Antireflection film

Abstract

To provide an antireflection film that is less likely to generate cracks even when bent or tensile stress is applied.SOLUTION: The antireflection film is formed on a surface of a substrate. The antireflection film includes at least one unit structures. Each unit structure includes a low refractive index layer having a refractive index lower than that of the substrate, and a high refractive index layer having a refractive index higher than that of the substrate and provided on a side of the substrate relative to the low refractive index layer. The high refractive index layer contains, for example, (A) at least one of niobium and cerium, (B) carbon, (C) fluorine, (D) oxygen, and (E) at least one of indium, tin, and bismuth.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to anti-reflective coatings. [Background technology]

[0002] There is a known technology for imparting functionality to a substrate by forming a thin film on the surface of the substrate. One example of such a thin film is an anti-reflection film. Anti-reflection films are disclosed in Patent Documents 1 and 2. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-65437 [Patent Document 2] Patent Publication No. 2021-198807 Summary of the Invention [Problem to be solved by the invention]

[0004] When an anti-reflection film is formed on a flexible substrate such as a flexible display, the anti-reflection film must be resistant to cracking even when bent or subjected to tensile stress.

[0005] In one aspect of the present disclosure, it is preferable to provide an anti-reflection film that is less likely to crack even when bent or subjected to tensile stress. [Means for solving the problem]

[0006] One aspect of the present disclosure is an anti-reflection coating formed on a surface of a substrate, the anti-reflection coating including a low-refractive index layer, the low-refractive index layer being an outermost layer of the anti-reflection coating and having a refractive index lower than that of the substrate, the low-refractive index layer including one or more of (a) silicon, (b) carbon, (c) fluorine, (d) oxygen, and (e) indium, tin, and bismuth. The anti-reflection film according to one aspect of the present disclosure is less likely to crack even when bent or subjected to tensile stress.

[0007] Another aspect of the present disclosure is an antireflection coating formed on a surface of a substrate, the antireflection coating comprising one or more units. The unit comprises a low-refractive index layer having a refractive index lower than that of the substrate, and a high-refractive index layer having a refractive index higher than that of the substrate and provided closer to the substrate than the low-refractive index layer. The high-refractive index layer contains (A) one or more of niobium and cerium, (B) carbon, (C) fluorine, (D) oxygen, and (E) one or more of indium, tin, and bismuth. The antireflection film according to another aspect of the present disclosure is less likely to crack even when bent or subjected to tensile stress.

[0008] Another aspect of the present disclosure is an antireflection coating formed on a surface of a substrate, the antireflection coating comprising one or more units. The unit comprises a low-refractive index layer having a refractive index lower than that of the substrate, and a high-refractive index layer having a refractive index higher than that of the substrate and provided closer to the substrate than the low-refractive index layer. The low-refractive index layer contains one or more of (a) silicon, (b) carbon, (c) fluorine, (d) oxygen, and (e) indium, tin, and bismuth.

[0009] The antireflection film according to another aspect of the present disclosure is less likely to crack even when bent or subjected to tensile stress. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a side cross-sectional view illustrating the configuration of a substrate and an anti-reflection film in a first embodiment. [Figure 2] FIG. 10 is a side cross-sectional view illustrating the configuration of a substrate and an anti-reflection film in a second embodiment. [Figure 3] FIG. 10 is a side cross-sectional view illustrating the configuration of a substrate and an anti-reflection film in a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Exemplary embodiments of the present disclosure will be described with reference to the drawings. First Embodiment 1. Composition of anti-reflection coating 1 The structure of an antireflection coating 1 will be described with reference to FIG. 1. The antireflection coating 1 is formed on the surface of a substrate 3. In the first embodiment, the antireflection coating 1 is formed by a low refractive index layer 5. The low refractive index layer 5 is the outermost layer of the antireflection coating 1. In this specification, the outermost layer means the layer formed on the outermost side as viewed from the substrate 3.

[0012] The refractive index n1 of the low refractive index layer 5 is lower than the refractive index n0 of the substrate 3. The low refractive index layer 5 contains one or more of (a) silicon, (b) carbon, (c) fluorine, (d) oxygen, and (e) indium, tin, and bismuth.

