Hard, scratch-resistant coatings for substrates

• US 6,652,974 B1
• Filed: 03/06/2002
• Issued: 11/25/2003
• Est. Priority Date: 05/18/1999
• Status: Expired due to Term

• Current Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Original Assignee: Cardinal IG Company (Cardinal Glass Industries Incorporated)
• Inventors: Krisko, Annette J.
• Primary Examiner(s): VerSteeg, Steven H.
• Application Number:
  US09/979,325
• Time in Patent Office: 629 Days
• Field of Search: 204/192.12, 204/192.15, 204/192.16, 204/192.23, 204/192.26, 428/428, 428/446, 428/704, 428/543
• US Class Current: 428/428
• CPC Class Codes: C03C 17/225 Nitrides
• CPC Class Codes: C03C 17/3435 comprising a nitride, oxynitride, boronitride or carbonitride
• CPC Class Codes: C03C 2217/281 Nitrides
• CPC Class Codes: C03C 2218/152 by cvd
• CPC Class Codes: C03C 2218/156 by magnetron sputtering
• CPC Class Codes: Y10T 428/8305 Miscellaneous [e.g., treated surfaces, etc.]

Abstract

A transparent, scratch-resistant, amorphous, easily washed coating on a transparent substrate, together with a method for its preparation. A substrate such as glass is introduced into a sputtering chamber, a silicon-containing target is sputtered in an atmosphere comprising nitrogen and a hydrocarbon gas to produce on the substrate a film containing a carbide of silicon and a nitride of silicon. The film preferably has a thickness in the range of about 30 Å to about 500 Å, and its surface preferably exhibits a contact angle with water below about 25°. The protective coating may be applied directly to a transparent substrate such as glass, or may be applied as a protective coating over an optical film stack carried by the substrate. If desired, a glass substrate may be coated on one side with the optical film stack and coated on the opposite side with the protective coating.

Claims

1. Method of producing a hard, scratch-resistant amorphous, easily washed coating on a substrate, comprising introducing said substrate into a magnetron sputtering chamber, and sputtering silicon from a silicon target while maintaining in said chamber a reactive atmosphere that includes nitrogen and a hydrocarbon gas to produce on said substrate a protective film, the film having a thickness in the range of about 30 Å

to about 500 Å and

having a contact angle with water below about 25°

.

2. The method of claim 1 wherein the molar concentration of hydrocarbon gas in said atmosphere of nitrogen and hydrocarbon gas ranges from about 5% to about 35%.

3. The method of claim 2 wherein said substrate is glass having an optical film stack thereon, said hard, scratch-resistant coating being formed on said film stack.

4. The method of claim 2 wherein said substrate is glass having an optical film stack on one surface thereof, said hard, scratch-resistant coating being formed on an opposite surface thereof.

5. The method of claim 2 wherein said substrate is glass, said method including the steps of passing said substrate sequentially through a series of magnetron sputtering chambers including one series of chambers for sputtering on one surface of the glass a series of films forming an optical film stack, and at least one chamber for sputtering on said film stack said hard, scratch-resistant amorphous coating.

6. The method of claim 2 wherein said substrate is glass, said method including the steps of passing said substrate sequentially through a series of magnetron sputtering chambers including one series of chambers for sputtering on one surface of the glass a series of films forming an optical film stack, and at least one chamber for sputtering on the reverse side of said substrate said hard, scratch-resistant amorphous coating.

7. The method of claim 1 wherein the atomic percentage of carbon to carbon plus nitrogen in said protective layer ranges from about 5% to about 35%.

8. The method of claim 7 wherein said substrate is glass having an optical film stack thereon, said hard, scratch-resistant coating being formed on said film stack.

9. The method of claim 7 wherein said substrate is glass having an optical film stack on one surface thereof, said hard, scratch-resistant coating being formed on an opposite surface thereof.

10. The method of claim 7 wherein said substrate is glass, said method including the steps of passing said substrate sequentially through a series of magnetron sputtering chambers including one series of chambers for sputtering on one surface of the glass a series of films forming an optical film stack, and at least one chamber for sputtering on said film stack said hard, scratch-resistant amorphous coating.

11. The method of claim 7 wherein said substrate is glass, said method including the steps of passing said substrate sequentially through a series of magnetron sputtering chambers including one series of chambers for sputtering on one surface of the glass a series of films forming an optical film stack, and at least one chamber for sputtering on the reverse side of said substrate said hard, scratch-resistant amorphous coating.

12. The method of claim 1 wherein said substrate is glass having an optical film stack thereon, said hard, scratch-resistant coating being formed on said film stack.

13. The method of claim 1 wherein said substrate is glass having an optical film stack on one surface thereof, said hard, scratch-resistant coating being formed on an opposite surface thereof.

14. The method of claim 1 wherein said substrate is glass, said method including the steps of passing said substrate sequentially through a series of magnetron sputtering chambers including one series of chambers for sputtering on one surface of the glass a series of films forming an optical film stack, and at least one chamber for sputtering on said film stack said hard, scratch-resistant amorphous coating.

15. The method of claim 1 wherein said substrate is glass, said method including the steps of passing said substrate sequentially through a series of magnetron sputtering chambers including one series of chambers for sputtering on one surface of the glass a series of films forming an optical film stack, and at least one chamber for sputtering on the reverse side of said substrate said hard, scratch-resistant amorphous coating.

16. The method of claim 15 wherein said method includes the step of simultaneously sputtering on both sides of said substrate in at least one sputtering chamber, an element of said optical film stack being sputtered on one surface of the substrate and said hard, scratch-resistant amorphous coating being sputtered on an opposite surface.

17. The method of claim 1 wherein the protective film includes a carbide of silicon and a nitride of silicon.

18. A film stack on a substrate, comprising, from the substrate outwardly, an optical film stack and a hard, scratch-resistant outer protective coating, the latter comprising an amorphous film containing a carbide of silicon and a nitride of silicon and having a thickness in the range of about 30 Å

to about 500 Å

, the protective coating having a surface exhibiting a contact angle with water not greater than 25°

.

19. The film stack of claim 18 wherein said hard, scratch-resistant outer protective layer is formed in a magnetron sputtering chamber by magnetron sputtering silicon from a silicon target while maintaining in said chamber a reactive atmosphere that includes nitrogen and a hydrocarbon gas.