U.S. patent application number 17/007843 was filed with the patent office on 2022-03-03 for low-e matchable coated articles having absorber film and corresponding methods.
This patent application is currently assigned to GUARDIAN GLASS, LLC. The applicant listed for this patent is GUARDIAN GLASS, LLC. Invention is credited to Salah BOUSSAAD, Brent BOYCE, Jingyu LAO, Philip J. LINGLE, Richard VERNHES, Yongli XU.
Application Number | 20220064060 17/007843 |
Document ID | / |
Family ID | 1000006150107 |
Filed Date | 2022-03-03 |
United States Patent
Application |
20220064060 |
Kind Code |
A9 |
XU; Yongli ; et al. |
March 3, 2022 |
LOW-E MATCHABLE COATED ARTICLES HAVING ABSORBER FILM AND
CORRESPONDING METHODS
Abstract
A low-E coating has good color stability (a low .DELTA.E* value)
upon heat treatment (HT). Thermal stability may be improved by the
provision of an as-deposited crystalline or substantially
crystalline layer of or including zinc oxide, doped with at least
one dopant (e.g., Sn), immediately under an infrared (IR)
reflecting layer of or including silver; and/or by the provision of
at least one dielectric layer of or including an oxide of
zirconium. These have the effect of significantly improving the
coating's thermal stability (i.e., lowering the .DELTA.E* value).
An absorber film may be designed to adjust visible transmission and
provide desirable coloration, while maintaining durability and/or
thermal stability. The dielectric layer (e.g., of or including an
oxide of Zr) may be sputter-deposited so as to have a monoclinic
phase in order to improve thermal stability.
Inventors: |
XU; Yongli; (Plymouth,
MI) ; BOYCE; Brent; (Novi, MI) ; BOUSSAAD;
Salah; (Auburn Hills, MI) ; LINGLE; Philip J.;
(Temperance, MI) ; LAO; Jingyu; (Saline, MI)
; VERNHES; Richard; (Auburn Hills, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GUARDIAN GLASS, LLC |
Auburn Hills |
MI |
US |
|
|
Assignee: |
GUARDIAN GLASS, LLC
AUBURN HILLS
MI
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20210147289 A1 |
May 20, 2021 |
|
|
Family ID: |
1000006150107 |
Appl. No.: |
17/007843 |
Filed: |
August 31, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16596632 |
Oct 8, 2019 |
10759693 |
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17007843 |
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16355966 |
Mar 18, 2019 |
10640418 |
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16596632 |
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16220037 |
Dec 14, 2018 |
10752541 |
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16355966 |
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16035810 |
Jul 16, 2018 |
10301215 |
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16220037 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C03C 2218/156 20130101;
C03C 2217/281 20130101; C03C 2217/24 20130101; C03C 17/366
20130101; C03C 2217/256 20130101; C03C 17/3644 20130101; C03C
17/3681 20130101; C03C 17/3642 20130101; C03C 2217/23 20130101;
C03C 17/3626 20130101 |
International
Class: |
C03C 17/36 20060101
C03C017/36 |
Claims
1-60. (canceled)
61. A coated article including a coating on a glass substrate,
wherein the coating comprises: a first crystalline or substantially
crystalline layer comprising zinc oxide, located on the glass
substrate; a first infrared (IR) reflecting layer comprising silver
located on the glass substrate and directly over and contacting the
first crystalline or substantially crystalline layer comprising
zinc oxide; at least one dielectric layer having monoclinic phase
and comprising an oxide of zirconium; wherein the at least one
dielectric layer having monoclinic phase and comprising the oxide
of zirconium is located: (1) between at least the glass substrate
and the first crystalline or substantially crystalline layer
comprising zinc oxide, and/or (2) between at least the first IR
reflecting layer comprising silver and a second IR reflecting layer
comprising silver of the coating; wherein the coated article is
configured to have, measured monolithically, at least two of: (i) a
transmissive .DELTA.E* value of no greater than 3.0 upon a
reference heat treatment for 12 minutes at a temperature of about
650 degrees C., (ii) a glass side reflective .DELTA.E* value of no
greater than 3.0 upon the reference heat treatment for 12 minutes
at a temperature of about 650 degrees C., and (iii) a film side
reflective .DELTA.E* value of no greater than 3.5 upon the
reference heat treatment for 12 minutes at a temperature of about
650 degrees C.
62. The coated article of claim 61, wherein the coating further
comprises an absorber film that comprises a layer comprising an
oxide of Ni and/or Cr located over and directly contacting a layer
comprising silver of the absorber film.
63. The coated article of claim 62, wherein the absorber film is
located over the first IR reflecting layer, so that the first IR
reflecting layer is located between at least the absorber film and
the glass substrate.
64. The coated article of claim 62, wherein a ratio of a physical
thickness of the first IR reflecting layer comprising silver to a
physical thickness of the layer comprising silver of the absorber
film is at least 8:1.
65. The coated article of claim 62, wherein the layer comprising
silver of the absorber film is less than 60 .ANG. thick.
66. The coated article of claim 62, wherein the layer comprising
silver of the absorber film is less than 30 .ANG. thick.
67. The coated article of claim 61, wherein the coated article is
configured to have, measured monolithically, all three of: (i) a
transmissive .DELTA.E* value of no greater than 3.0 upon a
reference heat treatment for 12 minutes at a temperature of about
650 degrees C., (ii) a glass side reflective .DELTA.E* value of no
greater than 3.0 upon the reference heat treatment for 12 minutes
at a temperature of about 650 degrees C., and (iii) a film side
reflective .DELTA.E* value of no greater than 3.5 upon the
reference heat treatment for 12 minutes at a temperature of about
650 degrees C.
68. The coated article of claim 61, wherein the at least one
dielectric layer comprising monoclinic phase is located at least
between at least the glass substrate and the first crystalline or
substantially crystalline layer comprising zinc oxide.
69. The coated article of claim 61, wherein the at least one
dielectric layer comprising monoclinic phase is located at least
between at least the first IR reflecting layer comprising silver
and the second IR reflecting layer comprising silver of the
coating.
70. The coated article of claim 61, wherein said coated article,
measured monolithically, has a visible transmission of at least
40%.
71. The coated article of claim 61, wherein the coating as
deposited further comprises a first amorphous or substantially
amorphous layer comprising zinc stannate located on the glass
substrate over at least the first IR reflecting layer comprising
silver.
72. The coated article of claim 61, wherein the at least one
dielectric layer comprising monoclinic phase comprises from 0-5%
nitrogen (atomic %).
73. The coated article of claim 61, wherein the at least one
dielectric layer comprising monoclinic phase comprises
ZrO.sub.2.
74. The coated article of claim 61, wherein the at least one
dielectric layer comprising monoclinic phase consists essentially
of the oxide of zirconium.
75. The coated article of claim 61, wherein the at least one
dielectric layer comprising monoclinic phase is configured to
realize a density change of at least 0.25 g/cm.sup.3 upon heat
treatment.
76. The coated article of claim 61, wherein the at least one
dielectric layer comprising monoclinic phase comprises an oxide of
zirconium, and has a metal content of at least 80% Zr.
77. The coated article of claim 61, wherein the at least one
dielectric layer comprising monoclinic phase and comprising the
oxide of zirconium has a thickness of from 40-170 .ANG..
78. The coated article of claim 61, wherein the at least one
dielectric layer comprising monoclinic phase and comprising the
oxide of zirconium, further comprises Si.
79. The coated article of claim 61, wherein no silicon nitride
based layer is located directly under and contacting the layer
comprising zinc oxide.
Description
[0001] This application is a Continuation-in-Part (CIP) of U.S.
application Ser. No. 16/355,966, filed Mar. 18, 2019, which is a
Continuation-in-Part (CIP) of U.S. application Ser. No. 16/220,037,
filed Dec. 14, 2018, which is a Continuation-in-Part (CIP) of U.S.
application Ser. No. 16/035,810, filed Jul. 16, 2018 (now U.S. Pat.
No. 10,031,215), the disclosures of which are all hereby
incorporated herein by reference in their entireties.
[0002] This invention relates to low-E coated articles that have
approximately the same color characteristics as viewed by the naked
eye both before and after heat treatment (e.g., thermal tempering),
and corresponding methods. Such articles may in certain example
embodiments combine two or more of: (1) desirable visible
transmission characteristics, (2) good durability before and/or
after heat treatment, (3) a low .DELTA.E* value which is indicative
of color stability upon heat treatment (HT), and/or (4) an absorber
film designed to adjust visible transmission and provide desirable
coloration for the coated article, while maintaining durability
and/or thermal stability. Such coated articles may be used
monolithically for windows, in insulating glass (IG) window units,
laminated window units, vehicle windshields, and/or other vehicle
or architectural or residential window applications.
BACKGROUND OF THE INVENTION
[0003] There is a need for substantial matchability (before heat
treatment vs. after heat treatment). Glass substrates are often
produced in large quantities and cut to size in order to fulfill
the needs of a particular situation such as a new multi-window
office building, vehicle window needs, etc. It is often desirable
in such applications that some of the windows and/or doors be heat
treated (i.e., tempered, heat strengthened or heat-bent) while
others need not be. Office buildings often employ IG units and/or
laminates for safety and/or thermal control. It is desirable that
the units and/or laminates which are heat treated (HT)
substantially match their non-heat treated counterparts (e.g., with
regard to color, reflectance, transmission, and/or the like, at
least on the side to be viewed from outside the building) for
architectural and/or aesthetic purposes.
[0004] Commonly owned U.S. Pat. No. 5,688,585 discloses a solar
control coated article including:
glass/Si.sub.3N.sub.4/NiCr/Si.sub.3N.sub.4. One object of the '585
patent is to provide a sputter coated layer system that after heat
treatment (HT) is matchable colorwise with its non-heat treated
counterpart. While the coating systems of the '585 patent are
excellent for their intended purposes, they suffer from certain
disadvantages. In particular, they tend to have rather high
emissivity and/or sheet resistance values (e.g., because no silver
(Ag) layer is disclosed in the '585 patent).
[0005] It has in the prior art been possible to achieve
matchability in systems other than those of the aforesaid '585
patent, between two different layer systems, one of which is heat
treated and the other is not. The necessity of developing and using
two different layer systems to achieve matchability creates
additional manufacturing expense and inventory needs which are
undesirable.
[0006] U.S. Pat. Nos. 6,014,872 and 5,800,933 (see Example B)
disclose a heat treatable low-E layer system including:
glass/TiO.sub.2/Si.sub.3N.sub.4/NiCr/Ag/NiCr/Si.sub.3N.sub.4.
Unfortunately, when heat treated this low-E layer system is not
approximately matchable colorwise with its non-heat treated
counterpart (as viewed from the glass side). This is because this
low-E layer system has a .DELTA.E* (glass side) value greater than
4.1 (i.e., for Example B, .DELTA.a*.sub.G is 1.49, .DELTA.b*.sub.G
is 3.81, and .DELTA.L* (glass side) is not measured; using Equation
(1) below then .DELTA.E* on the glass side must necessarily be
greater than 4.1 and is probably much higher than that).
[0007] U.S. Pat. No. 5,563,734 discloses a low-E coating system
including:
substrate/TiO.sub.2/NiCrN.sub.x/Ag/NiCrN.sub.x/Si.sub.3N.sub.4.
Unfortunately, it has been found that when high Nitrogen (N) flow
rates are used when forming the NiCrN.sub.x layers (see the high N
flow rate of 143 sccm in Table 1 of the '734 patent; translating
into about 22 sccm/kW), the resulting coated articles are not color
stable with heat treatment (i.e., they tend to have high .DELTA.E*
(glass side) values greater than 6.0). In other words, if subjected
to HT, the '734 patent low-E layer system would not be
approximately matchable colorwise with its non-heat treated
counterpart (as viewed from the glass side).
[0008] Moreover, it is sometimes desirable for a coated article to
have desirable visible transmission characteristics and/or good
durability (mechanical and/or chemical). Unfortunately, certain
known steps that are taken to adjust or improve visible
transmission characteristics and/or pre-HT durability tend to
degrade post-HT durability and thermal stability. Thus, it is often
difficult to obtain a combination of desirable visible transmission
values, thermal stability of color, and good durability.
[0009] In view of the above, it will be apparent to those skilled
in the art that there exists a need for a low-E coating or layer
system that after HT substantially matches in color and/or
reflection (as viewed by a naked human eye) its non-heat treated
counterpart. In other words, there exists a need in the art for a
low-E matchable coating or layering system. There also exists a
need in the art for a heat treatable system that can combine one or
more of: (1) desirable visible transmission characteristics (e.g.,
from about 30-75% measured monolithically, and/or from 30-70% as
measured in an IG unit), (2) good durability before and/or after
heat treatment, (3) a low .DELTA.E* value which is indicative of
color stability upon heat treatment (HT), and/or (4) an absorber
film designed to adjust visible transmission and provide desirable
coloration for the coated article, while maintaining durability
and/or thermal stability.
[0010] It is a purpose of this invention to fulfill one or more of
the above-listed needs, and/or other needs which will become more
apparent to the skilled artisan once given the following
disclosure.
SUMMARY
[0011] An example object of this invention is to provide a low-E
coating or layer system that has good color stability (a low
.DELTA.E* value) upon heat treatment (HT). Another example object
of this invention is to provide a low-E matchable coating or
layering system. Another example object, in certain example
embodiments, is to provide an absorber film in the low-E coating
which is designed to adjust visible transmission and provide
desirable coloration for the coated article, while maintaining
durability and/or thermal stability.
[0012] Example embodiments of this invention relate to low-E coated
articles that have approximately the same color characteristics as
viewed by the naked eye both before and after heat treatment (e.g.,
thermal tempering), and corresponding methods. Such articles may in
certain example embodiments combine two or more of: (1) desirable
visible transmission characteristics, (2) good durability before
and/or after heat treatment, (3) a low .DELTA.E* value which is
indicative of color stability upon heat treatment (HT), and/or (4)
an absorber film designed to adjust visible transmission and
provide desirable coloration for the coated article, while
maintaining durability and/or thermal stability.
[0013] In certain example embodiments, the optional absorber film
may be a multi-layer absorber film including a first layer of or
including silver (Ag), and a second layer of or including NiCr
which may be partially or fully oxided (NiCrO.sub.x). Such a
multi-layer absorber film may thus, in certain example embodiments,
be made up of a layer sequence of Ag/NiCrO.sub.x. This layer
sequence may be repeated in certain example instances. The silver
based layer in the absorber film is preferably sufficiently thin so
that its primary function is to absorb visible light and provide
desirable coloration (as opposed to being much thicker and
primarily function as an IR reflection layer). The NiCr or
NiCrO.sub.x is provided over and contacting the silver of the
absorber film in order to protect the silver, and also to
contribute to absorption.
[0014] A single layer of NiCr (or other suitable material) may also
be used as an absorber film in low-E coatings in certain example
embodiments of this invention. However, it has surprisingly been
found that using silver in an absorber film (single layer, or
multi-layer, absorber film) provides for several unexpected
advantages compared to a single layer of NiCr as the absorber.
First, it has been found that a single layer of NiCr as the
absorber tends to cause yellowish coloration in certain low-E
coating coated articles, which may not be desirable in certain
instances. In contrast, it has been surprisingly found that using
silver in an absorber films tends to avoid such yellowish
coloration and/or instead provide for more desirable neutral
coloration of the resulting coated article. Thus, the use of silver
in an absorber film has been found to provide for improved optical
characteristics. Second, the use of a single layer of NiCr as the
absorber tends to also involve providing silicon nitride based
layers on both sides of the NiCr so as to directly sandwich and
contact the NiCr therebetween. It has been found that the provision
of silicon nitride in certain locations in a coating stack may lead
to compromised thermal stability upon HT. In contrast, it has been
surprisingly found that when using silver in an absorber film a
pair of immediately adjacent silicon nitride layers are not needed,
so that thermal stability upon HT may be improved. Thus, the use of
silver in an absorber film has been found to provide for improved
thermal stability including lower .DELTA.E* values and therefor
improved matchability between HT and non-HT versions of the same
coating. The use of silver in an absorber film may also provide for
improved manufacturability in certain situations.
[0015] In certain example embodiments, surprisingly, and
unexpectedly, it has been found that the provision of an
as-deposited crystalline or substantially crystalline (e.g., at
least 50% crystalline, more preferably at least 60% crystalline)
layer of or including zinc oxide, doped with at least one dopant
(e.g., Sn), immediately under an infrared (IR) reflecting layer of
or including silver in a low-E coating has effect of significantly
improving the coating's thermal stability (i.e., lowering the
.DELTA.E* value). One or more such crystalline, or substantially
crystalline (e.g., at least 50% crystalline, more preferably at
least 60% crystalline), layers may be provided under one or more
corresponding IR reflecting layers comprising silver, in various
embodiments of this invention. Thus, the crystalline or
substantially crystalline layer of or including zinc oxide, doped
with at least one dopant (e.g., Sn), immediately under an infrared
(IR) reflecting layer of or including silver may be used in single
silver low-E coatings, double-silver low-E coatings, or triple
silver low-E coatings in various embodiments of this invention. In
certain example embodiments, the crystalline or substantially
crystalline layer of or including zinc oxide is doped with from
about 1-30% Sn, more preferably from about 1-20% Sn, most
preferably from about 5-15% Sn, with an example being about 10% Sn
(in terms of wt. %). The zinc oxide, doped with Sn, is in a
crystallized or substantially crystallized phase (as opposed to
amorphous or nanocrystalline) as deposited, such as via sputter
deposition techniques from at least one sputtering target(s) of or
including Zn and Sn. The crystallized phase of the doped zinc oxide
based layer as deposited, combined with the layer(s) between the
silver and the glass, allows the coated article to realize improved
thermal stability upon optional HT (lower the .DELTA.E* value). It
is believed that the crystallized phase of the doped zinc oxide
based layer as deposited (e.g., at least 50% crystalline, more
preferably at least 60% crystalline), combined with the layer(s)
between the IR reflecting layer and the glass, allows the silver of
the IR reflecting layer to have improved crystal structure with
texture but with some randomly oriented grains so that its
refractive index (n) changes less upon optional HT, thereby
allowing for improved thermal stability to be realized.
