Scratch-resistant coatings, substrates having scratch-resistant coatings and methods for producing same

• US 9,574,262 B2
• Filed: 04/03/2015
• Issued: 02/21/2017
• Est. Priority Date: 04/03/2014
• Status: Active Grant

• Current Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Original Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Inventors: Henn, Christian, Damm, Thorsten
• Primary Examiner(s): Shewareged, Betelhem
• Application Number:
  US14/678,513
• Publication Number:
  US 20150284840A1
• Time in Patent Office: 690 Days
• US Class Current: 1/1
• CPC Class Codes: C03C 17/007 containing a dispersed phase, e.g. particles, fibres or flakes, in a continuous phase
• CPC Class Codes: C03C 17/008 comprising a mixture of materials covered by two or more of the groups C03C17/02, C03C17/06, C03C17/22 and C03C17/28
• CPC Class Codes: C03C 17/225 Nitrides
• CPC Class Codes: C03C 17/3435 comprising a nitride, oxynitride, boronitride or carbonitride
• CPC Class Codes: C03C 17/3626 one layer at least containing a nitride, oxynitride, boronitride or carbonitride
• CPC Class Codes: C03C 2217/281 Nitrides
• CPC Class Codes: C03C 2217/283 Borides, phosphides
• CPC Class Codes: C03C 2217/45 Inorganic continuous phases
• CPC Class Codes: C03C 2217/465 having a specific shape
• CPC Class Codes: C03C 2217/475 Inorganic materials
• CPC Class Codes: C03C 2217/48 having a specific function
• CPC Class Codes: C03C 2217/78 Coatings specially designed to be durable, e.g. scratch-resistant
• CPC Class Codes: C03C 2218/154 by sputtering
• CPC Class Codes: C03C 2218/155 by reactive sputtering
• CPC Class Codes: C03C 2218/156 by magnetron sputtering
• CPC Class Codes: C23C 14/0617 AIII BV compounds, where A is Al, Ga, In or Tl and B is N, P, As, Sb or Bi
• CPC Class Codes: C23C 14/0647 Boron nitride
• CPC Class Codes: C23C 14/067 Borides
• CPC Class Codes: C23C 14/34 Sputtering
• CPC Class Codes: Y10T 428/24851 Intermediate layer is discontinuous or differential

Abstract

A substrate having a coating for enhanced scratch resistance is provided. The coating includes at least one high refractive index transparent hard material layer. The hard material layer includes crystalline aluminum nitride having a hexagonal crystal structure that exhibits a predominant (001) preferred orientation of the hexagonal symmetry.

Claims

1. A coated substrate comprising:

a substrate; and

a coating for enhanced scratch resistance, the coating comprising at least one high refractive index transparent hard material layer, wherein the hard material layer includes crystalline aluminum nitride and wherein the aluminum nitride has a hexagonal crystal structure exhibiting a predominant (001) preferred orientation of at least one of the following;

x(001)=I(001)/(I(001)+I(100)), and

y(001)=I(001)/(I(001)+I(101)),

as determined by an XRD measurement of the coating, that is greater than 0.5.

2. The coated substrate as in claim 1, wherein the coating has a modulus of elasticity at a test load of 10 mN from 80 to 250 Gpa.

3. The coated substrate as in claim 1, wherein the coating has a ratio of hardness to a modulus of elasticity at a test load of 10 mN that is at least 0.08.

4. The coated substrate as in claim 1, wherein the hexagonal crystal structure has an average crystallite size that is at most 25 nm.

5. The coated substrate as in claim 1, wherein the aluminum nitride of the hard material layer is doped with one or more nitrides and/or carbides and/or carbonitrides of elements selected from the group consisting of silicon, boron, zirconium, titanium, nickel, chromium, and carbon.

7. The coated substrate as in claim 1, wherein the hard material layer has a proportion of oxygen that is at most 10 wt %.

10. The coated substrate as in claim 1, further comprising an adhesion promoting layer disposed between the substrate and the hard material layer.

11. The coated substrate as in claim 10, wherein the adhesion promoting layer is formed from nitrides and/or oxides and/or carbides and/or carbonitrides and/or oxynitrides of elements selected from the group consisting of aluminum, silicon, boron, zirconium, titanium, nickel, chromium, and carbon.

12. The coated substrate as in claim 1, wherein the hard material layer is a sputter-deposited layer.

13. The coated substrate as in claim 1, wherein the coating has a coefficient of static friction μ

relative to metal bodies of μ

<

0.5.

14. The coated substrate as in claim 1, wherein the substrate is a material selected from the group consisting of glass, sapphire glass, borosilicate glass, aluminosilicate glass, soda-lime glass, synthetic quartz glass, lithium aluminosilicate glass, optical glass, crystal, and glass ceramic.

15. The coated substrate as in claim 1, wherein the substrate is a glass ceramic having a coefficient of thermal expansion α

_20-300 of smaller than 2*10-6 K-1.

16. The coated substrate as in claim 1, further comprising decorated areas at least in sections of the substrate, wherein the decorated areas are disposed between the substrate and the coating.

17. The coated substrate as in claim 1, wherein the coating is permanently resistant to temperatures of at least 300°

C.

18. The coated substrate as in claim 1, wherein the coating exhibits a transmittance T to light of wavelengths in the visible and/or infra-red range of at least 50%.

19. The coated substrate as in claim 1, wherein the aluminum nitride in the hard material layer has a degree of crystallization of at least 50%.

20. The coated substrate as in claim 1, wherein the hard material layer has a refractive index from 1.8 to 2.3, at a wavelength of 550 nm.

21. The coated substrate as in claim 1, wherein the hard material layer further comprises boron nitride.

22. The coated substrate as in claim 1, wherein the hard material layer further comprises silicon nitride.

25. The coated substrate as in claim 10, wherein the adhesion promoting layer has a thickness of one to 900 nm.

6. A coated substrate comprising:

a substrate; and

a coating for enhanced scratch resistance, the coating comprising at least one high refractive index transparent hard material layer, wherein the hard material layer includes crystalline aluminum nitride and wherein the aluminum nitride has a hexagonal crystal structure exhibiting a predominant (001) preferred orientation of hexagonal symmetry,

wherein the hard material layer has an aluminum content, based on dopant material, that is greater than 50 wt %.

8. A coated substrate comprising:

a substrate; and

a coating for enhanced scratch resistance, the coating comprising at least one high refractive index transparent hard material layer, wherein the hard material layer includes crystalline aluminum nitride and wherein the aluminum nitride has a hexagonal crystal structure exhibiting a predominant (001) preferred orientation of hexagonal symmetry,

wherein the coating comprises an additional cover layer which is disposed above the hard material layer.

9. The coated substrate as in claim 8, wherein the additional cover layer is formed from nitrides and/or oxides and/or carbides and/or carbonitrides and/or oxynitrides of elements selected from the group consisting of aluminum, silicon, boron, zirconium, titanium, and carbon.

23. The coated substrate as in claim 8, wherein the cover layer has a thickness of one to 100 nm.

24. The coated substrate as in claim 8, wherein the cover layer comprises silicon dioxide.