[0013] For example, if the substrate 3 is made of inorganic glass and has a refractive index n0 of 1.52, the refractive index n1 is less than 1.52. For example, if the substrate 3 is made of a resin film and has a refractive index n0 of 1.6, the refractive index n1 is less than 1.6.

[0014] There are no particular limitations on the compounding ratio of (a) silicon, (b) carbon, (c) fluorine, and (d) oxygen in the low refractive index layer 5. The low refractive index layer 5 may contain two or more of indium, tin, and bismuth, or may contain all of indium, tin, and bismuth. There are no particular limitations on the compounding ratio of indium, tin, and bismuth in the low refractive index layer 5.

[0015] Examples of the low refractive index layer 5 include the following: The main component of the low refractive index layer 5 is silicon oxide. A portion of the silicon oxide is substituted with an organic fluorine compound. The low refractive index layer 5 contains a small amount of indium, tin, or bismuth.

[0016] 2. Method for forming anti-reflection coating 1 The anti-reflection coating 1 can be formed by, for example, a sputtering method. The target material used in the sputtering method includes, for example, silicon oxide-polytetrafluoroethylene (PTFE) containing indium.

[0017] The target material is silicon oxide (SiO2), PTFE ((C2F4) n ), and indium (In). Therefore, the formed anti-reflection coating 1 contains silicon (Si), carbon (C), fluorine (F), oxygen (O), and indium (In).

[0018] The target material may contain at least one of tin (Sn) and bismuth (Bi) instead of or in addition to indium. In this case, the formed anti-reflection coating 1 contains at least one of tin and bismuth instead of or in addition to indium. When indium, tin, or bismuth is used as a sintering aid in producing a sputtering target, the strength of the target can be improved.

[0019] The anti-reflection film 1 may be formed by, for example, a chemical vapor deposition (CVD) method, an atomic layer deposition (ALD) method, a pulsed laser deposition (PLD) method, or a vacuum deposition method.

[0020] 3. Effects of Anti-Reflection Coating 1 (1A) The anti-reflection coating 1 suppresses reflection. Note that the refractive index n1 changes when the anti-reflection coating 1 contains indium, tin, or bismuth. (1B) The anti-reflection coating 1 contains, for example, an oxide of silicon. In this case, the anti-reflection coating 1 has scratch resistance.

[0021] (1C) Even when the anti-reflection coating 1 is bent or subjected to tensile stress, cracks are unlikely to occur in the anti-reflection coating 1. The reason for this is presumed to be as follows: Carbon and fluorine contained in the anti-reflection coating 1 bond to form organic fluorine bonds such as fluoroalkyl groups. When the anti-reflection coating 1 is bent or subjected to tensile stress, the organic fluorine bonds expand and contract, dispersing the external force applied to the entire anti-reflection coating 1 and thereby suppressing the occurrence of cracks.

[0022] Second Embodiment 1. Composition of anti-reflection coating 1 The structure of the antireflection coating 1 will be described with reference to FIG. 2. The antireflection coating 1 is formed on the surface of a substrate 3. The antireflection coating 1 includes one or more unit elements 7. When the antireflection coating 1 includes two or more unit elements 7, the two or more unit elements 7 are stacked in the thickness direction of the substrate 3. The thickness direction of the substrate 3 is the vertical direction in FIG. 2. In this embodiment, the unit element 7 closest to the substrate 3 is in contact with the substrate 3. The number of unit elements 7 is, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10. The number of unit elements 7 may be 11 or more.

[0023] Each of the units 7 includes a low refractive index layer 5 and a high refractive index layer 9. The refractive index n1 of the low refractive index layer 5 is lower than the refractive index n0 of the substrate 3. The refractive index n2 of the high refractive index layer 9 is higher than the refractive index n0 of the substrate 3. In one unit 7, the high refractive index layer 9 is provided closer to the substrate 3 than the low refractive index layer 5.