[0016] In certain example embodiments, it has also been
surprisingly and unexpectedly found that the provision of a
dielectric layer(s) of or including silicon oxide, zirconium oxide,
zirconium oxynitride, silicon zirconium oxide and/or silicon
zirconium oxynitride (e.g., SiZrO.sub.x, ZrO.sub.2, SiO.sub.2,
and/or SiZrO.sub.xN.sub.y) also provides for improved thermal
stability of the coated article, and thus lower the .DELTA.E*
values upon heat treatment (HT) such as thermal tempering. In
certain example embodiments, at least one dielectric layer(s) of or
including silicon oxide, zirconium oxide, silicon zirconium oxide
and/or silicon zirconium oxynitride (e.g., SiZrO.sub.x, ZrO.sub.2,
SiO.sub.2, and/or SiZrO.sub.xN.sub.y) may be provided: (i) in the
bottom dielectric portion of the coating under all silver based IR
reflecting layer(s), and/or (ii) in a middle dielectric portion of
the coating between a pair of silver based IR reflecting layers.
For example, the dielectric layer of or including silicon oxide,
zirconium oxide, silicon zirconium oxide and/or silicon zirconium
oxynitride may be provided directly under and contacting the
lowermost doped zinc oxide based layer in certain example
embodiments of this invention, and/or between a pair of zinc oxide
inclusive layers in a middle dielectric portion of the low-E
coating.
[0017] The dielectric layer(s) of or including silicon oxide,
zirconium oxide, silicon zirconium oxide and/or silicon zirconium
oxynitride may or may not be provided in combination with an
as-deposited crystalline or substantially crystalline (e.g., at
least 50% crystalline, more preferably at least 60% crystalline)
layer(s) of or including zinc oxide, doped with at least one dopant
(e.g., Sn), immediately under an infrared (IR) reflecting layer, in
various example embodiments of this invention.
[0018] In certain example embodiments, it has surprisingly and
unexpectedly been found that initially sputter-depositing the
dielectric layer(s) of or including zirconium oxide (e.g.,
ZrO.sub.2), zirconium oxynitride, silicon zirconium oxide and/or
silicon zirconium oxynitride (e.g., SiZrO.sub.x, ZrO.sub.2,
SiO.sub.2, and/or SiZrO.sub.xN.sub.y) so as to comprise a
monoclinic phase crystalline structure is advantageous in that it
results in improved thermal stability (lower .DELTA.E* value)
and/or reduced change in visible transmission (e.g., T.sub.vis or
TY) of the coated article upon heat treatment (HT). In certain
example embodiments, the monoclinic phase for the dielectric layer
(e.g., ZrO.sub.2) may be achieved by using a very high oxygen gas
flow for that layer during the sputter-deposition process of that
layer, and using a metallic sputtering target (e.g., Zr target).
For example, when sputter depositing layer 2 and/or 2'' to form a
layer having monoclinic phase, the sputter process for that layer
may implement an oxygen gas flow of at least 5 ml/kW, more
preferably of at least 6 ml/kW, more preferably at least 8 ml/kW,
and most preferably at least 10 ml/kW, where ml indicates the total
oxygen gas flow in the chamber and kW indicates power to the
target. It is noted that such high oxygen gas flows desired in
certain example embodiments of this case are counterintuitive, and
conventionally undesirable, because they reduce deposition rates
and thus created added time and expense in making coated articles.
While high oxygen gas flows are used to achieve the monoclinic
phase in connection with metal targets in certain example
embodiments when certain types of sputtering equipment is used,
this invention is not so limited, as it has been found that with
certain types of sputtering equipment the monoclinic phase may also
be achieved with low or lower oxygen gas flows.
[0019] It has been found that a significant partial or full phase
change away from monoclinic to tetragonal or cubic crystalline
structure, and corresponding density change, of the layer upon HT
tends to compensate for change in crystalline structure of the
silver layer(s) upon said HT, which appears to result in improved
thermal stability (lower .DELTA.E* value) and/or reduced change in
visible transmission (e.g., T.sub.vis or TY) of the coated article
upon HT. It has been surprisingly found that initially
sputter-depositing the dielectric layer(s) of or including
zirconium oxide, zirconium oxynitride, silicon zirconium oxide
and/or silicon zirconium oxynitride (e.g., SiZrO.sub.x, ZrO.sub.2,
SiO.sub.2, and/or SiZrO.sub.xN.sub.y) so as to comprise a
monoclinic phase crystalline structure is advantageous in that it
results in a high density change in the layer of at least about
0.25 g/cm.sup.3, more preferably of at least about 0.30 g/cm.sup.3,
and most preferably of at least about 0.35 g/cm.sup.3 (e.g., from
about 5.7 to about 6.1 g/cm.sup.3), upon HT which in turn
compensates for change in crystalline structure of the silver
layer(s) upon said HT, resulting in improved thermal stability
(lower .DELTA.E* value) and/or reduced change in visible
transmission (T.sub.vis or TY) of the coated article upon heat
treatment (HT). In certain example embodiments, this allows for
reduced change in visible transmission (T.sub.vis or TY) of the
coated article of no more than 1.2%, more preferably no more than
1.0%, and most preferably no more than 0.5%, due to HT, and/or a
reduced .DELTA.E* value.
[0020] It has also been surprisingly and unexpectedly found that
the provision of no silicon nitride based layer directly under and
contacting the lowermost doped zinc oxide based layer between the
glass substrate and the lowermost silver based layer, in
combination with the crystallized phase of the doped zinc oxide
based layer as deposited, allows for improved thermal stability
upon heat treatment (lower .DELTA.E* values) to be realized. It has
also been surprisingly and unexpectedly found that the provision of
no silicon nitride based layer in the middle section of the stack
between the two silver-based IR reflecting layers allows for
improved thermal stability upon heat treatment (lower .DELTA.E*
values) to be realized.
[0021] In certain example embodiments, measured monolithically
and/or in an IG unit with two panes, the coated article is
configured to realize one or more of: (i) a transmissive .DELTA.E*
value (where transmissive optics are measured) of no greater than
3.0 (more preferably no greater than 2.8, and most preferably no
greater than 2.5 or 2.3) upon HT for 8, 12 and/or 16 minutes at a
temperature of about 650 degrees C., (ii) a glass side reflective
.DELTA.E* value (where glass side reflective optics are measured)
of no greater than 3.0 (more preferably no greater than 2.5, more
preferably no greater than 2.0, and most preferably no greater than
1.5, no greater than 1.0, and/or no greater than 0.6) upon HT for
8, 12 and/or 16 minutes at a temperature of about 650 degrees C.,
and/or (iii) a film side reflective .DELTA.E* value (where film
side reflective optics are measured) of no greater than 3.5 (more
preferably no greater than 3.0, and most preferably no greater than
2.0, or no greater than 1.5, or 1.3) upon HT for 8, 12, 16 and/or
20 minutes at a temperature of about 650 degrees C. Of course, in
commercial practice the baking times may be for different/other
time periods, and these are for reference purposes. In certain
example embodiments, measured monolithically, the coated article is
configured to have a visible transmission (T.sub.vis or Y), before
or after any optional HT, of at least about 30%, more preferably of
at least about 40%, and most preferably of at least about 50%
(e.g., from about 45-60%). Coated articles herein may have, for
example, visible transmission from about 30-75% measured
monolithically, and/or from 30-70% as measured in an IG unit. Among
other things, the thickness, makeup, and/or number of layers of the
absorber may be adjusted to adjust visible transmission. In certain
example embodiments, measured monolithically, the coated article is
configured to have a glass side visible reflection (R.sub.gY or
RGY), measured monolithically, before or after any optional HT, of
no greater than about 20%.
[0022] In an example embodiment of this invention, there is
provided a coated article including a coating on a glass substrate,
wherein the coating comprises: a first crystalline or substantially
crystalline layer comprising zinc oxide doped with from about 1-30%
Sn (wt. %), provided on the glass substrate; a first infrared (IR)
reflecting layer comprising silver located on the glass substrate
and directly over and contacting the first crystalline or
substantially crystalline layer comprising zinc oxide doped with
from about 1-30% Sn; wherein no silicon nitride based layer is
located directly under and contacting the first crystalline or
substantially crystalline layer comprising zinc oxide doped with
from about 1-30% Sn; at least one dielectric layer having
monoclinic phase and comprising an oxide of zirconium; wherein the
at least one dielectric layer having monoclinic phase and
comprising the oxide of zirconium is located: (1) between at least
the glass substrate and the first crystalline or substantially
crystalline layer comprising zinc oxide doped with from about 1-30%
Sn (wt. %), and/or (2) between at least the first IR reflecting
layer comprising silver and a second IR reflecting layer comprising
silver of the coating; an optional absorber film including a layer
comprising silver, wherein a ratio of a physical thickness of the
first IR reflecting layer comprising silver to a physical thickness
of the layer comprising silver of the absorber film is at least 5:1
(more preferably at least 8:1, even more preferably at least 10:1,
and most preferably at least 15:1); and wherein the coated article
is configured to have, measured monolithically, at least two of:
(i) a transmissive .DELTA.E* value of no greater than 3.0 due to a
reference heat treatment for 12 minutes at a temperature of about
650 degrees C., (ii) a glass side reflective .DELTA.E* value of no
greater than 3.0 due to the reference heat treatment for 12 minutes
at a temperature of about 650 degrees C., and (iii) a film side
reflective .DELTA.E* value of no greater than 3.5 due to the
reference heat treatment for 12 minutes at a temperature of about
650 degrees C.
[0023] Such coated articles may be used monolithically for windows,
in insulating glass (IG) window units (e.g., on surface #2 or
surface #3 in IG window unit applications), laminated window units,
vehicle windshields, and/or other vehicle or architectural or
residential window applications.
[0024] This invention will now be described with respect to certain
embodiments thereof as illustrated in the following drawings,
wherein:
IN THE DRAWINGS
[0025] FIGS. 1(a), 1(b), 1(c), 1(d), 1(e), 1(f), 1(g), 1(h), and
1(i) are cross sectional views of coated articles according to
example embodiments of this invention.
[0026] FIG. 2 is a chart illustrating sputter-deposition conditions
for the sputter-deposition of the low-E coating of Example 1 on a 6
mm thick glass substrate, where the low-E coating is illustrated in
general by FIG. 1(a).
[0027] FIG. 3 is a chart illustrating sputter-deposition conditions
for the sputter-deposition of the low-E coating of Example 2 on a 6
mm thick glass substrate, where the low-E coating is illustrated in
general by FIG. 1(a).
[0028] FIG. 4 is a chart illustrating optical characteristics of
Example 1: as coated (annealed) before heat treatment in the
left-most data column, after 12 minutes of heat treatment at 650
degrees C. (HT), after 16 minutes of HT at 650 degrees C. (HTX),
and after 24 minutes of heat treatment at 650 degrees C. (HTXXX) in
the far right data column.
[0029] FIG. 5 is a chart illustrating optical characteristics of
Example 2: as coated (annealed) before heat treatment in the
left-most data column, after 12 minutes of heat treatment at 650
degrees C. (HT), after 16 minutes of HT at 650 degrees C. (HTX),
and after 24 minutes of heat treatment at 650 degrees C. (HTXXX) in
the far right data column.
[0030] FIG. 6 is a chart illustrating sputter-deposition conditions
for the sputter-deposition of the low-E coating of Example 3 on a
3.1 mm thick glass substrate, where the low-E coating is
illustrated in general by FIG. 1(a).
[0031] FIG. 7 is a chart illustrating sputter-deposition conditions
for the sputter-deposition of the low-E coating of Example 4 on a
3.1 mm thick glass substrate, where the low-E coating is
illustrated in general by FIG. 1(a).
[0032] FIG. 8 is a chart illustrating optical characteristics of
Examples 3-4: as coated (annealed) before heat treatment in the
left-most data column, after 8 minutes of heat treatment at 650
degrees C. (HT), after 12 minutes of HT at 650 degrees C. (HTX),
and after 20 minutes of heat treatment at 650 degrees C. (HTXXX) in
the far right data column.
[0033] FIG. 9 is a chart illustrating sputter-deposition conditions
for the sputter-deposition of the low-E coating of Example 5 on a 6
mm thick glass substrate, where the low-E coating is illustrated in
general by FIG. 1(a).
[0034] FIG. 10 is a chart illustrating optical characteristics of
Example 5: as coated (annealed) before heat treatment in the
left-most data column, after 12 minutes of heat treatment at 650
degrees C. (HT), after 16 minutes of HT at 650 degrees C. (HTX),
and after 24 minutes of heat treatment at 650 degrees C. (HTXXX) in
the far right data column.
[0035] FIG. 11 is a chart illustrating sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 6 on a 6 mm thick glass substrate, where the low-E coating
is illustrated in general by FIG. 1(a).
[0036] FIG. 12 is a chart illustrating optical characteristics of
Example 6: as coated (annealed) before heat treatment in the
left-most data column, after 12 minutes of heat treatment at 650
degrees C. (HT), after 16 minutes of HT at 650 degrees C. (HTX),
and after 24 minutes of heat treatment at 650 degrees C. (HTXXX) in
the far right data column.
[0037] FIG. 13 is chart illustrating sputter-deposition conditions
for the sputter-deposition of the low-E coating of Example 7 on a 6
mm thick glass substrate, where the low-E coating is illustrated in
general by FIG. 1(a).
[0038] FIG. 14 is a chart illustrating optical characteristics of
Example 7: as coated (annealed) before heat treatment in the
left-most data column, after 12 minutes of heat treatment at 650
degrees C. (HT), after 16 minutes of HT at 650 degrees C. (HTX),
and after 24 minutes of heat treatment at 650 degrees C. (HTXXX) in
the far right data column.
[0039] FIG. 15 is a chart illustrating sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 8 on a 6 mm thick glass substrate, where the low-E coating
is illustrated in general by FIG. 1(a).
[0040] FIG. 16 is a wavelength (nm) vs. refractive index (n) graph
illustrating the change in refractive index of the silver layer of
Example 8 from the as coated (AC) state to the heat treated (HT)
state.
[0041] FIG. 17 is a chart illustrating sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 9 on a 6 mm thick glass substrate, where the low-E coating
is illustrated in general by FIG. 1(a).
[0042] FIG. 18 is a chart illustrating optical characteristics of
Example 9: as coated (annealed) before heat treatment in the
left-most data column, after 12 minutes of heat treatment at 650
degrees C. (HT), and after 16 minutes of HT at 650 degrees C. (HTX)
in the far right data column.
[0043] FIG. 19 is a cross sectional view of a first Comparative
Example coated article.
[0044] FIG. 20 is a cross sectional view of a coated article
according to an embodiment of this invention, illustrating coatings
of Examples 1-10.
[0045] FIG. 21 is chart illustrating sputter-deposition conditions
for the sputter-deposition of the low-E coating of Example 10 on a
3.1 mm thick glass substrate, where the low-E coating is
illustrated in general by FIGS. 1(a) and 10.
[0046] FIG. 22 is an XRD Lin (Cps) vs. 2-Theta-Scale graph
illustrating, for Example 10, the relative small 66% change in peak
height of Ag (111) due to HT.
[0047] FIG. 23 is an XRD Lin (Cps) vs. 2-Theta-Scale graph
illustrating, for the first Comparative Example (CE), the relative
large 166% change in peak height of Ag (111) due to HT.
[0048] FIG. 24 is a chart illustrating sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 11 on a 6 mm thick glass substrate, where the low-E coating
is illustrated in general by FIG. 1(b).
[0049] FIG. 25 is a chart illustrating sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 12 on a 6 mm thick glass substrate, where the low-E coating
is illustrated in general by FIG. 1(b).
[0050] FIG. 26 is a chart illustrating sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 13 on a 6 mm thick glass substrate, where the low-E coating
is illustrated in general by FIG. 1(b).
[0051] FIG. 27 is a chart illustrating optical characteristics of
Examples 11-13: as coated (annealed) before heat treatment in the
left-most data column of each, after 12 minutes of heat treatment
at 650 degrees C. (HT), after 16 minutes of HT at 650 degrees C.
(HTX), and after 24 minutes of heat treatment at 650 degrees C.
(HTXXX) in the far right data column of each.
[0052] FIG. 28 is a chart illustrating sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 14 on a 6 mm thick glass substrate, where the low-E coating
is illustrated in general by FIG. 1(b).
[0053] FIG. 29 is a chart illustrating optical characteristics of
Example 14: as coated (annealed) before heat treatment in the
left-most data column, after 12 minutes of heat treatment at 650
degrees C. (HT), after 16 minutes of HT at 650 degrees C. (HTX),
and after 24 minutes of heat treatment at 650 degrees C. (HTXXX) in
the far right data column.
[0054] FIG. 30 is chart illustrating sputter-deposition conditions
for the sputter-deposition of the low-E coatings of Examples 15 and
16 on 6 mm thick glass substrates, where the low-E coatings of
these examples are illustrated in general by FIG. 1(b) with a
bottommost dielectric layer of ZrO.sub.2.
[0055] FIG. 31 is a chart illustrating optical characteristics of
Examples 15 and 16: as coated (annealed) before heat treatment in
the left-most data column, after 12 minutes of heat treatment at
650 degrees C. (HT), and after 16 minutes of HT at 650 degrees C.
(HTX) in the far right data column.
[0056] FIG. 32 is a chart illustrating sputter-deposition
conditions for the sputter-deposition of the low-E coatings of
Examples 17 and 18 on 6 mm thick glass substrates, where the low-E
coatings of these examples are illustrated in general by FIG. 1(b)
with a bottommost dielectric layer of SiO.sub.2 doped with about 8%
Al (wt. %)
[0057] FIG. 33 is a chart illustrating optical characteristics of
Examples 17 and 18: as coated (annealed) before heat treatment in
the left-most data column, after 12 minutes of heat treatment at
650 degrees C. (HT), and after 16 minutes of HT at 650 degrees C.
