EP4483219A1

EP4483219A1 - Anti-reflective multilayer film and method for manufacturing an anti-reflective multilayer film

Info

Publication number: EP4483219A1
Application number: EP22927529.2A
Authority: EP
Inventors: Shaopeng ZHU; Rong Wu; Wei Zhang; Oliver Chen
Original assignee: Applied Materials Inc
Current assignee: Applied Materials Inc
Priority date: 2022-02-21
Filing date: 2022-02-21
Publication date: 2025-01-01
Also published as: WO2023158442A1; CN119365799A; EP4483219A4

Abstract

An anti -reflective multilayer film and a method for manufacturing an anti-reflective multilayer film are provided. The anti-reflective multilayer film includes a substrate, at least one high-reflective layer over the substrate, and an uppermost low refractive index nanoporous layer over the least one high-reflective layer, wherein the at least one high-reflective layer has a refractive index of more than 1.7 and the uppermost low refractive index nanoporous layer has a refractive index of less than 1.7. The method includes: providing a substrate, depositing at least one high-reflective layer material on the substrate to form at least one high-reflective layer, and depositing a low refractive index layer material including low refractive index nanoparticles on the at least one high-reflective layer to form an uppermost low refractive index nanoporous layer, wherein the at least one high-reflective layer has a refractive index of more than 1.7 and the uppermost low refractive index nanoporous layer has a refractive index of less than 1.7.

Description

ANTI-REFLECTIVE MULTILAYER FILM AND METHOD FOR MANUFACTURING AN ANTI-REFLECTIVE MULTILAYER FILM

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to an anti-reflective multilayer film and a method for manufacturing an anti -reflective multilayer film.

BACKGROUND ART

[0002] In the last decades, displays have become omnipresent in our lives, showing up in a wide array of unlikely places - from refrigerators to windshields to helmets. Displays now enhance our lives by helping us plan, experience, monitor, organize, and create in all kinds of new ways. Accordingly, the use of displays in different applications has increased considerably.

[0003] Although display technology is over a hundred years old and several advancements have been made in this technological field, display technology still faces some constraints. For instance, displays are more likely to be used under the circumstances that result in lower visibility, such as in an environment in which the displays are exposed to ambient light or light from a lighting apparatus. In such situations, the displays act like a mirror and reflect anything illuminated within a field of view into the user's eyes, which results in a so-called specular reflection. Accordingly, the specular reflection is superimposed upon the display's own image, so the specular reflection reduces contrast, washes out the intended image, and causes difficulties for the user to read the display. Consequently, the specular reflection reduces the user's speed and accuracy, and gives rise to discomforts that include headaches and tired eyes.

[0004] Since specular reflection from displays result in such disadvantages, displays with improved anti -reflective performance have been conceived. [0005] As part of the development of displays with improved anti -reflective properties, recent techniques for reducing specular reflection in displays have been focused on applying anti -reflective layers, in which reflected light is reduced by canceling out reflected lights with each other, on a film pertaining to the displays.

[0006] However, further improvements for the anti -reflective film pertaining to the displays and the production of such a film are desired. There is particularly a need for a film, particularly for the displays, that exhibits enhanced anti -reflective properties which reduce specular reflection. Further, there is a need for methods for providing such an anti -reflective multilayer film to be used particularly in display technology, which is relatively easy and cost- effective to perform and provide robust anti -reflective layers, which also allows a modulation of the anti -reflective properties of the anti -reflective film pertaining to the displays.

SUMMARY

[0007] In light of the above, an anti -reflective multilayer film and a method for manufacturing an anti -reflective multilayer film are provided. Further aspects, advantages, and features of the present disclosure are apparent from the claims, the description, and the accompanying drawings.

[0008] According to an aspect of the present disclosure, an anti -reflective multilayer film is provided. The anti-reflective multilayer film includes a substrate, at least one high-reflective layer over the substrate, and an uppermost low refractive index nanoporous layer over the at least one high-reflective layer. Further, the at least one high-reflective layer has a refractive index of more than 1.7 and the uppermost low refractive index nanoporous layer has a refractive index of less than 1.7

[0009] According to another aspect of the present disclosure, a method for manufacturing an anti -reflective multilayer film is provided. The method includes: providing a substrate, depositing at least one high-reflective layer material on the substrate to form at least one high-reflective layer, and depositing a low refractive index layer material including low refractive index nanoparticles on the at least one high-reflective layer to form an uppermost low refractive index nanoporous layer. Further, the at least one high-reflective layer has a refractive index of more than 1.7 and the uppermost low refractive index nanoporous layer has a refractive index of less than 1.7

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments. The accompanying drawings relate to embodiments of the disclosure and are described in the following:

[0011] Figures 1 to 6 show schematic cross-sectional views of an anti- reflective multilayer film according to embodiments described herein;

[0012] Figure 7 shows a schematic view of a deposition apparatus used for manufacturing an anti -reflective multilayer film according to embodiments described herein;

[0013] Figure 8 shows a flow chart of a method for manufacturing an anti- reflective multilayer film according to embodiments described herein; and

[0014] Figure 9 shows a graph of reflectance of a comparable film having multiple anti -reflective layers and of an anti -reflective multilayer film according to embodiments described herein.

DETAILED DESCRIPTION OF EMBODIMENTS

[0015] Reference will now be made in detail to the various embodiments of the disclosure, one or more examples of which are illustrated in the figures. Within the following description of the drawings, the same reference numbers refer to same features. Generally, only the differences with respect to individual embodiments are described. Each example is provided by way of explanation of the disclosure and is not meant as a limitation of the disclosure. Further, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield yet a further embodiment. It is intended that the description includes such modifications and variations.

[0016] The need for a film, particularly for displays, that exhibits enhanced anti -reflective properties has become more relevant nowadays than ever due to an increase in the number of different applications where such film can be used, e.g. for displays. In this regard, a reduction of specular reflection from a film for displays results in the improvement of the user's speed and accuracy to read displays and in the reduction of discomforts that include headaches and tired eyes. Different strategies have been proposed to reduce the specular reflection from a film for displays, which include the use of a film pertaining to displays having multiple anti -reflective layers.

[0017] As an example, a low refractive index layer containing SiOx can be formed on the film pertaining to the displays by physical vapor deposition to reduce specular reflection in such displays. However, production costs derived from the physical vapor deposition are relatively high, deposition by physical vapor deposition is relatively slow, anti -reflective layers produced by physical vapor deposition are usually fragile, and a high control of thickness uniformity of the anti -reflective layers is necessary.

[0018] Further, although anti -reflective properties of the low refractive index layer containing SiOx on the film are relatively acceptable, and formation of further anti -reflective layers, e.g., multiple anti-reflective layers, on the film using physical vapor deposition is possible, anti -reflective layers with a lower refractive index than that of the low refractive index layer containing SiOx have been envisioned to improve the anti-reflective properties of the film pertaining to the displays.

[0019] As an alternative, anti -reflective layers can be also formed on a film pertaining to the displays by a wet coating process. The wet coating process produces anti-reflective layers with very low refractive indexes, a higher robustness, and a lower production cost. However, deposition of multiple layers applying the wet coating process is technically difficult, which impedes the formation of multiple anti -reflective layers on the film pertaining to the displays and makes difficult the production of such a film with multiple anti- reflective layers having different refractive indexes and the modulation of the anti -reflective properties of such film.

[0020] Therefore, there is a need for further improvements in the production of an anti -reflective film pertaining to the displays. There is particularly a need for a film, particularly for the displays, that exhibits enhanced anti -reflective properties which reduce specular reflection. Further, there is a need for methods for providing such anti -reflective multilayer films to be used particularly in display technology, which are relatively easy and cost-effective to perform and provide robust anti-reflective layers.

[0021] The present disclosure overcomes the above-mentioned drawbacks by providing an anti -reflective multilayer film and a method for manufacturing the multilayer anti -reflective film. In particular, since the anti -reflective multilayer film of the present disclosure includes at least one high-reflective layer having a refractive index of more than 1.7 over a substrate, particularly deposited by physical vapor deposition or chemical vapor deposition, and an uppermost low refractive index nanoporous layer having a refractive index of less than 1.7 over the at least one high-reflective layer, particularly deposited by a wet coating process, the anti-reflective multilayer film of the present disclosure shows a higher robustness and a better performance.

[0022] Further, the method for manufacturing an anti-reflective multilayer film allows a reduction of the production costs due to a reduction of deposition of layers conducted by physical vapor deposition or chemical vapor deposition and a reduction of deposition of multiple layers on a film, and the possibility of modulating the anti-reflective properties of the anti-reflective multilayer film. [0023] Before various embodiments of the present disclosure are described in more detail, some aspects with respect to some terms and expressions used herein are explained.

