Coated article with anti-reflective coating and method of making same

• US 20060210783A1
• Filed: 03/18/2005
• Published: 09/21/2006
• Est. Priority Date: 03/18/2005
• Status: Abandoned Application

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Inventors: Taylor, Thomas J., Seder, Thomas A.
• Application Number:
  US11/083,074
• Publication Number:
  US 20060210783A1
• Time in Patent Office: Days
• US Class Current: 428/212
• CPC Class Codes: C03C 17/225 Nitrides
• CPC Class Codes: C03C 17/23 Oxides C03C17/02 takes precedence
• CPC Class Codes: C03C 17/3411 with at least two coatings of inorganic materials C03C17/36, C03C17/42 take precedence
• CPC Class Codes: C03C 2217/211 SnO2
• CPC Class Codes: C03C 2217/281 Nitrides
• CPC Class Codes: C03C 2217/91 Coatings containing at least one layer having a composition gradient through its thickness
• CPC Class Codes: C03C 2218/15 from the vapour phase
• CPC Class Codes: C03C 23/0055 by ion implantation
• CPC Class Codes: C23C 16/029 Graded interfaces
• CPC Class Codes: C23C 16/453 passing the reaction gases through burners or torches, e.g. atmospheric pressure CVD C23C16/513 takes precedence; for flame or plasma spraying of coating material in the molten state C23C4/00
• CPC Class Codes: G02B 1/113 using inorganic layer materials only
• CPC Class Codes: G02B 1/12 by surface treatment, e.g. by irradiation
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree

Abstract

A substrate is treated so as to improve anti-reflection (AR) characteristics of a resulting coated article. In certain example embodiments, a glass substrate may be treated via ion implantation to increase a refractive index (n) value in a surface region thereof. In other example embodiments, an index-graded coating (single or multi-layer) may be formed on the substrate. In both embodiments, an AR coating

Claims

1. A method of making a coated article, the method comprising:

providing a glass substrate having an index of refraction (n) of from about 1.4 to 1.5;

implanting ions into a surface region of the glass substrate in a manner sufficient to cause an index of refraction at a surface of the glass substrate to increase to a value of from about 1.55 to 2.5, thus forming a glass substrate having a surface region that is ion implanted; and

forming an anti-reflective coating on the ion implanted surface region of the glass substrate.

2. The method of claim 1, wherein the anti-reflective coating comprises silicon oxide, and wherein the coated article has a visible transmission of at least about 60%.

3. The method of claim 1, wherein the ions comprise argon and/or nitrogen ions.

4. The method of claim 1, wherein the ions comprise nitrogen ions.

5. The method of claim 1, wherein the ions are implanted into the glass substrate to a depth of at least about 50 Å

.

6. The method of claim 1, wherein the ions are implanted into the glass substrate to a depth of at least about 100 Å

.

7. The method of claim 1, wherein the ions are implanted into the glass substrate to a depth of at least about 200 Å

.

8. The method of claim 1, wherein the ions are implanted into the glass substrate to a depth of at least about 300 Å

.

9. The method of claim 1, wherein the ion implantation is performed at a concentration of from about 10¹⁵ to 10¹⁹ atoms/cm².

10. The method of claim 1, wherein said implanting comprises implanting ions into the surface region of the glass substrate so as to cause an index of refraction at a surface of the glass substrate to increase to a value of from about 1.75 to 2.25.

11. The method of claim 1, wherein the anti-reflective coating has an index of refraction of no greater than about 1.65.

12. The method of claim 1, wherein the anti-reflective coating is in direct contact with the glass substrate.

13. The method of claim 1, wherein index of refraction changes in different locations in the ion implanted surface region, and wherein the depth of the ion implanted surface region is at least about ¼

a wavelength (I), given the following quarter wave equation;

I=4nd

where I is the wavelength, n is an index of refraction, and d is the depth in the glass substrate of the ion implanted surface region.

23. The method of claim 1, wherein the first target comprises silicon and the second target comprises tin.

24. The method of claim 1, wherein coating comprises a dielectric layer having an index of refraction value (n) which differs by no more than 0.25 from n_c [where n_c=square root of (n_g×

n_a), where n_a=1.0 and n_g is the refractive index of an upper portion of the ion implanted surface region of the glass substrate].

25. The method of claim 1, wherein coating comprises a dielectric layer having an index of refraction value (n) which differs by no more than 0.10 from n_c [where n_c=square root of (n_g×

n_a), where n_a=1.0 and n_g is the refractive index of an upper portion of the ion implanted surface region of the glass substrate].

14. A method of making a coated article, the method comprising:

providing a glass substrate;

implanting ions into a surface region of the glass substrate, without forming a new layer on the glass substrate, in a manner sufficient to cause an index of refraction at a surface of the glass substrate to increase; and

forming an anti-reflective coating on the ion implanted surface region of the glass substrate.

15. The method of claim 14, wherein a depth of the ion implanted surface region in the glass substrate is at least about ¼

a wavelength (I), given the following quarter wave equation;

I=4nd

where I is the wavelength, n is an index of refraction, and d is the depth in the glass substrate of the ion implanted surface region.

16. A method of making a coated article, the method comprising:

providing a glass substrate;

using flame pyrolysis to form a graded layer on the glass substrate, wherein the graded layer is Si and/or Sn graded; and

forming an anti-reflective coating over the graded layer.

17. The method of claim 16, wherein the graded layer includes more Sn at a location in the graded layer further from the glass substrate than at a location in the graded layer closer to the glass substrate.

18. The method of claim 16, wherein the graded layer includes less Si at a location in the graded layer further from the glass substrate than at a location in the graded layer closer to the glass substrate.

19. The method of claim 16, wherein the flame pyrolysis is performed at atmospheric pressure.

20. A method of making a coated article, the method comprising:

providing a glass substrate;

using flame pyrolysis to form a layer on the glass substrate, wherein the layer formed using flame pyrolysis is characterized by one or more of;

(a) the layer includes more of a first metal at a location in the layer further from the glass substrate than at a location in the layer closer to the glass substrate, and (b) the layer includes less Si at a location in the layer further from the glass substrate than at a location in the layer closer to the glass substrate.

21. The method of claim 20, wherein the first metal is Sn.

22. A method of making a coated article, the method comprising:

using at least first and second magnetron sputtering targets to deposit an index-graded anti-reflective film directly onto the surface of a glass substrate so as to directly contact the glass substrate;

varying the gas flows proximate the first and second targets and/or varying the materials of the first and second targets to sputter-deposit the index-graded anti-reflective film onto the surface of the glass substrate, and wherein an index of refraction of the anti-reflective film increases moving in a direction away from the glass substrate.

26. A coated article, comprising:

a glass substrate;

a surface region of the glass substrate that is ion implanted in a manner sufficient to cause an index of refraction at a surface of the glass substrate to be from about 1.55 to 2.5, thus providing a glass substrate having a surface region that is ion implanted; and

an anti-reflective coating on the ion implanted surface region of the glass substrate.

27. The coated article claim 26, wherein coating comprises a dielectric layer having an index of refraction value (n) which differs by no more than 0.10 from n_c [where n_c=square root of (n_g×

n_a), where n_a=1.0 and n_g is the refractive index of an upper portion of the ion implanted surface region of the glass substrate].

28. The coated article of claim 26, wherein the coated article has a visible transmission of at least about 60%.