(HTX) in the far right data column.
[0058] FIG. 34 is chart illustrating sputter-deposition conditions
for the sputter-deposition of the low-E coating of Comparative
Example 2 (CE 2) on a 6 mm thick glass substrate.
[0059] FIG. 35 is a chart illustrating optical characteristics of
Comparative Example 2 (CE 2): as coated (annealed) before heat
treatment in the left-most data column, after 12 minutes of heat
treatment at 650 degrees C. (HT), after 16 minutes of HT at 650
degrees C. (HTX), and after 24 minutes of heat treatment at 650
degrees C. (HTXXX) in the far right data column.
[0060] FIG. 36 illustrates at the top portion sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 19 on a 6 mm thick glass substrate where the low-E coating
is illustrated in general by FIG. 1(b), and at the bottom portion
illustrates optical characteristics of Example 19: as coated
(annealed; AC) before heat treatment, after 12 minutes of heat
treatment at 650 degrees C. (HT), after 16 minutes of HT at 650
degrees C. (HTX), and after 24 minutes of heat treatment at 650
degrees C. (HTXXX).
[0061] FIG. 37 illustrates at the top portion sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 20 on a 6 mm thick glass substrate where the low-E coating
is illustrated in general by FIG. 1(e), and at the bottom portion
illustrates optical characteristics of Example 20: as coated
(annealed; AC) before heat treatment, after 12 minutes of heat
treatment at 650 degrees C. (HT), after 16 minutes of HT at 650
degrees C. (HTX), and after 24 minutes of heat treatment at 650
degrees C. (HTXXX).
[0062] FIG. 38 illustrates at the top portion sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 21 on a 6 mm thick glass substrate where the low-E coating
is illustrated in general by FIG. 1(e), and at the bottom portion
illustrates optical characteristics of Example 21: as coated
(annealed; AC) before heat treatment, after 12 minutes of heat
treatment at 650 degrees C. (HT), after 16 minutes of HT at 650
degrees C. (HTX), and after 24 minutes of heat treatment at 650
degrees C. (HTXXX).
[0063] FIG. 39 illustrates at the top portion sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 22 on a 6 mm thick glass substrate where the low-E coating
is illustrated in general by FIG. 1(d), and at the bottom portion
illustrates optical characteristics of Example 22: as coated
(annealed; AC) before heat treatment, after 12 minutes of heat
treatment at 650 degrees C. (HT), after 16 minutes of HT at 650
degrees C. (HTX), and after 24 minutes of heat treatment at 650
degrees C. (HTXXX).
[0064] FIG. 40 illustrates at the top portion sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 23 on a 6 mm thick glass substrate where the low-E coating
is illustrated in general by FIG. 1(f), and at the bottom portion
illustrates optical characteristics of Example 23: as coated
(annealed; AC) before heat treatment, after 12 minutes of heat
treatment at 650 degrees C. (HT), after 16 minutes of HT at 650
degrees C. (HTX), and after 24 minutes of heat treatment at 650
degrees C. (HTXXX).
[0065] FIG. 41 illustrates at the top portion sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 24 on a 6 mm thick glass substrate where the low-E coating
is illustrated in general by FIG. 1(f), and at the bottom portion
illustrates optical characteristics of Example 24: as coated
(annealed; AC) before heat treatment, after 12 minutes of heat
treatment at 650 degrees C. (HT), after 16 minutes of HT at 650
degrees C. (HTX), and after 24 minutes of heat treatment at 650
degrees C. (HTXXX).
[0066] FIG. 42 illustrates at the top portion sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 25 on a 6 mm thick glass substrate where the low-E coating
is illustrated in general by FIG. 1(g), and at the bottom portion
illustrates optical characteristics of Example 25: as coated
(annealed; AC) before heat treatment, after 12 minutes of heat
treatment at 650 degrees C. (HT), after 16 minutes of HT at 650
degrees C. (HTX), and after 24 minutes of heat treatment at 650
degrees C. (HTXXX).
[0067] FIG. 43 illustrates at the top portion sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 26 on a 6 mm thick glass substrate where the low-E coating
is illustrated in general by FIG. 1(h), and at the bottom portion
illustrates optical characteristics of Example 26: as coated
(annealed; AC) before heat treatment, after 12 minutes of heat
treatment at 650 degrees C. (HT), after 16 minutes of HT at 650
degrees C. (HTX), and after 24 minutes of heat treatment at 650
degrees C. (HTXXX).
[0068] FIG. 44 illustrates at the top portion sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 27 on a 6 mm thick glass substrate where the low-E coating
is illustrated in general by FIG. 1(b), and at the bottom portion
illustrates optical characteristics of Example 27: as coated
(annealed; AC) before heat treatment, after 12 minutes of heat
treatment at 650 degrees C. (HT), after 16 minutes of HT at 650
degrees C. (HTX), and after 24 minutes of heat treatment at 650
degrees C. (HTXXX).
[0069] FIG. 45 illustrates at the top portion sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 28 on a 6 mm thick glass substrate where the low-E coating
is illustrated in general by FIG. 1(e), and at the bottom portion
illustrates optical characteristics of Example 28: as coated
(annealed; AC) before heat treatment, after 12 minutes of heat
treatment at 650 degrees C. (HT), after 16 minutes of HT at 650
degrees C. (HTX), and after 24 minutes of heat treatment at 650
degrees C. (HTXXX).
[0070] FIG. 46 illustrates at the top portion sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 29 on a 6 mm thick glass substrate where the low-E coating
is illustrated in general by FIG. 1(h) except that no layer 2'' is
provided in Example 29, and at the bottom portion illustrates
optical characteristics of Example 29: as coated (annealed; AC)
before heat treatment, after 12 minutes of heat treatment at 650
degrees C. (HT), after 16 minutes of HT at 650 degrees C. (HTX),
and after 24 minutes of heat treatment at 650 degrees C.
(HTXXX).
[0071] FIG. 47 illustrates at the top portion sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 30 on a 6 mm thick clear glass substrate where the low-E
coating is illustrated in general by FIG. 1(i); and at the bottom
portion illustrates optical characteristics of Example 30 measured
monolithically as coated (annealed; AC) before heat treatment,
after 12 minutes of heat treatment at 650 degrees C. (HT), and
after 16 minutes of HT at 650 degrees C. (HTX).
[0072] FIG. 48 illustrates at the top portion sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 31 on a 6 mm thick clear glass substrate where the low-E
coating is illustrated in general by FIG. 1(i); and at the bottom
portion illustrates optical characteristics of Example 31 measured
monolithically as coated (annealed; AC) before heat treatment,
after 12 minutes of heat treatment at 650 degrees C. (HT), and
after 16 minutes of HT at 650 degrees C. (HTX).
[0073] FIG. 49 illustrates at the top portion sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 32 on a 6 mm thick clear glass substrate where the low-E
coating is illustrated in general by FIG. 1(i); and at the bottom
portion illustrates optical characteristics of Example 32 measured
monolithically as coated (annealed; AC) before heat treatment,
after 12 minutes of heat treatment at 650 degrees C. (HT), and
after 16 minutes of HT at 650 degrees C. (HTX).
[0074] FIG. 50 illustrates at the top portion sputter-deposition
conditions for the sputter-deposition of the low-E coating of
Example 33 on a 6 mm thick clear glass substrate where the low-E
coating is illustrated in general by FIG. 1(i); and at the bottom
portion illustrates optical characteristics of Example 33 measured
monolithically as coated (annealed; AC) before heat treatment,
after 12 minutes of heat treatment at 650 degrees C. (HT), and
after 16 minutes of HT at 650 degrees C. (HTX).
[0075] FIG. 51 illustrates graphs for sputter-depositing a
ZrO.sub.2 layer using a metal Zr target (upper graph) and a ceramic
ZrOx target (lower graph), before and after HT, and shows that the
layer comprises a monoclinic phase (see the peak at m-ZrO.sub.2)
when the metal target was used, but not when the ceramic target was
used in this particular instance.
[0076] FIG. 52 is a cross sectional view of coated articles
according to example embodiments of this invention, similar to FIG.
1(i) in certain respects, including the layer stack for Examples
34-42 and Comparative Examples (CEs) 43-47.
[0077] FIG. 53 illustrates the optical data of Examples 34-42 as
coated (AC; annealed) before heat treatment in the left-most data
column of each example, and after 12 minutes of heat treatment at
650 degrees C. (HT) in the right data column of each example,
Examples 34-42 having a coating stack as shown in FIG. 1(i) and
FIG. 52 with monoclinic ZrO.sub.2 layers deposited with metal
target, and layer thicknesses for Examples 34-42 as shown in FIG.
55; where sample 7982 is Example 34, sample 8077 is Example 35,
sample 8085 is Example 36, sample 8090 is Example 37, sample 8091
is Example 38, sample 8097 is Example 39, sample 8186 is Example
40, sample 8187 is Example 41, and sample 8202 is Example 42.
[0078] FIG. 54 illustrates the optical data of Comparative Examples
(CEs) 43-47 as coated (AC; annealed) before heat treatment in the
left-most data column of each example, and after 12 minutes of heat
treatment at 650 degrees C. (HT) in the right data column of each
example, Examples 43-47 having a coating stack as shown in FIG.
1(i) and FIG. 52 with non-monoclinic ZrO.sub.2 layers deposited
with ceramic target, and layer thicknesses for Examples 43-47 as
shown in FIG. 56; where sample 8392 is CE 43, sample 8394 is CE 44,
sample 8395 is CE 45, sample 8396 is CE 46, and sample 8397 is CE
47.
[0079] FIG. 55 is a chart illustrating deposition process
conditions and layer thicknesses for Example 37 having monoclinic
ZrO.sub.2 layers, with total oxygen flow (ml) during the sputtering
process for each layer indicated by the sum of O.sub.2 setpoint,
O.sub.2 tune, and O.sub.2 offset, with the high oxygen gas flow
during sputter-deposition of the ZrO.sub.2 layers helping provide
the monoclinic phase of the ZrO.sub.2 layers of Example 37
(monoclinic Examples 34-36 and 38-42 had similar process
conditions).
[0080] FIG. 56 is a chart illustrating deposition process
conditions and layer thicknesses for Comparative Example (CE) 44
having non-monoclinic ZrO.sub.2 layers, with total oxygen flow (ml)
during the sputtering process for each layer indicated by the sum
of O.sub.2 setpoint, O.sub.2 tune, and O.sub.2 offset, with the low
oxygen gas flow during sputter-deposition of the ZrO.sub.2 layers
together with ceramic target helping provide the non-monoclinic
phase of the ZrO.sub.2 layers of Example 44 (non-monoclinic
Examples 43 and 45-47 had similar process conditions).
[0081] FIG. 57 is a chart illustrating deposition process
conditions and layer thicknesses for Example 48 having a monoclinic
ZrO.sub.2 layer deposited via a ceramic target.
[0082] FIG. 58 is a chart illustrating .DELTA.E* values for Example
48, with different heat treatment times.
[0083] FIG. 59 is a chart illustrating optical data and sheet
resistance data for coatings of Example 48.
DETAILED DESCRIPTION OF CERTAIN EXEMPLARY EMBODIMENTS OF THE
INVENTION
[0084] Referring now more particularly to the accompanying drawings
in which like reference numerals indicate like
parts/layers/materials throughout the several views.
[0085] Certain embodiments of this invention provide a coating or
layer system that may be used in coated articles that may be used
monolithically for windows, in insulating glass (IG) window units
(e.g., on surface #2 or surface #3 in IG window unit applications),
laminated window units, vehicle windshields, and/or other vehicle
or architectural or residential window applications. Certain
embodiments of this invention provide a layer system that combines
one or more of high visible transmission, good durability
(mechanical and/or chemical) before and/or after HT, and good color
stability upon heat treatment. It will be shown herein how certain
layers stacks surprisingly enable this unique combination.
[0086] With regard to color stability, certain embodiments of this
invention have excellent color stability (i.e., a low value of
.DELTA.E*; where .DELTA. is indicative of change in view of heat
treatment) with heat treatment (e.g., thermal tempering or heat
bending) monolithically and/or in the context of dual pane
environments such as IG units or windshields. Such heat treatments
(HTs) often necessitate heating the coated substrate to
temperatures of at least about 1100.degree. F. (593.degree. C.) and
up to 1450.degree. F. (788.degree. C.) [more preferably from about
1100 to 1200 degrees F., and most preferably from 1150-1200 degrees
F.] for a sufficient period of time to insure the end result (e.g.,
tempering, bending, and/or heat strengthening). Certain embodiments
of this invention combine one or more of (i) color stability with
heat treatment, and (ii) the use of a silver inclusive layer for
selective IR reflection.
[0087] Example embodiments of this invention relate to low-E coated
articles that have approximately the same color characteristics as
viewed by the naked eye both before and after heat treatment (e.g.,
thermal tempering), and corresponding methods. Such articles may in
certain example embodiments combine one or more of: (1) desirable
visible transmission characteristics, (2) good durability before
and/or after heat treatment, (3) a low .DELTA.E* value which is
indicative of color stability upon heat treatment (HT), and/or (4)
an absorber film designed to adjust visible transmission and
provide desirable coloration for the coated article, while
maintaining durability and/or thermal stability.
[0088] In certain example embodiments, the absorber film may be a
multi-layer absorber film including a first layer 57 of or
including silver (Ag), and a second layer 59 of or including NiCr
which may be partially or fully oxided (NiCrO.sub.x). See FIG. 1(i)
for example. Such a multi-layer absorber film 57, 59 may thus, in
certain example embodiments, be made up of a layer sequence of
Ag/NiCrO.sub.x. Elements from one layer may diffuse into an
adjacent layer due to HT or other factors. The NiCr based layer 59
of the absorber may be initially deposited in metallic form, or as
a suboxide, in certain example embodiments. The silver based layer
57 may be a continuous layer, and/or may optionally be doped, in
certain example embodiments. Moreover, the silver based layer 57 of
the absorber film is preferably sufficiently thin so that its
primary function is to absorb visible light and provide desirable
coloration (as opposed to being much thicker and primarily function
as an IR reflection layer). The NiCr or NiCrO.sub.x 59 is provided
over and contacting the silver 57 of the absorber film in order to
protect the silver, and also to contribute to absorption. In
certain example embodiments, the silver based layer 57 of the
absorber film may be no more than about 60 .ANG. thick, more
preferably no more than about 30 .ANG. thick, more preferably no
greater than about 20 .ANG. thick, and most preferably no greater
than about 15 .ANG. thick, and possibly no greater than about 12
.ANG. thick, in certain example embodiments of this invention. In
certain example embodiments, the NiCr based layer 59 of the
absorber film may be from about 5-200 .ANG. thick, more preferably
from about 10-110 .ANG. thick, and most preferably from about 40-90
.ANG. thick.
[0089] A single layer of NiCr (or other suitable material) may also
be used as an absorber film in low-E coatings in certain example
embodiments of this invention. For example, see absorber film 42 in
FIGS. 1(d) and 1(f). However, it has surprisingly been found that
using silver 57 in an absorber film (single layer, or multi-layer,
absorber film) provides for several unexpected advantages compared
to a single layer of NiCr as the absorber. First, it has been found
that a single layer of NiCr as the absorber tends to cause
yellowish coloration in certain low-E coating coated articles,
which may not be desirable in certain instances. In contrast, it
has been surprisingly found that using silver 57 in an absorber
films tends to avoid such yellowish coloration and/or instead
provide for more desirable neutral coloration of the resulting
coated article. Thus, the use of silver 57 in an absorber film has
been found to provide for improved optical characteristics. Second,
the use of a single layer of NiCr 42 as the absorber tends to also
involve providing silicon nitride based layers on both sides of the
NiCr so as to directly sandwich and contact the NiCr therebetween.
For example, see FIGS. 1(d) and 1(f). It has been found that the
provision of silicon nitride in certain locations in a coating
stack may lead to compromised thermal stability upon HT. In
contrast, it has been surprisingly found that when using silver in
an absorber film a pair of immediately adjacent silicon nitride
layers are not needed, so that thermal stability upon HT may be
improved. Thus, the use of silver 57 in an absorber film has been
found to provide for improved thermal stability including lower
.DELTA.E* values and therefor improved matchability between HT and
non-HT versions of the same coating. The use of silver in an
absorber film may also provide for improved manufacturability in
certain situations.
[0090] Surprisingly, and unexpectedly, it has been found that the
provision of an as-deposited crystalline or substantially
crystalline layer 3, 3'' (and/or 13) (e.g., at least 50%
crystalline, more preferably at least 60% crystalline) of or
including zinc oxide, doped with at least one dopant (e.g., Sn),
immediately under and directly contacting an infrared (IR)
reflecting layer of or including silver 7 (and/or 19) in a low-E
coating 30 has the effect of significantly improving the coating's
thermal stability (i.e., lowering the .DELTA.E* value).
"Substantially crystalline" as used herein means at least 50%
crystalline, more preferably at least 60% crystalline, and most
preferably at least 70% crystalline. One or more such crystalline,
or substantially crystalline, layers 3, 3'' 13 may be provided
under one or more corresponding IR reflecting layers comprising
silver 7, 19, in various example embodiments of this invention.
Thus, the crystalline or substantially crystalline layer 3 (or 3'')
and/or 13 of or including zinc oxide, doped with at least one
dopant (e.g., Sn), immediately under an infrared (IR) reflecting
layer 7 and/or 19 of or including silver may be used in single
silver low-E coatings, double-silver low-E coatings (e.g., such as
shown in FIG. 1 or FIG. 20), or triple silver low-E coatings in
various embodiments of this invention. In certain example
embodiments, the crystalline or substantially crystalline layer 3
and/or 13 of or including zinc oxide is doped with from about 1-30%
Sn, more preferably from about 1-20% Sn, more preferably from about
5-15% Sn, with an example being about 10% Sn (in terms of wt. %).
