

forming a dielectric layer on the glass substrate;

forming a layer comprising zinc oxide on the glass substrate over at least the dielectric layer by sputtering at least one cast target comprising zinc;

forming an infrared (IR) reflecting layer comprising silver on the glass substrate over and contacting the layer comprising zinc oxide; and

forming another dielectric layer on the glass substrate over at least the IR reflecting layer.

2. The method of claim 1, wherein the cast target is composed of zinc doped with from about 1-10% aluminum.

3. The method of claim 1, wherein the dielectric layer and the another dielectric layer are formed by sputtering targets formed by plasma spraying.

4. The method of claim 1, wherein the coating has a normal emissivity of less than or equal to 0.044.

5. The method of claim 1, wherein the coating has a normal emissivity of less than or equal to 0.043.

6. The method of claim 1, wherein the coating has an average resistivity of less than or equal to 4.35 H/cm².

7. The method of claim 1, wherein the coating has an average resistivity of less than or equal to 4.20 H/cm².

8. The method of claim 1, wherein the coated article has a visible transmission of at least about 60%.

9. The method of claim 1, wherein the dielectric layer comprises an oxide of titanium, and is in direct contact with the glass substrate.

10. The method of claim 1, further comprising forming a contact layer comprising an oxide of Ni and/or Cr on the glass substrate over and contacting the IR reflecting layer.

11. The method of claim 10, further comprising forming a layer comprising a metal oxide on the glass substrate over and contacting the contact layer comprising an oxide of Ni and/or Cr.

12. The method of claim 1, wherein the use of the cast target(s) to form the layer comprising zinc oxide causes the coating to realize a normal emissivity which is at least about 2% lower compared to if a target(s) formed by plasma spraying was used to form the layer comprising zinc oxide.

13. The method of claim 1, wherein the use of the cast target(s) to form the layer comprising zinc oxide causes the coating to realize a normal emissivity which is at least about 3% lower compared to if a target(s) formed by plasma spraying was used to form the layer comprising zinc oxide.

14. The method of claim 1, wherein the coated article is heat treated.

15. The method of claim 1, wherein the coating includes only one IR reflecting layer comprising silver.

16. The method of claim 1, wherein said another dielectric layer comprises silicon nitride.

17. The method of claim 1, further comprising coupling the glass substrate with the coating thereon to another substrate so as to form an IG window unit, wherein the IG window unit has a U-value of no greater than 1.25 W/(m²K).

18. The coated article of claim 1, further comprising coupling the glass substrate with the coating thereon to another substrate so as to form an IG window unit, wherein the IG window unit has a U-value of no greater than 1.15 W/(m²K).

19. A method of making a coated article including a coating supported by a glass substrate, the method comprising:

forming a contact layer on the glass substrate by sputtering at least one cast target;

forming an infrared (IR) reflecting layer on the glass substrate over and contacting the contact layer formed using the at least one cast target; and

forming a dielectric layer on the glass substrate over at least the IR reflecting layer.

20. The method of claim 19, wherein the cast target comprises zinc so that the contact layer comprises zinc oxide.

21. The method of claim 19, further comprising forming a layer comprising an oxide of titanium on the glass substrate so as to be located between the glass substrate and the contact layer.