Silicon titanium oxide coating, coated article including silicon titanium oxide coating, and method of making the same

Abstract

Certain example embodiments relate to a layer of or including Ti.sub.1-xSi.sub.xO.sub.y and/or a method of making the same. In certain example embodiments, the Ti.sub.1-xSi.sub.xO.sub.y-based layer may be substoichiometric with respect to oxygen. In certain example embodiments of this invention, the layer may include Ti.sub.1-xSi.sub.xO.sub.y where x is from about 0.05 to 0.95 (more preferably from about 0.1 to 0.9, and even more preferably from about 0.2 to 0.8, and possibly from about 0.5 to 0.8) and y is from about 0.2 to 2 (more preferably from about 1 to 2, and even more preferably from about 1.5 to 2, and possibly from about 1.9 to 2). The layer may have an index of refraction of from about 1.6 to 1.9. The layer may also be used with a transparent conductive oxide in a transparent conductive coating.

Claims

1. A coated article comprising an antireflection coating, wherein the anti-reflection coating comprises: a first layer having a medium index of refraction and comprising Ti.sub.1-xSi.sub.xO.sub.y, where x is greater than or equal to 0.5 and less than 0.95, and having a thickness of from about 30 to 70 nm; wherein in said first layer having the medium index of refraction and comprising Ti.sub.1-xSi.sub.xO.sub.y, y is from 0.2 to 2; a second layer having a comparatively higher index of refraction and comprising an oxide of titanium, and having a thickness of from about 80 to 110 nm; a third layer having an index of refraction lower than both the first and second layers, and comprising an oxide of silicon, having a thickness of from about 70 to 100 nm; wherein the second layer having the comparatively higher index of refraction and comprising the oxide of titanium is thicker than the first layer having the medium index of refraction, and wherein the second layer having the comparatively higher index of refraction and comprising the oxide of titanium is thicker than the third layer comprising the oxide of silicon.

2. The coated article of claim 1, wherein said second layer is located over and directly contacting the first layer.

3. The coated article of claim 2, wherein the third layer is located over and directly contacting the second layer.

4. The coated article of claim 1, wherein the second layer comprises TiO.sub.2.

5. The coated article of claim 1, wherein the third layer comprises SiO.sub.2.

6. The coated article of claim 1, wherein the antireflection coating consists essentially of the first, second and third layers.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other features and advantages may be better and more completely understood by reference to the following detailed description of exemplary illustrative embodiments in conjunction with the drawings, of which:

(2) FIG. 1 is a cross sectional view of a sputtering target according to an example embodiment of this invention, being used in sputter-depositing a layer on a substrate.

(3) FIG. 2 is a graph illustrating optical properties (n and k) of Ti.sub.1-xSi.sub.xO.sub.2 thin film layers according to example embodiments of this invention (compared to TiO.sub.2 and SiO.sub.2 thin film layers).

(4) FIG. 3 is a graph illustrating refractive index (n) values at 550 nm of thin film Ti.sub.1-xSi.sub.xO.sub.2 layers, as a function of different x values, showing that the index value (n) of the resulting sputter-deposited layer can be adjusted or tailored by adjusting the Ti/Si ratio in the target (i.e., by adjusting x in the target).

(5) FIG. 4 is a graph illustrating optical properties (n and k) of thin film layers of Ti.sub.1-xSi.sub.xO.sub.2-yN.sub.y (where x=0.75) according to example embodiments of this invention, as a function of adjusting the oxygen and nitrogen gas flows used when sputtering the layer (at the different N.sub.2/O.sub.2 ratios of 0, 3 and 7); illustrating that the increase of nitrogen gas in the sputtering process results in an increased index of refraction (n) value and absorption due to the increase in silicon nitride and titanium nitride in the resulting thin film layer.

(6) FIG. 5 is a graph illustrating optical properties (n and k) of thin film layers of Ti.sub.1-xSi.sub.xO.sub.2-yN.sub.y (using a N.sub.2/O.sub.2 gas flow ratio of 0.48 during sputtering), with varying x values; the figure illustrate that decreasing x results in an increase in refractive index (n) values and absorption due to an increase in titanium oxide and titanium nitride in the thin film layer.

