Substrate with dielectric multilayer film and method for manufacturing same

Abstract

A substrate (1) with a dielectric multilayer film is obtained by sequentially laminating a first dielectric laminated film (10) and a second dielectric laminated film (20) on a substrate (S), and the first dielectric laminated film (10) is obtained by sequentially laminating a first high-refractive-index film layer (a1) containing TiO2, a first low-refractive-index film layer (b1) containing SiO2, a first high-refractive-index film layer (a2) containing TiO2, and a first low-refractive-index film layer (b2) containing SiO2 from the substrate (S) side. In the second dielectric laminated film (20), a second high-refractive-index film layer (a3) containing Ta2O5 or Nb2O5 and a second low-refractive-index film layer (b3) containing SiO2 are laminated in this order from the substrate (S) side, and the thickness of a first low-refractive-index film layer (1022) farthest from the substrate (S) in the first dielectric laminated film (10) is 30 nm or more.

Description

Technical Field

[0001] The present invention relates to a substrate with a dielectric multilayer film and a method for manufacturing the same. Background Art

[0002] There are many known techniques for providing a dielectric multilayer film on the front surface of an optical device in order to obtain desired characteristics.

[0003] For example, Patent Document 1 listed below discloses a structure in which a dielectric multilayer film is provided on a substrate, and the dielectric multilayer film includes a plurality of low refractive index layers, high refractive index layers, and antireflection layers from the surface.

[0004] Patent Document 2 listed below discloses an optical filter component including a light-transmitting film including a plurality of first dielectric layers made of silicon oxide and a plurality of second dielectric layers made of titanium oxide on a surface of a substrate made of a light-transmitting material.

[0005] In addition, the following patent document 3 discloses an optical article having an inorganic thin film composed of multiple layers on a substrate, wherein the inorganic thin film is stacked with multiple silicon oxide layers and multiple metal oxide layers, and the metal oxide is a metal oxide containing at least one of zirconium, tantalum or titanium, and has a surface roughness of 0.55nm to 0.70nm.

[0006] In addition, Patent Document 4 listed below discloses a visible light reflector having a reflector stacked layer portion including a layer of a dielectric material composed of alternately stacked layers of Ta 2 O 5 and SiO 2 on a substrate.

[0007] In addition, the following patent document 5 discloses a polarization beam splitter, which is formed by alternately stacking a high refractive index dielectric film composed of a high refractive index material and a low refractive index dielectric film composed of a low refractive index material on a substrate, and examples of the high refractive index dielectric film include Ta2O5, TiO2, HfO2, ZrO2, LaTiO2, etc. X O Y , Y2O3, SiO2, MgF2 can be exemplified as low-refractive-index dielectric films.

[0008] In addition, Patent Document 6 listed below discloses an antireflection film consisting of a multilayer film having a total of 14 to 17 layers stacked on a substrate surface from the substrate side to the air side based on alternating layers of film seeds TiO2 and SiO2.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: International Publication No. 2021 / 111813

[0012] Patent Document 2: Japanese Patent Application Publication No. 2018-25732

[0013] Patent Document 3: Japanese Patent Application Publication No. 2012-118536

[0014] Patent Document 4: Japanese Patent Application Publication No. 2010-26030

[0015] Patent Document 5: Japanese Patent Application Publication No. 2003-114326

[0016] Patent Document 6: Japanese Patent Application Publication No. 2002-14203 Summary of the invention

[0017] On the other hand, there is also a known technique for providing a transparent anti-reflection film having a dielectric multilayer film on the front surface of an image display device to prevent external light from being reflected into the screen. However, in the conventional technique, when a dielectric multilayer film is formed on a substrate by sputtering (see the above-mentioned patent documents 1 to 2, 5 to 6, etc.), there is a problem that the residual stress of the obtained dielectric multilayer film is high, which becomes a major factor of warping and peeling. In particular, since the transparent anti-reflection film is formed on a cover glass or a film, it is very important to reduce the film stress in order to stabilize the characteristics for a long time.

[0018] Therefore, an object of the present invention is to provide a substrate with a dielectric multilayer film having reduced film stress and a method for manufacturing the same.

[0019] The present invention is as follows.