[0024] The term “layer stack” as used herein refers to a group of layers. The term “anti -reflective layer stack” as used herein refers to a group of layers that provide an anti-reflective property to a film against reflection of light, particularly specular reflection. The term “high-reflective layer stack” as used herein refers to a group of layers that provide a high-reflective property to a film such that the film has a refractive index of more than 1.7. An anti -reflective layer, a high-reflective layer, a layer stack, an anti-reflective layer stack or a high-reflective layer stack as described herein can be flexible and/or transparent. Similarly, an uppermost low refractive index nanoporous layer described in the present disclosure can be flexible and/or transparent. The term “transparent” as used herein can particularly include the capability of a structure to transmit light with relatively low scattering, so that, for example, light transmitted therethrough can be seen in a substantially clear manner.

[0025] The term “organic layer” may be understood as a layer made of an organic material, which is particularly formed on a substrate, e.g., on a substrate surface. The term “organic layer” may be also understood as a layer made of an organic layer material that fills recessed features formed in a substrate surface and/or overcoats a top surface of raised features formed on a substrate surface. Further, the term “organic layer” may refer to a layer that levels or flattens (in terms of planarization) the surface of a substrate, in particular a flexible substrate.

[0026] The term “organic layer material” may refer to a material composition that forms an organic layer. Further, in some embodiments, the term “organic layer material” may refer to a material composition that is provided (e.g. coated or applied) on a substrate, particularly on a substrate, e.g., on a substrate surface, and forms an organic layer. Similarly, the term “low refractive index layer material” may refer to a material composition that forms an uppermost low refractive index nanoporous layer. Further, in some embodiments, the term “low refractive index layer material'⁵ may refer to a material composition that is provided (e.g. coated or applied) on at least one high-reflective layer and forms an uppermost low refractive index nanoporous layer.

[0027] When reference is made to the terms “on”, “over”, or “followed by”, i.e. one layer being followed by the other, it is understood that the terms “on”, “over”, or “followed by” are used to define an order of layers, layer stacks, and/or films wherein the starting point is the substrate. This order is irrespective of whether the anti -reflective multilayer film is depicted upside down or not.

[0028] The term “dispersed” may be understood as a state in which particles, particularly organic particles, may be homogenously distributed or spread in an organic layer. The term “agglomerate” may be understood as a state in which particles, particularly organic particles, may be held together by weak physical interactions ultimately leading to at least a group of particles, particularly a group of organic particles, in a specific region of a layer, e.g. the organic layer.

[0029] The terms “substrate” or “flexible substrate” as used herein can particularly embrace flexible substrates such as a web or a foil. The term “substantially inflexible” is understood to distinguish over “flexible”. Specifically, a substantially inflexible substrate can have a certain degree of flexibility, e.g. a glass plate having a thickness of 0.9 mm or below, such as 0.5 mm or below, wherein the flexibility of the substantially inflexible substrate is small in comparison to the flexible substrates. The term “flexible” may also refer to being capable of being formed into a roll.

[0030] It is noted here that a flexible substrate or web as used within the embodiments described herein can typically be characterized in that the flexible substrate is bendable. The term “web” may be synonymously used with the term “strip”, the term “tape”, or the term “flexible substrate”. For example, the web, as described in embodiments herein, may be a foil or another flexible substrate. However, as described in more detail herein, the benefits of embodiments described herein may also be provided for non-flexible substrates or carriers of other inline deposition systems. Yet, it is understood that particular benefit can be utilized for flexible substrates and applications for manufacturing apparatuses on flexible substrates.

[0031] The term “refractive index” (or index of refraction) n of a material or optical medium is a dimensionless number describing how light, or any other radiation, propagates through that material. It is defined as n=c/v, where c is the speed of light in vacuum and v is the speed of light in the material.

[0032] The anti -reflective multilayer film according to embodiments described herein can have color neutrality. The color neutrality provides improved optical characteristics of the anti-reflective multilayer film.

[0033] Figure 1 shows a schematic cross-sectional view of an anti -reflective multilayer film 100 according to embodiments described herein. Although various embodiments of the present disclosure are described with reference to the anti-reflective multilayer film 100 for the sake of simplicity, the various embodiments referring to the anti -reflective multilayer film 100 of the present disclosure may also apply or refer to the anti-reflective multilayer films further described in the present disclosure.

[0034] According to some embodiments, which can be combined with other embodiments described herein, the anti -reflective multilayer film 100 includes a substrate 110, particularly a transparent substrate. Further, the anti -reflective multilayer film 100 includes at least one high-reflective layer 120 over the substrate 110. Furthermore, the anti -reflective multilayer film 100 includes an uppermost low refractive index nanoporous layer 130 over the at least one high- reflective layer 120. Moreover, the at least one high-reflective layer 120 has a refractive index of more than 1.7. In addition, the uppermost low refractive index nanoporous layer 130 has a refractive index of less than 1.7.

[0035] In some embodiments, the substrate 110 may comprise at least one material selected from the group consisting of polycarbonate, cellulose triacetate, cellulose acetate propionate, polyvinyl chloride, polyacrylate and/or derivatives of polyacrylate, polymethacrylate and/or derivatives of polymethacrylate, cyclo olefin polymer, polyethylene naphthalate, polyethylene terephthalate glycol, polyethylene terephthalate, polyimide, and combinations thereof.

[0036] In some embodiments, the substrate 110 may have a thickness equal to or smaller than 500 pm, particularly a thickness equal to or smaller than 400 pm and more particularly a thickness equal to or smaller than 300 pm. In some embodiments, the substrate 110 may have a thickness equal to or higher than 10 pm, particularly a thickness equal to or higher than 30 pm, and more particularly a thickness equal to or higher than 50 pm. In some embodiments, the substrate 110 may have a thickness of 10 pm or above and of 500 pm or below, particularly a thickness of 30 pm or above and of 400 pm or below, and more particularly a thickness of 50 pm or above and of 300 pm or below.

[0037] In some embodiments, the at least one high-reflective layer 120 can be directly disposed or deposited over the substrate 110. In some embodiments, the uppermost low refractive index nanoporous layer 130 can be directly disposed or deposited over the at least one high-reflective layer 120.

[0038] In some embodiments, the at least one high-reflective layer 120 can be a single high-reflective layer. In some embodiments, the single high- reflective layer may have a refractive index of at least 1.9. In some embodiments, the single high-reflective layer may have a refractive index of at least 1.9, particularly of at least 2, and more particularly of at least 2.1. In some embodiments, the single high-reflective layer of the at least one high-reflective layer 120 having a refractive index of at least 1.9 may include at least one of TiOx, NbOx, TaOx, ZrOx, an organic material such as a polymer material, and/or combinations thereof.

[0039] In some embodiments, the single high-reflective layer may have a refractive index of between 1.7 and 1.9. In some embodiments, the single high- reflective layer of the at least one high-reflective layer 120 having a refractive index of between 1.7 and 1.9 may include at least one of SiNx, SiN, SiOxNy, AlxOy, AlOxNy, an organic material such as a polymer material, and/or combinations thereof. [0040] In some embodiments, the uppermost low refractive index nanoporous layer 130 may include substantially spherical pores. In some embodiments, the substantially spherical pores may have a maximum DIO pore diameter of 100 nm, particularly a maximum D10 pore diameter of 80 nm, and more particularly a maximum D10 pore diameter of 60 nm and/or the substantially spherical pores may have a minimum D10 pore diameter of 30 nm, particularly a minimum D10 pore diameter of 35 nm, and more particularly a minimum D10 pore diameter of 40 nm.

[0041] In some embodiments, the substantially spherical pores may have a maximum D50 pore diameter of 100 nm, particularly a maximum D50 pore diameter of 80 nm, and more particularly a maximum D50 pore diameter of 60 nm and/or the substantially spherical pores may have a minimum D50 pore diameter of 30 nm, particularly a minimum D50 pore diameter of 35 nm, and more particularly a minimum D50 pore diameter of 40 nm.

[0042] In some embodiments, the substantially spherical pores may have a maximum D90 pore diameter of 100 nm, particularly a maximum D90 pore diameter of 80 nm, and more particularly a maximum D90 pore diameter of 60 nm and/or the substantially spherical pores may have a minimum D90 pore diameter of 30 nm, particularly a minimum D90 pore diameter of 35 nm, and more particularly a minimum D90 pore diameter of 40 nm.

[0043] The term “D10” refers to a pore diameter of substantially spherical pores in a pore size distribution or to a particle diameter of organic particles or low refractive index nanoparticles in a particle size distribution, wherein 10% of the substantially spherical pores in the pore size distribution have a lower pore diameter and 90% of the substantially spherical pores in the pore size distribution have a higher pore diameter or 10% of the organic particles or low refractive index nanoparticles in the particle size distribution have a lower particle diameter and 90% of the organic particles or low refractive index nanoparticles in the particle size distribution have a higher particle diameter.

