Heat stabilized sub-stoichiometric dielectrics

• US 8,137,742 B2
• Filed: 07/20/2007
• Issued: 03/20/2012
• Est. Priority Date: 02/25/2004
• Status: Active Grant

• Current Assignee: Cardinal CG Company (Cardinal Glass Industries Incorporated)
• Original Assignee: AGC Flat Glass North America Incorporated (AGC, Inc.)
• Inventors: Maschwitz, Peter
• Primary Examiner(s): BURKHART, ELIZABETH A
• Application Number:
  US11/780,531
• Publication Number:
  US 20080011408A1
• Time in Patent Office: 1,705 Days
• Field of Search: 427/162, 427/165
• US Class Current: 427/165
• CPC Class Codes: C03C 17/3423 at least one of the coatings comprising a suboxide
• CPC Class Codes: C03C 17/3435 comprising a nitride, oxynitride, boronitride or carbonitride
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3618 Coatings of type glass/inorganic compound/other inorganic layers, at least one layer being metallic
• CPC Class Codes: C03C 17/3626 one layer at least containing a nitride, oxynitride, boronitride or carbonitride
• CPC Class Codes: C03C 17/3639 Multilayers containing at least two functional metal layers
• CPC Class Codes: C03C 17/3644 the metal being silver
• CPC Class Codes: C03C 17/3657 the multilayer coating having optical properties
• CPC Class Codes: C03C 17/366 Low-emissivity or solar control coatings
• CPC Class Codes: C03C 2217/734 comprising an alternation of high and low refractive indexes
• CPC Class Codes: C03C 2218/156 by magnetron sputtering
• CPC Class Codes: G02B 5/285 comprising deposited thin solid films G02B5/281 - G02B5/289 take precedence; multilayered film filters for fibre optic multiplexing G02B6/29361
• CPC Class Codes: Y10S 428/913 Material designed to be responsive to temperature, light, moisture
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

A sub-stoichiometric oxide, nitride or oxynitride layer in an optical stack, alone or in direct contact with one or two stabilizing layers, stabilizes the optical properties of the stack. The stabilizing layer(s) can stabilize the chemistry and optical properties of the sub-stoichiometric layer during heating. The change in optical characteristics of the sub-stoichiometric layer upon heating can counter the change in optical characteristics of the rest of the optical stack.

Claims

1. A method of making an optical stack, the method comprising:

laminating a stabilizing layer and a sub-stoichiometric layer; and

producing an optical stack on a transparent glass substrate comprising the sub-stoichiometric layer in direct contact with the stabilizing layer, wherein

the sub-stoichiometric layer consists of

a homogenous sub-stoichiometric composition selected from the group consisting of oxides, nitrides, and oxynitrides, where

the sub-stoichiometric composition comprises at least one element selected from the group consisting of first metal elements and semiconductor elements, and

the sub-stoichiometric composition further comprises a sub-stoichiometric amount of at least one element selected from the group consisting of oxygen and nitrogen;

the stabilizing layer comprises

at least one element selected from the group consisting of second metal elements and semiconductor elements, and

a stoichiometric amount of the at least one element selected from the group consisting of oxygen and nitrogen; and

the sub-stoichiometric layer is from 10 to 100 nm thick and thicker than the stabilizing layer,

wherein the first metal elements are selected from the group consisting of Mg, Y, Ti, Zr, Nb, Ta, W, Zn, Al, In, Sn, Sb and Bi; and

the semiconductor elements are selected from the group consisting of Si and Ge.

2. A method of making an optical stack according to claim 1, the method further comprising:

heating the optical stack to at least 600°

C.

3. A method of making an optical stack according to claim 1, wherein the stabilizing layer is from 1 to 10 nm thick.

4. A method of making an optical stack according to claim 1, wherein

the first metal elements are selected from the group consisting of Mg, Zn, Al, In, Sn, Sb and Bi.

5. A method of making an optical stack according to claim 1, wherein the optical stack further comprises a metal layer and said metal layer comprises Ag.

6. A method of making an optical stack according to claim 1, wherein the second metal elements are selected from the group consisting of Ti, Zr, Hf, Nb, Ta, Mo, W, Al, Mg, and alloys, aluminides, and silicides thereof.