(7) FIG. 6 is a graph illustrating the reflection %, as a function of wavelength, of coated article including a 3-layered AR coating on both sides of a 5 mm thick float glass substrate (soda lime silica glass) (compared to reflection % of an uncoated 5 mm thick similar glass substrate), according to an example embodiment of this invention.

(8) FIG. 7 is a cross-sectional view generally of a coated article comprising an antireflective coating according to certain example embodiments of this invention.

(9) FIG. 8 is another cross-sectional view of a coated article comprising a more specific antireflective coating according to other example embodiments of this invention.

(10) FIG. 9 is a graph of reflection versus wavelength for a coated article according to certain example embodiments of this invention as compared to the reflection of a bare, uncoated glass substrate.

(11) FIG. 10 is a cross-sectional view of a coated article comprising a transparent conductive coating according to certain embodiments of this invention.

(12) FIG. 11 is a graph of transmission versus wavelength for a coated article comprising a layer made according to certain aspects of this invention, the layer being located underneath a transparent conductive oxide layer, as compared to a transparent conductive coating including only the transparent conductive oxide layer.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

(13) Performance of optical coatings such as low-E and/or antireflective (AR) coatings, especially multi-layered coatings for broadband applications, relies on precisely controlled layer thicknesses and optical properties (e.g., n and/or k) in each individual layer in the coating(s). Materials having unique properties, such as refractive index (n) and extinction coefficient (k), stress and adhesion to adjacent layers are chosen to optimize the coating performance with respect to reflection, color, durability, and/or the like. The target may be a rotating magnetron sputtering target in certain example embodiments although other types of target are also possible in other alternative embodiments. For example, a non-rotating target may be used instead and may be applicable to this invention. As an example, a drum coater may be designed in such a way that neither the target nor the drum holding the substrate rotates, but instead magnets in the target tube rotate.

(14) Certain example embodiments of this invention relate to optical coating fabricating using sputtering target(s) of or including Ti.sub.1-xSi.sub.xO.sub.y. Such targets can be fabricated into either planar or rotating magnetron targets in different example embodiments of this invention. The use of Ti.sub.1-xSi.sub.xO.sub.y as a target material permits sputtering targets to be made which can be used to sputter-deposit thin film layers with consistent and predictable optical properties (e.g., n and/or k), covering a large potential index of refraction (n) range and allowing excellent repeatability because the Ti/Si ratio in the target is pre-defined and fairly repeatable.

(15) The use of such sputtering targets is advantageous in that a large index (n) range from about 2.35 (x=0.05) to 1.6 (x=0.9) can be achieved in a dielectric oxide based thin film layer(s) without suffering significant absorption loss in the visible wavelength range. Moreover, another example advantage is that consistent optical properties (e.g., n and/or k of a resulting thin film) can be substantially predefined by setting x to a desired value during target fabrication. Yet another example advantage is that a high sputter-deposition rate can be achieved due to the partially oxidized phase (y less than 2.0) in the target. The target may be fully oxidized in other example embodiments, though. In certain example embodiments, aluminum may be added to the target in order to increase the conductivity of the target when the target comprises fully or near-fully oxidized silicon titanium oxide. Further, yet another example advantage is that improved adhesion to an optional adjacent metal layer(s) (e.g., an Ag layer, or a NiCr layer), metal oxide layer, metal nitride layer, or metal oxynitride layer, can be achieved due to the formation of a silicide (Ti and Si) at the layer interface(s).

(16) Certain example embodiments of this invention relate to a sputtering target of or including Ti.sub.1-xSi.sub.xO.sub.y and/or a method of making a coated article using such a sputtering target. In certain example embodiments, the target may be a rotatable magnetron sputtering target, a stationary planar target, or the like. In certain example embodiments, the Ti.sub.1-xSi.sub.xO.sub.y may be substoichiometric with respect to oxygen. In other example embodiments, it may be fully stoichiometric. In certain example embodiments of this invention, the target may be of or include Ti.sub.1-xSi.sub.xO.sub.y where x is from about 0.05 to 0.95 (more preferably from about 0.1 to 0.9, and even more preferably from about 0.2 to 0.8, and possibly from about 0.5 to 0.8) and y is from about 0.2 to 2 (more preferably from about 1 to 2, and even more preferably from about 1.5 to 2, and possibly from about 1.9 to 2). In certain example embodiments, y is greater than about 1.95 or 1.90. In other example embodiments, the target is doped with aluminum in order to achieve desired conductivity to facilitate DC, pulsed DC, or middle frequency (e.g., <200 kHz) AC magnetron sputtering. In certain example embodiments, y is at least 0.2 in order to maintain a desired deposition rate of the film during sputtering without a significant absorption loss in the visible range during reactive sputtering.

