Antireflective glazing

Abstract

The present invention relates to a coated article comprising a substrate and an antireflective stack on at least one main surface, the antireflective stack being a succession of high refractive index layers (hn) and low refractive index layers (ln), the antireflective stack is characterized in that at least one high refractive index layer (hn) is a silicon nitride layer doped with zirconium.

Description

Antireflective glazingTechnical Field

[0001] This invention relates to a highly transparent coated substrate. The high visible light transmittance is obtained thanks to an antireflective coating. An antireflective coating can be done with a succession of high and low refractive index layers. The coated substrate may be coated with the same antireflective stack on one side or on both sides to increase the light transmittance of the glazing. Such a glazing is particularly useful in any application requesting a good viewing through the substrate, as for examples in museum, shop, showcase, windshield...Prior Art

[0002] Antireflective glazing is well known for a long time and lot of examples exist for applications as electronics, lighting, appliances, architectural, automotive and display. They are generally made through deposition of layers alternating high and low refractive index. Antireflective glazing must fulfil criteria such as aesthetic (in particular colors in reflection and transmission, the market generally requesting a color as neutral as possible) and durability, but they also must be heat treatable, which means that they can be heat treated without impacting optical properties in a too large extend.

[0003] For example, EP3085673A1 discloses TiCh I SiCh sequence that may be repeated. For chemical durability, the stack is covered by a SiCh I SiZrOx top film deposited on the last TiCh layer.

[0004] W02001037006A1 discloses an antireflective coating comprising 4 layers consisting of hn / In / hn / In, where hn is a high refractive material (1.8-2.2) and In is a low refractive material (1.35-1.65). The purpose of this disclosure is to ensure antireflective effect at large viewing angles with a good aesthetic. This is done by increasing the last dielectric thickness and the hn layers have a lower refractive index than titanium dioxide (up to 2.2), as SnCh or SiN. SiN is a better choice for the heat treatability.

[0005] US20070188871 A1 discloses an antireflective stack comprising SiZrN as a high refractive layer but the invention is more concerned with the impact of the stack on the appearance related to different viewing angle.

[0006] The layers of the antireflective coating may be deposited with different techniques like PVD, CVD, PECVD, wet chemistry, and others amongst which PVD is often preferred. Most of the time, the low refractive index layer is a silicon oxide layer. Silicon oxide has huge advantage in terms of durability and optic impact but has the main disadvantage of having a very low deposition rate when using a PVD process. Such a low deposition rate creates a bottleneck for production and has also important cost impacts. A possible solution to the deposition low speed would be to have another deposition process. For example, W02012160145A1 discloses how PECVD can improve the deposition of different materials and namely SiCh. Using high energetical plasma, PECVD often operates at lower temperature than CVD. It allows to deposit a lot of different materials, like SiC>2, at higher speed. In the case of SiC>2, W02012160145A1 also explains that using hydrocarbon precursors like (for example) tetramethyldisiloxane (TMDSO) increases impurities, as carbon, in the final SiCh layer.

[0007] For the high refractive index layer, titanium oxide is often chosen.Nevertheless, when a stack including titanium oxide is heat treated, the structure of the titanium oxide is impacted through modifications in its crystal structure. This can impact the optical properties and should be avoided. Silicon nitride is a potential interest candidate, but its refractive index is quite low. To increase the refractive index of SiN, a possibility is to dope it with another metal as for example Al, Ti, Nb, Ta, Zr or Hf, but this is also known that adding such metal will also increase the absorption coefficient, which should be avoided when the final product must have a very high visible light transmittance.

