Anti-reflective coating film having continuous gradient refractive index and coating method

Abstract

The anti-reflection coating film is a multilayer anti-reflective coating film coated on at least one surface of a substrate, and comprises: an Al2O3 layer on the substrate; at least one AlOxFy layer on the Al2O3 layer; an AlF3 layer on the uppermost layer among the AlOxFy layers; and a porous Al2O3 layer on the AlF3 layer, wherein the layers are arranged in the order of high refractive index to low refractive index from the substrate side toward the air side. By the combination of the above configuration, the coating film of the present disclosure exhibits an optimal continuous gradient refractive index from the air, thereby reducing reflectance and preventing reflection over a wider wavelength range and at multiple angles.

Description

Anti-reflective coating film having a continuous gradient refractive index and coating method

[0001] The present disclosure relates to an anti-reflective coating film having a continuous gradient refractive index and a coating method, wherein the anti-reflective coating film comprises an Al2O3 layer on a substrate, wherein each layer is arranged in order from high refractive index to low refractive index from the substrate side to the air side; and one or more AlO on the Al2O3 layer. x F y Layer; the AlO x F y It includes an AlF3 layer on the uppermost layer of the layers; and a porous Al2O3 layer on the AlF3 layer.

[0002] Optical elements, such as lenses, filters, and displays for smartphones and tablets, are manufactured based on optical substrates such as quartz substrates, sapphire substrates, optical glass, and optical plastics. An anti-reflective coating is applied to these substrates. Reflection is the phenomenon in which some or all of light returns to the original medium when it travels through one medium and reaches the boundary with a medium of a different refractive index, and a coating designed to prevent this is called an anti-reflective coating.

[0003] When the refractive index of the above-mentioned material increases, the reflectance of the light incident surface and the light exit surface (light inlet / outlet surface) increases, and in the use of the optical element, the amount of effective light reaching the image surface decreases, and due to unnecessary reflected light, double images or flares are formed on the image surface, thereby degrading optical performance. To prevent this, anti-reflective coatings mainly use methods such as increasing transmittance by minimizing reflected light and minimizing scattered reflected light by changing the angle of reflected light.

[0004] With the popularization of energy devices such as optical devices and solar cells, there is an increasing need for anti-reflective coatings that can prevent reflection from a wider range of wavelengths and multiple angles. In addition, while anti-reflective coatings formed with a layered structure can have a gradient refractive index, there are limitations to reducing reflectivity due to the large difference in refractive index between the layers and, above all, the discontinuous refractive index of the outermost layer from air.

[0005] Accordingly, there is a need for research and development on an anti-reflection coating film having a continuous gradient refractive index from air to the substrate, and on excellent anti-reflection coating technology capable of exhibiting anti-reflection effects across a wide range of wavelengths and multiple angles.

[0006] In one aspect of the present disclosure, an anti-reflective coating film having a continuous gradient refractive index and a coating method are provided.

[0007] In one aspect of the present disclosure, an anti-reflective coating film and a coating method are provided that minimize the difference in refractive index with respect to air.

[0008] In one aspect of the present disclosure, an anti-reflective coating film having a continuous gradient refractive index from air to a substrate and a coating method are provided.

[0009] In one aspect of the present disclosure, an anti-reflective coating film and a coating method are provided, comprising an intermediate refractive index material having a continuous gradient refractive index between a high refractive index material and a low refractive index material.

[0010] In one aspect of the present disclosure, the present invention aims to provide an excellent anti-reflective coating film and a coating method having high transmittance even in broadband wavelength and visible light wavelength ranges.

[0011] In one aspect of the present disclosure, the aim is to provide a coating film and a coating method that enhance stability and process convenience.

[0012] In one aspect of the present disclosure, an optical element having excellent optical performance is provided by applying an anti-reflective coating film and a coating method according to the present disclosure.

[0013] The anti-reflective coating film of the present disclosure is an anti-reflective coating film having a laminated structure coated on one or more surfaces of a substrate, comprising: an Al2O3 layer on the substrate; and one or more Al2O3 layers on the Al2O3 layer. x F y Layer; the AlO x F y The uppermost layer of the layers includes an AlF3 layer; and a porous Al2O3 layer on the AlF3 layer; wherein each layer is arranged in order from high refractive index to low refractive index from the substrate side to the air side.

[0014] In one embodiment, the refractive index of the porous Al2O3 layer may be 1.01 or higher and less than 1.30.

[0015] In one embodiment, the thickness of the porous Al2O3 layer may be 10 to 500 nm.

[0016] In one embodiment, the porous Al2O3 layer may have a porosity of 5 to 95% that is gradient from the substrate side to the air side.

[0017] In one embodiment, the one or more AlOs x F y The layer may include an AlOF layer.

[0018] In one embodiment, the refractive index of the Al2O3 layer on the substrate may be 1.60 to 1.90.

[0019] In one embodiment, the refractive index of the AlF3 layer may be 1.30 to 1.45.

[0020] In one embodiment, the AlO x F y The refractive index of the layer may be greater than 1.35 and less than 1.90.

[0021] In one embodiment, the Al2O3 layer on the substrate, one or more AlO x F y Layer and the AlO x F y The total thickness of the layered AlF3 layer can be 30 to 500 nm.

[0022] In one embodiment, the Al2O3 layer on the substrate, one or more AlO x F y Layer and the AlO x F y In the layered AlF3 layer, the thickness of each layer may be 1 / 100 to 1 / 10 of the anti-reflection target wavelength value.

[0023] In one embodiment, the aforementioned coating film may have a transmittance of 90% or more at a wavelength of 190 nm to 2000 nm and a maximum transmittance value of 95% or more.

[0024] In addition, the anti-reflective coating method according to the present disclosure comprises the step of depositing an Al2O3 layer on one or more surfaces of a substrate; and on the Al2O3 layer on the substrate, one or more AlO x F y Step of forming a layer; the AlO x F y The method includes the step of depositing an AlF3 layer on the uppermost layer of the layers; and the step of depositing an Al2O3 layer on the AlF3 layer and immersing it in heated water to form a porous Al2O3 layer on the AlF3 layer.

[0025] In one embodiment, the temperature of the heated water may be 50 to 100°C.

[0026] In one embodiment, it may be immersed for 5 to 60 minutes.

[0027] In one embodiment, the deposition may be performed by atomic layer deposition.