[0024] The low refractive index layer 5 in this embodiment has, for example, the same configuration as the low refractive index layer 5 in the first embodiment. In this case, the configuration of the high refractive index layer 9 is not particularly limited. The high refractive index layer 9 contains, for example, (A) one or more of niobium and cerium, (B) carbon, (C) fluorine, (D) oxygen, and (E) one or more of indium, tin, and bismuth. In this case, the low refractive index layer 5 may be the same as or different from the low refractive index layer 5 in the first embodiment.

[0025] There are no particular limitations on the compounding ratio of (A) one or more of niobium and cerium, (B) carbon, (C) fluorine, and (D) oxygen in the high refractive index layer 9. The high refractive index layer 9 may contain two or more of indium, tin, and bismuth, or may contain all of indium, tin, and bismuth. There are no particular limitations on the compounding ratio of indium, tin, and bismuth in the high refractive index layer 9.

[0026] Examples of the high refractive index layer 9 include the following: The main component of the high refractive index layer 9 is niobium oxide (Nb2O5). Part of the niobium oxide is substituted with an organic fluorine compound. The high refractive index layer 9 also contains a small amount of indium, tin, or bismuth.

[0027] Examples of the high refractive index layer 9 include the following: The main component of the high refractive index layer 9 is cerium oxide. A portion of the cerium oxide is substituted with an organic fluorine compound. The high refractive index layer 9 also contains a small amount of indium, tin, or bismuth.

[0028] In the second embodiment, when the number of units 7 is 1, the number of low refractive index layers 5 and the number of high refractive index layers 9 are each 1. The low refractive index layer 5 is the outermost layer of the antireflection coating 1. The high refractive index layer 9 is located between the substrate 3 and the low refractive index layer 5. The low refractive index layer 5 has, for example, the same configuration as the low refractive index layer 5 in the first embodiment. The high refractive index layer 9 contains, for example, (A) one or more of niobium and cerium, (B) carbon, (C) fluorine, (D) oxygen, and (E) one or more of indium, tin, and bismuth.

[0029] 2. Method for forming anti-reflection coating 1 The anti-reflection coating 1 can be formed by, for example, a sputtering method, in which, for example, a first target and a second target can be used.

[0030] The target material constituting the first target is, for example, silicon oxide-PTFE containing indium, and the target material constituting the second target includes, for example, niobium or niobium oxide, or cerium or cerium oxide.

[0031] The anti-reflection film 1 may be formed by, for example, a CVD method, an ALD method, a PLD method, a vacuum deposition method, or the like.

[0032] 3. Effects of Anti-Reflection Coating 1 (2A) The anti-reflection coating 1 suppresses reflection. When the low refractive index layer 5 contains indium, tin, or bismuth, the refractive index n1 changes. When the high refractive index layer 9 contains indium, tin, or bismuth, the refractive index n2 changes.

[0033] (2B) The low refractive index layer 5 contains, for example, an oxide of silicon. In this case, the low refractive index layer 5 has scratch resistance. (2C) Even when the anti-reflection coating 1 is bent or subjected to tensile stress, cracks are unlikely to occur in the anti-reflection coating 1. The reason for this is presumed to be as follows: At least one of the low-refractive-index layer 5 and the high-refractive-index layer 9 contains carbon and fluorine. The carbon and fluorine bond to each other to form an organic fluorine bond such as a fluoroalkyl group. When the anti-reflection coating 1 is bent or subjected to tensile stress, the organic fluorine bond expands and contracts, dispersing the external force applied to the entire anti-reflection coating 1 and thereby suppressing the occurrence of cracks.

[0034] <Third embodiment> 1. Differences from the second embodiment The third embodiment has the same basic configuration as the second embodiment, and therefore the differences will be described below. Note that the same reference numerals as those in the second embodiment indicate the same configuration, and reference will be made to the preceding description.

[0035] In the second embodiment described above, the unit 7 closest to the substrate 3 is in contact with the substrate 3. In contrast, the third embodiment differs from the second embodiment in that a substrate-side low refractive index layer 11 is further provided between the unit 7 closest to the substrate 3 and the substrate 3, as shown in FIG.

[0036] The refractive index n3 of the substrate-side low refractive index layer 11 is lower than the refractive index n0 of the substrate 3. The substrate-side low refractive index layer 11 has, for example, the same configuration as the low refractive index layer 5 in the first or second embodiment. Alternatively, the substrate-side low refractive index layer 11 may have a different configuration from the low refractive index layer 5 in the first or second embodiment.