(17) The sputtering target may be sputtered in an atmosphere of or including one or more of Ar, Kr, He, O.sub.2 and/or N.sub.2 gas(es) in certain example embodiments of this invention. Other materials may be provided in the target in alternative example embodiments of this invention.

(18) Such a target may be used to permit layers with tunable indices of refraction (n) to be consistently achieved by sputter deposition. By adjusting the Ti and Si amounts in the target (e.g., the Ti/Si ratio in the target itself), layers of or including TiSiO.sub.x (e.g., where x is from about 1.5 to 2.0) can be formed by sputter-deposition and can achieve consist desired index values (n). For example, the more Si in the target, the lower the index of refraction (n) value of the resulting sputter-deposited layer. Likewise, the more Ti in the target (and thus the less Si), the higher the index of refraction (n) value of the resulting sputter-deposited layer. Thus, an improved technique is provided to consistently form sputter-deposited layers having an index of refraction (n) in the range of from about 1.6 to 2.35. In particular, a technique is provided that permits layers to be sputter-deposited in a manner that allows a desired refraction index (n) value in this range to be consistently achievable. While gas flows may be adjusted to alter or tailor the index (n) value of the resulting layer, another way to adjust the index (n) value of the resulting layer is to adjust the Ti/Si ratio in the target itself.

(19) The combination of Ti and Si in the target is advantageous in that Si and Ti form a suitable alloy. Since a ceramic target is used, including Ti and Si, the amounts of Ti and Si can be varied to allow the desired index (n) value to be obtained in the resulting layer. Moreover, the ceramic nature of the sputtering target is advantageous in that it permits higher sputtering rates to be achieved. The oxygen in the target is substoichiometric in certain example embodiments of this invention.

(20) Instead of Si, Al may be used to replace the Si in the target and the resulting sputter-deposited layer in certain example alternative embodiments of this invention. As another alternative, Al may be added to Ti.sub.1-xSi.sub.xO.sub.y targets as an additional material in certain example alternative embodiments of this invention. Adding Al to the target may allow the target to be more fully oxidized, which may result in a better or faster sputter rate without compromising the conductivity of the target. Other materials such as Zr, V, Hf, Nb, Ce, Sb, Bi, Zn, Sn and Mg may be used instead of Al in each of these respects in still further example embodiments of this invention. Moreover, as will be appreciated, nitrogen gas may also be used in the sputtering process in order to enhance absorption in both the UV and the visible ranges if desired. The addition of one or more of these elements may be used to improve durability, UV absorption, and/or adhesion to adjacent layer(s) in different example embodiments of this invention. In certain example embodiments, it is possible to add extra element(s) to achieved desired properties such as adhesion, stress and/or UV absorption without significantly adversely affecting the desired optical index value through adjustment of the Ti/Si ratio for instance. For example, adding Sb may increase not only UV absorption, but also index. The index may be brought back to a desired value by adding extra Si if desired.

(21) FIG. 1 is a cross sectional view of a sputtering target according to an example embodiment of this invention, being used in sputter-depositing a thin film layer on a substrate according to an example embodiment of this invention. The rotatable magnetron sputtering target shown in FIG. 1 includes a cathode tube within which is a stationary magnet bar array. The cathode tube is often made of stainless steel or some other conductive material. The target material (Ti.sub.1-xSi.sub.xO.sub.y in the FIG. 1 embodiment) is formed on the cathode tube by spraying, casting or pressing it onto the outer surface of the stainless steel cathode tube (optionally, a backing layer, which may be conductive, may be provided between the cathode tube and the target material layer). Each sputtering chamber in a sputtering apparatus includes one or more targets, and thus includes one or more of these cathode tubes. Different targets are used to sputter-deposit different layers of a multi-layer low-E or AR coating. For cylindrical rotatable magnetron sputtering targets, the cathode tube(s) may be held at a negative potential (e.g., 200 to 1500 V), and may be sputtered when rotating. When a target is rotating for example, due to the negative biased potential on the target, ions from the sputtering gas (e.g., argon, oxygen and/or nitrogen) discharge are accelerated into the target and dislodge, or sputter off, atoms of the target material. These atoms, in turn, together with the gas form the appropriate compound (e.g., TiSiO.sub.x) that is directed to the substrate in order to form a thin film or layer of the same (e.g., TiSiO.sub.x thin film shown in FIG. 1, where x may be about 2 in certain example instances, or may be slightly less than 2 in other example instances) on the substrate. The substrate may be a glass substrate as shown in FIG. 1 in certain example embodiments of this invention.