[0028] In one embodiment, the atomic layer deposition method may be performed using one or more types selected from aluminum chloride (AlCl3), trimethylaluminum (Al(CH3)3), triethylaluminum (Al2(C2H5)6) and aluminum acetate (Al(acac)3) as aluminum precursors.

[0029] In one embodiment, the atomic layer deposition method may be such that the Al2O3 layer is deposited under H2O conditions.

[0030] In one embodiment, the atomic layer deposition method may be such that the AlF3 layer is deposited under HF conditions.

[0031] In one embodiment, the one or more AlOs in the atomic layer deposition method x F y The layer may be formed by alternately depositing Al2O3 or AlF3 under H2O or HF conditions.

[0032] In one embodiment, an anti-reflective coating film having a continuous gradient refractive index and a coating method can be provided.

[0033] In one embodiment, an anti-reflective coating film and a coating method that minimize the difference in refractive index with air can be provided.

[0034] In one embodiment, an anti-reflective coating film having a continuous gradient refractive index from air to a substrate and a coating method can be provided.

[0035] In one embodiment, an anti-reflective coating film and a coating method may be provided, comprising an intermediate refractive index material having a continuous gradient refractive index between a high refractive index material and a low refractive index material.

[0036] In one embodiment, an excellent anti-reflective coating film and a coating method having high transmittance even in broadband wavelength and visible light wavelength ranges can be provided.

[0037] In one embodiment, a coating film and a coating method with improved stability and process convenience can be provided.

[0038] In one embodiment, an optical element having excellent optical performance can be provided by applying the anti-reflective coating film and coating method according to the present disclosure.

[0039] FIG. 1 illustrates, in one embodiment of the present disclosure, a cycle for forming Al2O3 or AlF3 by atomic layer deposition, and one or more AlO2s from said cycle, adjusted to an intermediate refractive index between them. x F y This is a drawing showing the formation of.

[0040] FIG. 2 illustrates one or more AlO2s formed by combining an Al2O3 cycle and an AlF3 cycle by atomic layer deposition in one embodiment of the present disclosure. x F y This is a graph showing the intermediate refractive index and the refractive index ranging from the high refractive index of Al2O3 to the low refractive index of AlF3.

[0041] FIG. 3 illustrates, in one embodiment of the present disclosure, an Al2O3 layer on a sapphire substrate, and three different AlO x F y Layer and the AlO x F y This is a transmittance graph according to an experimental example having a layered AlF3 layer structure.

[0042] FIG. 4 is a diagram showing an exemplary structure of an anti-reflective coating film in one embodiment of the present disclosure. The structure is consistent with the structure of Examples 1 to 4.

[0043] FIG. 5 is an SEM image of an experiment in which surface changes of an AIF3 thin film and an Al2O3 thin film were observed for a specific time in water heated to 90°C in one embodiment of the present disclosure.

[0044] FIG. 6 is an SEM image showing an anti-reflective coating film and a porous Al2O3 layer of the coating film in one embodiment of the present disclosure.

[0045] FIG. 7 is a transmittance graph of Example 1 and Comparative Examples 1 and 2 in one embodiment of the present disclosure.

[0046] FIG. 8 is a transmittance graph of Examples 1 to 4 and Comparative Example 3 in one embodiment of the present disclosure.

[0047] The following detailed description of the present disclosure is merely illustrative and is not limited to the specific embodiments described illustratively.

[0048] The terms used in this disclosure have been selected to be as widely used as possible, taking into account the function of this disclosure; however, these terms may vary depending on the intent of those skilled in the relevant field, case law, the emergence of new technologies, etc. Unless otherwise defined, technical and scientific terms used may have the meaning commonly understood by those skilled in the art to which this disclosure pertains.

[0049] In the present disclosure and claims, terms such as "comprising" or "having" mean that the features or components described in the specification are present, and unless specifically limited, this does not exclude the possibility that one or more other features or components may be added.

[0050] Singular expressions used in the present disclosure and claims include plural expressions unless the context clearly specifies them to be singular. Additionally, plural expressions include singular expressions unless the context clearly specifies them to be plural.

[0051] Additionally, the numerical ranges used in this disclosure include lower and upper limits and all values ​​within the range, increments logically derived from the form and width of the defined range, all of which are limited values, and all possible combinations of upper and lower limits of the numerical range defined in different forms. Unless specifically defined in this disclosure, values ​​outside the numerical range that may occur due to experimental error or rounding of values ​​are also included in the defined numerical range.

[0052] Terms such as "approximately" used in this disclosure are used to encompass tolerances when tolerances exist.

[0053] The anti-reflective coating film and coating method according to the present disclosure are described below.

[0054] The anti-reflective coating film according to the present disclosure is an anti-reflective coating film having a laminated structure coated on one or more surfaces of a substrate, comprising: an Al2O3 layer on the substrate; and one or more AlO2 layers on the Al2O3 layer. x F y Layer; the AlO x F y The uppermost layer of the layers includes an AlF3 layer; and a porous Al2O3 layer on the AlF3 layer; wherein each layer is arranged in order from high refractive index to low refractive index from the substrate side to the air side.

[0055] In addition, the anti-reflective coating method according to the present disclosure comprises the step of depositing an Al2O3 layer on one or more surfaces of a substrate; and on the Al2O3 layer on the substrate, one or more AlO x F y Step of forming a layer; the AlO x F yThe method comprises the steps of: depositing an AlF3 layer on the uppermost layer of the layers; and depositing an Al2O3 layer on the AlF3 layer and immersing it in heated water to form a porous Al2O3 layer on the AlF3 layer. By the coating method, an anti-reflective coating film with a gradient refractive index structure can be coated, and may be identical or similar to the anti-reflective coating film described above.

[0056] The coating film of the present disclosure can exhibit an optimal continuous gradient refractive index structure from air to a substrate by arranging each layer of the coating film from the combination of the above-described stacking structure and composition in order from high refractive index to low refractive index from the substrate side to the air side.

[0057] More specifically, first, the coating film of the present disclosure comprises an Al2O3 layer on a substrate, and one or more Al2O3 layers. x F y Layer and AlO x F y Including an AlF3 layer on the uppermost layer of the layers, high, medium, and low refractive indices can be exhibited, respectively; in particular, one or more AlO2s with a medium refractive index are combined with Al2O3 having a high refractive index and AlF3 having a low refractive index to control the refractive index to an intermediate level. x F y Including layers, the coating film from the above components can exhibit a continuous gradient refractive index.