[0008] As can be understood from the discussion above, a new type of antireflective stack that allows to improve the productivity, that allows a good aesthetic and durability, and which is heat treatable is still to be find.Object of the invention

[0009] The object of the invention is a coated article with high antireflective properties and a good aesthetic together with a good durability and that is heat treatable. Moreover, the new antireflective stack is obtained with a higher deposition rate and lower costs.Summary of invention

[0010] It is known that when the silicon nitride is doped with a metal, it can have a higher refractive index, but the absorbance may be affected. The inventors have now found that it was possible to increase the refractive index of SiN without impacting too much the absorption coefficient by the appropriate choice of the doping metal and the appropriate choice of its proportion. Another point is that the doped silicon nitride layer needs to be fully nitrided because residual metallic zirconium results in a high absorption with a very low light transmission and bad colour in transmission. The inventors have thus found that it was possible to build an antireflective stack with a doped silicon nitride high refractive layer resulting in a single side coated article characterized by a high visible light transmittance above 91% and a low reflectance below 6%. Therefore to keep a high transmission, the coated article of the invention does not contain any metallic layer, as for example a silver layer, that would be responsible for a decrease of light transmission.

[0011] The current antireflective Clearsight (AGC trademark) has the following structure: GL / TZO (12 nm) / SiAIO2(28 nm) / TZO (120 nm) / (Si(AI)O2 / SiZrOx) (86 nm). The resulting light transmittance is greater than 90% and the reflectance is lower than 6% when one side of the glass substrate is coated with the antireflective stack.

[0012] The inventors have now found that using SiZrN instead of TZO does not impact in a too large extend the reflection nor the light transmission of the stack. Some more absorption is observed but the appropriate choice of Zr ratio, the full nitration and the SiZrN thickness, will result in a negligeable impact on light absorption. The inventors have thus investigated the possibility of using the following stack: GL I SiZrN or TZO I SiO21 SiZrN I SiO2 / SiZrOx, assuming that the deposition technique could be CVD, PVD or PECVD for oneor another layer. Using the PECVD process would be an advantage for the productivity point of view.

[0013] Some samples have been prepared with a glass substrate and a single layer to see how some properties are impacted when the SiN layer is doped (table 1 ). The ratio of Zr and Hf in the layer of doped SiN are mass ratios based on the total amount of metal or semimetal in the layer (Si and doping metals). The n and k parameters respectively are the refractive index and the absorption coefficient given at 550 nm for the hn material. Those values have been obtained from the sample by simulation.

[0014] Table 1

[0015] Based on the values found above in the table 1 (n and k), some simulations have been done on the complete Clearsight stack incorporating the different materials which replace the hn layer. To evaluate the impact of the different materials, the resulting DTrand DRc values have been simulated and reported in the table 1. DTr is the difference of light transmittance and DRc is the difference of light reflectance on the coated side, both regarding the complete antireflective stack versus the original stack with TZO as high refractive index layers. Both DTr and DRc values show the impact of the dopant element(s) in the SiN layer.

[0016] On top of the low values for DTr and DRc, the modified stacks of the table above with doped SiN, show very little modifications in the colours in reflection and transmission. Nevertheless, a slight increase of the b* in transmission has been observed and results in a slight yellow colour. Replacing only the thicker TZO through SiZrN (instead of both TZO) does not improve the colour intransmission. Anyway, as shown in the examples, nor the transmittance or reflectance are impacted in a too large extend and the colour is acceptable.

[0017] The deposition rate by PVD of the SiZrN layer is more than 3 times higher than the deposition rate of TZO. In another advantageous embodiment of this invention, SiZrN may be deposited through a PECVD process which would still increase the deposition rate.

[0018] The claim 1 describes the invention in its most practical and preferred embodiment and depending claims cover various modifications and equivalent embodiments and are by no way a limitation of the invention.

[0019] The invention covers a coated article comprising a substrate and an antireflective stack on at least one main surface, the antireflective stack being a succession of high refractive index layers (hn) and low refractive index layers (In), the antireflective stack is characterized in that at least one high refractive index layer is a silicon nitride layer doped with zirconium and is fully nitrided, the ratio of zirconium related to the total of silicium and zirconium amount is comprised between 15 and 65 mass%, preferably between 20 and 45 mass%. More particularly, the Si / Zr ratio is 60 / 40 (weight %)

[0020] According to a preferred embodiment, the antireflective stack comprises outwardly from the substrate a first high refractive index layer (hn1), a first low refractive index layer (In1), a second high refractive index layer (hn2), a second low refractive index layer (In2).