(22) Sputter-deposited thin films of TiSiO.sub.x may be any suitable thickness in certain example embodiments of this invention. However, in certain example embodiments of this invention, the TiSiOx thin films may be sputter-deposited to a thickness on the substrate of from about 10 angstroms to 2.5 m, more preferably from about 10 to 900 angstroms (), more preferably from about 50 to 800 angstroms, and most preferably from about 100 to 600 angstroms. Coated articles according to this invention may be used for any suitable purpose, but windows, fireplace glass, furniture table tops and the like are particularly preferred. In certain example embodiments of this invention, windows having coatings according to certain example embodiments of this invention may have a visible transmission of at least about 50%, more preferably of at least about 60%. Moreover, the sputter-deposited TiSiOx thin films are substantially transparent according to certain example embodiments of this invention.

(23) FIG. 2 is a graph illustrating optical properties (n and k) of Ti.sub.1-xSi.sub.xO.sub.2 thin film layers according to example embodiments of this invention (compared to TiO.sub.2 and SiO.sub.2 thin film layers). FIG. 2 illustrates that Ti.sub.1-xSi.sub.xO.sub.2 inclusive thin film layers made on a substrate (directly or indirectly on the substrate in different instances) have index of refraction (n) values between those of TiO.sub.2 and SiO.sub.2 thin film layers due to the presence of both titanium oxide and silicon oxide in the Ti.sub.1-xSi.sub.xO.sub.2 inclusive thin film layers. FIG. 3 is a graph illustrating that the refractive index (n) value of thin film Ti.sub.1-xSi.sub.xO.sub.2 layers can be varied as a function of different x values (i.e., changing the Ti/Si ratio in the target and thus in the sputter-deposited layer). In particular, FIG. 3 illustrates that the refractive index (n) value can be varied from about 1.6 to 2.35 in certain example embodiments of this invention, and can be varied from about 1.6 to about 1.9 in certain preferred example embodiments, as x is changed in the target.

(24) In certain example embodiments of this invention, the gas used in the sputtering chamber where the Ti.sub.1-xSi.sub.xO.sub.y target is present may be a mixture of argon (Ar) and oxygen (O.sub.2) gases. This results in a sputter-deposited thin film layer of Ti.sub.1-xSi.sub.xO.sup.2 (if sufficient oxygen gas is used) on the glass substrate. However, it is possible to use other gas(es) as well. For example, a mixture of argon (Ar), oxygen (O.sub.2) and nitrogen (N.sub.2) gases may be used in the sputtering chamber in certain example embodiments of this invention. Different amounts of oxygen and nitrogen gases may be used in different example embodiments. It is also possible to use a mixture of Ar and N gas in the sputtering chamber(s) when sputtering the Ti.sub.1-xSi.sub.xO.sub.y target. It is also possible to use only argon, or only nitrogen gas in the sputtering chamber(s) when sputtering the Ti.sub.1-xSi.sub.xO.sub.y target. Other gases that can be used include He and/or Kr, for example. FIG. 4 is a graph illustrating optical properties (n and k) of thin film layers of Ti.sub.1-xSi.sub.xO.sub.2-yN.sub.y (where x=0.75) according to example embodiments of this invention, as a function of adjusting the oxygen and nitrogen gas flows in the sputtering chamber when sputtering the Ti.sub.1-xSi.sub.xO.sub.y target to form a layer of TiSiON. In FIG. 4, n and k of the resulting sputter-deposited layer are illustrated for different N.sub.2/O.sub.2 gas flow ratios of 0, 3 and 7, illustrating that an increase of nitrogen gas (and thus a reduction in oxygen gas in the sputtering chamber) in the sputtering process results in an increased index of refraction (n) value and absorption due to the increase in silicon nitride and titanium nitride in the resulting thin film layer. Accordingly, as the amount of nitrogen gas decreases (and thus oxygen gas amounts increase in the sputtering chamber), the refractive index (n) and absorption coefficient (k) of the layer decreases due to more titanium oxide and silicon oxide in the resulting layer.

