Glass or glass-ceramic substrate with scratch-resistant coating and method for the production thereof

• US 20100215950A1
• Filed: 10/30/2009
• Published: 08/26/2010
• Est. Priority Date: 10/31/2008
• Status: Active Grant

• Current Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Original Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Inventors: Schultz, Niko, Hahn, Andreas, Henn, Christian, Gabel, Falk
• Granted Patent: US 8,409,716 B2
• Time in Patent Office: Days
• US Class Current: 428/336
• CPC Class Codes: C03C 17/225 Nitrides
• CPC Class Codes: C03C 17/245 by deposition from the vapour phase
• CPC Class Codes: C03C 17/3435 comprising a nitride, oxynitride, boronitride or carbonitride
• CPC Class Codes: C03C 2217/78 Coatings specially designed to be durable, e.g. scratch-resistant
• CPC Class Codes: C03C 2217/91 Coatings containing at least one layer having a composition gradient through its thickness
• CPC Class Codes: C03C 2218/154 by sputtering
• CPC Class Codes: C23C 14/0676 Oxynitrides
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

The invention in general relates to glass or glass-ceramic products. In order to protect the surface of such products against scratching, a silicon oxynitride coating with special composition is provided.

Claims

1. A glass article with a scratch-resistant coating, comprising:

a glass or glass-ceramic substrate,

a silicon oxynitride layer deposited on the substrate as a scratch-resistant layer, wherein the silicon oxynitride layer has a ratio of atomic percentages of oxygen to nitrogen of more than 1 as measured with secondary-ion mass spectrometry and etching of the layer by means of a cesium ion beam.

2. The glass article according to claim 1, wherein the ratio of atomic percentages of oxygen to nitrogen in the silicon oxynitride layer amounts to 20 at most, as measured with secondary-ion mass spectrometry and etching of the layer by means of a cesium ion beam.

3. The glass article according to claim 1, wherein the silicon oxynitride layer is directly deposited onto a surface of the glass or glass-ceramic substrate.

4. The glass article according to claim 1, wherein the silicon oxynitride layer has a Vickers hardness of less than 1400.

5. The glass article according to claim 1, wherein the silicon oxynitride layer has a refractive index that is at most 1.9 and at least 1.6.

6. The glass article according to claim 1, wherein the silicon oxynitride layer has a layer thickness of at least 500 nanometers.

7. The glass article according to claim 1, wherein the substrate is transparent.

8. The glass article according to claim 7, wherein the glass article in the form of a coated plate that has an average transmission of at least 86% in a wavelength region between 400 nanometers and 650 nanometers.

9. The glass article according to claim 1, wherein the substrate comprises a volume-colored glass ceramic.

10. The glass article according to claim 1, wherein the silicon oxynitride layer has a morphology without structure.

11. The glass article according to claim 1, wherein the scratch-resistant layer comprises a scratch-resistant coating having multiple layer parts with at least one layer comprising the silicon oxynitride layer.

12. The glass article according to claim 11, wherein the scratch-resistant coating has multiple layer parts comprises an alternating layer system of at least one layer comprising the silicon oxynitride layer and at least one layer comprising a silicon nitride layer.

13. The glass article according to claim 1, wherein the silicon oxynitride layer comprises several first layer parts and several second layer parts following one another, the first layer parts having a higher oxygen content than the second layer parts.

14. The glass article according to claim 13, wherein the first layer parts have an oxygen content which is higher by a factor between 1.1 and 2 than the second layer parts.

15. The glass article according to claim 13, wherein the first and second layer parts each have a refractive index that differs by at most 0.25.

16. The glass article according to claim 13, wherein the silicon oxynitride layer is formed as a gradient layer having multiple layer parts.

22. The glass article according to claim 1, wherein the glass article is used as a viewing window for a motor vehicle, as a viewing window for a checkout scanner, or as a glass-ceramic cooktop.

17. A method for the production of a glass article with a scratch-resistant coating, comprising steps:

introducing a glass or glass-ceramic substrate into a vacuum chamber; and

sputtering, onto the substrate, a silicon oxynitride layer employing a plasma in a process gas containing oxygen and nitrogen and a silicon target, the process gas being adjusted by regulating a flow of oxygen to an average oxygen content of at least 20%.

18. The method according to claim 17, further comprising moving the substrate past the target multiple times.

19. The method according to claim 18, wherein the substrate is moved past the target at least four times.

20. The method according to claim 17, wherein the sputter step comprises using a power of more than 10 watts per cm² of target surface.

21. The method according to claim 17, wherein the silicon oxynitride layer is deposited with several first layer parts and several second layer parts following one another, the first layer parts having a higher oxygen content than the second layer parts, the variation of the oxygen content being obtained by moving the substrate past the target.