HOT TILE SPUTTERING SYSTEM

• US 20100252418A1
• Filed: 04/06/2010
• Published: 10/07/2010
• Est. Priority Date: 04/07/2009
• Status: Active Grant

• Current Assignee: Magna Mirrors of America Incorporated (Magna International Incorporated)
• Original Assignee: Magna Mirrors of America Incorporated (Magna International Incorporated)
• Inventors: Harlow, Jeffrey D., McCabe, Ian A.
• Granted Patent: US 8,673,122 B2
• Time in Patent Office: Days
• US Class Current: 204/192.150
• CPC Class Codes: C23C 14/3407 Cathode assembly for sputtering apparatus, e.g. Target
• CPC Class Codes: C23C 14/3421 using heated targets
• CPC Class Codes: H01J 37/3408 Planar magnetron sputtering
• CPC Class Codes: H01J 37/3423 Shape
• CPC Class Codes: H01J 37/3435 Target holders (includes backing plates and endblocks)
• CPC Class Codes: H01J 37/3497 Temperature of target

Abstract

A system and method for sputtering a coating onto a glass substrate in a vacuum deposition chamber includes providing a backing plate with a separating element disposed at the backing plate. At least one target element or tile is disposed on a surface of the separating element, wherein an expansion gap is provided to allow for expansion of the target relative to the separating element during the sputtering process. The method includes sputtering material from the target and heating the target to a substantially elevated temperature during the sputtering process. The separating element may be a sheet having a low-coefficient of friction surface, and the target may be disposed on the low-coefficient of friction surface of the separating element. The separating element may thermally insulate the target from the backing plate, whereby the target may be heated to a substantially greater temperature than the backing plate during the sputtering process.

Claims

1. A sputtering assembly for sputtering a coating onto a glass substrate in a vacuum deposition chamber, said sputtering assembly comprising:

a backing plate;

a separating element disposed at said backing plate;

at least one target element disposed at a surface of said separating element, wherein said at least one target element contacts said separating element; and

wherein at least one expansion gap is provided at or adjacent to said at least one target element to allow for thermal expansion of said at least one target element relative to said separating element during the sputtering process.

2. The sputtering assembly of claim 1, wherein said separating element comprises an electrically conductive material.

3. The sputtering assembly of claim 1, wherein said separating element comprises a sheet having a low-coefficient of friction surface, and wherein said at least one target element is disposed on said low-coefficient of friction surface of said separating element.

4. The sputtering assembly of claim 1, wherein said separating element comprises a graphite sheet.

5. The sputtering assembly of claim 1, wherein said separating element thermally insulates said at least one target element from said backing plate, whereby said at least one target element is heated to a substantially elevated temperature during the sputtering process.

6. The sputtering assembly of claim 5, wherein said at least one target element is heated to a substantially elevated temperature in the range of about 400 to 600 degrees C. during the sputtering process.

7. The sputtering assembly of claim 1, wherein said at least one target element comprises a plurality of target elements arranged on said separating sheet with expansion gaps established between adjacent target elements to allow for expansion of said target elements during the sputtering process.

8. The sputtering assembly of claim 1, wherein said at least one target element is retained at said backing plate via at least one clamping element.

9. The sputtering assembly of claim 8, wherein said clamping element comprises an expansion element so as to substantially retain said target element at said backing plate while allowing for expansion of said target element during the sputtering process.

10. The sputtering assembly of claim 1, wherein said sputtering assembly is for sputtering a transparent conductive coating onto a glass substrate of a mirror reflective element for a vehicular interior or exterior rearview mirror assembly.

11. A method of sputter coating a glass substrate comprising:

providing a glass substrate;

providing a sputtering assembly for sputtering a coating onto said glass substrate in a vacuum deposition chamber, wherein said sputtering assembly comprises a backing plate, a separating element disposed at said backing plate;

providing at least one target element, wherein said at least one target element is disposed at and is in contact with a surface of said separating element;

providing an expansion gap at or adjacent to said at least one target element to allow for expansion of said at least one target element during the sputtering process; and

sputtering material from said at least one target element and heating said at least one target element to a substantially elevated temperature during the sputtering process.

12. The method of claim 11, wherein said separating element comprises an electrically conductive material.

13. The method of claim 11, wherein said separating element comprises a sheet having a low-coefficient of friction surface, and wherein said at least one target element is disposed on said low-coefficient of friction surface of said separating element.

14. The method of claim 11, wherein said separating element comprises a graphite sheet.

15. The method of claim 11, wherein said separating element thermally insulates said at least one target element from said backing plate, whereby said at least one target element is heated to a substantially greater temperature than said backing plate during the sputtering process.

16. The method of claim 15, wherein said at least one target element is heated to a substantially elevated temperature in the range of about 400 to 600 degrees C. during the sputtering process.

17. The method of claim 11, wherein said at least one target element comprises a plurality of target elements arranged on said separating sheet with expansion gaps established between adjacent target elements to allow for movement of and expansion of said target elements during the sputtering process.

18. The method of claim 11, wherein said glass substrate comprises a glass substrate of a reflective element of a mirror assembly for a vehicle, and wherein said at least one target element comprises a metallic material for coating said glass substrate with a transparent conductive layer.

19. The method of claim 11 further comprising providing at least one clamping element for retaining said at least one target element at said separating element and said backing plate.

20. The method of claim 19, wherein said clamping element comprises an expansion element so as to substantially retain said target elements at said backing plate while allowing for expansion of said target elements during the sputtering process.