[0021] According to a preferred embodiment, the coated article of the invention comprises outwardly from the substrate a first high refractive index layer (hn1 ), a first low refractive index layer (In1) above and contacting the first high refractive index layer (hn1), a second high refractive index layer (hn2) above and contacting the first low refractive index layer (In1), a second low refractive index layer (In2) above and contacting the second high refractive index layer (hn2).

[0022] According to a more preferred embodiment, the antireflective stack comprises outwardly from the substrate a first high refractive index layer (hn1), a first low refractive index layer (In1), a second high refractive index layer (hn2), a second low refractive index layer (In2). The first high refractive index (hn1) is contacting the substrate.

[0023] According to a preferred embodiment, the antireflective stack comprises a top protecting layer deposited above the antireflective stack.

[0024] According to a preferred embodiment, the top protecting layer above the antireflective stack is a silicon oxide layer doped with zirconium, SiZrOx. The top protecting layer improves the durability. The silicon oxide layer doped with zirconium is such that the zirconium is present in a mass ratio of 35 % regarding the total amount of Si and Zr.

[0025] According to a preferred embodiment of the invention, each low refractive index layer is a silicon oxide-based layer.

[0026] According to a preferred embodiment of the invention, each high refractive index layer (hn1 , hn2) is a titanium oxide based layer or a silicon nitride based layer doped with zirconium.

[0027] The low refractive index silicon oxide layer may be doped with a metal as for example aluminium. When the silicon oxide-based layer is doped with aluminium, the aluminium is present in a molar ratio from 1 to 20 % regarding the total amount of Si and Al.

[0028] According to an embodiment of the invention, the coated article of claim 1 comprises no metallic layer, more particularly no silver layer.

[0029] According to an embodiment of the invention, the first high refractive index layer (hn1) has a thickness comprised between 7 and 15 nm, preferably between 9 and 13 nm.

[0030] According to an embodiment of the invention, the first low refractive index layer (In1) has a thickness comprised between 20 and 50 nm, preferably between 25 and 40 nm.

[0031] According to an embodiment of the invention, the second high refractive index layer (hn2) has a thickness comprised between 90 and 150 nm, preferably between 100 and 140 nm.

[0032] According to an embodiment of the invention, the second low refractive index layer (In2) has a thickness comprised between 55 and 85 nm, preferably between 65 and 75 nm.

[0033] According to an embodiment of the invention, the top protecting layer SiZrOx has a thickness comprised between 10 and 50 nm, preferably between 15 and

[0034] According to an embodiment of the invention, the second low refractive index In2 together with a SiZrOx top protecting layer have a thickness comprised between 70 and 110 nm, preferably between 80 and 100 nm.

[0035] The table 2 gives the preferred thickness ranges for the different layers of the invention, given outwardly from the substrate.

[0036] Table 2

[0037] The substrate may be any type of glass, preferably the substrate is a soda lime silicate float glass. Preferably the glass thickness is comprised between 1 and 12 mm, more preferably between 2 to 6 mm.

[0038] According to a particular embodiment of the invention, the antireflective stack is deposited on a single side of the glass substrate.

[0039] According to a particular embodiment of the invention, the antireflective stack is deposited on both side of the glass substrate.

[0040] According to a particular embodiment of the invention, the layers of the antireflective stack are deposited through PVD and I or PECVD process. This means that some layer(s) of the stack may be deposited through a PVD process, and some layer(s) of the stack may be deposited through a PECVD process.