[0058] In addition, the coating film of the present disclosure is AlO x F y By including an AlF3 layer on the uppermost layer, continuous gradient refractive index and coating film stability can be secured due to the unique low refractive index and high stability of AlF3. In particular, during the process of forming porous Al2O3, the AlF3 layer exhibits a stable structure without significant changes in surface structure even when exposed to heated water, thereby protecting other stacked layers located beneath the AlF3 layer.

[0059] In addition, the coating film of the present disclosure comprises a porous Al2O3 layer on an AlF3 layer, thereby minimizing the difference in refractive index with air to exhibit a continuous gradient refractive index from air to the substrate, and can exhibit an excellent anti-reflection effect by having high transmittance over a wide range of wavelengths. The porous Al2O3 layer may be formed by immersing Al2O3 in heated water to change its surface structure into porous Al2O3.

[0060] That is, in one embodiment, the anti-reflective coating film and the coating method are, for example, an anti-reflective coating film having a continuous gradient refractive index formed on a sapphire substrate, wherein AlO during the WIP (Water-induced Porosification) process x F y Due to the stability of the AlF3 layer deposited on the uppermost layer, the anti-reflective coating structure beneath the AlF3 layer is protected from heated water, and the surface structure of Al2O3 on the AlF3 layer changes to form a porous Al2O3 layer, which may reduce the refractive index with respect to air.

[0061] In the case of conventional anti-reflective coatings, they are limited to specific wavelengths or have limitations in reducing reflectance because it is difficult to achieve a continuous refractive index due to the large difference in refractive index with air. In contrast, the anti-reflective coating film of the present disclosure exhibits an optimal continuous gradient refractive index from the combination of the above components, thereby reducing reflectance and preventing reflection over a wider wavelength range and at multiple angles.

[0062] Each component is described in detail below.

[0063] In one embodiment, the substrate is not limited to any technical field in which an anti-reflective coating is applied as an optical substrate, and examples include optical elements and substrates used in displays, solar cells, etc. Depending on the substrate, the refractive index characteristics may differ, and the refractive index required for the coating film may differ slightly. In one embodiment, the anti-reflective coating film of the present disclosure may exhibit a refractive index lower than that of the substrate at the same wavelength.

[0064] In one embodiment, the coating film may be coated on one or more surfaces of a substrate, that is, on one or multiple surfaces of the substrate. The multiple surfaces may be a light incident surface and a light exit surface of the substrate, and, for example, may be one surface of the substrate and an opposite surface corresponding to that surface. When the coating film is coated on both the light incident surface and the light exit surface of the substrate, an effect of reducing reflectance appears on both surfaces, which may be desirable in terms of the performance of the optical element.

[0065] In one embodiment, the coating film of the present disclosure comprises an Al2O3 layer having a high refractive index on the substrate, and one or more Al2O3 layers having an intermediate refractive index on the Al2O3 layer. x F y Layer, one or more of the above AlO x F y An AlF3 layer having a low refractive index and a porous Al2O3 layer having a lower refractive index than the AlF3 layer may be sequentially provided on the uppermost layer of the layers. In the above structure, the porous Al2O3 layer comes into contact with air, and a continuous gradient refractive index from the substrate to the air and an excellent anti-reflection effect can be achieved.

[0066] In one embodiment, the Al2O3 layer may refer to a thin film containing Al2O3 or composed of Al2O3. Additionally, the AlF3 layer may refer to a thin film containing AlF3 or composed of AlF3. Furthermore, the one or more AlO x F y The layer is one or more types of AlO x F y Contains or one or more types of AlO x F y It may mean a thin film composed of. In addition, the porous Al2O3 layer may include porous Al2O3 that exhibits porosity due to a roughened surface structure, or it may mean a thin film composed of porous Al2O3.

[0067] In one embodiment, the anti-reflective coating film of the present disclosure can exhibit an anti-reflective effect for wavelengths in the ultraviolet to infrared region corresponding to a wavelength range of 190 nm to 2000 nm, narrowly 190 nm to 1700 nm, and more narrowly 300 nm to 1200 nm.

[0068] In addition, more specifically, the anti-reflective coating film may exhibit an anti-reflective effect for wavelengths in the visible light region, and the visible light region may be 380 to 800 nm, 380 to 780 nm, 380 to 750 nm, 400 to 800 nm, 400 to 780 nm, 400 to 750 nm, or values ​​within these wavelength ranges. In addition, the anti-reflective coating film may exhibit an anti-reflective effect for wavelengths in the ultraviolet and infrared regions, and the ultraviolet region may be 190 nm or more to less than 400 nm, narrowly 190 nm to less than 380 nm or within these wavelength ranges, and the infrared region may be greater than 750 nm to 2000 nm or less, greater than 780 nm to 2000 nm or narrowly 780 nm to 1700 nm or within these wavelength ranges.

[0069] The refractive index of each layer is explained in more detail below.

[0070] In one embodiment, the refractive index of the Al2O3 layer may be 1.60 to 1.90. A higher refractive index may be exhibited closer to a short wavelength, and a lower refractive index may be exhibited closer to a long wavelength. Specifically, it may be 1.60 or higher, 1.63 or higher, 1.65 or higher, 1.68 or higher, 1.70 or higher, 1.72 or higher, 1.75 or higher, 1.90 or lower, 1.85 or lower, 1.80 or lower, 1.78 or lower, 1.75 or lower, 1.73 or lower, 1.70 or lower, 1.67 or lower, or a value between the above numerical ranges. More specifically, the refractive index of the Al2O3 layer may have a value of 1.65 to 1.90 or within the above ranges in the ultraviolet region, and may have a value of 1.60 to 1.70 or within the above ranges in the visible light and infrared regions. At the same wavelength, the Al2O3 layer may have a lower refractive index than the substrate, and by positioning the Al2O3 layer having a high refractive index within the above range at the lowest point in contact with the substrate, a coating film having a continuous gradient refractive index from the substrate to the air side can be provided, and the coating film can exhibit an excellent anti-reflection effect.