[0044] The term “D50” refers to a pore diameter of substantially spherical pores in a pore size distribution or to a particle diameter of organic particles or low refractive index nanoparticles in a particle size distribution, wherein 50% of the substantially spherical pores in the pore size distribution have a lower pore diameter and 50% of the substantially spherical pores in the pore size distribution have a higher pore diameter or 50% of the organic particles or low refractive index nanoparticles in the particle size distribution have a lower particle diameter and 50% of the organic particles or low refractive index nanoparticles in the particle size distribution have a higher particle diameter. The term “D50” is also known as the median diameter.

[0045] The term “D90” refers to a pore diameter of substantially spherical pores in a pore size distribution or to a particle diameter of organic particles or low refractive index nanoparticles in a particle size distribution, wherein 90% of the substantially spherical pores in the pore size distribution have a lower pore diameter and 10% of the substantially spherical pores in the pore size distribution have a higher pore diameter or 90% of the organic particles or low refractive index nanoparticles in the particle size distribution have a lower particle diameter and 10% of the organic particles or low refractive index nanoparticles in the particle size distribution have a higher particle diameter.

[0046] Examples of methods for measuring pore size distribution and pore diameter according to the present disclosure are gas adsorption, e.g., according to ISO 15901-2:2022, mercury porosimeter, e.g., according to ISO 15901- 1 :2016, Brunauer, Emmett, and Teller (BET) method, e.g., according to ISO 9277:2010, and electron microscopic analysis.

[0047] In some embodiments, a D10 pore diameter of the substantially spherical pores can be less than 100% of the thickness of the uppermost low refractive index nanoporous layer 130, particularly less than 80% of the thickness of the uppermost low refractive index nanoporous layer 130, and more particularly less than 60% of the thickness of the uppermost low refractive index nanoporous layer 130. In some embodiments, a D50 pore diameter of the substantially spherical pores can be less than 100% of the thickness of the uppermost low refractive index nanoporous layer 130, particularly less than 80% of the thickness of the uppermost low refractive index nanoporous layer 130, and more particularly less than 60% of the thickness of the uppermost low refractive index nanoporous layer 130. In some embodiments, a D90 pore diameter of the substantially spherical pores can be less than 100% of the thickness of the uppermost low refractive index nanoporous layer 130, particularly less than 80% of the thickness of the uppermost low refractive index nanoporous layer 130, and more particularly less than 60% of the thickness of the uppermost low refractive index nanoporous layer 130.

[0048] In some embodiments, the uppermost low refractive index nanoporous layer 130 may have a thickness equal to or smaller than 180 nm, particularly a thickness equal to or smaller than 160 nm, and more particularly a thickness equal to or smaller than 140 nm and/or the uppermost low refractive index nanoporous layer 130 may have a thickness equal to or higher than 50 nm, particularly a thickness equal to or higher than 70 nm, and more particularly a thickness equal to or higher than 90 nm. In some embodiments, the uppermost low refractive index nanoporous layer 130 may have a thickness of 50 nm or above and of 180 nm or below, particularly a thickness of 70 nm or above and of 160 nm or below, and more particularly a thickness of 90 nm or above and of 400 nm or below.

[0049] In some embodiments, the uppermost low refractive index nanoporous layer 130 may have a refractive index of less than 1.4, particularly a refractive index of less than 1.35, and more particularly a refractive index of less than 1.3 and/or a refractive index of more than 1.1, particularly a refractive index of more than 1.15, and more particularly a refractive index of more than 1.2. In some embodiments, the uppermost low refractive index nanoporous layer 130 may have a refractive index of more than 1.1 and less than 1.4, particularly a refractive index of more than 1.15 and less than 1.35, and more particularly a refractive index of more than 1.2 and less than 1.30.

[0050] In some embodiments, the uppermost low refractive index nanoporous layer 130 may include oligomers and/or polymers derived from hydrolyzable organosilane compounds, e.g., hydrolyzable organosilane compounds having a fluorine-substituted alkyl group or fluorine-substituted alkyl groups, an alkyl group or alkyl groups, an alkoxy group or alkoxy groups, an acetoxy group or acetoxy groups, an oxime group or oxime groups, an enoxy group or enoxy groups, an aminoxy group or an aminoxy groups, or any combination thereof.

[0051] Figure 2 shows a schematic cross-sectional view of an anti -reflective multilayer film 200 according to further embodiments described herein. According to some embodiments, which can be combined with other embodiments described herein, the anti -reflective multilayer film 200 includes a substrate 210, particularly a transparent substrate. Further, the anti -reflective multilayer film 200 includes at least one high-reflective layer 220 over the substrate 210. Furthermore, the anti -reflective multilayer film 200 includes an uppermost low refractive index nanoporous layer 230 over the at least one high- reflective layer 120. In addition, the anti -reflective multilayer film 200 may include an organic layer 215 over the substrate 210 and under the at least one high-reflective layer 220. Moreover, the at least one high-reflective layer 220 has a refractive index of more than 1.7. In addition, the uppermost low refractive index nanoporous layer 230 has a refractive index of less than 1.7

[0052] In some embodiments, the organic layer 215 may have anti-glare and/or anti-scratch properties. In some embodiments, the organic layer 215 can be directly disposed or deposited on the substrate 210. In some embodiments, the at least one high-reflective layer 220 can be directly disposed or deposited on the organic layer 215. In some embodiments, no further layers or films are present between the substrate 210 and the organic layer 215, between the organic layer 215 and the at least one high-reflective layer 220, and/or between the at least one high-reflective layer 220 and the uppermost low refractive index nanoporous layer 230.

[0053] In some embodiments, the organic layer 215 may have a thickness equal to or smaller than 15 pm, particularly a thickness equal to or smaller than 12 pm and more particularly a thickness equal to or smaller than 9 pm. In some embodiments, the organic layer 215 may have a thickness equal to or higher than 1 pm, particularly a thickness equal to or higher than 4 pm, and more particularly a thickness equal to or higher than 7 pm. In some embodiments, the organic layer 215 may have a thickness of 1 pm or above and of 15 pm or below, particularly a thickness of 4 pm or above and of 12 pm or below, and more particularly a thickness of 7 pm or above and of 9 pm or below. In some embodiments, the organic layer 215 can have a sufficiently high degradation temperature to remain stable during subsequent processing, which can involve extreme temperatures.

[0054] In some embodiments, the organic layer material may comprise at least one cross-linkable polymer, particularly selected from the group consisting of a polyacrylic resin, an acrylic-urethane resin, an epoxy acrylic resin, a melamine resin, an amino resin, a polyurethane resin, a polyester resin, a polysiloxane resin, and combinations thereof.

[0055] According to further embodiments, the organic layer material may comprise monomers, particularly selected from the group consisting of urethane acrylates, isobornyl acrylate, dipentaerythritol pentaacrylates, epoxy acrylates blended with styrene, di -trimethylolpropane tetraacrylates, di ethylene glycol diacrylates, 1,3 -butylene glycol diacrylate, pentaacrylate esters, pentaerythritol tetraacrylates, pentaerythritol triacrylates, ethoxylated (3) trimethylolpropane triacrylates, ethoxylated (3) trimethylolpropane triacrylates, alkoxylated trifunctional acrylate esters, dipropylene glycol diacrylates, neopentyl glycol diacrylates, ethoxylated (4) bisphenol a dimethacrylates, cyclohexane dimethanol diacrylate esters, isobornyl methacrylate, cyclic diacrylates, and tris(2-hydroxy ethyl) isocyanurate triacrylate, acrylates of the foregoing methacrylates, and methacrylates of the foregoing acrylates.

[0056] In some embodiments, the organic layer material may also comprise monomers, particularly selected from the group consisting of vinyl ethers, vinyl naphthylene, acrylonitrile, and mixtures thereof, and/or acrylate oligomers. In some embodiments, the organic layer may include an organic layer material selected from the group consisting of poly(vinyl alcohol), poly(vinyl pyrrolidone), ethylene oxide polymers, polyurethanes, urethane- acrylic copolymers, acrylic polymers, particularly UV-crosslinked acrylic polymers, styrene-acrylic copolymers, vinyl polymers, polyesters, silicone polymers, and combinations thereof.

[0057] In some embodiments, the organic layer 215 may include organic particles, particularly protruding organic particles. The term “protruding particles” refers to organic particles that partially protrude from the organic layer 215 in a direction away from the substrate 210 and the organic layer 215.

[0058] In some embodiments, a D10 particle diameter of the organic particles, particularly of the protruding organic particles, can be less than 100% of the thickness of the organic layer 215, particularly less than 80% of the thickness of the organic layer 215, and more particularly less than 60% of the thickness of the organic layer 215. In some embodiments, a D50 particle diameter of the organic particles, particularly of the protruding organic particles, can be less than 100% of the thickness of the organic layer 215, particularly less than 80% of the thickness of the organic layer 215, and more particularly less than 60% of the thickness of the organic layer 215.

[0059] In some embodiments, a D90 particle diameter of the organic particles, particularly of the protruding organic particles, can be less than 200% of the thickness of the organic layer 215, particularly less than 150% of the thickness of the organic layer 215, and more particularly less than 110% of the thickness of the organic layer 215.