(25) FIG. 5 is a graph illustrating optical properties (n and k) of thin film layers of Ti.sub.1-xSi.sub.xO.sub.2-yN.sub.y (using a N.sub.2/O.sub.2 gas flow ratio of 0.48 in the sputtering chamber where the Ti.sub.1-xSi.sub.xO.sub.y target is located), with varying x values. FIG. 5 illustrates that decreasing x (i.e., reducing the amount of Si compared to Ti in the target and thus in the sputter-deposited layer) results in an increase in refractive index (n) values and absorption of the resulting layer due to an increase in titanium oxide and titanium nitride in the sputter-deposited thin film layer on the substrate. It is noted that instead of, or in addition to, adding nitrogen gas to the sputtering chamber during the sputtering of the Ti.sub.1-xSi.sub.xO.sub.y target, other metallic element(s) can be added to the target to modify the thin film properties. Using metallic elements in the target tends to result in thin film properties that are more predictable and repeatable.

(26) FIG. 6 is a graph illustrating the reflection %, as a function of wavelength, of coated article including a 3-layered AR coating on both sides of a 5 mm thick float glass substrate (soda lime silica glass); compared to reflection % of an uncoated 5 mm thick similar glass substrate. Each of the two AR coatings on the glass substrate were made up of, from the glass substrate outwardly, a 653 angstrom thick base layer of Ti.sub.0.28Si.sub.0.72O.sub.2, then a 959 angstrom thick layer of Ti.sub.0.80Si.sub.0.20O.sub.2, and then on top furthest from the glass substrate a 885 angstrom thick layer of SiO.sub.2. Thus, the refractive index of the silicon oxide layer on top was the lowest, and that of the middle layer the highest. The refractive indices of the layers were 1.79, 2.25, and 1.46 for x=0.72, 0.20 and 1.00, respectively. Moreover, this AR coating improved adhesion among the different layers of the coating, and had a wide process window.

(27) In certain example embodiments, the targets described herein and/or other targets may be used to form a medium index layer comprising Ti.sub.x-1Si.sub.xO.sub.y. The medium index layer may be a part of a three-layered AR coating as shown in FIG. 7, in certain example embodiments. The Ti.sub.x-1Si.sub.xO.sub.y-based medium index layer 5 may or may not be produced by sputtering from a Ti.sub.x-1Si.sub.xO.sub.y-based target, according to different embodiments.

(28) A three-layer AR coating including a medium index layer 5 based on Ti.sub.x-1Si.sub.xO.sub.y may be used to replace a single oxynitride-based layer and/or a bi-layer comprising TiOx/SiOx in some instances. In certain example embodiments, when an AR coating consists of a single oxynitride-based layer, the ratio of reactive gases O.sub.2 to N.sub.2 gas may need to be strictly controlled. Further, in other embodiments, when an AR coating consists of a bi-layer TiOx/SiOx film, the thickness of each layer may need to be precisely controlled during deposition. A three-layer AR coating including a medium index layer 5 based on Ti.sub.x-1Si.sub.xO.sub.y may be advantageous in certain example embodiments in that the environment in which it is formed does not necessarily have to be as strictly controlled, and also in that precise thickness control of each layer is not required to the same extent.

(29) In certain example embodiments, the ratio of Si to Ti in layer 5 may impact its refractive index. In some instances, increasing the amount of Si in layer 5 will reduce the refractive index of the layer. However, in certain example embodiments, the silicon oxide in the Ti.sub.x-1Si.sub.xO.sub.y based target may have a higher sputter yield than titanium oxide and/or Ti. Therefore, there may be more Si than Ti in the layer, even if the target had approximately equal amounts of Si and Ti (atomically) in the target. In other words, in certain instances, the ratio of Si to Ti (atomically) in the final layer may be greater than the ratio of Si to Ti in the target.