[0071] In one embodiment, the refractive index of the AlF3 layer may be 1.30 to 1.45. A higher refractive index may be exhibited closer to a short wavelength, and a lower refractive index may be exhibited closer to a long wavelength. Specifically, it may be 1.30 or higher, 1.31 or higher, 1.32 or higher, 1.33 or higher, 1.35 or higher, 1.37 or higher, 1.45 or lower, 1.43 or lower, 1.40 or lower, 1.39 or lower, 1.38 or lower, 1.37 or lower, or a value between the above numerical ranges. More specifically, the refractive index of the AlF3 layer may have a value of 1.35 to 1.45 or within these ranges in the ultraviolet region, and may have a value of 1.30 to 1.40 or within these ranges in the visible light and infrared regions. By having a low refractive index as in the above range, the AlF3 layer can provide a coating film having a continuous gradient refractive index from the air side having a low refractive index, and the coating film can exhibit an excellent anti-reflection effect.

[0072] In one embodiment, the refractive index of the porous Al2O3 layer may be 1.01 or higher and less than 1.30. A higher refractive index may be exhibited closer to a short wavelength, and a lower refractive index may be exhibited closer to a long wavelength. Specifically, it may be 1.01 or higher, 1.05 or higher, 1.10 or higher, 1.13 or higher, 1.15 or higher, 1.17 or higher, 1.20 or higher, less than 1.30, less than 1.27, less than 1.25, less than 1.23, less than 1.21, less than 1.20, or a value between the above numerical ranges. At the same wavelength, the porous Al2O3 layer may have a lower refractive index than the AlF3 layer, and when in contact with air, which has a very low refractive index, it may exhibit a low refractive index as described above, thereby minimizing the difference in refractive index with air. In other words, this allows for the provision of a coating film having a continuous gradient refractive index optimized from air, and can exhibit a superior anti-reflection effect compared to conventional methods.

[0073] In one embodiment, the porous Al2O3 is a porous Al2O3, and may be a form in which the surface structure is changed to porous by immersing Al2O3 in heated water. Al2O3, a conventional high-refractive-index material, exhibits porosity through the water-induced porosification (WIP) process, and its refractive index is significantly reduced, so that it may have a lower refractive index than the AlF3 layer as described above. As an example, the porous Al2O3 may exhibit a surface structure shape similar to grass.

[0074] In one embodiment, the temperature of the heated water may be 50 to 100°C. Specifically, it may be 50°C or higher, 70°C or higher, 80°C or higher, 90°C or higher, 100°C or lower, or a value between the above numerical ranges. At temperatures below the above range, porosity is insufficient, so the refractive index is not sufficiently lowered or the rate is very slow, and at temperatures exceeding the above range, the physical properties of the porous Al2O3 may be deformed or the underlying AIF3 may be affected. That is, performing the process at a temperature within the above range allows the porosity process to be sufficiently carried out without affecting the anti-reflective structure of the underlying coating film.

[0075] In one embodiment, the immersion time may be performed for 5 to 60 minutes. Specifically, it may be 5 minutes or more, 10 minutes or more, 15 minutes or more, 60 minutes or less, 45 minutes or less, 30 minutes or less, 25 minutes or less, or a value between the above numerical ranges. Porosity may be insufficient at a time below the above range, and at a time above the above range, there may be no significant difference in terms of porosity and, above all, it may affect the underlying AIF3. That is, performing the process within the above range allows the porosity process to be sufficiently achieved without affecting the anti-reflective structure of the underlying coating film. Preferably, performing the process for 10 to 30 minutes, and more preferably for 10 minutes or more to less than 25 minutes, may exhibit excellent transmittance over a wider wavelength range.

[0076] In one embodiment, the porous Al2O3 layer can be dried by N2 blow drying after immersion.

[0077] In one embodiment, the thickness of the porous Al2O3 layer may be 10 to 500 nm. Specifically, it may be 10 nm or more, 30 nm or more, 50 nm or more, 80 nm or more, 100 nm or more, 130 nm or more, 150 nm or more, 170 nm or more, 500 nm or less, 450 nm or less, 400 nm or less, 350 nm or less, 300 nm or less, 250 nm or less, 200 nm or less, or have a value between the above numerical ranges. The thickness of the porous Al2O3 layer may increase compared to the Al2O3 layer before immersion in heated water. The thickness of the porous Al2O3 layer may have different optimal values ​​depending on the wavelength range intended for the anti-reflection effect.

[0078] For example, for an anti-reflection effect in the visible light region, the thickness of the porous Al2O3 layer may be optimized to a thickness of 50 to 200 nm, and the thickness of the initial Al2O3 layer deposited therein may be 20 to 50 nm. As an experimental example, the initial Al2O3 layer deposited to a thickness of 50 nm may be immersed in heated water to form a porous Al2O3 layer with a thickness of 150 to 200 nm, but this may vary depending on the water temperature, immersion time, initial deposition thickness, etc.

[0079] In one embodiment, the porous Al2O3 layer may have a porosity of 5 to 95% that is gradient from the substrate side to the air side. Specifically, the porous Al2O3 layer may exhibit a form in which the number or size of pores increases from the substrate side to the air side, thereby increasing the porosity, and this may be a structure formed during the process of immersion in heated water. Since a higher porosity acts as a medium similar to air, the coating film of the present disclosure may further contribute to a continuous gradient refractive index structure from the porous Al2O3 layer exhibiting such gradient porosity.

[0080] In one embodiment, the root mean surface roughness (Rq) of the porous Al2O3 layer may be 20 to 50 nm. Specifically, it may be 20 to 50 nm, 25 to 50 nm, 25 to 45 nm, 30 to 50 nm, 30 to 45 nm, 30 to 40 nm, 35 to 50 nm, 35 to 45 nm, 40 to 50 nm, or a value between the above numerical ranges. This may be because the Al2O3 layer has a smooth surface before being immersed in heated water, so the Rq value is at the level of 0.1 to 0.3 nm, and then the surface structure changes as porosity is achieved, causing the roughness to gradually increase.

[0081] In one embodiment, the AlO in the visible light region x F yThe refractive index of the layer may be greater than 1.35 and less than 1.90. Specifically, it may be greater than 1.35, greater than 1.40, greater than 1.43, greater than 1.45, greater than 1.50, less than 1.90, less than 1.85, less than 1.70, less than 1.68, less than 1.65, or a value between the above numerical ranges. In addition, in one embodiment, under the same wavelength conditions, the AlO x F y The refractive index of the layer has a value smaller than the refractive index of the Al2O3 layer, and can have a value higher than the refractive index of the AlF3 layer. That is, the above AlO x F y The layer is the refractive index of the AlF3 layer under the same wavelength conditions. <AlO x F y Refractive index of the layer <Al2O3층의 굴절률의 관계식을 만족할 수 있다. AlO x F y The layer has an intermediate refractive index between the AlF3 layer and the Al2O3 layer as in the above range, thereby providing a coating film with a continuous gradient refractive index, and the coating film can exhibit an excellent anti-reflective effect.