[0060] In some embodiments, the organic particles, particularly the protruding organic particles, can be spherical. The term "spherical" in the present disclosure is to be understood to include arcuate surfaces. Further, the term “spherical” means a surface of an organic particle, particularly of a protruding organic particle, a surface of a low refractive index nanoparticle or a surface of a pore that has a curvature in any direction. Accordingly, the term “spherical” may refer to a spherical, oval, elliptical surface. [0061] The term “spherical” in connection with an organic particle, particularly with a protruding organic particle, with a low refractive index nanoparticle or with a pore does not mean that all organic particles, particularly protruding organic particles, all low refractive index nanoparticles or all pores are spherical, it means that most organic particles, particularly protruding organic particles, low refractive index nanoparticles or pores, such as more than 90%, preferably 95%, most preferably 99% of the organic particles, particularly protruding organic particles, low refractive index nanoparticles or pores are essentially spherical.

[0062] In particular, the term “spherical” refers to a perfectly round geometric surface. Further, the term “substantially spherical” is to be interpreted as a surface of an organic particle, particularly of a protruding organic particle, a surface of a low refractive index nanoparticle or a surface of a pore that has a curvature in any direction with a technical tolerance of the method used to manufacture such organic particles, particularly protruding organic particles, low refractive index nanoparticles or pores.

[0063] According to some embodiments, the organic particles, particularly the protruding organic particles, may include a material selected from the group consisting of poly(methyl methacrylate), poly(butyl methacrylate), copolymers of methyl acrylate, copolymers of butyl methacrylate, and combinations thereof. In particular, the organic particles, particularly the protruding organic particles, may include a crosslinked material selected from the group consisting of crosslinked poly(methyl methacrylate), crosslinked poly(butyl methacrylate), crosslinked copolymers of methyl acrylate, crosslinked copolymers of butyl methacrylate, and combinations thereof.

[0064] Organic particles, particularly the protruding organic particles, can be manufactured by various procedures. For example, Makhlouf et al. present a method for the manufacturing of crosslinked acrylic polymer microparticles (US 4,180,619 A).

[0065] In some embodiments, the organic layer 215 may also include dispersed organic particles, e.g., completely surrounded by an organic layer material in the organic layer 215, and/or agglomerated organic particles, e.g., completely surrounded by an organic layer material in the organic layer 215.

[0066] The size (e.g., dimensions) of the organic particles or low refractive index nanoparticles described herein can be determined by dynamic light scattering, disc centrifugation, particle tracking analysis, tunable resistive pulse sensing, atomic force microscopy, and/or electron microscopy. Such methods for determining the particle size distribution are known in the art. Particularly, the size of the organic particles of the organic layer 215 or the size of the low refractive index nanoparticles can be determined by dynamic light scattering according to ISO 13320:2020, e.g., Particle size analysis — Laser diffraction methods. ISO 13320:2020 considers the particles as being spherical and, therefore, particle size is reported as a volume equivalent sphere diameter.

[0067] In some embodiments, the organic particles, particularly the protruding organic particles, may have a maximum D10 particle diameter of 5 pm, particularly a maximum D10 particle diameter of 4 pm, and more particularly a maximum D10 particle diameter of 2.5 pm. In some embodiments, the organic particles, particularly the protruding organic particles, may have a minimum D10 particle diameter of 0.8 pm, particularly a minimum D10 particle diameter of 1 pm, and more particularly a minimum D10 particle diameter of 1.5 pm. In some embodiments, the organic particles, particularly the protruding organic particles, may have a minimum D10 particle diameter of 0.8 pm and a maximum D10 particle diameter of 5 pm, particularly a minimum D10 particle diameter of 1 pm and a maximum D10 particle diameter of 4 pm, and more particularly a minimum D10 particle diameter of 1.5 pm and a maximum D10 particle diameter of 2.5 pm.

[0068] In some embodiments, the organic particles, particularly the protruding organic particles, may have a maximum D50 particle diameter of 5 pm, particularly a maximum D50 particle diameter of 4 pm, and more particularly a maximum D50 particle diameter of 2.5 pm. In some embodiments, the organic particles, particularly the protruding organic particles, may have a minimum D50 particle diameter of 0.8 pm, particularly a minimum D50 particle diameter of 1 pm, and more particularly a minimum D50 particle diameter of 1.5 pm. In some embodiments, the organic particles, particularly the protruding organic particles, may have a minimum D50 particle diameter of 0.8 pm and a maximum D50 particle diameter of 5 pm, particularly a minimum D50 particle diameter of 1 pm and a maximum D50 particle diameter of 4 pm, and more particularly a minimum D50 particle diameter of 1.5 pm and a maximum D50 particle diameter of 2.5 pm.

[0069] In some embodiments, the organic particles, particularly the protruding organic particles, may have a maximum D90 particle diameter of 5 pm, particularly a maximum D90 particle diameter of 4 pm, and more particularly a maximum D90 particle diameter of 2.5 pm. In some embodiments, the organic particles, particularly the protruding organic particles, may have a minimum D90 particle diameter of 0.8 pm, particularly a minimum D90 particle diameter of 1 pm, and more particularly a minimum D90 particle diameter of 1.5 pm. In some embodiments, the organic particles, particularly the protruding organic particles, may have a minimum D90 particle diameter of 0.8 pm and a maximum D90 particle diameter of 5 pm, particularly a minimum D90 particle diameter of 1 pm and a maximum D90 particle diameter of 4 pm, and more particularly a minimum D90 particle diameter of 1.5 pm and a maximum D90 particle diameter of 2.5 pm.

[0070] The properties of the organic particles described in the present disclosure, e.g. material or particle diameter, also refer to properties of protruding organic particles, dispersed organic particles and/or agglomerated organic particles.

[0071] In some embodiments, the anti-reflective multilayer film 200 may further include a seed layer between the organic layer 215 and the at least one high-reflective layer 220. Accordingly, the seed layer may be deposited on the organic layer 215, e.g. by chemical vapor deposition or physical vapor deposition, for example sputtering or evaporation. Some examples of materials of the seed layer can be SiOx, TiOx, NbOx, SiNx, and/or combinations thereof. In some embodiments, the seed layer may have a thickness of between 0 and 5 nm.

[0072] In some embodiments, a refractive index of the organic lay er 215 and a refractive index of the organic particles, particularly protruding organic particles, can be substantially the same. Accordingly, the term “substantially” is understood particularly when referring to a refractive index of the organic particles, particularly protruding organic particles, and a refractive index of the organic layer to allow for a deviation of a difference between the refractive index of the organic particles, particularly protruding organic particles, and the refractive index of the organic layer ±0.05 or below, and particularly ±0.02 or below.

[0073] Since the refractive indexes of the organic layer 215 and the organic particles, particularly protruding organic particles, are similar, a reduction in the internal scattering of light at the interface between the organic particles, particularly protruding organic particles, and the organic layer 215 is observed and, consequently, specular reflections are reduced.

[0074] The refractive index of particles, e.g., low refractive index nanoparticles or organic particles, layers or films can be determined as described, for instance, in ISO 13320:2020, e.g., Particle size analysis — Laser diffraction methods or in ISO 489: 1999 Plastics - Determination of refractive index.

[0075] In some embodiments, a surface of the substrate 210 onto which the organic layer 215 is provided, e.g. coated or otherwise joined, can be treated to improve adhesion. Useful surface treatments include electrical discharge in the presence of a suitable reactive or non-reactive atmosphere (e.g., plasma, glow discharge, corona discharge, dielectric barrier discharge or atmospheric pressure discharge); chemical pretreatment; or flame pretreatment.

[0076] Figure 3 shows a schematic cross-sectional view of an anti -reflective multilayer film 300 according to further embodiments described herein. According to some embodiments, which can be combined with other embodiments described herein, the anti -reflective multilayer film 300 includes a substrate 310, particularly a transparent substrate. Further, the anti -reflective multilayer film 300 includes at least one high-reflective layer 320 over the substrate 310.

[0077] Furthermore, the anti -reflective multilayer film 300 includes an uppermost low refractive index nanoporous layer 330 over the at least one high- reflective layer 320. In addition, the anti -reflective multilayer film 300 may include an organic layer 315 over the substrate 310 and under the at least one high-reflective layer 320. Moreover, the at least one high-reflective layer 320 has a refractive index of more than 1.7. In addition, the uppermost low refractive index nanoporous layer 330 has a refractive index of less than 1.7

[0078] In some embodiments, the at least one high-reflective layer 320 can be a layer stack. In some embodiments, the layer stack can be a high-reflective layer stack. According to some embodiments, the layer stack of the present embodiments may include a number of layers formed (e.g. by deposition) one on top of another. In some embodiments, the layer stack can be directly disposed or deposited on the organic layer 315. In some embodiments, the layers of the layer stack can be directly disposed or deposited on each other.