[0037] In the third embodiment, when the number of units 7 is 1, the number of low-refractive-index layers 5 and the number of high-refractive-index layers 9 are each 1. The low-refractive-index layer 5 is the outermost layer of the anti-reflection coating 1. The high-refractive-index layer 9 is located between the substrate 3 and the low-refractive-index layer 5. The low-refractive-index layer 5 has, for example, the same configuration as the low-refractive-index layer 5 in the first embodiment. The high-refractive-index layer 9 contains, for example, (A) one or more of niobium and cerium, (B) carbon, (C) fluorine, (D) oxygen, and (E) one or more of indium, tin, and bismuth. The substrate-side low-refractive-index layer 11 is located between the substrate 3 and the high-refractive-index layer 9.

[0038] 2. Method for forming anti-reflection coating 1 The anti-reflection coating 1 can be formed by, for example, a sputtering method, in which, for example, a first target and a second target can be used.

[0039] The target material constituting the first target is, for example, silicon oxide-PTFE containing indium, and the target material constituting the second target includes, for example, niobium or niobium oxide, or cerium or cerium oxide.

[0040] The anti-reflection film 1 may be formed by, for example, a CVD method, an ALD method, a PLD method, a vacuum deposition method, or the like.

[0041] 3. Effects of Anti-Reflection Coating 1 According to the third embodiment described above in detail, the effects of the second embodiment described above are achieved.

[0042] <Example> 1. Deposition of anti-reflection films S1 to S12 Antireflection films S1 to S12 shown in Table 1 were formed on the surface of a substrate 3. The substrate 3 was a PET film (manufactured by Toray, Lumirror T160 (product name)). The film thickness of the substrate 3 was 100 μm.

[0043] [Table 1]

[0044] The anti-reflection film S1 consisted of a low refractive index layer 5_1. The low refractive index layer 5_1 was the outermost layer of the anti-reflection film S1. The low refractive index layer 5_1 had a refractive index n1 lower than the refractive index n0 of the substrate 3. The low refractive index layer 5_1 was a layer made of silicon oxide, PTFE, and indium. The low refractive index layer 5_1 consisted of one layer. The film thickness of one layer was 81 nm.

[0045] The antireflection films S2 to S4 basically had the same configuration as the antireflection film S1. However, in the antireflection film S2, the low refractive index layer 5_1 was made of three laminated layers. The thickness of each of the three layers was 27 nm. The three layers were made of silicon oxide, PTFE, and indium, respectively.

[0046] In the antireflection film S3, the low refractive index layer 5_1 was composed of five laminated layers. Each of the five layers had a thickness of 16 nm. The five layers were made of silicon oxide, PTFE, and indium, respectively.

[0047] In the antireflection film S4, the low refractive index layer 5_1 was composed of 10 laminated layers. Each of the 10 layers had a thickness of 8 nm. Each of the 10 layers was made of silicon oxide, PTFE, and indium.

[0048] The anti-reflection film S5 was composed of a high refractive index layer 9_1. The high refractive index layer 9_1 had a refractive index n2 higher than the refractive index n0 of the substrate 3. The high refractive index layer 9_1 was a layer made of niobium oxide, PTFE, and indium. The high refractive index layer 9_1 consisted of one layer. The film thickness of one layer was 113 nm.

[0049] The antireflection films S6 to S8 basically had the same configuration as the antireflection film S5. However, in the antireflection film S6, the high refractive index layer 9_1 was composed of three laminated layers. The thickness of each of the three layers was 37 nm. The three layers were each composed of niobium oxide, PTFE, and indium.

[0050] In addition, in the anti-reflection film S7, the high refractive index layer 9_1 was composed of five laminated layers. Each of the five layers had a thickness of 22 nm. The five layers were made of niobium oxide, PTFE, and indium, respectively.

[0051] In addition, in the antireflection film S8, the high refractive index layer 9_1 was composed of 10 laminated layers. Each of the 10 layers had a thickness of 11 nm. Each of the 10 layers was made of niobium oxide, PTFE, and indium.