[0041] According to a particular embodiment of the invention, some layer(s) of another antireflective stack is I are deposited through a CVD process on the air side of the glass substrate during the glass manufacturing process. In this case, the first high refractive index layer is TiCh and has a thickness comprised between 6 and 9 nm, the first low refractive index layer In1 is silicon oxide and has a thickness comprised between 25 and 35 nm and the second high refractive index layer is SnO2 and has a thickness comprised between 80 and 90 nm. Those 3 first layers are deposited through a CVD process. The last low refractive index layer, as well as the top protecting layer are deposited througha PVD, a CVD or a PECVD process and have together a thickness comprised between 80 and 95 nm. The antireflective stack of the invention is further deposited on the tin side of the glass substrate to build a two sides coated glass.

[0042] According to another embodiment of the invention, another antireflective stack deposited through a CVD process includes a transparent conductive oxide as a second high refractive index layer. In this case, the first high refractive index layer deposited on the air side of the glass substrate is TiCh and has a thickness comprised between 6 and 9 nm, the first low refractive index layer In1 is silicon oxide and has a thickness comprised between 25 and 35 nm and the second high refractive index layer is a doped SnCh layer and has a thickness comprised between 320 and 470 nm. For this second CVD embodiment (with a TCO), the SnCh is advantageously doped with fluor or antimony. The last low refractive index layer, as well as the top protecting layer are deposited through a PVD, a CVD or a PECVD process and have together a thickness comprised between 80 and 95 nm.

[0043] According to a particular embodiment, the antireflective stack made by CVD may have a top protecting layer which is also deposited by CVD and which is a silica layer doped with tin.

[0044] Advantageously, the coated article of the invention may be used as glazing for architectural or automotive applications, it can also be useful for appliance, cover sheet, or any other application where a high transparency and a low reflectance is requested.

[0045] Chemical and mechanical durability tests show that the antireflective article of the invention has a durability comparable to the one of the current antireflective stack sold under the trade name “Clearsight” and having the following structure: GL I TZO (12 nm) I SiAICh (28 nm) I TZO (120 nm) I SiCh + SiZrOx (86 nm).Brief description of drawings

[0046] This and other aspects of the present invention will now be described with reference to details discussed below. The following description and drawings are illustrative of the disclosure and are not to be construed as limiting thedisclosure. The drawings are not to scale and should not be considered as a limitation of the invention.

[0047] The Fig.1 illustrates a coated article of the invention.

[0048] The fig.2 illustrates a particular embodiment of the coated article of the invention incorporating a top protecting layer deposited above the antireflective stack of the invention.

[0049] The fig.3 illustrates a particular embodiment of the coated article of the invention wherein an antireflective stack is deposited on both sides of a substrate.

[0050] The fig.4 illustrates a particular embodiment of the invention wherein the air side of a glass substrate is coated with an antireflective stack, partially deposited by CVD.Description

[0051] Definitions- As used herein, the term comprising or comprise, are to be construed as being inclusive and open ended, and not exclusive. Specifically, when used in the specification and claims, the terms "comprise" and "comprising" and variations thereof mean the specified features, steps or components are included. These terms are not to be interpreted to exclude the presence of other features, steps or components.- For the sake of clarity, when using terms like “under”, "below", "above", "lower", "upper", “upon”, "first" or "last" herein, it is always in the context of a sequence of layers starting from the glass below, going upward, further away from the glass. Such sequences may comprise additional intermediate layers, in between the defined layers, if nothing else is specified.- Unless otherwise defined, all technical and scientific terms used herein are intended to have the same meaning as commonly understood to one of ordinary skill in the art.- Without any specification, speaking about thickness means geometrical thickness.- By main surface of the substrate, we mean one of the two larger surfaces of the substrate. For example, a glass substrate has two main surfaces and small perpendicular surfaces at the edges of the substrate. One of the main surfaces of a glass substrate is called the air side surface and correspond to the upward surface during the manufacturing process of glass. On the opposite, the tin side is the surface contacting the tin bath during the manufacturing process.- By antireflective stack, we hereby mean a stack of thin layers from which a very low reflectance is resulting, more particularly the low reflectance is below 6%. The antireflective stack of the invention does not contain any metallic layer.- Speaking about the SiZrN layer, by fully nitride, we hereby mean that all zirconium is in a nitride form. This is obvious that some unavoidable metallic zirconium traces are possible. One must understand that those traces are as low as possible.- By titanium oxide based layer we hereby mean a layer that contains at least 55 wt.% of TiO2 whatever the rest may be.- The substrate may be any kind of transparent material but more particularly, the substrate is glass and in a preferred manner, the substrate is a soda lime silicate float glass.