[0082] In one embodiment, the AlO x F y The layer may be controlled to an intermediate refractive index as described above by including a composite of high-refractive-index Al2O3 and low-refractive-index AlF3, and the AlO x F y The refractive index of the layer can vary depending on the ratio of Al2O3 and AlF3. In other words, the refractive index can be controlled by changing it almost continuously between the two materials, Al2O3 and AlF3. An example is AlO x F y The higher the content of Al2O3 contained in the layer, the higher the refractive index can be, and the higher the content of AlF3, the lower the refractive index can be.

[0083] In one embodiment, two or more different AlOs x Fy In cases where layers are included, AlO is arranged in order from highest refractive index to lowest refractive index, from the lower Al2O3 layer side to the upper AlF3 layer side, according to the relative refractive indices between them. x F y The layers may be arranged. That is, two or more different AlOs x F y In the case of including a layer, AlO x F y The layer with the highest refractive index among the layers is in contact with the Al2O3 layer, and AlO x F y AlO with the lowest refractive index among the layers x F y The layer may come into contact with the AlF3 layer.

[0084] In one embodiment, the one or more AlOs x F y The layer is a single layer of AlO with one combination of x and y values. x F y Layers or two or more AlOs having different combinations of x and y values x F y It can mean a layer.

[0085] In one embodiment, the AlO x F y The x and y values ​​may represent the ratio of the combined Al2O3 and AlF3 included, simplified for aluminum as described above, expressed as positive numbers greater than 0 and less than 10. That is, two or more different AlO x F y The layer comprises two or more types of AlO with different ratios of complexed Al2O3 and AlF3, and consequently having different combinations of x and y values. x F y Each layer may be individually included, and these layers may exhibit different refractive indices.

[0086] In one embodiment, the AlO x Fy The layer may be a composite formed in a stacked form of alternating Al2O3 and AlF3. Specifically, the above AlO x F y The layer may include one or more Al2O3 layers and one or more AlF3 layers. The above AlO x F y Depending on the ratio of the Al2O3 layer and the AlF3 layer included in the layer, the combination of the x and y values ​​can be determined.

[0087] To explain with an example, two or more AlOs with different combinations of x and y values x F y The layer is the first AlO x F y Layer, second AlO x F y Layer, … , nth AlO x F y It may include layers, and each of these layers may include Al2O3 layers and AlF3 layers in different proportions.

[0088] In one embodiment, the AlO x F y Not only the ratio of Al2O3 and AlF3 in the layers, but also the alternating stacking of Al2O3 and AlF3 layers and the thickness of these layers can affect the refractive index.

[0089] In one embodiment, one AlO x F y In the layer, the thicknesses of one Al2O3 layer and one AlF3 layer may be the same or different from each other, and one AlO x F y The ratio of the sum of the total thicknesses of the Al2O3 layers to the sum of the total thicknesses of the AlF3 layers in the layer is the corresponding AlO x F y The ratio of Al2O3 to AlF3 in the layer may be the same or different.

[0090] In one embodiment, the AlO x F yIn the layers, the ratio of Al2O3 and AlF3 may refer to the volume ratio of the entire Al2O3 layer to the entire AlF3 layer, and may also refer to the ratio of the number of Al2O3 layers and AlF3 layers when the thickness of each layer is the same. Furthermore, in one embodiment, the AlO x F y The ratio of Al2O3 and AlF3 in the layer may be a ratio to the number of Al2O3 deposition cycles and AlF3 deposition cycles.

[0091] As an example, as shown in Fig. 1, by alternately performing deposition cycles of Al2O3 and AlF3 and varying the ratio of the number of deposition cycles, various forms of AlO with alternately stacked Al2O3 and AlF3 are obtained. x F y Layers can be manufactured. In addition, as an experimental example as shown in FIG. 2, various types of AlO can be produced to have various intermediate refractive indices in the range between Al2O3 and AlF3 by varying the cycle execution ratio. x F y It can be confirmed that it can be manufactured. In addition, FIG. 2 shows, as an example, Al2O3 layers, AlF3 layers, and AlO composited in various ratios. x F y The refractive index of the layer by wavelength can be checked.

[0092] In addition, in one embodiment, AlO is varied by changing the ratio of the number of cycles performed. x F y In the process of controlling the refractive index of the layer, the Al2O3 deposition cycle and the AlF3 deposition cycle may be performed alternately for every cycle, or if one of them performs one cycle, the other one performs multiple cycles, or if one of them performs multiple cycles, the other one also performs multiple cycles in the same manner, and may be repeated.

[0093] In one embodiment, the AlO x Fy The ratio of Al2O3 to AlF3 in the layer may be 1:0.1 to 10. Specifically, it may be 1:0.1 to 10, 1:0.3 to 10, 1:0.5 to 10, 1:0.1 to 8, 1:0.1 to 6, 1:0.1 to 5, or a value between the above numerical ranges.

[0094] In one embodiment, the one or more AlOs x F y The layer may include an AlOF layer. Additionally, the AlOF layer may be a composite of Al2O3 and AlF3 in a 1:1 ratio.

[0095] In one embodiment, one or more AlO x F y In each layer, each AlO x F y The layers can have the same thickness. In addition, each AlO x F y The thickness of the layer is the Al2O3 layer and AlO on the substrate. x F y The thickness of the layered AlF3 layer may be the same or similar.

[0096] In one embodiment, the Al2O3 layer on the substrate, one or more AlO x F y Layer and the AlO x F y The total thickness of the AlF3 layer may be 30 nm to 500 nm. Specifically, it may be 30 nm or more, 50 nm or more, 80 nm or more, 100 nm or more, 120 nm or more, 150 nm or more, 200 nm or more, 500 nm or less, 450 nm or less, 400 nm or less, 350 nm or less, 300 nm or less, 250 nm or less, 200 nm or less, 150 nm or less, or a value between the above numerical ranges. However, the optimal thickness may vary depending on the wavelength band for which the anti-reflection effect is targeted.