7. A method of making an optical stack, the method comprising:

laminating a first stabilizing layer, a sub-stoichiometric layer and a second stabilizing layer; and

producing an optical stack on a transparent glass substrate comprising the substoichiometric layer sandwiched between and in direct contact with the first stabilizing layer and the second stabilizing layer, wherein

the sub-stoichiometric layer consists of

a sub-stoichiometric composition selected from the group consisting of oxides, nitrides, and oxynitrides, where

the sub-stoichiometric composition comprises at least one element select from the group consisting of first metal elements and semiconductor elements, and

the sub-stoichiometric composition further comprises a sub-stoichiometric amount of at least one element selected from the group consisting of oxygen and nitrogen;

the first stabilizing layer and the second stabilizing layer each comprises

at least one element selected from the group consisting of second metal elements and semiconductor elements, and

a stoichiometric amount of the at least one element selected from the group consisting of oxygen and nitrogen

wherein the first metal elements are selected from the group consisting of Mg, Y, Ti, Zr, Nb, Ta, W, Zn, Al, In, Sn, Sb and Bi; and

the semiconductor elements are selected from the group consisting of Si and Ge.

8. A method of making an optical stack according to claim 7, the method further comprising:

heating the optical stack to at least 600°

C.

9. A method of making an optical stack according to claim 7, wherein

the stabilizing layer is from 1 to 10 nm thick, and

the sub-stoichiometric layer is from 10 to 100 nm thick and thicker than the stabilizing layer.

10. A method of making an optical stack according to claim 7, wherein

the first metal elements are selected from the group consisting of Mg, Zn, Al, In, Sn, Sb and Bi.

11. A method of making an optical stack according to claim 7, wherein the sub-stoichiometric layer has an index of refraction, n, such that n >

2.3.

12. A method of making an optical stack according to claim 7, wherein the sub-stoichiometric layer has an extinction coefficient, k, such that 0.03 <

k <

0.15.

13. A method of making an optical stack according to claim 7, wherein

the optical stack further comprises a metal layer;

and

the sub-stoichiometric layer and the stabilizing layer are between the transparent glass substrate and the metal layer.

14. A method of making an optical stack according to claim 7, further comprising:

tempering the optical stack on the transparent substrate; and

wherein a glass side reflection tempering color shift of the optical stack on the transparent glass substrate is 3.0 or less.

15. A method of making an optical stack according to claim 7, further comprising:

tempering the optical stack on the transparent substrate; and

wherein a optical stack side reflection tempering color shift of the optical stack on the transparent glass substrate is 3.7 or less.

16. A method of making an optical stack according to claim 7, wherein the optical stack further comprises a metal layer and said metal layer comprises Ag.

17. A method of making an optical stack according to claim 7, wherein the second metal elements are selected from the group consisting of Ti, Zr, Hf, Nb, Ta, Mo, W, Al, Mg, and alloys, aluminides, and silicides thereof.

18. A method of making an optical stack, comprising:

laminating a stabilizing layer and a sub-stoichiometric layer; and

producing an optical stack on a transparent glass substrate comprising the sub-stoichiometric layer in direct contact with the stabilizing layer, wherein

the sub-stoichiometric layer consists of

a homogeneous sub-stoichiometric composition selected from the group consisting of oxides, nitrides and oxynitrides, where

the sub-stoichiometric composition comprises at least one element selected from the group consisting of metal elements and semiconductor elements, and

the sub-stoichiometric composition further comprises a sub-stoichiometric amount of at least one element selected from the group consisting of oxygen and nitrogen;

the stabilizing layer comprises

the at least one element selected from the group consisting of metal elements and semiconductor elements, and

a stoichiometric amount of the at least one element selected from the group consisting of oxygen and nitrogen; and

the sub-stoichiometric layer is from 10 to 100 nm thick and thicker than the stabilizing layer,

wherein the sub-stoichiometric layer has an index of refraction, n, such that n >

2.3.

19. A method of making an optical stack, comprising:

laminating a stabilizing layer and a sub-stoichiometric layer; and

producing an optical stack on a transparent glass substrate comprising the sub-stoichiometric layer in direct contact with the stabilizing layer, wherein

the sub-stoichiometric layer consists of

a homogeneous sub-stoichiometric composition selected from the group consisting of oxides, nitrides and oxynitrides, where

the sub-stoichiometric composition comprises at least one element selected from the group consisting of metal elements and semiconductor elements, and

the sub-stoichiometric composition further comprises a sub-stoichiometric amount of at least one element selected from the group consisting of oxygen and nitrogen;

the stabilizing layer comprises

the at least one element selected from the group consisting of metal elements and semiconductor elements, and

a stoichiometric amount of the at least one element selected from the group consisting of oxygen and nitrogen; and

the sub-stoichiometric layer is from 10 to 100 nm thick and thicker than the stabilizing layer,

wherein the sub-stoichiometric layer has an extinction coefficient, k, such that 0.03<

k <

015.