[0079] In some embodiments, the single high-reflective layer, e.g., of the at least one high-reflective layer 120 or 220, or at least one of the layers of the layer stack, e.g., of the at least one high-reflective layer 320, may have a thickness of more than 5 nm, particularly a thickness of more than 20 nm, and more particularly a thickness of more than 30 nm. In some embodiments, the single high-reflective layer, e.g., of the at least one high-reflective layer 120 or 220, or at least one of the layers of the layer stack, e.g., of the at least one high- reflective layer 320, may have a thickness of less than 120 nm, particularly a thickness of less than 100 nm, and more particularly a thickness of less than 80 nm.

[0080] In some embodiments, the single high-reflective layer, e.g., of the at least one high-reflective layer 120 or 220, or at least one of the layers of the layer stack, e.g., of the at least one high-reflective layer 320, may have a thickness in the range of 5 nm and 120 nm, particularly in the range of 20 nm to 100 nm, and more particularly in the range of 30 nm to 80 nm. Thicknesses and/or optical properties of the individual layers of the layer stack can be different.

[0081] According to some embodiments, which can be combined with other embodiments described herein, the layer stack, e.g., of the at least one high- reflective layer 320, may have a thickness of more than 20 nm, particularly a thickness of more than 40 nm, and more particularly a thickness of more than 60 nm. In some embodiments, the layer stack, e.g., of the at least one high- reflective layer 320, may have a thickness of less than 160 nm, particularly a thickness of less than 140 nm, and more particularly a thickness of less than 120 nm. In some embodiments, the layer stack, e.g., of the at least one high- reflective layer 320, may have a thickness of 20 nm or above and of 160 nm or below, particularly a thickness of 40 nm or above and of 140 nm or below, and more particularly a thickness of 60 nm or above and of 120 nm or below.

[0082] The layer stack of the present disclosure may include alternating layers, particularly alternating layers comprising different materials. The layers of the layer stack may include a medium refractive index material, e.g., having a refractive index between 1.7 and 1.9, and a high refractive index material, e.g., having a refractive index of at least 1.9, or a low refractive index material, e.g., having a refractive index of less than 1.7, and a high refractive index material, e.g., having a refractive index of at least 1.9, in an alternating manner.

[0083] According to some embodiments, a layer stack may include two layers. Accordingly, the layer stack may include a first layer 321 and a second layer 322 arranged in this order.

[0084] With reference to Figure 3, the first layer 321 may have a refractive index of between 1.7 and 1.9 and the second layer 322 may have a refractive index of at least 1.9, particularly of 2. In some embodiments, the first layer 321 of the layer stack may include at least one of SiNx, SiN, SiOxNy, AlxOy, AlOxNy, an organic material such as a polymer material, and/or combinations thereof. In some embodiments, the second layer 322 of the layer stack may include at least one of TiOx, NbOx, TaOx, ZrOx, an organic material such as a polymer material, and/or combinations thereof. As an example, a layer stack may include two layers in the following order SiNx/TiOx.

[0085] Figure 4 shows a schematic cross-sectional view of an anti -reflective multilayer film 400 according to further embodiments described herein. According to some embodiments, which can be combined with other embodiments described herein, the anti -reflective multilayer film 400 includes a substrate 410, particularly a transparent substrate. Further, the anti -reflective multilayer film 400 includes at least one high-reflective layer 420 over the substrate 410. Furthermore, the anti -reflective multilayer film 300 includes an uppermost low refractive index nanoporous layer 430 over the at least one high- reflective layer 420. In addition, the anti -reflective multilayer film 400 may include an organic layer 415 over the substrate 410 and under the at least one high-reflective layer 420. Moreover, the at least one high-reflective layer 420 has a refractive index of more than 1.7. In addition, the uppermost low refractive index nanoporous layer 430 has a refractive index of less than 1.7

[0086] According to some embodiments, which can be combined with other embodiments described herein, at least one high-reflective layer 420 can be a layer stack. The layer stack may include three layers. Accordingly, the layer stack may include a first layer 421, a second layer 422, and a third layer 423 arranged in this order. In some embodiments, the first layer 421 and the third layer 423 may have a refractive index of at least 1.9, particularly of about 2. In some embodiments, the second layer 422 may have a refractive index of less than 1.7, particularly a refractive index of less than 1.5, and more particularly of 1.46.

[0087] In some embodiments, the first layer 421 of the layer stack may include at least one of TiOx, NbOx, TaOx, ZrOx, an organic material such as a polymer material, and/or combinations thereof. In some embodiments, the second layer 422 of the layer stack may include at least one of SiOx, MgFx, SiOxNy, an organic material such as a polymer material, and/or combinations thereof. [0088] In some embodiments, the third layer 423 of the layer stack may include at least one of TiOx, NbOx, TaOx, ZrOx, an organic material such as a polymer material, and/or combinations thereof. As an example, the first layer 421 may include or be made of TiOX, the second layer 422 may include or be made of SiOx, and the third layer 423 may include or be made of NbOx. As another example, a layer stack may include three layers in the following order NbOx/SiOx/TiOx.

[0089] According to some embodiments, which can be combined with other embodiments described herein, a layer stack may include further layers over the third layer, particularly a fourth layer and a fifth layer or a fourth layer, a fifth layer, a sixth layer, and a seventh layer, as exemplarily shown in Figures 5 and 6, respectively. A layer stack with five layers may be referred to as NONON and a layer stack with seven layers may be referred to as N0N0N0N.

[0090] The symbols N and O may denote a material of the layers of the layer stack. In some embodiments, the symbol N denotes the material or layer with a high refractive index (e.g., TiOx) and the symbol O denotes the material or layer with a low refractive index (e.g., SiOx). The low refractive index can be in the range of 1.4 to 1.6, specifically about n=1.46. However, it is to be understood that the present disclosure is not limited to TiOx and SiOx, and that any suitable materials having the high refractive index of at least 1.9 and the low refractive index of less than 1.7 could be used for the layers with the high refractive index and the layers with the low refractive index, respectively.

[0091] In some embodiments, an extinction coefficient of the materials with the high refractive index and the low refractive index can be small. The index of refraction and the extinction coefficient are the real part and the imaginary part, respectively, of the complex index of refraction. Particularly, when light passes through a medium, some part of the light will be absorbed. This effect can be described by defining the complex index of refraction as being equal to n+ik. The real part “n” indicates the phase velocity, while the imaginary part “ik” indicates the amount of absorption loss when the electromagnetic wave propagates through the material. [0092] In Figure 5, an anti -reflective multilayer film 500 according to further embodiments of the present disclosure is depicted. The anti-reflective multilayer layer film 500 of Figure 5 is similar to the anti -reflective multilayer film 400 of Figure 4 with the difference being that the layer stack of the at least one high-reflective layer 520 includes further layers and the corresponding layer stack may be referred to as NONON.

[0093] For instance, the anti -reflective multilayer film 500 includes a substrate 510, particularly a transparent substrate. Further, the anti -reflective multilayer film 500 includes at least one high-reflective layer 520 over the substrate 510. Furthermore, the anti -reflective multilayer film 300 includes an uppermost low refractive index nanoporous layer 430 over the at least one high- reflective layer 420. Moreover, the at least one high-reflective 520 layer has a refractive index of more than 1.7. Further, the uppermost low refractive index nanoporous layer 530 has a refractive index of less than 1.7. In addition, the anti-reflective multilayer film 500 may include an organic layer 515 over the substrate 510 and under the at least one high-reflective layer 520. The layer stack of the at least one high-reflective layer 520 of the anti -reflective multilayer film 500 may be referred to as NONON.

[0094] Referring to Figure 5, the layer stack may include a first layer 521, a second layer 522, a third layer 523, a fourth layer 524, and a fifth layer 525 arranged in this order. The first layer 521, the third layer 523, and the fifth layer 525 may have a refractive index of at least 1.9, and the second layer 522 and the fourth layer 524 may have a refractive index of less than 1.7.

[0095] As an example, the first layer 521, the third layer 523, and the fifth layer 525 may include or be made of TiOx, and the second layer 522 and the fourth layer 524 may include or be made of SiO2.

[0096] In Figure 6, an anti -reflective multilayer film 600 according to further embodiments of the present disclosure is depicted. The anti-reflective multilayer film 600 of Figure 6 is similar to the anti -reflective multilayer film 400 of Figure 4 with the difference being that the layer stack of the at least one high-reflective layer 620 includes further layers and the corresponding layer stack may be referred to as N0N0N0N.

[0097] For instance, the anti -reflective multilayer film 600 includes a substrate 610, particularly a transparent substrate. Further, the anti -reflective multilayer film 600 includes at least one high-reflective layer 620 over the substrate 610. Furthermore, the anti -reflective multilayer film 600 includes an uppermost low refractive index nanoporous layer 630 over the at least one high- reflective layer 620. Moreover, the at least one high-reflective layer 620 has a refractive index of more than 1.7. In addition, the uppermost low refractive index nanoporous layer 630 has a refractive index of less than 1.7

[0098] In addition, the anti -reflective multilayer film 600 may include an organic layer 615 over the substrate 610 and under the at least one high- reflective layer 620. The layer stack of the at least one high-reflective layer 620 of the anti -reflective multilayer film 600 may be referred to as NONONON.