[0097] In one embodiment, the Al2O3 layer on the substrate, one or more AlO x F y Layer and the AlO x F y In the AlF3 layer, the thickness of each layer may be 1 / 100 to 1 / 10 of the anti-reflection target wavelength value. Specifically, it may be 1 / 100 or more, 1 / 80 or more, 1 / 60 or more, 1 / 50 or more, 1 / 40 or more, 1 / 10 or less, 1 / 15 or less, 1 / 20 or less, or a value between the above numerical ranges. Preferably, it may have a thickness between 1 / 20 and 1 / 10 of the anti-reflection target wavelength value. By controlling the thickness of each layer to a thickness within the above numerical ranges, the anti-reflection effect of the coating film at the anti-reflection target wavelength can be maximized.

[0098] In a specific embodiment, to maximize the anti-reflection effect in the visible light region, the Al2O3 layer on the substrate, one or more AlO x F y Layer and the AlO x F y The total thickness of the layered AlF3 layer can be optimized to a thickness of 30 nm to 300 nm. Preferably, a thickness of 50 to 200 nm, more preferably 100 to 200 nm, and most preferably 100 to 150 nm may be desirable. At the thickness within the above range, the maximum transmittance and high average transmittance within the wavelength range of visible light can be exhibited, thereby maximizing the anti-reflection effect for visible light. However, it is not necessarily limited to this, and as mentioned above, other optimized thickness values ​​between 30 nm and 500 nm may be used in the infrared and ultraviolet regions.

[0099] Regarding the anti-reflection effect for the above-mentioned visible light region, the Al2O3 layer on the substrate, one or more AlO x F y Layer and the AlO x F yAn experimental example optimizing the total thickness of the layered AlF3 layers and the thickness of each layer is described. In the example according to Fig. 3, the composition is identically an Al2O3 layer on a sapphire substrate, with three different AlO layers x F y Layer and the AlO x F y After designing a 5-layer structure consisting of three layers of AlF, the thickness of each layer was set to 10 nm, 20 nm, 30 nm, and 40 nm, and the total thickness was made to 50 nm, 100 nm, 150 nm, and 200 nm, and the anti-reflection effect was experimentally verified.

[0100] As a result, the average transmittance in the wavelength range of 400 to 1100 nm was 88.80%, 95.05%, 96.76%, and 96.94% at thicknesses of 50 nm, 100 nm, 150 nm, and 200 nm, respectively, and the maximum transmittance and corresponding wavelength at each thickness were 96.53% at 260 nm (50 nm thickness), 98.4% at 474 nm (100 nm thickness), 98.36% at 674 nm (150 nm thickness), and 98.38% at 885 nm (200 nm thickness). In addition, the 50 nm thickness showed a transmittance of approximately 92% at 400 nm, and the 200 nm thickness showed a transmittance of approximately 96% at 400 nm. For reference, the sapphire substrate showed an average transmittance of 85.84% and a peak transmittance of 86.13% at 1100 nm.

[0101] From these experimental results, in the coating film of the present disclosure, the Al2O3 layer on the substrate, one or more AlO x F y Layer and the AlO x F yRegarding the total thickness of the AlF3 layer, the optimal thickness can be appropriately adjusted according to the wavelength band where the anti-reflection effect is targeted, and it was confirmed that an anti-reflection effect can be exhibited within the wavelength range of visible light when the thickness is 30 to 200 nm, or more narrowly, 50 to 200 nm. However, since the average transmittance in the visible light region is relatively low in the case of a thickness of 50 nm, a thickness of 100 to 200 nm, which exhibits a higher average transmittance than this, may be preferable. Even better, a thickness of 100 to 150 nm can exhibit a higher average transmittance as well as a maximum transmittance within the visible light region, thereby maximizing the anti-reflection effect for visible light.

[0102] In light of the above experimental examples, particularly for an anti-reflection effect in the visible light region, in one embodiment, an Al2O3 layer on the substrate, one or more AlO x F y Layer and the AlO x F y In the layered AlF3 layer, the thickness of one layer may be 10 nm to 50 nm. Specifically, it may be 10 nm or more, 20 nm or more, 30 nm or more, 50 nm or less, 40 nm or less, or a value between the above numerical ranges. Preferably, when the thickness of one layer is 20 to 40 nm, it can exhibit a higher average transmittance in the visible light region as well as a maximum transmittance, thereby maximizing the anti-reflection effect for visible light.

[0103] However, as described above, the Al2O3 layer, one or more AlO2 x F y Layer and the AlO x F yThe thickness of a single layer in the AlF3 layer is not necessarily limited to this range and can be optimized to a value outside the above range depending on the region within the ultraviolet to infrared region where an anti-reflection effect is targeted. In one embodiment, the Al2O3 layer on the substrate, one or more AlO x F y Layer and the AlO x F y In the AlF3 layer, the thickness of each layer may be 10 to 100 nm. Specifically, it may be 10 nm or more, 20 nm or more, 30 nm or more, 40 nm or more, 50 nm or more, 100 nm or less, 80 nm or less, 50 nm or less, 40 nm, 30 nm or less, or a value between the above numerical ranges, and may be selected according to the anti-reflection target wavelength.

[0104] In one embodiment, the total thickness of the coating film may be 40 to 1000 nm. Specifically, for an anti-reflection effect in the visible light region, an Al2O3 layer on the substrate, one or more AlO x F y layer, the above AlO x F y When the total thickness of the layered AlF3 layer and the porous Al2O3 layer is 80 to 400 nm, it can preferably be 100 to 400 nm, and more preferably 100 to 300 nm.

[0105] Furthermore, in one embodiment, when the anti-reflective coating film of the present disclosure aims for an anti-reflective effect in the visible light region, experimentally confirmed results show that two or more different AlOs in the coating film x F y The difference in transmittance and anti-reflection effects resulting from the inclusion of layers in the composition may not show a significant difference. Therefore, for process convenience and efficiency, as an example, an Al2O3 layer, a single AlO x F y It may have a structure of a layer, an AlF3 layer, and a porous Al2O3 layer, but one or more AlOx F y It is acceptable to include layers, and it is not necessarily limited to this.

[0106] In one embodiment, the deposition may be performed by atomic layer deposition (ALD). For example, the ALD may be performed at a temperature of 100 to 400 °C and at 0.1 to 10 Torr.

[0107] In addition, in one embodiment, the process may be carried out by including one or more types selected from aluminum chloride (AlCl3), trimethylaluminum (Al(CH3)3), triethylaluminum (Al2(C2H5)6), and aluminum acetate (Al(acac)3) as the aluminum precursor. In one embodiment, an inert gas such as argon or nitrogen may be used as the carrier gas for the aluminum precursor.