20. A method of making an optical stack, comprising:

laminating a stabilizing layer and a sub-stoichiometric layer; and

producing an optical stack on a transparent glass substrate comprising the sub-stoichiometric layer in direct contact with the stabilizing layer, wherein

the sub-stoichiometric layer consists of

a homogeneous sub-stoichiometric composition selected from the group consisting of oxides, nitrides and oxynitrides, where

the sub-stoichiometric composition comprises at least one element selected from the group consisting of metal elements and semiconductor elements, and

the sub-stoichiometric composition further comprises a sub-stoichiometric amount of at least one element selected from the group consisting of oxygen and nitrogen;

the stabilizing layer comprises

the at least one element selected from the group consisting of metal elements and semiconductor elements, and

a stoichiometric amount of the at least one element selected from the group consisting of oxygen and nitrogen; and

the sub-stoichiometric layer is from 10 to 100 nm thick and thicker than the stabilizing layer,

wherein the optical stack further comprises a metal layer; and

the sub-stoichiometric layer and the stabilizing layer are between the transparent glass substrate and the metal layer.

21. A method of making an optical stack, comprising:

laminating a stabilizing layer and a sub-stoichiometric layer; and

producing an optical stack on a transparent glass substrate comprising the sub-stoichiometric layer in direct contact with the stabilizing layer, wherein

the sub-stoichiometric layer consists of

a homogeneous sub-stoichiometric composition selected from the group consisting of oxides, nitrides and oxynitrides, where

the sub-stoichiometric composition comprises at least one element selected from the group consisting of metal elements and semiconductor elements, and

the sub-stoichiometric composition further comprises a sub-stoichiometric amount of at least one element selected from the group consisting of oxygen and nitrogen;

the stabilizing layer comprises

the at least one element selected from the group consisting of metal elements and semiconductor elements, and

a stoichiometric amount of the at least one element selected from the group consisting of oxygen and nitrogen; and

the sub-stoichiometric layer is from 10 to 100 nm thick and thicker than the stabilizing layer,

tempering the optical stack on the transparent substrate; and

wherein a glass side reflection tempering color shift of the optical stack on the transparent glass substrate is 3.0 or less.

22. A method of making an optical stack, comprising:

laminating a stabilizing layer and a sub-stoichiometric layer; and

producing an optical stack on a transparent glass substrate comprising the sub-stoichiometric layer in direct contact with the stabilizing layer, wherein

the sub-stoichiometric layer consists of

a homogeneous sub-stoichiometric composition selected from the group consisting of oxides, nitrides and oxynitrides, where

the sub-stoichiometric composition comprises at least one element selected from the group consisting of metal elements and semiconductor elements, and

the sub-stoichiometric composition further comprises a sub-stoichiometric amount of at least one element selected from the group consisting of oxygen and nitrogen;

the stabilizing layer comprises

the at least one element selected from the group consisting of metal elements and semiconductor elements, and

a stoichiometric amount of the at least one element selected from the group consisting of oxygen and nitrogen; and

the sub-stoichiometric layer is from 10 to 100 nm thick and thicker than the stabilizing layer,

tempering the optical stack on the transparent substrate; and

wherein an optical stack side reflection tempering color shift of the optical stack on the transparent glass substrate is 3.7 or less.

23. A method of making an optical stack, comprising:

providing an optical stack comprising a transmission control layer selected from the group consisting of NiCrO_x , NiO_x CrO_x CuO_xand FeO_x;

selecting a thickness of the transmission control layer is from 2 to 20 nm

so that during tempering of the optical stack an absolute change in transmission of the optical stack is 1.00% or less, and

tempering the optical stack, and wherein the method of selecting a thickness of an optical stack further comprises;

providing a plurality of optical stacks having two or more silver layers in which the thickness of the transmission control layer varies;

determining a change in transmission through each of said plurality of optical coatings before and after tempering;

estimating a zero transmission change thickness of the transmission control layer above which the change in transmission is positive and below which the change in transmission is negative, and

selecting the thickness of the transmission control layer after determining the zero transmission change thickness.

24. A method of making an optical stack according to claim 23, wherein during the tempering the absolute change in transmission of the optical stack is 0.50% or less.

25. A method of making an optical stack according to claim 23, wherein during the tempering the absolute change in transmission of the optical stack is 0.25% or less.

26. A method of making an optical stack according to claim 23, wherein the transmission control layer is a layer of sub-stoichiometric NiCrO_x.

27. A method of making an optical stack according to claim 26, wherein the layer of sub-stoichiometric NiCrO_x layer is homogeneous.

28. A method of making an optical stack according to claim 23, wherein the selected thickness of the transmission control layer is from 3 to 12 nm.