[0052] Symbol and acronyms meaning

[0053] The refractive index (n) and absorption coefficient (k) values are obtained from the simulations after Ultrascan measurements in a known manner for the skilled person. Both values are given for a wavelength of the light equal to 550 nm.

[0054] When speaking about heat treatment, it consists in particular of heating the glass sheet to a temperature higher than 560° C in air, e.g., between 560°C and 700°C, and in particular around 640°C to 680°C, for a period of about 3, 4, 6, 8, 10, 12 or even 15 m inutes, depending on the type of treatment and the thickness of the sheet. In the case of a bending treatment, the glass sheet may then be bent to the desired shape. The toughening treatment consists of abruptly cooling the surface of the flat or bent glass sheet by air jets or cooling fluid to obtain a mechanical reinforcement of the sheet.

[0055] By tempering vector, we hereby mean the difference in optical parameters before and after heat treatment.

[0056] The optical characteristics are measured in accordance with the norm EN410 (2011) and colour parameters are given in accordance with international colour system CIELAB.

[0057] The chemical durability is assessed in accordance with the norm EN 1096-2 (2012):The climatic chamber (annex B) test is performed on a 21 day basis. The test results are given on a scale from 1 to 5 (5 being the best, 3 being acceptable but limit).

[0058] The Cleveland test (Clev) is a test where there is a continual water condensation on the coating thanks to a water heating at 55°C-60°C (corresponding to vapor temperature of 50C°-55°C). Results are given on a scale from 0 to 5 (5 being the best, 3 being acceptable but limit)

[0059] The neutral salt spray test (NSST): The samples are placed in a humidity chamber with a solution saturated with NaCI sprayed at 35°C (EN 1096-2 (2012); annex D).

[0060] pH 13 test: A tray is filled with the prepared solution in order to immerse half size of 100x100 mm2samples. The samples are held in the solution by a rack and are immersed in the solution for 48 hours. After 48 hours, the samples are rinsed and dried with blowing air and evaluated.

[0061] For all chemical durability test, results are given on a scale from 1 to 5, 5 being the best.Description of embodiments / examples

[0062] The invention will be illustrated by some examples but one must understand that those examples, given for illustrative purpose, are by no way limiting the scope of the invention. Deposition technics like CVD, PVD or PECVD are very well known by the skilled person and will not be detailed to a too large extend to avoid useless information.

[0063] For the examples, the substrate is a soda lime silicate float glass characterized by a thickness of 4 mm. The raw glass without the antireflective stack has a transmittance of 90 % and a reflectance of 8 %.

[0064] In the table 3 below, a single layer SiZrN is prepared in different deposition conditions. A SiZr metallic target with a weight % composition of Si / Zr: 60 / 40 has been used for making the lab sample described below. The first example (ref.6) is made from a SiAl target without another doping element and the resulting layer is SiAIN. The PVD process is performed under an atmosphere with argon and nitrogen. The samples are coated with a single Si(Zr)N layer with a thickness comprised between 68 and 88 nm. The values given in the table 3 thus concern a single hn layer.