[0099] Referring to Figure 6, the layer stack may include a first layer 621, a second layer 622, a third layer 623, a fourth layer 624, a fifth layer 625, a sixth layer 626, and a seventh layer 627 arranged in this order. The first layer 621, the third layer 623, the fifth layer 625, and the seventh layer 627 may have a refractive index of at least 1.9, and the second layer 622, the fourth layer 624, and the sixth layer 626 may have a refractive index of less than 1.7.

[00100] As an example, the first layer 621, the third layer 623, the fifth layer 625, and the seventh layer 627 may include or be made of TiOx, and the second layer 622, the fourth layer 624, and the sixth layer 626 may include or be made of SiO₂.

[00101] According to some embodiments, which can be combined with other embodiments described herein, even numbered layers of the layer stack may have a refractive index of less than 1.7, particularly a refractive index of less than 1.5, and more particularly of 1.46. In some embodiments, odd numbered layers of the layer stack may have a refractive index of at least 1.9, particularly of 2.0. The terms “odd” and “even” as used throughout this application refer to parity in mathematics, i.e. that an integer is even if it is evenly divisible by two and odd if it is not even. As an example, the odd numbered layers of the layer stack can be the first, third, fifth etc. layers, and the even numbered layers of the layer stack can be the second, fourth, sixth, etc. layers. Thus, the numbering excludes any other layers that could additionally be provided, such as seed layers, hard coatings, adhesive layers and the like.

[00102] As an example, the odd numbered layers of the layer stack of the at least one high-reflective layer 320, 420, 520 or 620 may have a refractive index of about at least 1.9, particularly of about 2. The even numbered layers of the layer stack of the at least one high-reflective layer 320, 420, 520 or 620 may have a refractive index of less than 1.7, particularly a refractive index of less than 1.5, and more particularly of about 1.46.

[00103] According to some embodiments, the odd numbered layers of the layer stack of the at least one high-reflective layer 520 or 620 include at least one of TiOx, NbOx, TaOx, ZrOx, an organic material such as a polymer material, and/or combinations thereof, and/or the even numbered layers of the layer stack of the at least one high-reflective layer 520 or 620 include at least one of SiOx, MgFx, SiOxNy, an organic material such as a polymer material, and/or combinations thereof.

[00104] By successively providing layers with alternating or different refractive indexes, a layer stack of the at least one high-reflective layer 320, 420, 520 or 620 having improved anti -refl ection characteristics can be provided.

[00105] According to some embodiments, which can be combined with other embodiments described herein, the layers (e.g. the even numbered layers) of the layer stack of the at least one high-reflective layer 320, 420, 520 or 620 can be provided by depositing at least one high-reflective layer material containing SiOx, MgFx, SiOxNy, an organic material such as a polymer material, and/or combinations thereof, or the like. As another example, the layers (e.g. the odd numbered layers) of the layer stack of the at least one high-reflective layer 320, 420, 520 or 620 can be provided by depositing at least one high-reflective layer material containing TiOx, NbOx, TaOx, ZrOx, an organic material such as a polymer material, and/or combinations thereof, or the like.

[00106] As an example, the single high-reflective layer having a refractive index of at least 1.9 can be provided by depositing a layer material containing TiOx, NbOx, TaOx, ZrOx, an organic material such as a polymer material, and/or combinations thereof, or the like. As another example, the single high- reflective layer having a refractive index of between 1.7 and 1.9 can be provided by depositing a layer material containing SiNx, , SiN, SiOxNy, AlxOy, AlOxNy, an organic material such as a polymer material, and/or combinations thereof, or the like.

[00107] According to some implementations, the layers of the layer stack can be manufactured by chemical vapor deposition or physical vapor deposition, for example sputtering or evaporation.

[00108] According to some embodiments, which can be combined with other embodiments herein, the thickness of each of the odd numbered layers of the layer stack of the at least one high-reflective layer 320, 420, 520 or 620, can be less than the thickness of each of the even numbered layers of the layer stack of the at least one high-reflective layer 320, 420, 520 or 620.

[00109] In some embodiments, no further layers or films are present between the layers of the layer stack. In some other embodiments, further layers can be provided between at least some of the layers of the layer stack of the at least one high-reflective layer 320, 420, 520 or 620.

[00110] Methods for depositing a layer material for instance on a substrate or on an organic layer may include a physical vapor deposition (PVD) process, a chemical vapor deposition (CVD) process, a plasma enhanced chemical vapor deposition (PECVD) process, etc. As an example, the process is performed in a process apparatus or process chamber, where a substrate, particularly a substrate including an organic layer over the substrate to be coated, is located. A deposition material is provided in the apparatus. A plurality of materials such as oxides, nitrides or carbides thereof may be used for deposition. Further, other processes like etching, structuring, annealing, or the like can be conducted in processing chambers.

[00111] Figure 7 shows a schematic view of an apparatus 700, e.g. a roll-to- roll deposition apparatus, for depositing layer materials to form layers of a layer stack of the at least one high-reflective layer of the anti -reflective multilayer film according to embodiments described herein.

[00112] The apparatus 700 can include at least three chamber portions 702A, 702B, and 702C. At chamber portion 702C, one or more deposition sources 730 and optionally an etching station 740 can be provided as processing tools. A substrate 741, in particular a substrate including an organic layer, is provided on a first roll 764, e.g. having a winding shaft. The substrate 741 is unwound from the first roll 764 as indicated by the substrate movement direction shown by arrow 708. A separation wall 701 is provided for separation of chamber portions 702A and 702B. The separation wall 701 can further be provided with gap sluices 745 for having the substrate 741 pass therethrough. A vacuum flange 712 provided between the chamber portions 702B and 702C can be provided with openings to take up at least some processing tools.

[00113] The substrate 741 is moved through the deposition areas provided at a coating drum 710 and corresponding to positions of the deposition sources 730. During operation, the coating drum 710 rotates around an axis such that the substrate 741, particularly including an organic layer, moves in the direction of arrow 708. According to some embodiments, the substrate 741 layer is guided via one, two or more rollers from the roll 764 to the coating drum 710 and from the coating drum 710 to the second roll 764’, e.g. having a winding shaft, on which the substrate 741, particularly including an organic layer, is wound after processing thereof.

[00114] According to some embodiments, the deposition sources 730 can be configured for depositing the at least one high-reflective layer of the anti- reflective multilayer film as described in embodiments of the present disclosure. As an example, at least one deposition source 730 can be adapted for deposition of the layer material having a refractive index of at least 1.9 and at least one deposition source 730 of the rest of the deposition sources 730 can be adapted for deposition of the layer material having the refractive index of less than 1.7.

[00115] For instance, a first deposition source can be configured for depositing a first layer, a second deposition source can be configured for depositing a second layer, and a third deposition source can be configured for depositing a third layer.

[00116] In some implementations, the first chamber portion 702A is separated in an interleaf chamber portion unit 702A1 and a substrate chamber portion unit 702A2. Additionally, interleaf rolls 766/766’ and interleaf rollers 705 can be provided as a modular section of the apparatus 700. The apparatus 700 can further include a pre-heating unit 794 to heat the substrate. Further, additionally or alternatively a pre-treatment plasma source 792, e.g. an RF (radio frequency) plasma source can be provided to treat the substrate, particularly including an organic layer, with a plasma prior to entering chamber portion 702C.

[00117] According to yet further embodiments, which can be combined with other embodiments described herein, optionally also an optical measurement unit 794 for evaluating the result of the substrate processing and/or one or more ionization units 792 for adapting the charge on the substrate, particularly including an organic layer, can be provided.

[00118] According to some embodiments, the layer material may be chosen according to the deposition process and the later application of the coated substrate. For instance, a layer material of the deposition sources 730 may be silicon. As an example, oxide-, nitride- or carbide-layers, which can include such materials, can be deposited by providing the layer material from the source or by reactive deposition, i.e. the layer material from the source reacts with chemicals like oxygen, nitride, or carbon from a processing gas.

[00119] According to an aspect of the present disclosure and as shown in Figure 8, a method 800 for manufacturing an anti -reflective multilayer film is provided. The method 800 includes providing a substrate (stage 810). The method further includes depositing at least one high-reflective layer material on the substrate, particularly on an organic layer being on the substrate, to form at least one high-reflective layer (stage 820). Additionally, the method includes depositing (e.g. coating or applying) a low refractive index layer material including low refractive index nanoparticles on the at least one high-reflective layer to form an uppermost low refractive index nanoporous layer (stage 830). Moreover, the at least one high-reflective layer has a refractive index of more than 1.7. In addition, the uppermost low refractive index nanoporous layer has a refractive index of less than 1.7

[00120] In some embodiments, depositing at least one high-reflective layer material on the substrate, particularly on an organic layer being on the substrate, to form at least one high-reflective layer may include alternately depositing at least a first layer material and a second layer material on the substrate, particularly on an organic layer being on the substrate, to form at least one high-reflective layer being a layer stack, particularly to form at least a first layer, a second layer, and a third layer, more particularly to form at least a first layer, a second layer, a third layer, a fourth layer, and a fifth layer, and even more particularly to form at least a first layer, a second layer, and a third layer, a fourth layer, a fifth layer, a sixth layer, and a seventh layer, to be arranged in this order.