The zinc oxide, doped with Sn, is in a crystallized or
substantially crystallized phase (as opposed to amorphous or
nanocrystalline) in layer 3 and/or 13 as deposited, such as via
sputter deposition techniques from at least one sputtering
target(s) of or including Zn and Sn. The crystallized phase of the
doped zinc oxide based layer 3 and/or 13 as deposited, combined
with the layer(s) between the silver 7 and/or 19 and the glass 1,
allows the coated article to realize improved thermal stability
upon optional HT (lower the .DELTA.E* value). It is believed that
the crystallized phase of the doped zinc oxide based layer 3 and/or
13 as deposited, combined with the layer(s) between the silver and
the glass, allows the silver 7 and/or 19 deposited thereover to
have improved crystal structure with texture but with some randomly
oriented grains so that its refractive index (n) changes less upon
optional HT, thereby allowing for improved thermal stability to be
realized.
[0091] It has also been surprisingly and unexpectedly found that
the provision of a dielectric layer(s) (e.g., 2 and/or 2'') of or
including silicon oxide, zirconium oxide, silicon zirconium oxide
and/or silicon zirconium oxynitride (e.g., SiZrO.sub.x, ZrO.sub.2,
SiO.sub.2, and/or SiZrO.sub.xN.sub.y) also provides for improved
thermal stability of the coated article as shown for example in
FIGS. 1(b)-1(i), and thus lower the .DELTA.E* values upon heat
treatment (HT) such as thermal tempering. In certain example
embodiments, at least one dielectric layer (e.g., 2 and/or 2'') of
or including silicon oxide, zirconium oxide, silicon zirconium
oxide and/or silicon zirconium oxynitride (e.g., SiZrO.sub.x,
ZrO.sub.2, SiO.sub.2, and/or SiZrO.sub.xN.sub.y) may be provided:
(i) in the bottom dielectric portion of the coating under all
silver based IR reflecting layer(s) (e.g., see FIGS. 1(b)-1(i)),
and/or (ii) in a middle dielectric portion of the coating between a
pair of silver based IR reflecting layers (e.g., see FIGS.
1(e)-1(i)). For example, the dielectric layer (e.g., 2 and/or 2'')
of or including silicon oxide, zirconium oxide, silicon zirconium
oxide and/or silicon zirconium oxynitride may be provided directly
under and contacting the lowermost doped zinc oxide based layer
(e.g., 3) in certain example embodiments of this invention, and/or
between a pair of zinc oxide inclusive layers (e.g., between 11 and
13, or between 11 and 3'') in a middle dielectric portion of the
low-E coating.
[0092] The dielectric layer(s) (e.g., 2 and/or 2'') of or including
silicon oxide (e.g., SiO.sub.2), zirconium oxide (e.g., ZrO.sub.2),
silicon zirconium oxide and/or silicon zirconium oxynitride may or
may not be provided in combination with an as-deposited crystalline
or substantially crystalline (e.g., at least 50% crystalline, more
preferably at least 60% crystalline) layer(s) (e.g., 3 and/or 13)
of or including zinc oxide, doped with at least one dopant (e.g.,
Sn), immediately under an infrared (IR) reflecting layer, in
various example embodiments of this invention. Both approaches,
which may be used together, but need not be used together, improve
thermal stability thereby lowering .DELTA.E* values. For example,
in certain embodiments where the dielectric layer(s) (e.g., 2
and/or 2'') of or including silicon oxide (e.g., SiO.sub.2),
zirconium oxide (e.g., ZrO.sub.2), silicon zirconium oxide and/or
silicon zirconium oxynitride is used, the contact/seed layer
immediately under one or both silver(s) may be of or including zinc
oxide doped with aluminum (instead of with Sn) and that
contact/seed layer need not be crystalline (e.g., see FIGS. 42, 43
and 46; and Examples 25, 26 and 29).
[0093] In certain example embodiments, it has surprisingly and
unexpectedly been found that initially sputter-depositing the
dielectric layer(s) 2 and/or 2'' of or including zirconium oxide,
zirconium oxynitride, silicon zirconium oxide and/or silicon
zirconium oxynitride (e.g., SiZrO.sub.x, ZrO.sub.2, SiO.sub.2,
and/or SiZrO.sub.xN.sub.y) so as to comprise a monoclinic phase
crystalline structure is advantageous in that it results in
improved thermal stability (lower .DELTA.E* value) and/or reduced
change in visible transmission (e.g., T.sub.vis or TY) of the
coated article upon heat treatment (HT). For example, see FIGS.
1(a)-1(i), 51-53, and 55. The dielectric layer(s) 2 and/or 2'' may,
in certain example embodiments, further include other material(s)
such as Ti and/or Nb. In certain example embodiments, the
monoclinic phase (e.g., see the m-ZrO.sub.2 peaks in the upper
graph of FIG. 51) for the dielectric layer (e.g., ZrO.sub.2) 2
and/or 2'' may be achieved by using a very high oxygen gas flow for
that layer during the sputter-deposition process of that layer, and
using a metallic sputtering target (e.g., metal Zr or SiZr target)
(e.g., see FIG. 55). It is noted that such high oxygen gas flows
desired in certain example embodiments of this case are
counterintuitive for zirconium oxide based layers, and
conventionally undesirable, because they reduce deposition rates
and thus created added time and expense in making coated articles.
It has been found that a significant partial or full phase change
away from monoclinic phase (see m-ZrO.sub.2 peaks in the upper
graph of FIG. 51) to tetragonal or cubic crystalline structure (see
c-ZrO.sub.2 in FIG. 51), and corresponding density change, of the
layer 2 and/or 2'' upon HT tends to compensate for change in
crystalline structure of the silver based layer(s) 7, 57, and/or 19
upon said HT, which appears to result in improved thermal stability
(lower .DELTA.E* value) and/or reduced change in visible
transmission (e.g., T.sub.vis or TY) of the coated article upon HT.
In FIG. 51, note how the monoclinic phase (see m-ZrO.sub.2 peaks in
upper graph of in FIG. 51) exists in the top graph (high oxygen
flow during deposition, and metal Zr target), but does not exist in
the bottom graph (low oxygen flow during deposition, and ceramic
ZrOx target). And, also in the top graph of FIG. 51, it can be seen
how the monoclinic phase (see m-ZrO.sub.2 peaks) is higher before
HT, and lower after HT. It has been surprisingly found that
initially sputter-depositing the dielectric layer(s) 2 and/or 2''
of or including zirconium oxide, zirconium oxynitride, silicon
zirconium oxide and/or silicon zirconium oxynitride (e.g.,
SiZrO.sub.x, ZrO.sub.2, SiO.sub.2, and/or SiZrO.sub.xN.sub.y) so as
to comprise a monoclinic phase crystalline structure is
advantageous in that it results in a high density change in the
layer 2 and/or 2'' of at least about 0.25 g/cm.sup.3, more
preferably of at least about 0.30 g/cm.sup.3, and most preferably
of at least about 0.35 g/cm.sup.3 (e.g., from about 5.7 to about
6.1 g/cm.sup.3), due to HT which in turn compensates for change in
crystalline structure of the silver based layer(s) 7, 19, and/or 57
due to said HT, resulting in improved thermal stability (lower
.DELTA.E* value) and/or reduced change in visible transmission
(T.sub.vis or TY) of the coated article upon heat treatment (HT).
In certain example embodiments, this allows for reduced change in
visible transmission (T.sub.vis or TY) of the coated article of no
more than 1.2%, more preferably no more than 1.0%, and most
preferably no more than 0.5%, due to HT, and/or a reduced .DELTA.E*
value.
[0094] It has also surprisingly been found that increased
thicknesses for the dielectric layer(s) 2 and/or 2'' of or
including silicon oxide, zirconium oxide, zirconium oxynitride,
silicon zirconium oxide and/or silicon zirconium oxynitride (e.g.,
SiZrO.sub.x, ZrO.sub.2, SiO.sub.2, and/or SiZrO.sub.xN.sub.y) tend
to result in smaller changes in sheet resistance (R.sub.s) and
visible transmission upon HT, and thus lower .DELTA.E* values of
the coated article. In certain example embodiments, one or both of
the dielectric layer(s) 2 and/or 2'' of or including silicon oxide,
zirconium oxide, zirconium oxynitride, silicon zirconium oxide
and/or silicon zirconium oxynitride (e.g., SiZrO.sub.x, ZrO.sub.2,
SiO.sub.2, and/or SiZrO.sub.xN.sub.y) may each have a physical
thickness of from about 10-400 angstroms (.ANG.), more preferably
from about 40-170 .ANG., and most preferably from about 80-140
.ANG..
[0095] It has also been surprisingly and unexpectedly found that
the provision of no silicon nitride based layer (e.g.,
Si.sub.3N.sub.4, optionally doped with 1-10% Al or the like)
directly under and contacting the lowermost doped zinc oxide based
layer 3 between the glass substrate 1 and the lowermost silver
based layer 7, in combination with the crystallized or
substantially crystallized phase of the doped zinc oxide based
layer 3 as deposited, allows for improved thermal stability upon
heat treatment (lower .DELTA.E* values) to be realized. For
example, see the coatings of FIGS. 1(a)-1(d) and 1(i). Moreover, in
certain example embodiments, there is no amorphous or substantially
amorphous layer located between the glass substrate 1 and the first
IR reflecting layer comprising silver 7. It has also been
surprisingly and unexpectedly found that the provision of no
silicon nitride based layer in the middle section of the stack
between the two silver-based IR reflecting layers 7 and 19 allows
for improved thermal stability upon heat treatment (lower .DELTA.E*
values) to be realized (e.g., see FIGS. 1(a)-1(i)).
[0096] In certain example embodiments, it has also been found that
providing an absorber layer (e.g., NiCr, NiCrN.sub.x, NbZr, and/or
NbZrN.sub.x) 42 between the glass substrate and the dielectric
layer 2 of or including silicon oxide, zirconium oxide, silicon
zirconium oxide and/or silicon zirconium oxynitride (e.g.,
SiZrO.sub.x, ZrO.sub.2, SiO.sub.2, and/or SiZrO.sub.xN.sub.y) may
advantageously reduce glass side visible reflection (R.sub.gY) of
the coated article in a desirable manner and allows the visible
transmission to be tuned in a desirable manner. The absorber layer
42 may be provided between and contacting a pair of silicon nitride
based layers 41 and 43 (e.g., of or including Si.sub.3N.sub.4,
optionally doped with 1-10% Al or the like, and optionally
including from 0-10% oxygen) in certain example embodiments, such
as shown in FIGS. 1(d) and 1(f) for instance. See also FIG. 39 and
Example 22 for instance. In other example embodiments, the stack
made up of the absorber layer 42, between nitride based dielectric
layers 41 and 43, may be located at other position(s) within the
stack.
[0097] In certain example embodiments, measured monolithically, in
view of the above structure (e.g., see FIGS. 1(a)-1(i)), the coated
article is configured to realize one or more of: (i) a transmissive
.DELTA.E* value (where transmissive optics are measured) of no
greater than 3.0 (more preferably no greater than 2.8, or 2.5, and
most preferably no greater than 2.3) upon HT for 8, 12 and/or 16
minutes at a temperature of about 650 degrees C., (ii) a glass side
reflective .DELTA.E* value (where glass side reflective optics are
measured) of no greater than 3.0 (more preferably no greater than
2.5, more preferably no greater than 2.0, even more preferably no
greater than 1.5, and most preferably no greater than 1.0, or 0.6)
upon HT for 8, 12 and/or 16 minutes at a temperature of about 650
degrees C., and/or (iii) a film side reflective .DELTA.E* value
(where film side reflective optics are measured) of no greater than
3.5 (more preferably no greater than 3.0, and most preferably no
greater than 2.0, more preferably no greater than 1.5, and possibly
no greater than 1.2) upon HT for 8, 12 and/or 16 minutes at a
temperature of about 650 degrees C.
[0098] In certain example embodiments, measured monolithically, the
coated article is configured to have a visible transmission
(T.sub.vis or Y), before or after any optional HT, of at least
about 30%, more preferably of at least about 35%, more preferably
of at least about 40%, more preferably of at least about 50%. In
certain example embodiments, the low-E coating has a sheet
resistance (SR or R.sub.s) of no greater than 20 ohms/square, more
preferably no greater than 10 ohms/square, and most preferably no
greater than 2.5 or 2.2 ohms/square, before and/or after optional
heat treatment. In certain example embodiments, the low-E coating
has a hemispherical emissivity/emittance (Eh) of no greater than
0.08, more preferably no greater than 0.05, and most preferably no
greater than 0.04. The value .DELTA.E* is important in determining
whether or not upon heat treatment (HT) there is matchability, or
substantial matchability, in the context of this invention. Color
herein is described by reference to the conventional a*, b* values,
which in certain embodiments of this invention are both negative in
order to provide color in the desired substantially neutral color
range tending to the blue-green quadrant. For purposes of example,
the term .DELTA.a* is simply indicative of how much color value a*
changes due to heat treatment.
[0099] The term .DELTA.E* (and .DELTA.E) is well understood in the
art and is reported, along with various techniques for determining
it, in ASTM 2244-93 as well as being reported in Hunter et. al.,
The Measurement of Appearance, 2nd Ed. Cptr. 9, page 162 et seq.
[John Wiley & Sons, 1987]. As used in the art, .DELTA.E* (and
.DELTA.E) is a way of adequately expressing the change (or lack
thereof) in reflectance and/or transmittance (and thus color
appearance, as well) in an article after or due to heat treatment.
.DELTA.E may be calculated by the "ab" technique, or by the Hunter
technique (designated by employing a subscript "H"). .DELTA.E
corresponds to the Hunter Lab L, a, b scale (or L.sub.h, a.sub.h,
b.sub.h). Similarly, .DELTA.E* corresponds to the CIE LAB Scale L*,
a*, b*. Both are deemed useful, and equivalent for the purposes of
this invention. For example, as reported in Hunter et. al.
referenced above, the rectangular coordinate/scale technique (CIE
LAB 1976) known as the L*, a*, b* scale may be used, wherein:
[0100] L* is (CIE 1976) lightness units [0101] a* is (CIE 1976)
red-green units [0102] b* is (CIE 1976) yellow-blue units
[0103] and the distance .DELTA.E* between L*.sub.o a*.sub.o
b*.sub.o and L*.sub.1 a*.sub.1 b*.sub.1 is:
.DELTA.E*=[(.DELTA.L*).sup.2+(.DELTA.a*).sup.2+(.DELTA.b*).sup.2].sup.1/-
2 (1)
where:
.DELTA.L*=L*.sub.1-L*.sub.o (2)
.DELTA.a*=a*.sub.1-a*.sub.o (3)
.DELTA.b*=b*.sub.1-b*.sub.o (4)
where the subscript "o" represents the coated article before heat
treatment and the subscript "1" represents the coated article after
heat treatment; and the numbers employed (e.g., a*, b*, L*) are
those calculated by the aforesaid (CIE LAB 1976) L*, a*, b*
coordinate technique. In a similar manner, .DELTA.E may be
calculated using equation (1) by replacing a*, b*, L* with Hunter
Lab values a.sub.h, b.sub.h, L.sub.h. Also within the scope of this
invention and the quantification of .DELTA.E* are the equivalent
numbers if converted to those calculated by any other technique
employing the same concept of .DELTA.E* as defined above.
[0104] In certain example embodiments of this invention, the low-E
coating 30 includes two silver-based IR reflecting layers (e.g.,
see FIGS. 1(a)-1(i)), although this invention is not so limited in
all instances (e.g., three silver based IR reflecting layers can be
used in certain instances). It will be recognized that the coated
articles of FIGS. 1(a)-1(i) are illustrated in monolithic form.
However, these coated articles may also be used in IG window units
for example.
[0105] Because of materials stability, baking at high temperature
(e.g., 580-650 degrees C.) causes change to chemical compositions,
crystallinity and microstructures or even phases of dielectric
layer materials. High temperature also causes interface diffusion
or even reaction, as a consequence composition, roughness and index
change at interface locations. As a result, optical properties such
as index n/k and optical thickness change upon heat treatment. The
IR materials, for example Ag, have undergone change too. Typically,
Ag materials go through crystallization, grain growth or even
orientation change upon heat treatment. These changes often cause
conductivity and particularly index n/k changes which have big
impact to the optical and thermal properties of a low-E coating. In
addition, the dielectric and the change of dielectrics also has a
significant impact on IR reflecting layers such as silver
undergoing heat treatment. Moreover, silver may have more change in
one layer stack than in others merely because of the materials and
the layer stacks themselves. If the silver changes are beyond some
limit, then it may not be acceptable aesthetically after heat
treatment. We have found that to get thermal stability of a low-E
coating, doped zinc oxide crystallized materials on glass either
directly or indirectly with a thin modification layer(s) may be
used under silver of an IR reflecting layer. Crystalline or
substantially crystalline doped zinc oxide in these locations has
been found to change less during heat treatment, and result in
smaller silver changes with respect to properties such as indices
(e.g., n and/or k) and thus less overall color change upon heat
treatment.