[0065] Table 3

[0066] From the table 3 above, it appears that when using a SiZr target, 35 or 50% vol of nitrogen is not sufficient to have a stoichiometric SiZrN layer (see ref.7 or 8). There is thus some residual metallic Zr and this results in a very high absorbance, a low light transmittance and a yellow colour in transmission. As can be seen, the SiN layer without Zr results in 3.01% absorbance, the best result with SiZrN (fully nitrided) is 4.2%. This shows that not only the ratio of Zr / Si is important but also, the residual amount of metal in the SiZrN layer. For this reason, it has been decided to go on with a N2 / Ar ratio equal to 60 / 40. Moreover, it has been found that a 60 / 40 N2 / Ar ratio allows a DDR of 5.6 nm.m / min / kw) while increasing the nitrogen gas results in decreasing the DDR (to about 4) without improving the light transmission or the absorption. By comparison, the DDR for TZO deposition is 1.7, which means deposition of SiZrN is more than 3 times better.

[0067] In the next table (table 4) complete antireflective stacks have been prepared:a first stack corresponding to the current antireflective stack (see § 0045) with TZO as hn (ex.12), the 3 following stacks where both TZO layers have been replaced by a SiZrN layer (examples 13 to 15) and 2 more examples of stack where only the thicker TZO has been replaced by a SiZrN layer (examples 16 and 17). This third solution (only one SiZrN) would be enough to solve the bottleneck issue in term of DDR. For each layer, the thickness is given in nm between the brackets.

[0068] Table 4

[0069] Optical properties of the stacks presented in the table 4 are given in the table 5. Concerning the colour parameters, the b* parameter in transmission is significantly higher when both TZO are replaced by a SiZrN layer. Keeping the thinner TZO and replacing only the thicker does not improve the yellow colour in transmission. The level of reflection remains comparable to the current Clearsight product. For the reflection, it appears that the colour parameters are less impacted especially with only one SiZrN layer. The table 5 also shows how it is possible to play with the thicknesses of individual layers to improve namely the b* parameter.

[0070] Table 5

[0071] To demonstrate the heat treatability of the stacks, the coated glass substrates examples of the table 4 have been heat treated (heat treatment conditions: 670°C, 3.5 min) and the tempering vectors (difference before and after heattreatment) have been assessed and are mentioned in the table 6. The transmittance and reflectance vectors are given in % and are measured at a 2° angle (illuminant D65) while the colour vectors are measured at an angle of 10°. As can be seen in the table 6, results are quite good, showing possibility to temper the coated glass substrates of the invention.

[0072] Table 6

[0073] Finally, durability has been checked. In the table 7, results from the chemical durability evaluation are given before heat treatment (BB) and after heat treatment (AB). Three samples have been compared: the reference Clearsight (ex.12), the case where both TZO are replaced through SiZrN (ex.13) and the case where only the thicker TZO is replaced by SiZrN (ex.16).

[0074] Table ?

[0075] In a same way the mechanical durability is comparable to the one of the current anti reflective stack.

[0076] This shows it is now possible to have a product as good as the current Clearsight (with a small point of attention on the colour in transmission) that allows a good production speed, which is heat treatable and that is as durable.