[00121] In some embodiments, depositing at least one high-reflective layer material on the substrate, particularly on an organic layer being on the substrate, to form at least one high-reflective layer may include depositing a first layer material and a second layer material on the substrate, particularly on an organic layer being on the substrate, to form a layer stack, particularly to form a first layer and a second layer to be arranged in this order.

[00122] In some embodiments, depositing at least one high-reflective layer material on the substrate, particularly on an organic layer being on the substrate, to form at least one high-reflective layer may include depositing a single high-reflective layer material on the substrate, particularly on an organic layer being on the substrate, to form a single high-reflective layer having a refractive index of at least 1.9 or having a refractive index of between 1.7 and 1.9.

[00123] In some embodiments, the single high-reflective layer material may include at least one of TiOx, NbOx, TaOx, ZrOx, an organic material such as a polymer material, and/or combinations thereof. In some embodiments, the single high-reflective layer material may include at least one of SiNx, , SiN, SiOxNy, AlxOy, AlOxNy, an organic material such as a polymer material, and/or combinations thereof.

[00124] In some embodiments, alternately depositing at least a first layer material and a second layer material on the substrate may include alternately depositing a first layer material including at least one of TiOx, NbOx, TaOx, ZrOx, an organic material such as a polymer material, and/or combinations thereof, and a second layer material including SiOx, MgFx, SiOxNy, an organic material such as a polymer material, and/or combinations thereof.

[00125] In some embodiments, depositing a first layer material and a second layer material on the substrate, particularly on an organic layer being on the substrate, to form a layer stack, particularly to form a first layer and a second layer to be arranged in this order, may include depositing a first layer material including at least one of TiOx, NbOx, TaOx, ZrOx, an organic material such as a polymer material, and/or combinations thereof, and a second layer material including SiOx, MgFx, SiOxNy, an organic material such as a polymer material, and/or combinations thereof.

[00126] In some embodiments, depositing a first layer material and a second layer material on the substrate, particularly on an organic layer being on the substrate, to form a layer stack, particularly to form a first layer and a second layer to be arranged in this order, may include depositing a first layer material including at least one of SiNx, , SiN, SiOxNy, AlxOy, AlOxNy, an organic material such as a polymer material, and/or combinations thereof and a second layer material including at least one of TiOx, NbOx, TaOx, ZrOx, an organic material such as a polymer material, and/or combinations thereof. [00127] According to some embodiments and in reference to the layer stack, a first layer material may be deposited for instance on the substrate, particularly on an organic layer being on the substrate. Then, a second layer material may be deposited on or over the first layer. Afterwards, a third layer material may be deposited on or over the second layer. Thereafter, a fourth layer material may be deposited on or over the third layer. In some embodiments, a fifth layer material may be deposited on or over the fourth layer. In some embodiments, a sixth layer material may be deposited on or over the fifth layer. Further, a seventh layer material may be deposited on or over the sixth layer. Accordingly, the first layer material, the second layer material, the third layer material, etc. correspond to the first layer, the second layer, the third layer, etc., respectively, as described for embodiments of the present disclosure above.

[00128] Although in the present examples of Figures 3 to 6, two, three, five or seven layers corresponding to the layer stack are arranged over each other, the present embodiments are not limited thereto. Any number of layers can be arranged, as it is for instance described above. In some embodiments, the at least one high-reflective layer or the layer stack can be treated with a PFPE- silane solution to provide an anti-smudge effect.

[00129] According to further embodiments, depositing at least one high- reflective layer material on the substrate, particularly on an organic layer being on the substrate, to form at least one high-reflective layer may be conducted by physical vapor deposition or chemical vapor deposition, for example sputtering or evaporation.

[00130] In some embodiments, providing a substrate may include depositing (e.g. coating or applying) an organic layer material on the substrate to form an organic layer. In some embodiments, the organic layer material may include organic particles. In some embodiments, the term “organic layer material” may refer to a material composition that is provided (e.g. coated or applied) on a substrate, particularly on a substrate surface, and includes an organic layer material and organic particles, and forms an organic layer including organic particles, particularly protruding organic particles. [00131] The term “low refractive index layer material” may refer to a material composition that forms a low refractive index nanoporous layer. Further, in some embodiments, the term “low refractive index layer material” may refer to a material composition that is provided (e.g. coated or applied) on the at least one high-reflective layer and forms a low refractive index nanoporous layer.

[00132] In some embodiments, the low refractive index nanoparticles may have a maximum DIO particle diameter of 100 nm, particularly a maximum D10 particle diameter of 80 nm, and more particularly a maximum D10 particle diameter of 60 nm and/or the low refractive index nanoparticles may have a minimum D10 particle diameter of 30 nm, particularly a minimum D10 particle diameter of 35 nm, and more particularly a minimum D10 particle diameter of 40 nm.

[00133] In some embodiments, the low refractive index nanoparticles may have a maximum D50 particle diameter of 100 nm, particularly a maximum D50 particle diameter of 80 nm, and more particularly a maximum D50 particle diameter of 60 nm and/or the low refractive index nanoparticles may have a minimum D50 particle diameter of 30 nm, particularly a minimum D50 particle diameter of 35 nm, and more particularly a minimum D50 particle diameter of 40 nm.

[00134] In some embodiments, the low refractive index nanoparticles may have a maximum D90 particle diameter of 100 nm, particularly a maximum D90 particle diameter of 80 nm, and more particularly a maximum D90 particle diameter of 60 nm and/or the low refractive index nanoparticles may have a minimum D90 particle diameter of 30 nm, particularly a minimum D90 particle diameter of 35 nm, and more particularly a minimum D90 particle diameter of 40 nm.

[00135] In some embodiments, the low refractive index nanoparticles may include SiOx. In some embodiments, the low refractive index nanoparticles may have a hollow structure. Since the low refractive index nanoparticles have a similar composition to that of the low refractive index layer material, the low refractive index nanoparticles are completely incorporated in the low refractive index layer material when forming the uppermost low refractive index nanoporous layer while keeping the corresponding hollow structure of the low refractive index nanoparticles and, thus, only a resulting nanostructure can be observed in the uppermost low refractive index nanoporous layer without distinction between low refractive index nanoparticles, in particular an outer shell of the low refractive index nanoparticles, and the low refractive index layer material. In some embodiments, the low refractive index nanoparticles may have a refractive index of 1.17 to 1.40, particularly 1.17 to 1.35, and more particularly 1.17 to 1.40.

[00136] In some embodiments, the low refractive index layer material may include monomers and/or oligomers including hydrolyzable organosilane compounds, e.g., hydrolyzable organosilane compounds having a fluorinesubstituted alkyl group or fluorine-substituted alkyl groups, an alkyl group or alkyl groups, an alkoxy group or alkoxy groups, an acetoxy group or acetoxy groups, an oxime group or oxime groups, an enoxy group or enoxy groups, an aminoxy group or an aminoxy groups or any combination thereof.

[00137] According to some embodiments, a material composition of a low refractive index layer material can be 10 to 75 wt% of low refractive index nanoparticles and the remainder of the low refractive index layer material, particularly 25 to 65 wt% of low refractive index nanoparticles and the remainder of the low refractive index layer material, and more particularly 40 to 50 wt% of low refractive index nanoparticles and the remainder of the low refractive index layer material.

[00138] In some embodiments, depositing (e.g. coating or applying) a low refractive index layer material including low refractive index nanoparticles on the at least one high-reflective layer to form an uppermost low refractive index nanoporous layer may include mixing a low refractive index layer material, low refractive index nanoparticles, and optionally at least one organic solvent. In some embodiments, depositing (e.g. coating or applying) a low refractive index layer material including low refractive index nanoparticles on the at least one high-reflective layer to form an uppermost low refractive index nanoporous layer may include curing or crosslinking, e.g. by heating.

[00139] According to some embodiments, depositing (e.g. coating or applying) an organic layer material on the substrate to form an organic layer may include mixing an organic layer material and at least one organic solvent and optionally organic particles. In some embodiments, depositing (e.g. coating or applying) an organic layer material on the substrate to form an organic layer may include removing at least one organic solvent from the organic layer material, e.g. by using heating and/or vacuum. In some embodiments, depositing (e.g. coating or applying) an organic layer material on the substrate to form an organic layer may include curing or crosslinking, e.g. by heating and/or by using an electron beam apparatus, a UV light source, an electrical discharge apparatus or another suitable apparatus.