[0052] The antireflection film S9 had a configuration in which a high refractive index layer 9_1, a low refractive index layer 5_1, a high refractive index layer 9_2, and a low refractive index layer 5_2 were stacked in this order from the side of the substrate 3. The high refractive index layer 9_1 and the low refractive index layer 5_1 correspond to one unit 7. Furthermore, the high refractive index layer 9_2 and the low refractive index layer 5_2 correspond to one unit 7.

[0053] The low refractive index layer 5_1 and the low refractive index layer 5_2 each had a refractive index n1 that was lower than the refractive index n0 of the substrate 3. The high refractive index layer 9_1 and the high refractive index layer 9_2 each had a refractive index n2 that was higher than the refractive index n0 of the substrate 3. The high refractive index layer 9_1 was provided closer to the substrate 3 than the low refractive index layer 5_1. The high refractive index layer 9_2 was provided closer to the substrate 3 than the low refractive index layer 5_2.

[0054] The high refractive index layer 9_1 was a layer made of niobium oxide, PTFE, and indium. The high refractive index layer 9_1 consisted of one layer. The thickness of one layer was 13 nm. The low refractive index layer 5_1 was a layer made of silicon oxide, PTFE, and indium. The low refractive index layer 5_1 consisted of one layer. The thickness of one layer was 30 nm.

[0055] The high refractive index layer 9_2 was a layer made of niobium oxide, PTFE, and indium. The high refractive index layer 9_2 consisted of one layer. The film thickness of one layer was 113 nm. The low refractive index layer 5_2 was a layer made of silicon oxide, PTFE, and indium. The low refractive index layer 5_2 consisted of one layer. The film thickness of one layer was 81 nm.

[0056] The antireflection films S10 to S12 basically had the same configuration as the antireflection film S9. However, in the antireflection film S10, the high refractive index layer 9_1 was made up of three laminated layers. The thickness of each of the three layers was 4 nm. The three layers were made of niobium oxide, PTFE, and indium, respectively.

[0057] In the antireflection film S10, the low refractive index layer 5_1 was composed of three laminated layers. Each of the three layers had a thickness of 10 nm. The three layers were made of silicon oxide, PTFE, and indium, respectively.

[0058] In the antireflection film S10, the high refractive index layer 9_2 was composed of three laminated layers. Each of the three layers had a thickness of 37 nm. The three layers were made of niobium oxide, PTFE, and indium, respectively.

[0059] In the antireflection film S10, the low refractive index layer 5_2 was composed of three laminated layers. Each of the three layers had a thickness of 27 nm. The three layers were made of silicon oxide, PTFE, and indium, respectively.

[0060] In the antireflection film S11, the high refractive index layer 9_1 was composed of five laminated layers. Each of the five layers had a thickness of 3 nm. The five layers were made of niobium oxide, PTFE, and indium, respectively.

[0061] In the antireflection film S11, the low refractive index layer 5_1 was composed of five laminated layers. Each of the five layers had a thickness of 6 nm. The five layers were made of silicon oxide, PTFE, and indium, respectively.

[0062] In the antireflection film S11, the high refractive index layer 9_2 was composed of five laminated layers. Each of the five layers had a thickness of 22 nm. The five layers were made of niobium oxide, PTFE, and indium, respectively.

[0063] In the antireflection film S11, the low refractive index layer 5_2 was composed of five laminated layers. Each of the five layers had a thickness of 16 nm. The five layers were made of silicon oxide, PTFE, and indium, respectively.

[0064] In the antireflection film S12, the high refractive index layer 9_1 was composed of 10 laminated layers. Each of the 10 layers had a thickness of 1.3 nm. Each of the 10 layers was made of niobium oxide, PTFE, and indium.

[0065] In the antireflection film S12, the low refractive index layer 5_1 was composed of 10 laminated layers. Each of the 10 layers had a thickness of 3 nm. Each of the 10 layers was made of silicon oxide, PTFE, and indium.