Claims

ClaimsClaim 1. A coated article comprising a substrate and an antireflective stack of the invention on at least one main surface of said substrate, the antireflective stack being a succession of high refractive index layers (hn) and low refractive index layers (In), the antireflective stack is characterized in that at least one high refractive index layer (hn) is a silicon nitride layer doped with zirconium and fully nitrided, the ratio of zirconium related to the total of silicium and zirconium amount is comprised between 15 and 65 mass%, preferably between 20 and 45 mass%.Claim 2. The coated article of claim 1 wherein the antireflective stack comprises outwardly from the substrate a first high refractive index layer (hn1), a first low refractive index layer (In1), a second high refractive index layer (hn2), a second low refractive index layer (In2).Claim 3. The coated article of claim 1 wherein the antireflective stack comprises outwardly from the substrate a first high refractive index layer (hn1), a first low refractive index layer (In1) above and contacting the first high refractive index layer (hn1), a second high refractive index layer (hn2) above and contacting the first low refractive index layer (In1), a second low refractive index layer (In2) above and contacting the second high refractive index layer (hn2).Claim 4. The coated article of claim 1 wherein the antireflective stack comprises outwardly from the substrate a first high refractive index layer (hn1), a first low refractive index layer (In1), a second high refractive index layer (hn2), a second low refractive index layer (In2) and the first high refractive index layer hn1 is contacting the substrate.Claim 5. The coated article of claim 1 wherein the antireflective stack comprises a top protecting layer deposited above the antireflective stack.Claim 6. The coated article of claim 4 wherein the top protecting layer is a silicon oxide doped with zirconium and has a 35 mass % of zirconium related to the total weight of Si and Zr.Claim 7. The coated article of claim 1 wherein each low refractive index layer (In 1 ,In2) is a silicon oxide-based layer.Claim 8. The coated article of claim 1 wherein each high refractive index layer (hn1 , hn2) is a titanium oxide based layer or a silicon nitride based layer doped with zirconium.Claim 9. The coated article of claim 1 that comprises no metallic layer, more particularly, no silver layer.Claim 10. The coated article of claim 1 wherein the antireflective stack comprises outwardly from the substrate a first high refractive index layer (hn1) with a thickness comprised between 7 and 15 nm, preferably between 9 and 13 nm.Claim 11. The coated article of claim 1 wherein the antireflective stack comprises a first low refractive index layer (In1) deposited above the first high refractive index layer (hn1), the first low refractive index In1 having a thickness comprised between 20 and 50 nm, preferably between 25 and 40 nm.Claim 12. The coated article of claim 1 wherein the antireflective stack comprises a second high refractive index layer (hn2) deposited above the first low refractive index layer (In1), the second high refractive index hn2 having a thickness comprised between 90 and 150 nm, preferably between 100 and 140 nm.Claim 13. The coated article of claim 1 wherein the antireflective stack comprises a second low refractive index layer (In2) deposited above the second high refractive index layer (hn2), the second low refractive index In2 having a thickness comprised between 55 and 85 nm, preferably between 65 and 75 nm.Claim 14. The coated article of claim 1 wherein a top protecting layer (SiZrOx) is deposited above and in contact with the second low refractive index layer In2, the top protecting layer having a thickness comprised between 10 and 50 nm, preferably between 15 and 25 nm.Claim 15. The coated article of claim 1 wherein the second low refractive index In2 together with a SiZrOx top protecting layer have a thickness comprised between 70 and 110 nm, preferably between 80 and 100 nm.Claim 16. The coated article of claim 1 wherein the substrate is any type of glass, preferably the substrate is soda lime silicate float glass.Claim 17. The coated article of claim 1 wherein both main surfaces of the substrate are coated with the antireflective stack of the invention.Claim 18. The coated article of claim 1 wherein the air side of the glass substrate is coated with an antireflective stack comprising a first TiCh hn layer with a thickness comprised between 6 and 9 nm, a first SiCh In layer with a thickness comprised between 25 and 35 nm and a second SnCh hn layer with a thickness comprised between 80 and 90 nm, wherein those three first layers of the antireflective stack are deposited through a CVD process.Claim 19. The coated article of claim 1 wherein the air side of the glass substrate is coated with an antireflective stack comprising a first TiCh hn layer with a thickness comprised between 6 and 9 nm, a first SiCh In layer with a thickness comprised between 25 and 35 nm and a second doped SnCh hn layer with a thickness comprised between 320 and 470 nm, wherein those three first layers of the antireflective stack are deposited through a CVD process and wherein the SnO2 layer is doped with F or Sb.Claim 20. The coated article of claim 18 or 19 wherein a SiCh top protecting layer is a SiO2 layer doped with tin and is deposited through a CVD process. Claim 21. The coated article of claim 18 or 19 wherein a SiCh top protecting layer is a SiO2 doped with zirconium and is deposited through a PVD process. Claim 22. Use of coated article of claim 1 as a glazing for appliance, cover sheet, architectural or automotive application.

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