[0108] In one embodiment, the Al2O3 layer may be deposited by atomic layer deposition under H2O conditions. Specifically, the Al2O3 layer may be deposited by injecting an aluminum precursor, purging with an inert gas, and then injecting H2O. In addition, in one embodiment, the AlF3 layer may be deposited under HF conditions. Specifically, the AlF3 layer may be deposited by injecting an aluminum precursor, purging with an inert gas, and then injecting HF. After each deposition cycle, the next cycle may be performed after purging with an inert gas again. As a non-limiting example, the injection step and the purging step may each be performed within 0.1 to 30 seconds.

[0109] In one embodiment, the Al2O3 layer may be deposited at a rate of 0.1 to 0.2 nm / cycle, and the AlF3 layer may be deposited at a rate of 0.05 to 0.15 nm / cycle. However, this may vary depending on changes in pressure, time, etc. in the ALD process, and is not necessarily limited thereto.

[0110] In addition, in one embodiment, the one or more AlOs x F y The layer may be formed by alternately depositing Al2O3 or AlF3 under H2O or HF conditions, and each deposition cycle may be performed as the aforementioned Al2O3 deposition cycle and AlF3 deposition cycle.

[0111] In one embodiment, the ALD process may be performed by further including spacers to form a coating film on both sides of the substrate.

[0112] In one embodiment, the coating film may exhibit an average transmittance of 90% or more at a wavelength of 190 nm to 2000 nm, more narrowly at 400 to 1100 nm, more narrowly at a wavelength in the visible light region, and preferably an average transmittance of 95% or more, most preferably an average transmittance of 97% or more, and a maximum transmittance value of 95% or more, preferably a maximum transmittance value of 99%.

[0113] In the following, embodiments of the present disclosure are further described with reference to specific experimental examples. The embodiments and comparative examples included in the experimental examples are merely illustrative of the present disclosure and are not intended to limit the appended claims. It is obvious to those skilled in the art that various changes and modifications to the embodiments are possible within the scope and spirit of the present disclosure, and that such variations and modifications fall within the scope of the appended claims.

[0114] [Example 1]

[0115] An atomic layer deposition (ALD) process was applied as follows to a sapphire substrate (thickness approximately 430 μm) to sequentially deposit an Al2O3 layer with a thickness of 33 nm, an AlOF layer with a thickness of 33 nm, and an AlF3 layer with a thickness of 33 nm on the substrate, and then an Al2O3 layer with a thickness of 50 nm was deposited once more on the AlF3 layer.

[0116] A spacer (thickness 700 μm) was introduced into the ALD chamber, and the same deposition process was performed on both sides of the sapphire substrate. The entire deposited substrate was then immersed in water heated to 90°C for 15 minutes to porous the Al2O3 layer on the AlF3 layer, followed by N2 blow drying. The stacked structure of the completed coating film was as shown in Fig. 4.

[0117] The above atomic layer deposition process was performed at 125 °C under 1 Torr conditions, and trimethylaluminium (TMA) was used as the aluminum precursor and N2 was used as the carrier gas for TMA and injected into the ALD chamber at a flow rate of 100 sccm.

[0118] The Al2O3 deposition cycle was performed at a rate of 0.15 nm / cycle. In this cycle, TMA was injected for 0.5 seconds, followed by purging with argon gas at 100 sccm for 10 seconds, and then Al2O3 was deposited by injecting H2O at 100 sccm for 1 second. Finally, argon purging was performed by injecting argon gas at 100 sccm for 15 seconds.

[0119] The AlF3 deposition cycle was performed at a rate of 0.1 nm / cycle. In this cycle, TMA was injected for 1 second, followed by purging with argon gas at 100 sccm for 30 seconds, and then AlF3 was deposited by injecting H2O at 100 sccm for 1 second. Then, argon purging was performed by injecting argon gas at 100 sccm for 30 seconds.

[0120] The deposition of AlOF was performed by alternating the deposition cycle of Al2O3 and the deposition cycle of AlF3 in a 1:1 ratio, specifically by performing the cycles five times each until a thickness of 33 nm was reached.

[0121] [Example 2]

[0122] The procedure was carried out in the same manner as Example 1, except that the sample was immersed in heated water for 10 minutes.

[0123] [Example 3]

[0124] The procedure was carried out in the same manner as Example 1, except that the sample was immersed in heated water for 25 minutes.

[0125] [Example 4]

[0126] The procedure was carried out in the same manner as Example 1, except that the sample was immersed in heated water for 30 minutes.

[0127] [Comparative Example 1]

[0128] In Example 1, the procedure was carried out in the same manner as Example 1, except that a 50 nm thick Al2O3 layer was not deposited once more on the AlF3 layer, i.e., a porous Al2O3 layer was not formed.

[0129] [Comparative Example 2]

[0130] In Example 1, only the process of depositing a 50 nm thick Al2O3 layer on a sapphire substrate and immersing it in heated water was performed identically and designated as Comparative Example 2.

[0131] [Comparative Example 3]

[0132] The procedure was carried out in the same manner as Example 1, except that the process of immersing the Al2O3 layer on the AlF3 layer in heated water after deposition was not performed.

[0133] [Evaluation Method]

[0134] 1. SEM

[0135] Changes in the surface structure of the porous Al2O3 layer according to immersion time were confirmed using FE-SEM (S-4800, Hitachi).

[0136] 2. Transmittance

[0137] Transmittance was measured using a UV-vis spectrophotometer (LAMBDA365+, Perkin Elmer) equipped with a film holder at a scan speed of 300 nm / min from 400 to 1100 nm.

[0138] The results evaluated using the above evaluation method are explained below.

[0139] First, Figure 5 shows SEM images observing changes in surface structure at different immersion times when AlF3 and Al2O3 thin films were immersed in water heated to 90°C. The AlF3 thin film exhibited excellent stability, although slight surface changes occurred at immersion times of 30 minutes or more. On the other hand, the Al2O3 thin film showed a result where the surface became rough and porosity increased, and the surface porosity increased further as the immersion time increased.

[0140] Figure 6 is an SEM image showing the anti-reflective coating film on a sapphire substrate and the porous Al2O3 layer of the coating film according to Example 1.

[0141] Next, the transmittance of the examples and comparative examples in FIGS. 7 and FIGS. 8 was compared.

[0142] Example 1 showed excellent transmittance of about 97% or more in a wide wavelength range of 400 to 1100 nm in FIGS. 7 and FIGS. 8, and preferably showed significantly excellent transmittance of about 99% in the range of 600 to 1100 nm.