[0066] In the antireflection film S12, the high refractive index layer 9_2 was composed of 10 laminated layers. Each of the 10 layers had a thickness of 11 nm. Each of the 10 layers was made of niobium oxide, PTFE, and indium.

[0067] In the antireflection film S12, the low refractive index layer 5_2 was composed of 10 laminated layers. Each of the 10 layers had a thickness of 8 nm. Each of the 10 layers was made of silicon oxide, PTFE, and indium.

[0068] The anti-reflection films S1 to S12 were each formed by sputtering under the following film forming conditions: Sputtering power: 100W Gas composition: Ar or Ar-2% O2 Gas pressure: 1Pa "Ar-2%O2" is a gas containing 2% by volume of oxygen and the remainder being argon. The target used to form the high refractive index layers 9_1 and 9_2 was a niobium oxide-PTFE-indium sintered target. The target used to form the low refractive index layers 5_1 and 5_2 was a silicon oxide-PTFE-indium sintered target. The film thickness of each layer of the antireflection films S1 to S12 was controlled by adjusting the opening and closing times of the shutter in the sputtering device.

[0069] The high refractive index layers 9_1 and 9_2 had a refractive index n2 of 2.136 at a wavelength of 550 nm, and the low refractive index layers 5_1 and 5_2 had a refractive index n1 of 1.45 at a wavelength of 550 nm.

[0070] 2. Evaluation of anti-reflection coatings S1 to S12 (2-1) Stretching test A stretching test was carried out on each of the antireflection films S1 to S12. The stretching test was carried out by the following method. A test piece was cut out from a film consisting of the substrate 3 and the antireflection film 1. The test piece was in the shape of a strip. The length of the long side of the test piece was 80 mm. The length of the short side of the test piece was 10 mm.

[0071] Both ends of the test piece in the long side direction were fixed to a tensile tester (TG Seaton ISC-2 / 100). Next, both ends of the test piece were pulled so that the test piece was elongated at a rate of 5 mm / min. When the elongation A, expressed by the following formula (1), reached 2%, 5%, and 10%, the surface of the test piece was observed using a laser microscope to determine whether or not cracks were present.

[0072] Equation (1) A = (ΔL / L) × 100 In formula (1), ΔL is the elongation of the test piece, and L is the initial value of the length of the long side of the test piece.

[0073] Table 2 shows the results of observation of the surface of the test piece when the elongation A was 2%, 5%, and 10%.

[0074] [Table 2]

[0075] In Table 2, "○" indicates that no cracks occurred, "△" indicates that cracks occurred in a part of the surface, and "×" indicates that cracks occurred over the entire surface. Cracks were less likely to occur in the antireflection films S1 to S4 and S9 to S12 than in the antireflection films S5 to S8. The reason that cracks were less likely to occur in the antireflection films S9 to S12 is presumably because the interlayer bonding strength was improved due to an interfacial reaction between the layer made of silicon oxide, PTFE, and indium (i.e., the low refractive index layers 5_1 and 5_2) and the layer made of niobium oxide, PTFE, and indium (i.e., the high refractive index layers 9_1 and 9_2).

[0076] (2-2) Bending test A bending test was conducted on each of the antireflection films S1 to S12. The bending test was performed as follows. Test pieces were cut out from a film consisting of a substrate 3 and an antireflection film 1. The test pieces were then wrapped around round rods. The diameters R of the round rods were 1 mmφ, 2 mmφ, and 3 mmφ. The surfaces of the test pieces were then observed using a laser microscope to determine whether or not cracks were present. The observation results of the test piece surfaces are shown in Table 2.

[0077] In Table 2, "◯" indicates that no cracks occurred, "△" indicates that cracks occurred in some areas, and "×" indicates that cracks occurred over the entire surface. Cracks were less likely to occur in the antireflection films S1 to S4 and S9 to S12 than in the antireflection films S5 to S8.

[0078] (2-3) Other tests The antireflection films S1 to S12 were each evaluated for reflectance at a wavelength of 550 nm and hardness. Elemental analysis was also performed on the low-refractive-index layer 5_1 of the antireflection film S1 and the high-refractive-index layer 9_1 of the antireflection film S5. The reflectance was measured using a spectrophotometer (U4100 manufactured by Hitachi High-Technologies Corporation).