[0106] FIG. 1(a) is a side cross sectional view of a coated article
according to an example non-limiting embodiment of this invention,
where the low-E coating 30 has two silver-based IR reflecting
layers 7 and 19. The coated article includes substrate 1 (e.g.,
clear, green, bronze, or blue-green glass substrate from about 1.0
to 10.0 mm thick, more preferably from about 3.0 mm to 8.0 mm
thick), and low-E coating (or layer system) 30 provided on the
substrate 1 either directly or indirectly. The coating (or layer
system) 30 includes, in FIG. 1(a) for example: dielectric layer 3
of or including zinc oxide, doped with at least one metal dopant
(e.g., Sn and/or Al), which is crystalline or substantially
crystalline as deposited; infrared (IR) reflecting layer of or
including silver 7 located over and directly contacting layer 3;
contact layer 9 of or including Ni and/or Cr (e.g., NiCr,
NiCrO.sub.x, NiCrN.sub.x, NiCrON, NiCrM, NiCrMoO.sub.x, etc.), Ti,
or other suitable material, over and directly contacting the IR
reflecting layer 7; dielectric layer 11 of or including zinc
stannate (e.g., ZnSnO, Zn.sub.2SnO.sub.4, or other suitable
stoichiometry) or other suitable material, which may be amorphous
or substantially amorphous as deposited; another dielectric layer
13 of or including zinc oxide, doped with at least one dopant
(e.g., Sn), which is crystalline or substantially crystalline as
deposited; another infrared (IR) reflecting layer of or including
silver 19 located over and directly contacting layer 13; another
contact layer 21 of or including Ni and/or Cr (e.g., NiCr,
NiCrO.sub.x, NiCrN.sub.x, NiCrON, NiCrM, NiCrMoO.sub.x, etc.), Ti,
or other suitable material, over and directly contacting the IR
reflecting layer 19; another dielectric layer 23 of or including
zinc stannate (e.g., ZnSnO, Zn.sub.2SnO.sub.4, or other suitable
stoichiometry) or other suitable material such as tin oxide, which
may be amorphous or substantially amorphous as deposited; and
amorphous or substantially amorphous dielectric layer 25 of or
including silicon nitride (e.g., Si.sub.3N.sub.4, or other suitable
stoichiometry) which may optionally be doped with Al and/or O. The
layers shown in FIG. 1(a) may be deposited by sputter-deposition or
in any other suitable manner.
[0107] As explained herein, it has been found that the presence of
as-deposited crystalline or substantially crystalline layer 3
and/or 13 of or including zinc oxide, doped with at least one
dopant (e.g., Sn), immediately under and directly contacting an
infrared (IR) reflecting layer of or including silver 7 and/or 19
in a low-E coating 30 has the effect of significantly improving the
coating's thermal stability (i.e., lowering the .DELTA.E* value).
In certain example embodiments, the crystalline or substantially
crystalline layer 3 and/or 13 of or including zinc oxide is doped
with from about 1-30% Sn, more preferably from about 1-20% Sn, more
preferably from about 5-15% Sn, with an example being about 10% Sn
(in terms of wt. %).
[0108] In certain example embodiments, the dielectric zinc stannate
(e.g., ZnSnO, Zn.sub.2SnO.sub.4, or the like) based layers 11 and
23 may be deposited in an amorphous or substantially amorphous
state (it/they may become crystalline or substantially crystalline
upon heat treatment). It has been found that having similar amounts
of Zn and Sn in the layer, or more Sn than Zn in the layer, helps
ensure that the layer is deposited in an amorphous or substantially
amorphous state. For example, the metal content of amorphous zinc
stannate based layers 11 and 23 may include from about 30-70% Zn
and from about 30-70% Sn, more preferably from about 40-60% Zn and
from about 40-60% Sn, with examples being about 52% Zn and about
48% Sn, or about 50% Zn and 50% Sn (weight %, in addition to the
oxygen in the layer) in certain example embodiments of this
invention. Thus, for example, the amorphous or substantially
amorphous zinc stannate based layers 11 and/or 23 may be
sputter-deposited using a metal target comprising about 52% Zn and
about 48% Sn, or about 50% Zn and about 50% Sn, in certain example
embodiments of this invention. Optionally, the zinc stannate based
layers 11 and 23 may be doped with other metals such as Al or the
like. Depositing layers 11 and 23 in an amorphous, or substantially
amorphous, state, while depositing layers 3 and 13 in a
crystalline, or substantially crystalline, state, has been found to
advantageously allow for improved thermal stability to be realized
in combination with good optical characteristics such as acceptable
transmission, color, and reflection. It is noted that zinc stannate
layers 11 and/or 23 may be replaced with respective layer(s) of
other material(s) such as tin oxide, zinc oxide, zinc oxide doped
with from 1-20% Sn (as discussed elsewhere herein regarding layers
11, 13), or the like.
[0109] Dielectric layer 25, which may be an overcoat, may be of or
include silicon nitride (e.g., Si.sub.3N.sub.4, or other suitable
stoichiometry) in certain embodiments of this invention, in order
to improve the heat treatability and/or durability of the coated
article. The silicon nitride may optionally be doped with Al and/or
O in certain example embodiments, and also may be replaced with
other material such as silicon oxide or zirconium oxide in certain
example embodiments.
[0110] Infrared (IR) reflecting layers 7 and 19 are preferably
substantially or entirely metallic and/or conductive, and may
comprise or consist essentially of silver (Ag), gold, or any other
suitable IR reflecting material. IR reflecting layers 7 and 19 help
allow the coating to have low-E and/or good solar control
characteristics. The IR reflecting layers may, however, be slightly
oxidized in certain embodiments of this invention.
[0111] Other layer(s) below or above the illustrated coating in
FIG. 1 may also be provided. Thus, while the layer system or
coating is "on" or "supported by" substrate 1 (directly or
indirectly), other layer(s) may be provided therebetween. Thus, for
example, the coating of FIG. 1(a) may be considered "on" and
"supported by" the substrate 1 even if other layer(s) are provided
between layer 3 and substrate 1. Moreover, certain layers of the
illustrated coating may be removed in certain embodiments, while
other layer(s) may be added between the various layers or the
various layer(s) may be split with other layer(s) added between the
split sections in other embodiments of this invention without
departing from the overall spirit of certain embodiments of this
invention.
[0112] While various thicknesses and materials may be used in
layers in different embodiments of this invention, example
thicknesses and materials for the respective layers on the glass
substrate 1 in the FIG. 1(a) embodiment are as follows, from the
glass substrate outwardly:
TABLE-US-00001 TABLE 1 Example Materials/Thicknesses; FIG. 1(a)
Embodiment Preferred Range More Preferred Example Layer Glass
({acute over (.ANG.)}) ({acute over (.ANG.)}) (.ANG.) Sn-doped ZnO
20-900 (or 350-550 {acute over (.ANG.)} 470 .ANG. (layer 3)
100-900) {acute over (.ANG.)} Ag (layer 7) 60-260 {acute over
(.ANG.)} 100-170 {acute over (.ANG.)} 151 .ANG. NiCrO.sub.x (layer
9) 10-100 {acute over (.ANG.)} 20-45 {acute over (.ANG.)} 41 .ANG.
ZnSnO (layer 11) 200-1200 .ANG. 500-900 .ANG. 736 .ANG. Sn-doped
ZnO 60-900 {acute over (.ANG.)} 120-400 {acute over (.ANG.)} 177
.ANG. (layer 13) Ag (layer 19) 80-280 {acute over (.ANG.)} 140-250
{acute over (.ANG.)} 232 .ANG. NiCrO.sub.x (layer 21) 10-100 {acute
over (.ANG.)} 20-45 {acute over (.ANG.)} 41 .ANG. ZnSnO (layer 23)
10-750 .ANG. 70-200 .ANG. 108 .ANG. Si.sub.3N.sub.4 (layer 25)
10-750 {acute over (.ANG.)} 100-240 {acute over (.ANG.)} 191
.ANG.
[0113] The FIG. 1(b) embodiment is the same as the FIG. 1(a)
embodiment discussed above and elsewhere herein, except that the
low-E coating 30 in the FIG. 1(b) embodiment also includes a
substantially transparent dielectric layer 2 of or including
silicon zirconium oxide, zirconium oxide, silicon oxide, and/or
silicon zirconium oxynitride (e.g., SiZrO.sub.x, ZrO.sub.2,
SiO.sub.2, SiAlO.sub.2, and/or SiZrO.sub.xN.sub.y) under and
directly contacting the doped zinc oxide based layer 3. It has been
found that this additional layer 2 provides for further improved
thermal stability of the coated article, and thus an even lower the
.DELTA.E* value (e.g., a lower glass side reflective .DELTA.E*
value) upon heat treatment (HT) such as thermal tempering. The
dielectric layer 2 of or including silicon zirconium oxide,
zirconium oxide, silicon oxide, and/or silicon zirconium oxynitride
(e.g., SiZrO.sub.x, ZrO.sub.2, SiO.sub.2, SiAlO.sub.2, and/or
SiZrO.sub.xN.sub.y) may be provided directly under and contacting
the lowermost doped zinc oxide based layer 3 in certain example
embodiments of this invention, as shown in FIG. 1(b). In certain
example embodiments of this invention, dielectric layer 2 of or
including silicon zirconium oxide, zirconium oxide, silicon oxide,
and/or silicon zirconium oxynitride (e.g., SiZrO.sub.x, ZrO.sub.2,
SiO.sub.2, SiAlO.sub.2, and/or SiZrO.sub.xN.sub.y) may be from
about 20-600 .ANG. thick, more preferably from about 40-400 .ANG.
thick, and most preferably from about 50-300 .ANG. thick. The
thicknesses above for the FIG. 1(a) embodiment may also apply to
FIGS. 1(b)-1(i).
[0114] When layer 2 (or 2', or 2'') is of or includes SiZrO.sub.x
and/or SiZrO.sub.xN.sub.y, it has been found that providing more Si
than Zr in that layer is advantageous from an optical point of view
with a low refractive index (n) and improved antireflection and
other optical characteristics. For example, in certain example
embodiments, when layer 2 (or 2', or 2'') is of or includes
SiZrO.sub.x and/or SiZrO.sub.xN.sub.y, metal content of the layer
may comprise from 51-99% Si, more preferably from 70-97% Si, and
most preferably from 80-90% Si, and from 1-49% Zr, more preferably
from 3-30% Zr, and most preferably from 10-20% Zr (atomic %). In
example embodiments, transparent dielectric layer 2 of or including
SiZrO.sub.x and/or SiZrO.sub.xN.sub.y may have a refractive index
(n), measured at 550 nm, of from about 1.48 to 1.68, more
preferably from about 1.50 to 1.65, and most preferably from about
1.50 to 1.62.
[0115] The FIG. 1(c) embodiment is the same as the FIG. 1(b)
embodiment discussed above and elsewhere herein, except that the
low-E coating 30 in the FIG. 1(c) embodiment also includes a
substantially transparent dielectric layer 2' of or including
silicon nitride (e.g., Si.sub.3N.sub.4, optionally doped with 1-10%
Al or the like, and optionally including from 0-10% oxygen, or
other suitable stoichiometry) and/or silicon zirconium oxynitride,
located between and contacting the glass substrate 1 and the
dielectric layer 2. Layer 2' may also be of or including aluminum
nitride (e.g., AlN).
[0116] The FIG. 1(d) embodiment is the same as the FIG. 1(b)
embodiment discussed above and elsewhere herein, except that the
low-E coating 30 in the FIG. 1(d) embodiment also includes a
metallic or substantially metallic absorber layer 42 sandwiched
between and contacting silicon nitride based layers 41 and 43
(e.g., Si.sub.3N.sub.4, optionally doped with 1-10% Al or the like,
and optionally including from 0-10% oxygen). Dielectric layer(s) 41
and/or 43 may also be of or include aluminum nitride (e.g., AlN) in
certain example embodiments. The absorber layer 42 may be of or
including NiCr, NbZr, Nb, Zr, or nitrides thereof, or other
suitable material, in example embodiments of this invention. The
absorber layer 42 preferably contains from 0-10% oxygen (atomic %),
more preferably from 0-5% oxygen. In certain example embodiments,
it has been found that providing an absorber layer (e.g., NiCr,
NiCrN.sub.x, NbZr, and/or NbZrN.sub.x) 42 between the glass
substrate and the dielectric layer 2 of or including silicon
zirconium oxide, zirconium oxide, silicon oxide, and/or silicon
zirconium oxynitride (e.g., SiZrO.sub.x, ZrO.sub.2, SiO.sub.2,
SiAlO.sub.2, and/or SiZrO.sub.xN.sub.y) advantageously reduces
glass side visible reflection (R.sub.gY) of the coated article in a
desirable manner, and allows the visible transmission to be tuned
in a desirable manner See, for example, FIG. 39 and Example 22. In
certain example embodiments, the absorber layer 42 may be from
about 10-150 .ANG. thick, more preferably from about 30-80 .ANG.
thick. In certain example embodiments, the silicon nitride based
layers 41 and 43 may be from about 50-300 .ANG. thick, more
preferably from about 70-140 .ANG. thick. For instance, in Example
22 and FIG. 39, the absorber layer 42 is a nitride of NiCr, and is
about 1.48 nm thick. In other example embodiments, the stack made
up of the absorber layer 42, between nitride based dielectric
layers 41 and 43, may be located at other position(s) within the
stack.
[0117] Referring to FIGS. 1(a)-1(d), another transparent dielectric
layer (not shown) of or including ZrO.sub.2, SiZrO.sub.x and/or
SiZrO.sub.xN.sub.y may be provided either between layers 11 and 13.
In certain example embodiments, zinc stannate inclusive layer 11
may be omitted, or may be replaced with such another transparent
dielectric layer of or including ZrO.sub.2, SiZrO.sub.x and/or
SiZrO.sub.xN.sub.y. It is also possible for doped zinc oxide layer
13 to be split with such another layer transparent dielectric layer
of or including ZrO.sub.2, SiZrO.sub.x and/or SiZrO.sub.xN.sub.y.
For example, in certain example embodiments, when such an
additional layer is of or includes SiZrO.sub.x and/or
SiZrO.sub.xN.sub.y, metal content of the layer may comprise from
51-99% Si, more preferably from 70-97% Si, and most preferably from
80-90% Si, and from 1-49% Zr, more preferably from 3-30% Zr, and
most preferably from 10-20% Zr (atomic %), and may contain from
0-20% nitrogen, more preferably from 0-10% nitrogen, and most
preferably from 0-5% nitrogen (atomic %). For instance, at least
one dielectric layer (e.g., 2 and/or 2'') of or including silicon
oxide, zirconium oxide, zirconium oxynitride, silicon zirconium
oxide and/or silicon zirconium oxynitride (e.g., SiZrO.sub.x,
ZrO.sub.2, SiO.sub.2, and/or SiZrO.sub.xN.sub.y) may be provided:
(i) in the bottom dielectric portion of the coating under all
silver based IR reflecting layer(s) (e.g., see FIGS. 1(b)-1(i)),
and/or (ii) in a middle dielectric portion of the coating between a
pair of silver based IR reflecting layers (e.g., see FIGS.
1(e)-1(i)).
[0118] As explained above and shown in the figures, the coated
article may include a dielectric layer(s) 2, 2'' (e.g., ZrO.sub.2
or SiZrO.sub.x) as shown in FIGS. 1(b)-(i), which may possibly be
located under and directly contacting the first crystalline or
substantially crystalline layer 3 comprising zinc oxide doped with
from about 1-30% Sn, and/or below a zinc oxide inclusive layer 3''.
The dielectric layer(s) 2 (and 2'') may be of or include silicon
oxide optionally doped with Al, zirconium oxide (e.g., ZrO.sub.2),
zirconium oxynitride, silicon zirconium oxide and/or silicon
zirconium oxynitride (e.g., SiZrO.sub.x, ZrO.sub.2, SiO.sub.2,
and/or SiZrO.sub.xN.sub.y). The dielectric layer 2 (or 2'') may be
in direct contact with the glass substrate 1 (e.g., see FIGS. 1(b),
1(e), 1(g), 1(h)). The dielectric layer(s) 2, 2'' may each have a
physical thickness of from about 10-600 .ANG., more preferably from
about 40-400 .ANG., more preferably from about 50-300 .ANG., and
most preferably from about 50-200 .ANG., or from about 40-170 or
80-140 .ANG.. The dielectric layer(s) 2, 2'' is/are preferably an
oxide based dielectric layer, and preferably contains little or no
nitrogen. For example, the dielectric layer(s) 2, 2'' may each
comprise from 0-20% nitrogen, more preferably from 0-10% nitrogen,
and most preferably from 0-5% nitrogen (atomic %).
[0119] The FIG. 1(i) embodiment is based on the embodiments of
FIGS. 1(a)-(b), 1(e), and 1(h) discussed herein, and layer and
performance descriptions regarding those embodiments also apply to
FIG. 1(i). However, the FIG. 1(i) embodiment also includes an
absorber film made up of layers 57 and 59, where the absorber film
is provided in the central portion of the layer stack and over
dielectric layers 11, 2'' and 3'' as described herein. Layer 3''
may be zinc stannate, zinc oxide, zinc aluminum oxide, or dope zinc
oxide as discussed above in different embodiments of this
invention. Layer 2'' is discussed above, and may be of or include
silicon oxide optionally doped with Al, zirconium oxide (e.g.,
ZrO.sub.2), silicon zirconium oxide and/or silicon zirconium
oxynitride (e.g., SiZrO.sub.x, ZrO.sub.2, SiO.sub.2, and/or
SiZrO.sub.xN.sub.y).
[0120] In the FIG. 1(i) embodiment, the absorber film may be a
multi-layer absorber film including a first layer 57 of or
including silver (Ag), and a second layer 59 of or including NiCr
which may be partially or fully oxided (NiCrO.sub.x), and possibly
slightly nitrided. Such a multi-layer absorber film 57, 59 may
thus, in certain example embodiments, be made up of a layer
sequence of Ag/NiCrO.sub.x. This layer sequence may be repeated in
certain example instances. For example, the absorber film may be
made up of a layer sequence of Ag/NiCrO.sub.x/Ag/NiCrO.sub.x, or
Ag/NiCrO.sub.x/Ag/NiCrO.sub.x/Ag/NiCrO.sub.x, in certain example
embodiments of this invention, which each of the layers in the
sequence contributing to the light absorption. Elements from one
layer may diffuse into an adjacent layer due to HT or other
factors. The NiCr based layer 59 of the absorber may be initially
deposited in metallic form, or as a suboxide, in certain example
embodiments. The silver based layer 57 may be a continuous layer,
and/or may optionally be doped, in certain example embodiments.