[00140] According to some embodiments, the organic layer material or the low refractive index layer material can be deposited (e.g. coated or applied) by using any suitable technique. For instance, the organic layer material or the low refractive index layer material can be deposited by using a coating method, and particularly by a solution coating method, particularly selected from the group consisting of gravure coating, flow coating, curtain coating, dip coating, spray coating, and a combination thereof. In some embodiments, depositing (e.g. coating or applying) a low refractive index layer material including low refractive index nanoparticles on the at least one high-reflective layer to form an uppermost low refractive index nanoporous layer can be conducted by a wet coating process.

[00141] According to further embodiments, the organic layer material or the low refractive index layer material may additionally comprise at least one additive, such as cross-linkers and catalysts, e.g. photo-initiators.

[00142] In some embodiments, removing the solvent using conventional techniques may be followed by crosslinking, for example, using an electron beam apparatus, a UV light source, an electrical discharge apparatus or another suitable apparatus. In some embodiments, the organic layer material or the low refractive index layer material can also be cured or crosslinked via exposure to light (e.g., DUV, i-line, g-line, and/or broad band) in addition to, or in lieu of, heating. The conditions for forming the organic layer or the low refractive index nanoporous layer can depend upon the particular organic layer material or low refractive index layer material used, and may result in a dried, cured, and/or crosslinked organic layer or a dried, cured, and/or crosslinked low refractive index nanoporous layer.

[00143] According to some embodiments, a material composition of an organic layer material can be 5 to 30 wt% of organic particles and the remainder of organic layer material, particularly 8 to 25 wt% of organic particles and the remainder of the organic layer material, and more particularly 10 to 20 wt% of organic particles and the remainder of the organic layer material. In some embodiments, a material composition of an organic layer material can be 2.5 to 15 wt% of organic particles, 35 wt% to 48 wt% of organic layer material, and the remainder at least one organic solvent, particularly 4 to 12.5 wt% of organic particles, 37 wt% to 46 wt% of organic layer material, and the remainder at least one organic solvent, and more particularly 5 to 10 wt% of organic particles, 39 wt% to 44 wt% of organic layer material, and the remainder at least one organic solvent. In some embodiments, a mass of organic layer material provided on a substrate per m² of substrate can be 2 g to 15 g, particularly 4 to 13 g, and more particularly 6 to 11 g.

[00144] Figure 9 shows a graph of a reflectance of a comparable film having multiple anti -reflective layers and an anti -reflective multilayer film according to embodiments described herein. The term “reflectance” as used herein is the fraction of incident electromagnetic power that is reflected. The term “reflectance” may be synonymously used with the term “reflectivity”.

[00145] In Figure 9, the y-axis of the graph denotes a reflectance in % (percent), and the x-axis denotes a wavelength (lambda) in units of nanometer (nm). Denoted with reference numeral 910 is a reflectance of a comparable polyethylene terephthalate film having multiple anti-reflective layers (SiNx with a thickness of 71 nm, TiOx with a thickness of 50 nm, and SiOx with a thickness of 86 nm) deposited by physical vapor deposition, wherein the reflectance is less than 20 percent in a range from about 360 nm to about 710 nm. Denoted with reference numerals 920a and 920b are reflectances at two different measuring points of an anti -reflective multilayer film according to embodiments described herein having a polyethylene terephthalate substrate, a layer including SiNx with a thickness of 120 nm over the substrate and deposited by physical vapor deposition, and an uppermost low refractive index nanoporous layer, wherein the reflectances at the two different measuring points are less than 6 percent in a range from about 360 nm to about 710 nm. As shown in Figure 9, a lower reflectance can be achieved at least for some regions of a visible spectrum with anti -reflective multilayer films according to embodiments described in the present disclosure.

[00146] While the foregoing is directed to embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

1. Anti -reflective multilayer film, comprising: a substrate; at least one high-reflective layer over the substrate; and an uppermost low refractive index nanoporous layer over the at least one high-reflective layer, wherein the at least one high-reflective layer has a refractive index of more than 1.7 and the uppermost low refractive index nanoporous layer has a refractive index of less than 1.7.

2. Anti-reflective multilayer film according to claim 1, wherein the uppermost low refractive index nanoporous layer comprises substantially spherical pores and the substantially spherical pores have a maximum D50 pore diameter of 100 nm, particularly a maximum D50 pore diameter of 80 nm, and more particularly a maximum D50 pore diameter of 60 nm and/or the substantially spherical pores have a minimum D50 pore diameter of 30 nm, particularly a minimum D50 pore diameter of 35 nm, and more particularly a minimum D50 pore diameter of 40 nm.

3. Anti -reflective multilayer film according to any of claims 1 or 2, wherein the uppermost low refractive index nanoporous layer has a refractive index of less than 1.4, particularly a refractive index of less than 1.35, and more particularly a refractive index of less than 1.3 and/or a refractive index of more than 1.1, particularly a refractive index of more than 1.15, and more particularly a refractive index of more than 1.2

4. Anti -reflective multilayer film according to any of the preceding claims, wherein the uppermost low refractive index nanoporous layer has a thickness equal to or smaller than 180 nm, particularly a thickness equal to or smaller than 160 nm, and more particularly a thickness equal to or smaller than 140 nm and/or the uppermost low refractive index nanoporous layer has a thickness equal to or higher than 50 nm, particularly a thickness equal to or higher than 70 nm, and more particularly a thickness equal to or higher than 90 nm.

5. Anti -reflective multilayer film according to any of the preceding claims, wherein the at least one high-reflective layer is a single high- reflective layer having a refractive index of at least 1.9 or a single high-reflective layer having a refractive index of between 1.7 and 1.9.

6. Anti -reflective multilayer film according to any of claims 1 to 4, wherein the at least one high-reflective layer is a layer stack including: a first layer and a second layer arranged in this order, wherein the first layer has a refractive index of between 1.7 and 1.9; and wherein the second layer has a refractive index of at least 1.9.

7. Anti -reflective multilayer film according to any of claims 1 to 4, wherein the at least one high-reflective layer is a layer stack including: a first layer, a second layer, and a third layer arranged in this order, wherein the first layer and the third layer have a refractive index of at least 1.9, and wherein the second layer has a refractive index of less than 1.7.

8. Anti-reflective multilayer film according to claim 7, wherein the layer stack further comprises further layers over the third layer, particularly a fourth layer and a fifth layer or a fourth layer, a fifth layer, a sixth layer, and a seventh layer.

9. Anti -reflective multilayer film according to any of claims 7 or 8, wherein odd numbered layers of the layer stack have the refractive index of at least 1.9, particularly of 2.0.

10. Anti -reflective multilayer film according to any of claims 7 to 9, wherein even numbered layers of the layer stack have a refractive index of less than 1.7, particularly a refractive index of less than 1.5, and more particularly of 1.46.

11. Anti -reflective multilayer film according to any of claims 6 to 10, wherein the layer stack has a thickness of less than 160 nm, particularly a thickness of less than 140 nm, and more particularly a thickness of less than 120 nm and/or the layer stack has a thickness of more than 20 nm, particularly a thickness of more than 40 nm, and more particularly a thickness of more than 60 nm.

12. Anti-reflective multilayer film according to any of the preceding claims, wherein the anti -reflective multilayer film further comprises an organic layer over the substrate and under the at least one high- reflective layer and the organic layer comprises an organic layer material selected from the group consisting of poly(vinyl alcohol), poly(vinyl pyrrolidone), ethylene oxide polymers, polyurethanes, urethane-acrylic copolymers, acrylic polymers, particularly UV- crosslinked acrylic polymers, styrene-acrylic copolymers, vinyl polymers, polyesters, silicone polymers, and combinations thereof.

13. Method for manufacturing an anti -reflective multilayer film, comprising: providing a substrate; depositing at least one high-reflective layer material on the substrate to form at least one high-reflective layer; and depositing a low refractive index layer material including low refractive index nanoparticles on the at least one high-reflective layer to form an uppermost low refractive index nanoporous layer, wherein the at least one high-reflective layer has a refractive index of more than 1.7 and the uppermost low refractive index nanoporous layer has a refractive index of less than 1.7.

14. Method for manufacturing an anti -reflective multilayer film according to claim 13, wherein the low refractive index nanoparticles have a maximum D50 particle diameter of 100 nm, particularly a maximum D50 particle diameter of 80 nm, and more particularly a maximum D50 particle diameter of 60 nm and/or the low refractive index nanoparticles have a minimum D50 particle diameter of 30 nm, particularly a minimum D50 particle diameter of 35 nm, and more particularly a minimum D50 particle diameter of 40 nm.

15. Method for manufacturing an anti-reflective multilayer film of claim 14, wherein depositing at least one high-reflective layer material on the substrate to form at least one high-reflective layer is conducted by physical vapor deposition or chemical vapor deposition and depositing a low refractive index layer material including low refractive index nanoparticles on the at least one high-reflective layer is conducted by a wet coating process.