[0079] Hardness was measured using a nanoindenter (TI Premier, manufactured by Bruker). Elemental analysis was performed using an energy dispersive X-ray spectroscopy (EDX) unit attached to a scanning electron microscope (JEOL JSM-6700F).

[0080] The measurement results of the reflectance of the antireflection films S1 to S12 are shown in Table 2. The measurement results of the hardness of the antireflection films S1 to S12 are shown in Table 2. The result of elemental analysis of the low refractive index layer 5_1 in the antireflection film S1 was 12.3 wt % PTFE, 1.3 wt % indium, and the remainder silicon oxide. The result of elemental analysis of the high refractive index layer 9_1 in the antireflection film S5 was 12.3 wt % PTFE, 1.3 wt % indium, and the remainder niobium oxide.

[0081] <Other embodiments> Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms.

[0082] (1) In the first embodiment, the antireflection film 1 may further include a high-refractive index layer 9 between the substrate 3 and the low-refractive index layer 5, the high-refractive index layer 9 having a refractive index n2 higher than the refractive index n0 of the substrate 3. The high-refractive index layer 9 is, for example, the same as the high-refractive index layer 9 in the second or third embodiment.

[0083] In the first embodiment, the antireflection coating 1 may include a high-refractive-index layer 9 between the substrate 3 and the low-refractive-index layer 5, and may further include a substrate-side low-refractive-index layer 11 between the substrate 3 and the high-refractive-index layer 9, the substrate-side low-refractive-index layer 11 having a refractive index n3 lower than the refractive index n0 of the substrate 3. The substrate-side low-refractive-index layer 11 is, for example, similar to the substrate-side low-refractive-index layer 11 in the third embodiment.

[0084] (2) In the second embodiment, the antireflection film 1 may further include a layer other than the unit 7. In the second embodiment, the unit 7 may further include a layer other than the low refractive index layer 5 and the high refractive index layer 9.

[0085] (3) In the third embodiment, the antireflection film 1 may further include a layer other than the unit 7 and the substrate-side low refractive index layer 11. In the third embodiment, the unit 7 may further include a layer other than the low refractive index layer 5 and the high refractive index layer 9.

[0086] (4) The function of one component in each of the above embodiments may be shared among multiple components, or the functions of multiple components may be performed by one component. Also, part of the configuration of each of the above embodiments may be omitted. Furthermore, at least part of the configuration of each of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0087] (5) The present disclosure can also be realized in various forms, such as an anti-reflective product including the above-described anti-reflective film 1 and substrate 3, a system including the anti-reflective film 1 as a component, and a method for manufacturing the anti-reflective film 1.

[0088] [Technical idea disclosed in this specification] [Item 1] An anti-reflection film formed on the surface of a substrate, a low refractive index layer which is an outermost layer of the antireflection film and has a refractive index lower than that of the substrate; the low refractive index layer comprises (a) silicon, (b) carbon, (c) fluorine, (d) oxygen, and (e) one or more of indium, tin, and bismuth; Anti-reflective coating. [Item 2] Item 1. The anti-reflection film according to item 1, a high refractive index layer having a refractive index higher than that of the substrate is further provided between the substrate and the low refractive index layer; the high refractive index layer contains (A) one or more of niobium and cerium, (B) carbon, (C) fluorine, (D) oxygen, and (E) one or more of indium, tin, and bismuth; Anti-reflective coating. [Item 3] Item 2. The antireflection film according to item 2, a substrate-side low-refractive-index layer between the substrate and the high-refractive-index layer, the low-refractive-index layer having a refractive index lower than that of the substrate; Anti-reflective coating. [Item 4] An anti-reflection film formed on the surface of a substrate, One or more units are provided, The unit comprises: a low refractive index layer having a refractive index lower than the refractive index of the substrate; a high refractive index layer having a refractive index higher than that of the substrate and provided closer to the substrate than the low refractive index layer; Equipped with the high refractive index layer contains (A) one or more of niobium and cerium, (B) carbon, (C) fluorine, (D) oxygen, and (E) one or more of indium, tin, and bismuth; Anti-reflective coating. [Item 5] Item 4. The antireflection film according to item 4, a substrate-side low-refractive-index layer having a refractive index lower than that of the substrate is further provided between the unit closest to the substrate and the substrate; Anti-reflective coating. [Item 6] Item 4 or 5. The antireflection film according to item 4 or 5, the low refractive index layer comprises (a) silicon, (b) carbon, (c) fluorine, (d) oxygen, and (e) one or more of indium, tin, and bismuth; Anti-reflective coating. [Item 7] An anti-reflection film formed on the surface of a substrate, One or more units are provided, The unit comprises: a low refractive index layer having a refractive index lower than the refractive index of the substrate; a high refractive index layer having a refractive index higher than that of the substrate and provided closer to the substrate than the low refractive index layer; Equipped with the low refractive index layer comprises (a) silicon, (b) carbon, (c) fluorine, (d) oxygen, and (e) one or more of indium, tin, and bismuth; Anti-reflective coating. [Item 8] Item 7. The anti-reflection film according to item 7, a substrate-side low-refractive-index layer having a refractive index lower than that of the substrate is further provided between the unit closest to the substrate and the substrate; Anti-reflective coating. [Item 9] The antireflection film according to any one of items 1 to 8, The substrate is a glass material or a plastic material. Anti-reflective coating. [Explanation of symbols]