(30) FIG. 7 shows an example embodiment of an antireflection coating on a glass substrate, comprising medium index layer 5, high index layer 7, and low index layer 9. In certain example embodiments, layer 5 comprises Ti.sub.x-1Si.sub.xO.sub.y, where x is from about 0.05 to 0.95 and y is from about 0.2 to 2, more preferably where x is from about 0.1 to 0.9, and y is from about 1 to 2, and most preferably where x is from about 0.2 to 0.8, and y is from about 1.5 to 2. In other example embodiments, x may be at least about 0.5, or greater than about 0.5. In embodiments where x is greater than or equal to 0.5, the layer may be sputtered by a target comprising more Si than Ti (e.g., atomically). In further example embodiments, x may be greater than or equal to 0.5 even when the target does not comprise more Si than Ti (e.g., atomically).

(31) In other example embodiments, particularly when the target includes Al, Ti.sub.x-1Si.sub.xO.sub.y-based layer 5 may further include Al and/or an alloy thereof. In further example embodiments, the Si may be replaced entirely by Al and/or an alloy thereof.

(32) In other example embodiments, Zn, Sn, In, alloys thereof (particularly Ti-based alloys), and/or oxides thereof may be used to replace Ti in Ti.sub.x-1Si.sub.xO.sub.y-based layer 5. Such a replacement may increase the refractive index of the layer in certain example embodiments.

(33) An exemplary embodiment of an AR coating comprising layer 5 as the medium index layer is shown in FIG. 8. A glass substrate is provided. In certain example embodiments, the substrate may be soda lime glass. In other example embodiments, the substrate may be of a different type of glass and/or different type of material. Layer 5 may be sputter deposited from a target as described herein in certain example embodiments. In certain example embodiments, the refractive index of layer 5 may be controlled by the ratio of Si to Ti in the sputtering target. The sputtering target may be ceramic and/or metallic according to different example embodiments.

(34) In certain example embodiments, the refractive index of layer 5 may be from about 1.5 to 2.0, more preferably from about 1.6 to 1.9, and most preferably from about 1.65 to 1.85. In order to achieve a refractive index is one of the aforesaid ranges, the target material may comprise more Si than Ti (atomically and/or by weight). In certain example embodiments, the ratio of Si to Ti in the target may be from about 10:1 to 3:2 (1.5 to 10 times as much Si as Ti), more preferably from about 9:2 to 3:2 (1.5 to 4.5 times as much Si as Ti), and most preferably from about 3:1 to 2:1 (2 to 3 times as much Si as Ti); with an example ratio of Si to Ti in the target being about 7:3 (2.33 times as much Si as Ti). These example ratios are example atomic percentage ratios. In certain example embodiments, during the deposition of layer 5, O.sub.2 may be used as the reactive gas. In certain example embodiments, O.sub.2 is the only reactive gas used. This may be advantageous in certain example instances in that there may be reduced concern about the index uniformity of the layer across a large area and/or consistency during a long period of production. In certain example embodiments, the ratio of Si to Ti in the layer may be different than the ratio of Si to Ti in the target. In certain example embodiments, the ratio of Si to Ti in the layer may be higher than the ratio of Si to Ti in the target (e.g., atomically and/or by weight).

(35) Layer 5 may have a thickness of from about 20 to 80 nm, more preferably from about 30 to 70 nm, and most preferably from about 40 to 60 nm, with an example ideal thickness being about 50 nm. In certain example embodiments, layer 5 may have a smaller thickness than both of layers 7 and 9.

(36) Layer 7 may be a high index layer in certain example embodiments. In certain examples, layer 7 may be of or include a metal oxide such as, for example, titanium oxide. Layer 7 may be stoichiometric or substoichiometric according to different example embodiments. Layer 7 may have a refractive index of from about 2.0 to 2.6, more preferably from about 2.1 to 2.4. In certain example embodiments, layer 7 may have a thickness of from about 50 to 150 nm, more preferably from about 75 to 125 nm, and most preferably from about 80 to 110 nm, with an example ideal thickness being about 95 nm.

(37) Layer 9 may be a comparatively low index layer in certain example embodiments. The refractive index of layer 9 may be lower than that of both layers 5 and 7 in certain example embodiments. In certain examples, layer 9 may be of or include a metal oxide, a metal nitride, or a metal oxynitride. For instance, in certain example embodiments, layer 9 may be of or include silicon oxide. Layer 9 may be stoichiometric or sub-stoichiometric according to different example embodiments. Layer 9 may have a refractive index of from about 1.3 to 1.6, more preferably from about 1.4 to 1.6. In certain example embodiments, layer 9 may have a thickness of from about 40 to 140 nm, more preferably from about 65 to 115 nm, and most preferably from about 70 to 100 nm, with an example ideal thickness being about 85 nm.