Examples 30-47 of example embodiments of this invention relate to
at least the FIG. 1(i) embodiment (see FIGS. 47-56). Moreover, as
explained herein, in certain example embodiments, in certain
example embodiments it has surprisingly and unexpectedly been found
that initially sputter-depositing the dielectric layer(s) 2 and/or
2'' of or including silicon oxide, zirconium oxide, zirconium
oxynitride, silicon zirconium oxide and/or silicon zirconium
oxynitride (e.g., SiZrO.sub.x, ZrO.sub.2, SiO.sub.2, and/or
SiZrO.sub.xN.sub.y) so as to comprise a monoclinic phase
crystalline phase (see m-ZrO.sub.2 peaks in the upper graph of FIG.
51) is advantageous in that it results in improved thermal
stability (lower .DELTA.E* value) and/or reduced change in visible
transmission (e.g., T.sub.vis or TY) of the coated article upon
heat treatment (HT).
[0121] The silver based layer 57 of the absorber film is preferably
sufficiently thin so that its primary function is to absorb visible
light and provide desirable coloration (as opposed to being much
thicker and primarily function as an IR reflection layer). The NiCr
or NiCrO.sub.x 59 is provided over and contacting the silver 57 of
the absorber film in order to protect the silver, and also to
contribute to absorption. In certain example embodiments, the
silver based layer 57 of the absorber film may be no more than
about 30 .ANG. thick, more preferably no greater than about 20
.ANG. thick, and most preferably no greater than about 15 .ANG.
thick, and possibly no greater than about 12 .ANG. thick, in
certain example embodiments of this invention. In certain example
embodiments, the NiCr based layer 59 of the absorber film may be
from about 5-200 .ANG. thick, more preferably from about 10-110
.ANG. thick, and most preferably from about 40-90 .ANG. thick. In
certain example embodiments, the ratio of Ag/NiCrO.sub.x in the
absorber film may be 1:Z (where 0.1<Z<20, more preferably
where 2<Z<15, and most preferably where 3<Z<12), with
an example being about 1:5.
[0122] With respect to the silver based layer 57 of the absorber
film being sufficiently thin so that its primary function is to
absorb visible light and provide desirable coloration (as opposed
to being much thicker and primarily function as an IR reflection
layer), the ratio of the physical thickness of the IR reflecting
layer 7 (e.g., silver) to the physical thickness of the silver
based layer 57 is preferably at least 5:1, more preferably at least
about 8:1, even more preferably at least about 10:1, and even more
preferably at least about 15:1. Likewise, the ratio of the physical
thickness of the IR reflecting layer 19 (e.g., silver) to the
physical thickness of the silver based layer 57 is preferably at
least 5:1, more preferably at least about 8:1, even more preferably
at least about 10:1, and even more preferably at least about
15:1.
[0123] While a single layer of NiCr (or other suitable material)
may also be used as an absorber film in low-E coatings in certain
example embodiments of this invention (e.g., see absorber film 42
in FIGS. 1(d) and 1(f)), it has surprisingly been found that using
silver 57 in an absorber film (single layer, or multi-layer,
absorber film) of FIG. 1(i) provides for several unexpected
advantages compared to a single layer of NiCr as the absorber.
First, it has been found that a single layer of NiCr as the
absorber tends to cause yellowish coloration in certain low-E
coating coated articles, which may not be desirable in certain
instances. In contrast, it has been surprisingly found that using
silver 57 in an absorber films tends to avoid such yellowish
coloration and/or instead provide for more desirable neutral
coloration of the resulting coated article. Thus, the use of silver
57 in an absorber film has been found to provide for improved
optical characteristics. Second, the use of a single layer of NiCr
42 as the absorber tends to also involve providing silicon nitride
based layers on both sides of the NiCr so as to directly sandwich
and contact the NiCr therebetween. For example, see FIGS. 1(d) and
1(f). It has been found that the provision of silicon nitride in
certain locations in a coating stack may lead to compromised
thermal stability upon HT. In contrast, it has been surprisingly
found that when using silver in an absorber film as shown in FIG.
1(i) for example, a pair of immediately adjacent silicon nitride
layers are not needed, so that thermal stability upon HT may be
improved. Thus, the use of silver 57 in an absorber film has been
found to provide for improved thermal stability including lower
.DELTA.E* values and therefor improved matchability between HT and
non-HT versions of the same coating. The use of silver in an
absorber film may also provide for improved manufacturability in
certain situations.
[0124] While the absorber film 57, 59 in FIG. 1(i) is provided in
the central portion of the layer stack between the IR reflecting
layers 7 and 19, it is also possible to provide such an absorber
film 57, 59 instead in the lower portion of the layer stack below
the bottom IR reflecting layer 7, or in another suitable location.
For example, the FIG. 1(i) embodiment may be modified by moving
directly adjacent and contacting layers 57 and 59 to a position
between layers 2 and 3, so that layers 2 and 57 contact each other,
and layers 59 and 3 contact each other. As another example, the
FIG. 1(i) embodiment may be modified by moving the sequence of
three layers 3''/57/59 from the central portion of the stack to a
position between layers 2 and 3 in FIG. 1(i), so that layers 2 and
3'' contact each other, and layers 59 and 3 contact each other.
However, it has been surprisingly found that by providing the
absorber film 57, 59 in the central portion of the layer stack as
shown in FIG. 1(i), optical characteristics such as SHGC and glass
side reflectance may be improved.
[0125] FIG. 1(i) illustrates layer 59 of the absorber film as of or
including NiCrO.sub.x (partially or fully oxided). However, layer
59 of the absorber film may be of or include other metal based
materials (e.g., NiCr, Ni, Cr, NiCrO.sub.x, NiCrN.sub.x, NiCrON,
NiCrM, NiCrMoO.sub.x, Ti, or other suitable material).
[0126] It is noted that zinc stannate layers 11 and/or 23 may be
replaced with respective layer(s) of other material(s) such as tin
oxide, zinc oxide, zinc oxide doped with from 1-20% Sn (as
discussed elsewhere herein regarding layers 3, 3'', 13), or the
like, in any embodiment herein.
[0127] While various thicknesses and materials may be used in
layers in different embodiments of this invention, example
thicknesses and materials for the respective layers on the glass
substrate 1 in the FIG. 1(i) embodiment are as follows, from the
glass substrate outwardly:
TABLE-US-00002 TABLE 1' Example Materials/Thicknesses; FIG. 1(i)
Embodiment Preferred Range More Preferred Example Layer Glass
({acute over (.ANG.)}) ({acute over (.ANG.)}) (.ANG.)
ZrO.sub.x/SiZrO.sub.x (layer 2) 10-600 {acute over (.ANG.)} 10-400
{acute over (.ANG.)} 80-140 .ANG. Sn-doped ZnO 20-900 (or 100-550
{acute over (.ANG.)} 223 .ANG. (layer 3) 100-900) {acute over
(.ANG.)} Ag (layer 7) 60-260 {acute over (.ANG.)} 100-170 {acute
over (.ANG.)} 151 .ANG. NiCrO.sub.x (layer 9) 10-100 {acute over
(.ANG.)} 20-45 {acute over (.ANG.)} 41 .ANG. ZnSnO (layer 11)
100-1200 .ANG. 150-500 .ANG. 280 .ANG. ZrO.sub.x/SiZrO.sub.x (layer
2'') 10-600 {acute over (.ANG.)} 10-400 {acute over (.ANG.)} 80-140
.ANG. Sn-doped ZnO 20-900 {acute over (.ANG.)} 50-150 {acute over
(.ANG.)} 100 .ANG. (layer 3'') Ag (layer 57) 3-30 {acute over
(.ANG.)} 4-20 {acute over (.ANG.)} 5-15 .ANG. NiCrO.sub.x (layer
59) 5-200 {acute over (.ANG.)} 10-110 {acute over (.ANG.)} 40-90
.ANG. Sn-doped ZnO 60-900 {acute over (.ANG.)} 120-400 {acute over
(.ANG.)} 331 .ANG. (layer 13) Ag (layer 19) 80-280 {acute over
(.ANG.)} 120-250 {acute over (.ANG.)} 156 .ANG. NiCrO.sub.x (layer
21) 10-100 {acute over (.ANG.)} 20-45 {acute over (.ANG.)} 41 .ANG.
ZnSnO (layer 23) 10-750 .ANG. 70-200 .ANG. 103 .ANG.
Si.sub.3N.sub.4 (layer 25) 10-750 {acute over (.ANG.)} 100-240
{acute over (.ANG.)} 214 .ANG.
[0128] In certain embodiments of this invention, layer systems
herein (e.g., see FIGS. 1(a)-(i)) provided on clear monolithic
glass substrates (e.g., 6 mm thick glass substrates for example
reference purposes) have color as follows before heat treatment, as
viewed from the glass side of the coated article (R.sub.G %) (Ill.
C, 2 degree Observer):
TABLE-US-00003 TABLE 2 Reflection/Color (R.sub.G) Before and/or
After Heat Treatment General Preferred R.sub.gY (%) 5-35%, or 5-20%
8-18% a.sub.g* -5.0 to +4.0 -3.5 to +2.0 b.sub.g* -16.0 to 0.0
-14.0 to -5.0
Comparative Examples 1 and 2
[0129] FIG. 19 is a cross sectional view of a first Comparative
Example (CE) coated article, and FIG. 23 is an XRD Lin (Cps) vs.
2-Theta-Scale graph illustrating, for the first Comparative Example
(CE), the relative large 166% change in Ag (111) peak height due to
heat treatment.
[0130] A difference between the first Comparative Example coating
(see FIG. 19), and Examples 1-24, 27-28, and 30-33 below, is that
the lowermost dielectric stack of the coating in the first
Comparative Example is made up of a Zn.sub.2SnO.sub.4 layer, and a
zinc oxide based layer that is doped with aluminum. The metal
content of the zinc stannate layer (Zn.sub.2SnO.sub.4 is a form of
zinc stannate) is about 50% Zn and about 50% Sn (wt. %); and thus
the zinc stannate layer is sputter-deposited in amorphous form. The
overall thickness of the lowermost dielectric stack in the first CE
was about 400-500 angstroms, with the zinc stannate layer making up
the majority of that thickness. FIG. 23 illustrates, for the first
Comparative Example (CE), the relative large 166% change in Ag
(111) peak height due to heat treatment at about 650 degrees C.
which is indicative of a significant change in structure of the
silver layers during the heat treatment, and which is consistent
with the .DELTA.E* values over 4.0 realized by the Comparative
Example. Thus, the first CE was undesirable because of the
significant changes in the Ag (111) peak, and the high of .DELTA.E*
values over 4.0, due to heat treatment. In contrast with the first
Comparative Example, Examples 1-24, 27-28, and 30-33 below had a
crystalline or substantially crystalline layer 3, 13 with a metal
content of either 90(Zn)/10(Sn) or 85(Zn)/15(Sn) directly under and
contacting silver 7, 19, and realized significantly improved/lower
.DELTA.E* values.
[0131] A second Comparative Example (CE 2) is shown in FIGS. 34-35.
FIG. 34 is chart illustrating sputter-deposition conditions for the
sputter-deposition of the low-E coating of Comparative Example 2
(CE 2) on a 6 mm thick glass substrate. The layer stack of CE 2 is
the same as that shown in FIG. 1(b) of the instant application,
except that the lowermost dielectric layer in CE 2 is made of
silicon nitride (doped with about 8% aluminum) instead of the
SiZrO.sub.x shown in FIG. 1(b). Thus, the bottom dielectric stack
in CE 2 is made up of only this silicon nitride based layer and a
zinc oxide layer 3 doped with about 10% Sn. The thicknesses of the
layers of the coating of CE 2 are in the far right column of FIG.
34. For example, the bottom silicon nitride based layer, doped with
Al (sputtered from an SiAl target in an atmosphere of Ar and
N.sub.2 gas), is 10.5 nm thick in CE 2, the zinc oxide layer 3
doped with about 10% Sn directly under the bottom silver is 32.6 nm
thick in CE 2, and so forth.
[0132] It can be seen in FIG. 35 that CE 2 suffers from relatively
high glass side reflective .DELTA.E* values (.DELTA.E*R.sub.g) and
film side reflective .DELTA.E* values (.DELTA.E*R.sub.f) over 4.0,
due to heat treatments of 12, 16, and 24 minutes. For example, FIG.
35 shows that CE has a relatively high glass side reflective
.DELTA.E* value (.DELTA.E*R.sub.g) of 4.9 and a relatively high
film side reflective .DELTA.E* value (.DELTA.E*R.sub.f) of 5.5 due
to heat treatment for 12 minutes. FIG. 35 is a chart illustrating
optical characteristics of Comparative Example 2 (CE 2): as coated
(annealed) before heat treatment in the left-most data column,
after 12 minutes of heat treatment at 650 degrees C. (HT), after 16
minutes of HT at 650 degrees C. (HTX), and after 24 minutes of heat
treatment at 650 degrees C. (HTXXX) in the far right data column.
These relatively high .DELTA.E* values of CE 2 are undesirable.
[0133] Accordingly, Comparative Example 2 (CE 2) in FIGS. 34-35
demonstrates that undesirably high .DELTA.E* values are realized,
even when a crystalline or substantially crystalline zinc oxide
layer 3 doped with about 10% Sn is provided directly below the
bottom silver layer 7, when the only layer between that layer 3 and
the glass substrate 1 is a silicon nitride based layer. The
difference between the CE 2 coating, and Examples 1-24, 27-28, and
30-33 below, is that Examples 1-24, 27-28, and 30-33 below were
surprisingly and unexpectedly able to realize much improved (lower)
.DELTA.E* values using the crystalline or substantially crystalline
zinc oxide layer 3 doped with about 10% or 15% Sn, by not having a
silicon nitride based layer located directly below and contacting
the crystalline or substantially crystalline zinc oxide layer 3
doped with about 10% or 15% Sn.
[0134] Examples 11-14, 19-21, and 26-33 below also demonstrate that
replacing the bottom silicon nitride based layer of CE 2 with a
SiZrO.sub.x or ZrO.sub.2 layer 2 dramatically improves/lowers
.DELTA.E* values in an unexpected manner.
Examples 1-48
[0135] Surprisingly and unexpectedly, it was found that when the
lowermost dielectric stack 5, 6 of the Comparative Example (CE)
(made up mostly by the zinc stannate layer which is amorphous as
deposited) in FIG. 19 was replaced with a crystalline or
substantially crystalline Sn-doped zinc oxide layer 3 of similar
thickness (the rest of the stack remained substantially the same)
contacting the silver based layer, with no silicon nitride based
layer directly under and contacting the crystalline or
substantially crystalline layer 3, the result was a much more
thermally stable product with significant lower .DELTA.E* values
and a much smaller change in Ag (111) peak height due to heat
treatment at about 650 degrees C. The metal content of the
crystalline or substantially crystalline Sn-doped zinc oxide layer
3 in Examples 1-24, 27-28, and 30-48 was approximately 90% Zn and
10% Sn (wt. %) (see also 85% Zn, and 15% Sn metal content for "85"
regarding layer 13 in Example 19), which helped allow the Sn-doped
zinc oxide layers 3, 13 in Examples 1-24, 27-28, 30-48 to be
sputter-deposited in crystalline or substantially crystalline form
(as opposed to the amorphous form in the CE). For instance, FIG. 20
illustrates the layer stack of Example 10, FIG. 21 illustrates the
sputter-deposition conditions and layer thicknesses of Example 10,
and FIG. 22 illustrates the much smaller 66% change in Ag (111)
peak height due to heat treatment at about 650 degrees C. for
Example 10 which is consistent with the much lower .DELTA.E* values
realized by Examples 1-24, 27-28 and 30-33. FIG. 16 also
illustrates the relatively small refractive index (n) shift, upon
heat treatment, for Example 8.
[0136] The Example coated articles (each annealed and heat
treated), Examples 1-48, were made in accordance with certain
example embodiments of this invention. Indicated example coatings
30 were sputter-deposited via the sputtering conditions (e.g., gas
flows, voltage, and power), sputtering targets, and to the layer
thicknesses (nm) shown in FIGS. 2, 3, 6, 7, 9, 11, 13, 15, 21,
24-26, 28, 30, 32, and 36-57. For example, FIG. 2 shows the
sputtering conditions, sputtering targets used for
sputter-depositing, and the layer thicknesses for the coating of
Example 1, FIG. 3 shows the sputtering conditions, sputtering
targets used for sputter-depositing, and the layer thicknesses for
the coating of Example 2, FIG. 6 shows the sputtering conditions,
sputtering targets used for sputter-depositing, and the layer
thicknesses for the coating of Example 3, FIG. 7 shows the
sputtering conditions, sputtering targets used for
sputter-depositing, and the layer thicknesses for the coating of
Example 4, and so forth. Meanwhile, data for the indicated
Examples, including visible transmission (TY or T.sub.vis), glass
side visible reflectance (R.sub.gY or RGY), film side visible
reflectance (R.sub.fY or RFY), a* and b* color values, L* values,
and sheet resistance (SR or R.sub.s) are shown in FIGS. 4, 5, 8,
10, 12, 14, 18, 27, 29, 31, 33, and 36-56. As explained above,
.DELTA.E* values are calculated using the L*, a*, and b* values,
taken before and after heat treatment, for a given example. For
instance, a glass side reflective .DELTA.E* value (.DELTA.E*.sub.G
or .DELTA.E*R.sub.g) is calculated using the glass side reflective
L*, a*, and b* values, taken before and after heat treatment, for a
given example. As another example, a film side reflective .DELTA.E*
value (.DELTA.E*.sub.F or .DELTA.E*R.sub.f) is calculated using the
glass side reflective L*, a*, and b* values, taken before and after
heat treatment, for a given example. As another example, a
transmissive .DELTA.E* value (.DELTA.E*.sub.T) is calculated using
the glass side reflective L*, a*, and b* values, taken before and
after heat treatment, for a given example.