[0020] (1) A substrate with a dielectric multilayer film, comprising a dielectric multilayer film on the substrate,

[0021] The dielectric multilayer film is composed of a first dielectric multilayer film and a second dielectric multilayer film stacked in order from the substrate side.

[0022] The first dielectric laminate film is formed by alternately laminating the first high refractive index film layer containing TiO2 and the first low refractive index film layer containing SiO2 in the same number starting from the substrate side.

[0023] The second dielectric laminate film is alternately laminated in the same number of second high refractive index film layers containing Ta2O5 or Nb2O5 and second low refractive index film layers containing SiO2 in order from the substrate side.

[0024] The thickness of the first low-refractive-index film layer farthest from the substrate in the first dielectric stack film is 30 nm or more.

[0025] (2) A substrate with a dielectric multilayer film according to (1) above, wherein the ratio (T1 / T2) of the thickness T1 of the first high refractive index film layer farthest from the substrate in the first dielectric multilayer film to the thickness T2 of the second high refractive index film layer closest to the substrate in the second dielectric multilayer film is 0.7 to 1.4.

[0026] (3) The substrate with a dielectric multilayer film according to (1) or (2) above, wherein the total film thickness of the dielectric multilayer film is 300 nm or less.

[0027] (4) A substrate with a dielectric multilayer film according to (1) or (2) above, wherein the thickness of the second low refractive index film layer farthest from the substrate in the second dielectric multilayer film is 75 nm to 105 nm.

[0028] (5) A substrate with a dielectric multilayer film according to (1) or (2) above, wherein the total number of layers of the first high refractive index film layer, the first low refractive index film layer, the second high refractive index film layer and the second low refractive index film layer in the dielectric multilayer film is 6 to 12 layers.

[0029] (6) The dielectric multilayer film-attached substrate according to (5) above, wherein the total number of layers is 6.

[0030] (7) A substrate with a dielectric multilayer film according to (6) above, wherein the dielectric multilayer film comprises, in order from the substrate side: a first high refractive index film layer a1 containing TiO2, a first low refractive index film layer b1 containing SiO2, a first high refractive index film layer a2 containing TiO2, a first low refractive index film layer b2 containing SiO2, a second high refractive index film layer a3 containing Ta2O5 or Nb2O5, and a second low refractive index film layer b3 containing SiO2.

[0031] (8) A substrate with a dielectric multilayer film according to (6) above, wherein the dielectric multilayer film comprises, in order from the substrate side: a first high refractive index film layer a1 containing TiO2 with a film thickness of less than 20 nm, a first low refractive index film layer b1 containing SiO2 with a film thickness of 30 nm to 50 nm, a first high refractive index film layer a2 containing TiO2 with a film thickness of 10 nm to 50 nm, a first low refractive index film layer b2 containing SiO2 with a film thickness of 30 nm to 50 nm, a second high refractive index film layer a3 containing Ta2O5 or Nb2O5 with a film thickness of 15 nm to 50 nm, and a second low refractive index film layer b3 containing SiO2 with a film thickness of 75 nm to 105 nm.

[0032] (9) The dielectric multilayer film-attached substrate according to (1) or (2) above, wherein the substrate comprises at least one of glass and resin.

[0033] (10) The substrate with a dielectric multilayer film according to (1) or (2) above, further comprising an adhesion layer between the substrate and the dielectric multilayer film.

[0034] (11) A method for manufacturing a substrate with a dielectric multilayer film, wherein the substrate with a dielectric multilayer film comprises a dielectric multilayer film composed of a first dielectric stacked film and a second dielectric stacked film on the substrate, the method comprising the following steps:

[0035] The first dielectric laminate film is formed by alternately laminating the same number of first high refractive index film layers containing TiO2 and first low refractive index film layers containing SiO2 on the substrate, and

[0036] The second dielectric laminate film is formed by alternately laminating the same number of second high refractive index film layers containing Ta2O5 or Nb2O5 and second low refractive index film layers containing SiO2 on the first dielectric laminate film.

[0037] The thickness of the first low-refractive-index film layer farthest from the substrate in the first dielectric laminate film is set to be 30 nm or more.

[0038] According to one embodiment of the present invention, it is possible to provide a substrate with a dielectric multilayer film having reduced film stress and a method for manufacturing the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a cross-sectional view schematically showing a configuration example of a substrate with a dielectric multilayer film in an embodiment of the present invention.