[0143] On the other hand, in the case of GRIN ARC corresponding to Comparative Example 1 in Fig. 7, the transmittance of approximately 97% gradually decreased from 500 nm, and at 1100 nm, it showed a minimum transmittance of approximately 90%, exhibiting a significantly reduced anti-reflection effect compared to Example 1. In addition, in the case of Hy ARC (dotted line) corresponding to Comparative Example 2, it maintained a transmittance of approximately 94% from 400 to 1100 nm, but the maximum transmittance was also approximately 95%, showing a reduced anti-reflection effect compared to Example 1.

[0144] In addition, in Figure 8, Examples 2 to 4, in which Example 1 and the immersion times were changed to 10 minutes, 20 minutes, and 25 minutes, respectively, showed high transmittance compared to Comparative Example 3 (Al2O3scarificial / GRIN) in which no immersion was performed.

[0145] As described above, preferably, Example 1 exhibited excellent transmittance of about 97% or more in a wide wavelength range of 400 to 1100 nm and about 99% transmittance in the range of 600 to 1100 nm. In addition, particularly in the range of 400 nm to 800 nm, Example 2 exhibited a transmittance of at least about 93% to a maximum of about 99%, Example 3 maintained a transmittance of about 97% to 98%, and Example 4 also maintained a transmittance of about 96% to 97%, whereas Comparative Example 3 exhibited a reduced anti-reflection effect by showing a transmittance of about 75% to about 96%, which is significantly lower than the minimum value of the Examples.

[0146] In addition, in the 800 to 1100 nm range, Comparative Example 3 showed a transmittance of only about 96% to 97%, exhibiting a reduced anti-reflection effect compared to the significantly superior transmittance of Examples 1 and 2, which reached a maximum transmittance of about 99%. Furthermore, in the 800 to 1100 nm range, Examples 3 and 4 were at a similar level to Comparative Example 3, but from about 1000 nm onwards, they showed a transmittance higher than that of Comparative Example 3.

[0147] From this, it is confirmed that the embodiments of the present disclosure can achieve transmittance of up to 99% in the 400 to 1100 nm range, thereby exhibiting a very excellent anti-reflection effect, and also exhibit a significantly improved anti-reflection effect in a wide wavelength band including the visible light range compared to comparative examples.

[0148] From the evaluation results described above, it was confirmed that the anti-reflective coating film of the present disclosure, through the combination of the aforementioned configurations, exhibits an optimal continuous gradient refractive index from air to the substrate, thereby having a significant reduction in reflectance compared to conventional coatings and effectively preventing reflection even across a wide wavelength range.

[0149] Although embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments and may be implemented in various different forms, and those skilled in the art will understand that the present disclosure may be implemented in other specific forms without changing the technical concept or essential features of the present disclosure. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

1. An anti-reflective coating film having a laminated structure coated on one or more surfaces of a substrate, Al2O3 layer on the surface; One or more AlOs on the above Al2O3 layer x F y floor; The above AlO x F y AlF3 layer on the uppermost layer of the layers; and It includes a porous Al2O3 layer on the above AlF3 layer, An anti-reflective coating film in which each layer is arranged in order from high refractive index to low refractive index from the substrate side to the air side.

2. In Paragraph 1, An anti-reflective coating film having a refractive index of 1.01 or higher and less than 1.30 of the porous Al2O3 layer.

3. In Paragraph 1, An anti-reflective coating film having a porous Al2O3 layer with a thickness of 10 to 500 nm.

4. In Paragraph 1, The above porous Al2O3 layer has a porosity of 5 to 95% that is gradient from the substrate side to the air side, and is an anti-reflective coating film.

5. In Paragraph 1, The above one or more AlO x F y An anti-reflective coating film comprising an AlOF layer.

6. In Paragraph 1, An anti-reflective coating film having a refractive index of 1.60 to 1.90 of the Al2O3 layer described above.

7. In Paragraph 1, An anti-reflective coating film having a refractive index of 1.30 to 1.45 of the above AlF3 layer.

8. In Paragraph 1, The above AlO x F y Anti-reflective coating film having a refractive index greater than 1.35 and less than 1.

90.

9. In Paragraph 1, Al2O3 layer as described above, one or more AlO x F y Layer and the AlO x F y An anti-reflective coating film having a total thickness of 30 to 500 nm of the layered AlF3 layer.

10. In Paragraph 1, Al2O3 layer as described above, one or more AlO x F y Layer and the AlO x F y An anti-reflective coating film in which, in a layer of AlF3, the thickness of each layer is 1 / 100 to 1 / 10 of the anti-reflective target wavelength value.

11. A coating film according to any one of claims 1 to 10, An anti-reflective coating film having a transmittance of 90% or more at a wavelength of 190 nm to 2000 nm and a maximum transmittance value of 95% or more.

12. A step of depositing an Al2O3 layer on one or more surfaces of the substrate; On the Al2O3 layer described above, one or more AlO x F y Step of forming a layer; The above AlO x F y A step of depositing an AlF3 layer on the uppermost layer of the layers; and An anti-reflective coating method comprising the step of depositing an Al2O3 layer on the AlF3 layer and immersing in heated water to form a porous Al2O3 layer on the AlF3 layer.

13. In Paragraph 12, An anti-reflective coating method in which the temperature of the heated water is 50 to 100 ℃.

14. In Paragraph 13, The step of forming the porous Al2O3 layer above; is an anti-reflective coating method in which the layer is immersed for 5 to 60 minutes.

15. In Paragraph 12, An anti-reflective coating method in which the above deposition is performed by atomic layer deposition.

16. In Paragraph 15, An anti-reflective coating method wherein the atomic layer deposition described above is performed by including one or more types of aluminum precursors selected from aluminum chloride (AlCl3), trimethylaluminum (Al(CH3)3), triethylaluminum (Al2(C2H5)6) and aluminum acetate (Al(acac)3) as aluminum precursors.

17. In Paragraph 15, The step of depositing the above Al2O3 layer is deposited under H2O conditions, an anti-reflective coating method.

18. In Paragraph 15, The step of depositing the above AlF3 layer is deposited under HF conditions, an anti-reflective coating method.

19. In Paragraph 15, The above one or more AlO x F y An anti-reflective coating method in which a layer is formed by alternately depositing Al2O3 or AlF3 under H2O or HF conditions.

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