[0089] 1...anti-reflection film, 3...substrate, 5...low refractive index layer, 7...unit, 9...high refractive index layer, 11...substrate-side low refractive index layer

Claims

1. An anti-reflection film formed on the surface of a substrate, a low refractive index layer which is an outermost layer of the antireflection film and has a refractive index lower than that of the substrate; the low refractive index layer comprises (a) silicon, (b) carbon, (c) fluorine, (d) oxygen, and (e) one or more of indium, tin, and bismuth; Anti-reflective coating.

2. The anti-reflection film according to claim 1 , a high refractive index layer having a refractive index higher than that of the substrate is further provided between the substrate and the low refractive index layer; The high refractive index layer contains (A) one or more of niobium and cerium, (B) carbon, (C) fluorine, (D) oxygen, and (E) one or more of indium, tin, and bismuth. Anti-reflective coating.

3. The anti-reflection film according to claim 2, a substrate-side low-refractive-index layer between the substrate and the high-refractive-index layer, the low-refractive-index layer having a refractive index lower than that of the substrate; Anti-reflective coating.

4. An anti-reflection film formed on the surface of a substrate, One or more units are provided, The unit comprises: a low refractive index layer having a refractive index lower than the refractive index of the substrate; a high refractive index layer having a refractive index higher than that of the substrate and provided closer to the substrate than the low refractive index layer; Equipped with The high refractive index layer contains (A) one or more of niobium and cerium, (B) carbon, (C) fluorine, (D) oxygen, and (E) one or more of indium, tin, and bismuth. Anti-reflective coating.

5. The anti-reflection film according to claim 4, a substrate-side low-refractive-index layer having a refractive index lower than that of the substrate is further provided between the unit closest to the substrate and the substrate; Anti-reflective coating.

6. The anti-reflection film according to claim 4 or 5, the low refractive index layer comprises (a) silicon, (b) carbon, (c) fluorine, (d) oxygen, and (e) one or more of indium, tin, and bismuth; Anti-reflective coating.

7. An anti-reflection film formed on the surface of a substrate, One or more units are provided, The unit comprises: a low refractive index layer having a refractive index lower than the refractive index of the substrate; a high refractive index layer having a refractive index higher than that of the substrate and provided closer to the substrate than the low refractive index layer; Equipped with the low refractive index layer comprises (a) silicon, (b) carbon, (c) fluorine, (d) oxygen, and (e) one or more of indium, tin, and bismuth; Anti-reflective coating.

8. The anti-reflection film according to claim 7, a substrate-side low-refractive-index layer having a refractive index lower than that of the substrate is further provided between the unit closest to the substrate and the substrate; Anti-reflective coating.

9. The antireflection film according to any one of claims 1 to 5, 7 and 8, The substrate is a glass material or a plastic material. Anti-reflective coating.

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