(38) FIG. 9 is a graph of reflection versus wavelength at the surface of a bare soda lime glass substrate and the reflection of a glass substrate with the 3 layer AR coating described above on its first surface. FIG. 9 shows that the reflection is significantly reduced (as compared to an uncoated glass substrate) through the use of a 3 layered AR coating comprising a medium index layer based on Ti.sub.1-xSi.sub.xO.sub.y. In certain example instances, the reflection is reduced from about 8% in the visible spectrum to about 4% in the visible spectrum. In certain example embodiments, reflection is reduced to less than 8%, more preferably less than 6%, still more preferably less than 5%, and sometimes even to about 4% or even lower, e.g., in the visible spectrum.

(39) In certain example embodiments, medium index layer 5 may be suitable as an AR coating for wavelengths from visible to near, short-wave, and/or mid-wave IR (e.g., to approximately 5,000 nm). Advantageously, certain example embodiments may result in 3-layer AR coating with reduced absorption, e.g., in wavelengths ranging from visible up to and including the mid-IR or any sub-range therein.

(40) In another example of an AR coating incorporating medium index layer 5, layer 5 was of Ti.sub.1-xSi.sub.xO.sub.y, and had a refractive index of 1.75 and a thickness of approximately 107 nm, layer 7 was of TiO.sub.x and had a thickness of approximately 16 nm, and layer 9 was of SiO.sub.x and had a thickness of approximately 113 nm.

(41) In a further example embodiment of an AR coating incorporating medium index layer 5, layer 5 was of Ti.sub.1-xSi.sub.xO.sub.y, and had a refractive index of 1.75 and a thickness of approximately 74 nm, layer 7 was of TiO.sub.x and had a thickness of approximately 104 nm, and layer 9 was of SiO.sub.x and had a thickness of approximately 92 nm. Therefore, though preferred thickness ranges are discussed above, there are many suitable thicknesses that will result in a desirable 3-layer AR coating.

(42) FIG. 10 illustrates a different example application of a layer based on Ti.sub.1-xSi.sub.xO.sub.y. In certain example embodiments, layer 5 may be deposited underneath a transparent conductive oxide layer to be part of a transparent conductive coating. FIG. 10 shows a glass substrate, Ti.sub.1-xSi.sub.xO.sub.y-based layer 5, with TCO layer 11 formed over layer 5.

(43) An example TCO/TCC coating can be found in U.S. Publication No. 2010/0040892, which is hereby incorporated by reference.

(44) In certain example embodiments, when used with a TCO layer in a transparent conductive coating, layer 5 may have a thickness of from about 40 to 100 nm, more preferably from about 50 to 90 nm, and most preferably from about 60 to 80 nm. TCO layer 11 may have a thickness of from about 100 to 500 nm, more preferably from about 200 to 400 nm, and most preferably from about 250 to 350 nm, in certain embodiments.

(45) The refractive index of layer 5 when used with a TCO layer in a TCC may be from about 1.55 to 1.9, more preferably from about 1.6 to 1.75, and most preferably from about 1.65 to 1.7, with an example refractive index being 1.68, in certain example embodiments. Layer 5 may be substoichiometric with respect to oxygen in certain example embodiments so as to have a reduced effect on the conductivity of the overall coating.

(46) FIG. 11 is a graph of transmission versus wavelength for a transparent conductive coating with and without a layer based on titanium silicon oxide located between a TCO layer and the glass substrate. It can be seen from FIG. 11 that the transmission increases when layer 5 is included in the TCC in the 400-500 nm wavelength range, and again in the wavelength range of from about 600 to 800 nm. Therefore, when increased transmission in those ranges is desired, a TCC including a layer comprising Ti.sub.1-xSi.sub.xO.sub.y, made according to the methods described herein, may be advantageous in certain example embodiments. As can be seen from the FIG. 11 graph, the transmission is roughly the same with and without the SiTiOx layer having an index of refraction of 1.68, for example, at least in the visible spectrum.

(47) While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.