[0137] For examples having approximately 3 mm thick glass
substrates, in FIGS. 4, 5, 8, 10, 12, 14, and 18, "HT" refers to
heat treatment at 650 degrees for about 8 minutes, "HTX" refers to
heat treatment at 650 degrees for about 12 minutes, and "HTXXX"
refers to heat treatment at 650 degrees for about 20 minutes. And
for examples having approximately 6 mm thick glass substrates, in
FIGS. 4, 5, 8, 10, 12, 14, 18, 27, 29, 31, 33, and 36-56 "HT"
refers to heat treatment at 650 degrees for about 12 minutes, "HTX"
refers to heat treatment at 650 degrees for about 16 minutes, and
"HTXXX" refers to heat treatment at 650 degrees for about 24
minutes. The heat treatment temperatures and times are for
reference purposes only (e.g., to simulate examples of different
tempering and/or heat bending processes).
[0138] FIGS. 4 and 5, for instance, illustrate the .DELTA.E* values
for Examples 1 and 2, respectively. The data for Example 1 is
explained below in detail, for purposes of example and explanation,
and that discussion also applies to the data for Examples 2-33.
[0139] As shown in FIG. 4, Example 1 as coated (prior to heat
treatment) had a visible transmission (TY or T.sub.vis) of 74.7%, a
transmissive L* value of 89.3, a transmissive a* color value of
-4.7, a transmissive b* color value of 5.8, a glass side
reflectance (R.sub.gY) of 9.6%, a glass side reflective L* value of
37.1, a glass side reflective a* color value of -1.1, a glass side
reflective b* color value of -10.1, a film side reflectance
(R.sub.fY) of 9.9%, a film side reflective L* value of 37.7, a film
side reflective a* color value of -1.5, a film side reflective b*
color value of -5.7, and a sheet resistance (SR) of 2.09
ohms/square. FIG. 2 shows the thicknesses of the layers in Example
1. In particular, FIG. 2 shows that the layer thicknesses for
Example 1 were are follows: glass/crystalline Sn-doped ZnO(47.0
nm)/Ag(15.1 nm)/NiCrO.sub.x (4.1 nm)/amorphous zinc stannate(73.6
nm)/crystalline Sn-doped ZnO(17.7 nm)/Ag(23.2 nm)/NiCrO.sub.x (4.1
nm)/amorphous zinc stannate(10.8 nm)/silicon nitride doped with
aluminum (19.1 nm).
[0140] The coated article of Example 1, which had a 6 mm thick
glass substrate 1, was then heat treated. As shown in FIG. 4,
Example 1 following heat treatment at 650 degrees C. for about 12
minutes had a visible transmission (TY or T.sub.vis) of 77.0%, a
transmissive L* value of 90.3, a transmissive a* color value of
-3.5, a transmissive b* color value of 4.9, a glass side
reflectance (R.sub.gY) of 9.8%, a glass side reflective L* value of
37.5, a glass side reflective a* color value of -0.7, a glass side
reflective b* color value of -10.5, a film side reflectance
(R.sub.fY) of 10.2%, a film side reflective L* value of 38.1, a
film side reflective a* color value of -1.4, a film side reflective
b* color value of -8.0, a sheet resistance (SR) of 1.75, a
transmissive .DELTA.E* value of 1.8, a glass side reflective
.DELTA.E* value 0.7, and a film side reflective .DELTA.E* value of
2.4.
[0141] It will be appreciated that these .DELTA.E* values for
Example 1 (and also those for Examples 2-48) are much improved
(significantly lower) than those of the prior art discussed in the
background and compared to the values over 4.0 for the Comparative
Examples (CEs) discussed above. Thus, the data from the examples
demonstrates, for example, that when the lowermost dielectric
stacks of the Comparative Examples was replaced with at least a
crystalline or substantially crystalline Sn-doped zinc oxide layer
of similar thickness (the rest of the stack remained substantially
the same), with no silicon nitride based layer directly under and
contacting the crystalline or substantially crystalline Sn-doped
zinc oxide layer 3, the result was a much more thermally stable
product with significant lower .DELTA.E* values and a much smaller
change in Ag (111) peak height due to heat treatment.
[0142] Other examples show these same unexpected results, compared
to the Comparative Example. In general, the Examples demonstrate
that the crystalline or substantially crystalline Sn-doped zinc
oxide layer, and/or the layer(s) 2, 2'' of or including
SiZrO.sub.x, ZrO.sub.x, SiO.sub.2, significantly improved .DELTA.E*
values. For example, Examples 1-10 had layer stacks generally shown
by FIG. 1(a) where the only dielectric layer beneath the bottom
silver was the crystalline or substantially crystalline Sn-doped
zinc oxide layer 3 with a metal content of approximately 90% Zn and
10% Sn (wt. %). In Examples 11-14, 19-24, 27-28 metal content of
the crystalline or substantially crystalline Sn-doped zinc oxide
layer 3 was approximately 90% Zn and 10% Sn (wt. %), directly over
a SiZrO.sub.x layer 2 where metal content of the layer 2 was about
85% Si and 15% Zr (atomic %). In Examples 30-48 the crystalline or
substantially crystalline Sn-doped zinc oxide layer 3 was
approximately 90% Zn and 10% Sn (wt. %), and provided directly over
a ZrO.sub.2 layer 2 as shown in FIGS. 1(i) and 52. In Examples
15-16 metal content of the crystalline or substantially crystalline
Sn-doped zinc oxide layer 3 was approximately 90% Zn and 10% Sn
(wt. %), directly over a ZrO.sub.2 layer 2; and in Examples 17-18
metal content of the crystalline or substantially crystalline
Sn-doped zinc oxide layer 3 was approximately 90% Zn and 10% Sn
(wt. %), directly over a SiO.sub.2 layer 2 doped with about 8% Al
(atomic %). These examples surprisingly and unexpectedly realized
much improved .DELTA.E* values compared to the Comparative Examples
1-2.
[0143] The layer stacks of Examples 1-10 are generally illustrated
by FIG. 1(a). The layer stacks of Examples 11-14, 19 and 27 are
generally illustrated by FIG. 1(b), with layer 2 being of
SiZrO.sub.x. The layer stacks of Examples 15-16 are generally
illustrated by FIG. 1(b), with layer 2 being of ZrO.sub.2. The
layer stacks of Examples 17-18 are generally illustrated by FIG.
1(b), with layer 2 being of SiO.sub.2. The layer stacks of Examples
20-21 and 28 are generally illustrated by FIG. 1(e), with layers 2
and 2'' being of SiZrO.sub.x. The layer stacks of Examples 23-24
are generally illustrated by FIG. 1(f), with layers 2 and 2'' being
of SiZrO.sub.x. The layer stack of Example 25 is generally
illustrated by FIG. 1(g), with layers 2 and 2'' being of
SiZrO.sub.x. The layer stack of Example 22 is generally illustrated
by FIG. 1(d), with layer 2 being of SiZrO.sub.x. The layer stack of
Example 26 is generally illustrated by FIG. 1(h), with layers 2 and
2'' being of SiZrO.sub.x, oxide layer 3'having a meal content 90%
Zn and 10% Sn, and oxide layers 3, 13 being zinc oxide doped with
about 4-8% Al. The layer stack of Example 29 is generally
illustrated by FIG. 1(h), except that layer 2'' is not present in
Example 29, and with layer 2 being of SiZrO.sub.x, oxide layer
3'having a metal content 90% Zn and 10% Sn, and oxide layers 3, 13
being zinc oxide doped with about 4-8% Al. The layer stacks of
Examples 30-48 are generally illustrated by FIGS. 1(i) and 52, with
layers 2 and 2'' being of ZrO.sub.2. These examples surprisingly
and unexpectedly realized much improved .DELTA.E* values compared
to the Comparative Examples 1-2. These examples demonstrate that
the crystalline or substantially crystalline Sn-doped zinc oxide
layer(s) (e.g., layer 3 and/or 13), and/or the dielectric layer(s)
2, 2'' of or including SiZrO.sub.x, ZrO.sub.x, SiO.sub.2,
significantly improved/lowered .DELTA.E* values.
[0144] For instance, comparing Examples 23-24 (SiZrO.sub.x layer
2'' added to the center dielectric portion of the coating as shown
in FIG. 1(f)) to Example 22 (no such layer 2'' in the center
dielectric portion as shown in FIG. 1(d)) demonstrates and
evidences that the addition of the SiZrO.sub.x layer 2'' in
Examples 23-24 unexpectedly improved/lowered at least glass side
reflective .DELTA.E* values. Thus, it will be appreciated that the
addition of the SiZrO.sub.x layer 2'' provides for unexpected
results.
[0145] Furthermore, comparing Example 28 (SiZrO.sub.x layer 2''
added to the center dielectric portion of the coating as shown in
FIG. 1(e)) to Example 27 (no such layer 2'' in the center
dielectric portion as shown in FIG. 1(b)) further demonstrates and
evidences that the addition of the SiZrO.sub.x layer 2'' in Example
28 unexpectedly improved/lowered glass side reflective .DELTA.E*
values. Thus, it will again be appreciated that the addition of the
SiZrO.sub.x or ZrO.sub.2 layer 2'' provides for unexpected results
with respect to improving thermal stability. Examples 30-48 are
generally illustrated by FIGS. 1(i) and 52 including absorber film
57, 59, with layers 2 and 2'' being of ZrO.sub.2 in these examples.
These examples surprisingly and unexpectedly realized much improved
.DELTA.E* values compared to the Comparative Examples 1-2. Examples
30-48 demonstrate that the crystalline or substantially crystalline
Sn-doped zinc oxide layer(s) (e.g., layer 3 and/or 13), and the
dielectric layer(s) 2, 2'' of or including ZrO.sub.2, significantly
improved/lowered .DELTA.E* values in an unexpected manner Examples
30-48 further demonstrate that providing the absorber film
including silver inclusive layer 57 and NiCrO.sub.x inclusive layer
59 allows the visible transmission to be tuned to a desirable value
without sacrificing thermal stability or desired color of the
resulting coated article. For example, Examples 30-48 with the
Ag/NiCrO.sub.x absorber film (57, 59) as shown in FIG. 1(i) have
surprisingly more neutral glass side reflective b* values (Rg b*,
or R-out b*) values compared to Examples 23-24 where the single
NiCr layer absorber was utilized.
[0146] Comparing Examples 34-42 and 48, to Comparative Examples
(CEs) 43-47, it can be seen that it has surprisingly and
unexpectedly been found that initially sputter-depositing the
dielectric layer(s) 2 and/or 2'' of or including silicon oxide,
zirconium oxide, zirconium oxynitride, silicon zirconium oxide
and/or silicon zirconium oxynitride (e.g., SiZrO.sub.x, ZrO.sub.2,
SiO.sub.2, and/or SiZrO.sub.xN.sub.y) so as to comprise a
monoclinic phase crystalline structure in Examples 34-42 and 48 is
advantageous in that it results in improved thermal stability
(lower .DELTA.E* value) and/or reduced change in visible
transmission (e.g., T.sub.vis or TY) of the coated article upon
heat treatment (HT). Generally speaking, CEs 43-47, which may still
be according to certain example embodiments of this invention, had
less preferred (higher) .DELTA.E* values due to nonmonoclinic
ZrO.sub.2 layers 2, 2'', compared to Examples 34-42 and 48 which
had monoclinic ZrO.sub.2 layers 2, 2'' and thus improved/lower
.DELTA.E* values. In certain example embodiments, in connection
with certain sputtering equipment, the monoclinic phase (e.g., see
the m-ZrO.sub.2 peaks in the upper graph of FIG. 51) for the
dielectric layer (e.g., ZrO.sub.2) 2 and/or 2'' may be achieved by
using a high oxygen gas flow for that layer during the
sputter-deposition process of that layer, and using a metallic
sputtering target (e.g., metal Zr or SiZr target) (e.g., see FIG.
55), as in Examples 34-42. In this respect, FIG. 51 illustrates
graphs for sputter-depositing a ZrO.sub.2 layer using a metal Zr
target (upper graph) and a ceramic ZrO.sub.x target (lower graph),
before and after HT, and shows that the layer comprises a
monoclinic phase (see the peak at m-ZrO.sub.2) when the metal
target with high gas flow (e.g., see FIG. 55) was used, but not
when the ceramic target was used in certain situations. It is
noted, however, that it has been found that monoclinic phase for
layer 2 and/or 2'' may indeed be achieved when the
sputter-depositing uses a ceramic target such as in Example 48,
with low or high oxygen gas flows, depending upon the type of
sputtering equipment used.
[0147] FIG. 52 (see also FIG. 1(i)) is a cross sectional view of
coated articles according to Examples 34-42, 48 and Comparative
Examples (CEs) 43-47. FIG. 53 illustrates the optical data of
Examples 34-42 as coated (AC; annealed) before heat treatment in
the left-most data column of each example, and after 12 minutes of
heat treatment at 650 degrees C. (HT) in the right data column of
each example, Examples 34-42 having a coating stack as shown in
FIG. 1(i) and FIG. 52 with monoclinic ZrO.sub.2 layers 2 and 2''
deposited with metal Zr target, and layer thicknesses for Examples
34-42 as shown in FIG. 55; where sample 7982 is Example 34, sample
8077 is Example 35, sample 8085 is Example 36, sample 8090 is
Example 37, sample 8091 is Example 38, sample 8097 is Example 39,
sample 8186 is Example 40, sample 8187 is Example 41, and sample
8202 is Example 42.
[0148] FIG. 55 is a chart illustrating deposition process
conditions and layer thicknesses for Example 37 having monoclinic
ZrO.sub.2 layers, with total oxygen flow (ml) during the sputtering
process for each layer indicated by the sum of O.sub.2 setpoint,
O.sub.2 tune, and O.sub.2 offset, with the high oxygen gas flow
during sputter-deposition of the ZrO.sub.2 layers helping provide
the monoclinic phase of the ZrO.sub.2 layers 2 and 2'' of Example
37 (monoclinic Examples 34-36 and 38-42 had similar process
conditions). In the FIG. 52 and FIG. 1(i) embodiments, it is noted,
for example, that the center ZrO.sub.2 layer 2'' may be omitted in
certain example instances.
[0149] FIG. 57 is a chart illustrating deposition process
conditions and layer thicknesses for Example 48 having monoclinic
ZrO.sub.2 layer 2 (layer 2'' was omitted), where the ZrO layer 2
having monoclinic phase was sputter-deposited using a ceramic
ZrO.sub.x target. The layer stack of Example 48 is shown in FIGS.
1(i) and 52 (with layer 2'' omitted), and the respective layer
thicknesses are provided in FIG. 57. FIG. 58 illustrates the
.DELTA.E* values for coatings according to Example 48 after various
heat treatment times, and FIG. 59 illustrates optical data and
sheet resistance data for the coatings according to Example 48.
[0150] FIG. 54 illustrates the optical data of Comparative Examples
(CEs) 43-47 as coated (AC; annealed) before heat treatment in the
left-most data column of each example, and after 12 minutes of heat
treatment at 650 degrees C. (HT) in the right data column of each
example, Examples 43-47 having a coating stack as shown in FIG.
1(i) and FIG. 52 with non-monoclinic ZrO.sub.2 layers deposited
with ceramic target, and layer thicknesses for Examples 43-47 as
shown in FIG. 56; where sample 8392 is CE 43, sample 8394 is CE 44,
sample 8395 is CE 45, sample 8396 is CE 46, and sample 8397 is CE
47. FIG. 56 is a chart illustrating deposition process conditions
and layer thicknesses for Comparative Example (CE) 44 having
nonmonoclinic ZrO.sub.2 layers 2 and 2'', with total oxygen flow
(ml) during the sputtering process for each layer indicated by the
sum of O.sub.2 setpoint, O.sub.2 tune, and O.sub.2 offset, with the
low oxygen gas flow during sputter-deposition of the ZrO.sub.2
layers together with ceramic ZrO.sub.x target helping provide the
non-monoclinic phase of the ZrO.sub.2 layers of Example 44
(nonmonoclinic Examples 43 and 45-47 had similar process
conditions).
[0151] Comparing Examples 34-42, 48 to Comparative Examples (CEs)
43-47, it can be seen that Examples 34-42, 48 with the monoclinic
ZrO.sub.2 layers 2 and 2'' as-deposited realized lower/better
.DELTA.E* values, and thus improved thermal stability and color
matching upon HT, than did Examples 43-47 which had nonmonoclinic
phase ZrO.sub.2 layers 2 and 2''.
[0152] Certain terms are prevalently used in the glass coating art,
particularly when defining the properties and solar management
characteristics of coated glass. Such terms are used herein in
accordance with their well known meaning. For example, as used
herein:
[0153] Intensity of reflected visible wavelength light, i.e.
"reflectance" is defined by its percentage and is reported as
R.sub.xY or R.sub.x (i.e. the Y value cited below in ASTM
E-308-85), wherein "X" is either "G" for glass side or "F" for film
side. "Glass side" (e.g. "G" or "g") means, as viewed from the side
of the glass substrate opposite that on which the coating resides,
while "film side" (i.e. "F" or "f") means, as viewed from the side
of the glass substrate on which the coating resides.
[0154] Color characteristics are measured and reported herein using
the CIE LAB a*, b* coordinates and scale (i.e. the CIE a*b*
diagram, Ill. CIE-C, 2 degree observer). Other similar coordinates
may be equivalently used such as by the subscript "h" to signify
the conventional use of the Hunter Lab Scale, or Ill. CIE-C,
10.degree. observer, or the CIE LUV u*v* coordinates. These scales
are defined herein according to ASTM D-2244-93 "Standard Test
Method for Calculation of Color Differences From Instrumentally
Measured Color Coordinates" Sep. 15, 1993 as augmented by ASTM
E-308-85, Annual Book of ASTM Standards, Vol. 06.01 "Standard
Method for Computing the Colors of Objects by 10 Using the CIE
System" and/or as reported in IES LIGHTING HANDBOOK 1981 Reference
Volume.
[0155] Visible transmittance can be measured using known,
conventional techniques. For example, by using a spectrophotometer,
such as a Perkin Elmer Lambda 900 or Hitachi U4001, a spectral
curve of transmission is obtained. Visible transmission is then
calculated using the aforesaid ASTM 308/2244-93 methodology. A
lesser number of wavelength points may be employed than prescribed,
if desired. Another technique for measuring visible transmittance
is to employ a spectrometer such as a commercially available
Spectrogard spectrophotometer manufactured by Pacific Scientific
Corporation. This device measures and reports visible transmittance
directly. As reported and measured herein, visible transmittance
(i.e. the Y value in the CIE tristimulus system, ASTM E-308-85), as
well as the a*, b*, and L* values, and glass/film side reflectance
values, herein use the Ill. C.,2 degree observer standard.
[0156] Another term employed herein is "sheet resistance". Sheet
resistance (R.sub.s) is a well known term in the art and is used
herein in accordance with its well known meaning. It is here
reported in ohms per square units. Generally speaking, this term
refers to the resistance in ohms for any square of a layer system
on a glass substrate to an electric current passed through the
layer system. Sheet resistance is an indication of how well the
layer or layer system is reflecting infrared energy, and is thus
often used along with emittance as a measure of this
characteristic. "Sheet resistance" may for example be conveniently
measured by using a 4-point probe ohmmeter, such as a dispensable
4-point resistivity probe with a Magnetron Instruments Corp. head,
Model M-800 produced by Signatone Corp. of Santa Clara, Calif.
[0157] The terms "heat treatment" and "heat treating" as used
herein mean heating the article to a temperature sufficient to
achieve thermal tempering, heat bending, and/or heat strengthening
of the glass inclusive coated article. This definition includes,
for example, heating a coated article in an oven or furnace at a
temperature of least about 580 degrees C., more preferably at least
about 600 degrees C., including 650 degrees C., for a sufficient
period to allow tempering, bending, and/or heat strengthening. In
certain instances, the heat treatment may be for at least about 8
minutes or more as discussed herein.
[0158] In an example embodiment of this invention, there is
provided a coated article including a coating on a glass substrate,
wherein the coating comprises: a first crystalline or substantially
crystalline layer comprising zinc oxide doped with from about 1-30%
Sn (wt. %), provided on the glass substrate; a first infrared (IR)
reflecting layer comprising silver located on the glass substrate
and directly over and contacting the first crystalline or
substantially crystalline layer comprising zinc oxide doped with
from about 1-30% Sn; wherein no silicon nitride based layer is
located directly under and contacting the first crystalline or
substantially crystalline layer comprising zinc oxide doped with
from about 1-30% Sn; at least one dielectric layer having
monoclinic phase and comprising an oxide of zirconium (e.g.,
ZrO.sub.2), and optionally further including other element(s) such
as Si; wherein the at least one dielectric layer comprising the
oxide of zirconium is located: (1) between at least the glass
substrate and the first crystalline or substantially crystalline
layer comprising zinc oxide doped with from about 1-30% Sn (wt. %),
and/or (2) between at least the first IR reflecting layer
comprising silver and a second IR reflecting layer comprising
silver of the coating; optionally an absorber film including a
layer comprising silver, wherein a ratio of a physical thickness of
the first IR reflecting layer comprising silver to a physical
thickness of the layer comprising silver of the absorber film is at
least 5:1 (more preferably at least 8:1, even more preferably at
least 10:1, and most preferably at least 15:1); and wherein the
coated article is configured to have, measured monolithically, at
least two of: (i) a transmissive .DELTA.E* value of no greater than
3.0 due to a reference heat treatment for 12 minutes at a
temperature of about 650 degrees C., (ii) a glass side reflective
.DELTA.E* value of no greater than 3.0 due to the reference heat
treatment for 12 minutes at a temperature of about 650 degrees C.,
and (iii) a film side reflective .DELTA.E* value of no greater than
3.5 due to the reference heat treatment for 12 minutes at a
temperature of about 650 degrees C.
[0159] The coated article of the immediately preceding paragraph
may be configured to have, measured monolithically, all three of:
(i) a transmissive .DELTA.E* value of no greater than 3.0 due to a
reference heat treatment for 12 minutes at a temperature of about
650 degrees C., (ii) a glass side reflective .DELTA.E* value of no
greater than 3.0 due to the reference heat treatment for 12 minutes
at a temperature of about 650 degrees C., and (iii) a film side
reflective .DELTA.E* value of no greater than 3.5 due to the
reference heat treatment for 12 minutes at a temperature of about
650 degrees C.
[0160] In the coated article of any of the preceding two
paragraphs, the least one dielectric layer comprising the oxide of
zirconium may be located at least between at least the glass
substrate and the first crystalline or substantially crystalline
layer comprising zinc oxide doped with from about 1-30% Sn (wt.
%).
[0161] In the coated article of any of the preceding three
paragraphs, the least one dielectric layer comprising the oxide of
zirconium may be located at least between at least the first IR
reflecting layer comprising silver and the second IR reflecting
layer comprising silver of the coating.
[0162] In the coated article of any of the preceding four
paragraphs, the at least one dielectric layer comprising the oxide
of zirconium may include both a first layer comprising an oxide of
zirconium, and a second layer comprising an oxide of zirconium
(each of which may further include additional element(s) such as
Si); wherein the first layer may be located between at least the
glass substrate and the first crystalline or substantially
crystalline layer comprising zinc oxide doped with from about 1-30%
Sn (wt. %); and wherein the second layer may be located between at
least the first IR reflecting layer comprising silver and the
second IR reflecting layer comprising silver of the coating.
[0163] In the coated article of any of the preceding five
paragraphs, the at least one dielectric layer may comprise or
consist essentially of the oxide of zirconium and/or an oxide of
silicon and zirconium (e.g., SiZrO.sub.x). For instance, the
dielectric layer comprising the oxide of silicon and zirconium may
have a metal content of from 51-99% Si and from 1-49% Zr, more
preferably from 70-97% Si and from 3-30% Zr (atomic %).
[0164] In the coated article of any of the preceding six
paragraphs, the at least one dielectric layer may comprise
ZrO.sub.2.
[0165] In the coated article of any of the preceding seven
paragraphs, the first crystalline or substantially crystalline
layer comprising zinc oxide may be doped with from about 1-20% Sn,
more preferably from about 5-15% Sn (wt. %).
[0166] In the coated article of any of the preceding eight
paragraphs, the first crystalline or substantially crystalline
layer comprising zinc oxide doped with Sn may be crystalline or
substantially crystalline as sputter-deposited.
[0167] The coated article according to any of the preceding nine
paragraphs may be configured to have, measured monolithically, all
of: (i) a transmissive .DELTA.E* value of no greater than 2.5 due
to a reference heat treatment for 12 minutes at a temperature of
about 650 degrees C., (ii) a glass side reflective .DELTA.E* value
of no greater than 2.5 due to the reference heat treatment for 12
minutes at a temperature of about 650 degrees C., and (iii) a film
side reflective .DELTA.E* value of no greater than 3.0 due to the
reference heat treatment for 12 minutes at a temperature of about
650 degrees C.
[0168] The coated article according to any of the preceding ten
paragraphs may be configured to have, measured monolithically, at
least two of: (i) a transmissive .DELTA.E* value of no greater than
2.3 due to a reference heat treatment for 16 minutes at a
temperature of about 650 degrees C., (ii) a glass side reflective
.DELTA.E* value of no greater than 2.0 due to the reference heat
treatment for 16 minutes at a temperature of about 650 degrees C.,
and (iii) a film side reflective .DELTA.E* value of no greater than
3.0 due to the reference heat treatment for 16 minutes at a
temperature of about 650 degrees C.
[0169] The coated article according to any of the preceding eleven
paragraphs may be configured so that the coating may have a sheet
resistance (R.sub.s) of no greater than 20 ohms/square, more
preferably no greater than 10 ohms/square, and most preferably no
greater than 2.5 ohms/square.
[0170] The coated article according to any of the preceding twelve
paragraphs may have, measured monolithically, a visible
transmission of at least 35%, more preferably of at least 50%, and
more preferably of at least 68%.
[0171] In the coated article of any of the preceding thirteen
paragraphs, the coating as deposited may further comprise a first
amorphous or substantially amorphous layer comprising zinc stannate
located on the glass substrate over at least the first IR
reflecting layer comprising silver. The first amorphous or
substantially amorphous layer comprising zinc stannate may have a
metal content of from about 40-60% Zn and from about 40-60% Sn (wt.
%).
[0172] In the coated article of any of the preceding fourteen
paragraphs, the coating may further comprise a contact layer
located over and directly contacting the first IR reflecting layer
comprising silver. The contact layer may comprise Ni and/or Cr, and
may or may not be oxided and/or nitrided.
[0173] In the coated article of any of the preceding fifteen
paragraphs, the coating may further comprise: the second IR
reflecting layer comprising silver located on the glass substrate
over at least the first IR reflecting layer comprising silver, a
second crystalline or substantially crystalline layer comprising
zinc oxide doped with from about 1-30% Sn (wt. %), located under
and directly contacting the second IR reflecting layer comprising
silver; and wherein no silicon nitride based layer need be located
between the glass substrate and the second IR reflecting layer
comprising silver.
[0174] In the coated article of any of the preceding sixteen
paragraphs, the coating may further comprise an amorphous or
substantially amorphous layer, as deposited, comprising zinc
stannate located on the glass substrate over at least the second IR
reflecting layer comprising silver. The amorphous or substantially
amorphous layer comprising zinc stannate, which is amorphous or
substantially amorphous as deposited, may have a metal content of
from about 40-60% Zn and from about 40-60% Sn (wt. %). In certain
example embodiments, the coating may further comprise a layer
comprising silicon nitride located over at least the amorphous or
substantially amorphous layer comprising zinc stannate.
[0175] The coated article of any of the preceding seventeen
paragraphs may be thermally tempered.
[0176] The coated article of any of the preceding eighteen
paragraphs may further comprise a metallic or substantially
metallic absorber layer located between the glass substrate and the
first IR reflecting layer. The absorber layer may be sandwiched
between and contacting first and second layers comprising silicon
nitride. The absorber layer may comprise Ni and Cr (e.g., NiCr,
NiCrMo), or any other suitable material such as NbZr. The
dielectric layer comprising at least one of (a), (b), and (c) may
be located between at least the absorber layer and the first
crystalline or substantially crystalline layer comprising zinc
oxide.
[0177] In the coated article of any of the preceding nineteen
paragraphs, the at least one dielectric layer comprising the oxide
of zirconium may comprise from 0-20% nitrogen, more preferably from
0-10% nitrogen, and most preferably from 0-5% nitrogen (atomic
%).
[0178] In the coated article of any of the preceding twenty
paragraphs, the absorber film may further comprises a layer
comprising an oxide of Ni and/or Cr located over and directly
contacting the layer comprising silver of the absorber film.
[0179] In the coated article of any of the preceding twenty-one
paragraphs, the absorber film may be located over the first IR
reflecting layer, so that the first IR reflecting layer is located
between at least the absorber film and the glass substrate.
[0180] In the coated article of any of the preceding twenty-two
paragraphs, the ratio of the physical thickness of the first IR
reflecting layer comprising silver to the physical thickness of the
layer comprising silver of the absorber film may be at least 8:1,
more preferably at least 10:1, and even more preferably at least
15:1.
[0181] In the coated article of any of the preceding twenty-three
paragraphs, the layer comprising silver of the absorber film may be
less than 30 .ANG. thick, more preferably less than 20 .ANG. thick,
and even more preferably less than 15 .ANG. thick.
[0182] In the coated article of any of the preceding twenty-four
paragraphs, the coated article need not be thermally tempered.
[0183] In the coated article of any of the preceding twenty-five
paragraphs, the at least one dielectric layer having monoclinic
phase and comprising the oxide of zirconium may include two such
layers comprising zirconium oxide and may be located both: (1)
between at least the glass substrate and the first crystalline or
substantially crystalline layer comprising zinc oxide doped with
from about 1-30% Sn (wt. %), and (2) between at least the first IR
reflecting layer comprising silver and the absorber film.
[0184] In the coated article of any of the preceding twenty-six
paragraphs, the at least one dielectric layer having monoclinic
phase may comprise from 0-5% nitrogen (atomic %).
[0185] In the coated article of any of the preceding twenty-seven
paragraphs, the at least one dielectric layer having monoclinic
phase may comprise an oxide of zirconium (e.g., ZrO.sub.2), and may
optionally further include Si.
[0186] In the coated article of any of the preceding twenty-seven
paragraphs, the at least one dielectric layer having monoclinic
phase may consist essentially of an oxide of zirconium.
[0187] In the coated article of any of the preceding twenty-eight
paragraphs, the at least one dielectric layer having monoclinic
phase may be configured to realize a density change of at least
0.25 g/cm.sup.3 upon said reference heat treatment, more preferably
to realize a density change of at least 0.30 g/cm.sup.3 upon said
reference heat treatment, and most preferably to realize a density
change of at least 0.35 g/cm.sup.3 upon said reference heat
treatment.
[0188] In the coated article of any of the preceding twenty-nine
paragraphs, the at least one dielectric layer having monoclinic
phase may comprise an oxide of zirconium, and may have a metal
content of at least 80% Zr.
[0189] In the coated article of any of the preceding thirty
paragraphs, the at least one dielectric layer having monoclinic
phase may comprise an oxide of zirconium and/or may have a
thickness of from 40-250 .ANG., more preferably from 40-170 .ANG.,
and most preferably from 80-140 .ANG..
[0190] In the coated article of any of the preceding thirty-one
paragraphs, the coated article may be configured to have, measured
monolithically, two or three of: (i) a transmissive .DELTA.E* value
of no greater than 3.0 upon a reference heat treatment for 12
minutes at a temperature of about 650 degrees C., (ii) a glass side
reflective .DELTA.E* value of no greater than 1.5 upon the
reference heat treatment for 12 minutes at a temperature of about
650 degrees C., and (iii) a film side reflective .DELTA.E* value of
no greater than 1.5 upon the reference heat treatment for 12
minutes at a temperature of about 650 degrees C.
[0191] The coated article of any of the preceding thirty-two
paragraphs may be provided as a monolithic window, or in an IG
window unit coupled to another glass substrate.
[0192] In to coated article of any of the preceding thirty-three
paragraphs, the at least one dielectric layer comprising monoclinic
phase may further comprise tetragonal phase before and/or after a
reference heat treatment.
[0193] In an example embodiment, there is provided a method of
making a coated article including a coating on a glass substrate,
the method comprising: sputter-depositing a layer comprising zinc
on the glass substrate; sputter-depositing a first infrared (IR)
reflecting layer comprising silver on the glass substrate over and
contacting the layer comprising zinc oxide; sputter-depositing at
least one dielectric layer (e.g., oxide of zirconium, such as
ZrO.sub.2) having monoclinic phase on the glass substrate, wherein
the dielectric layer having monoclinic phase comprises an oxide of
zirconium (and which may further include other element(s) such as
Si); wherein the at least one dielectric layer having monoclinic
phase and comprising the oxide of zirconium is located: (1) between
at least the glass substrate and the layer comprising zinc oxide,
and/or (2) between at least the first IR reflecting layer
comprising silver and a second IR reflecting layer comprising
silver of the coating; and wherein the coated article is configured
to have, measured monolithically, at least two of: (i) a
transmissive .DELTA.E* value of no greater than 3.0 upon a
reference heat treatment for 12 minutes at a temperature of about
650 degrees C., (ii) a glass side reflective .DELTA.E* value of no
greater than 3.0 upon the reference heat treatment for 12 minutes
at a temperature of about 650 degrees C., and (iii) a film side
reflective .DELTA.E* value of no greater than 3.5 upon the
reference heat treatment for 12 minutes at a temperature of about
650 degrees C. T
[0194] In the method of the immediately preceding paragraph, said
sputter-depositing at least one dielectric layer having monoclinic
phase on the glass substrate may use an oxygen gas flow of at least
6 ml/kW, more preferably an oxygen gas flow of at least 8 or 10
ml/kW.
[0195] In the method of any of the preceding two paragraphs, the at
least one dielectric layer having monoclinic phase may comprise
ZrO.sub.2, and may further include Si.
[0196] In the method of any of the preceding three paragraphs, the
coated article may be configured to have, measured monolithically,
at least two or all three of: (i) a transmissive .DELTA.E* value of
no greater than 3.0 upon a reference heat treatment for 12 minutes
at a temperature of about 650 degrees C., (ii) a glass side
reflective .DELTA.E* value of no greater than 1.5 upon the
reference heat treatment for 12 minutes at a temperature of about
650 degrees C., and (iii) a film side reflective .DELTA.E* value of
no greater than 1.5 upon the reference heat treatment for 12
minutes at a temperature of about 650 degrees C.
[0197] The method of any of the preceding four paragraphs may
further comprise heat treating the coated article via said
reference heat treatment so that the at least one dielectric layer
having monoclinic phase realizes a density change of at least 0.25
g/cm.sup.3 upon said reference heat treatment, more preferably at
least 0.30 g/cm.sup.3, and most preferably of at least 0.35
g/cm.sup.3.
[0198] In the method of any of the preceding five paragraphs, said
sputter-depositing of the at least one dielectric layer having
monoclinic phase on the glass substrate may use a metal target, or
a ceramic target.
[0199] In the method of any of the preceding six paragraphs, said
at least one dielectric layer comprising monoclinic phase may
further comprise tetragonal phase before and/or after said
reference heat treatment.
[0200] In the method of any of the preceding seven paragraphs, the
at least one dielectric layer comprising monoclinic phase may be
configured to have a monoclinic peak thereof reduce upon said
reference heat treatment.
[0201] Once given the above disclosure many other features,
modifications and improvements will become apparent to the skilled
artisan. Such other features, modifications and improvements are
therefore considered to be a part of this invention, the scope of
which is to be determined by the following claims:
* * * * *