[0040] Figure 2 This is a cross-sectional view schematically showing a particularly preferred configuration example of a substrate with a dielectric multilayer film according to an embodiment of the present invention.

[0041] Figure 3 This is a graph showing the film thickness of the dielectric multilayer films produced in Examples.

[0042] Figure 4 This is a graph showing the film stress of the dielectric multilayer film produced in the example. DETAILED DESCRIPTION

[0043] Hereinafter, embodiments of the present invention will be described in detail.

[0044] It should be noted that in this specification, the presence of other layers, films, etc. on the main surface of a substrate or on a dielectric multilayer film or other film is not limited to the manner in which the other layers, films, etc. are arranged in contact with the above-mentioned main surface, layer or film, as long as the layers, films, etc. are arranged in the upper direction thereof.

[0045] <Substrates with dielectric multilayer films>

[0046] First, the structure of the substrate with a dielectric multilayer film according to the embodiment of the present invention will be described.

[0047] Figure 1 This is a cross-sectional view schematically showing a configuration example of a substrate with a dielectric multilayer film in an embodiment of the present invention.

[0048] The dielectric multilayer film is formed by sequentially stacking a first dielectric multilayer film 10 and a second dielectric multilayer film 20 on a substrate S. In other words, the dielectric multilayer film has a first portion consisting of the first dielectric multilayer film 10 and a second portion consisting of the second dielectric multilayer film 20 on the substrate S in this order.

[0049] The first dielectric laminate film 10 is formed by alternately laminating a first high refractive index film layer 101 containing TiO2 and a first low refractive index film layer 102 containing SiO2 from the substrate S side, and this alternating lamination can be repeated multiple times. The number of the first high refractive index film layer 101 and the number of the first low refractive index film layer 102 in the first dielectric laminate film 10 is the same.

[0050] In this specification, a high refractive index film layer refers to a dielectric film having a higher refractive index than that of a substrate, and a low refractive index film layer refers to a dielectric film having a lower refractive index than the high refractive index layer.

[0051] The second dielectric laminate film 20 is formed by alternately laminating a second high refractive index film layer 201 containing Ta2O5 or Nb2O5 and a second low refractive index film layer 202 containing SiO2 from the substrate S side, and this alternating lamination can be repeated multiple times. The number of the second high refractive index film layer 201 and the number of the second low refractive index film layer 202 in the second dielectric laminate film 20 are the same.

[0052] In addition, the thickness of the first low-refractive-index film layer 1022 which is farthest from the substrate S in the first dielectric multilayer film 10 is 30 nm or more.

[0053] If the dielectric multilayer film is regarded as a whole, the dielectric multilayer film is formed by alternately stacking the same number of high refractive index film layers and low refractive index film layers in sequence from the substrate S side. In addition, when observed from the substrate S side, the first layer is a high refractive index film layer and the last layer is a low refractive index film layer, thereby reducing the film stress of the dielectric multilayer film and also reducing the light reflectivity (SCI Y) described later.

[0054] In this embodiment, the first high refractive index film layer 101 may also contain a high refractive index material other than TiO2. In this case, a high refractive index material having a higher film stress than Ta2O5 and Nb2O5 is preferred. However, from the perspective of embodying the effect of the present invention, the first high refractive index film layer 101 does not contain Ta2O5 or Nb2O5. That is, the first dielectric laminate film 10 does not contain "the second high refractive index film layer 201 containing Ta2O5 or Nb2O5".

[0055] Similarly, the second high refractive index film layer 201 may also contain a high refractive index material other than Ta2O5 or Nb2O5. In this case, a high refractive index material having a film stress lower than that of TiO2 is preferred. However, from the perspective of embodying the effects of the present invention, the second high refractive index film layer 201 does not contain TiO2. That is, the "first high refractive index film layer 101 containing TiO2" does not exist in the second dielectric laminate film 20.

[0056] As described above, the first dielectric laminated film 10 is formed by alternately laminating the first high refractive index film layer 101 containing TiO2 and the first low refractive index film layer 102 containing SiO2 in sequence from the substrate S side. In addition, the second dielectric laminated film 20 is formed by alternately laminating the second high refractive index film layer 201 containing Ta2O5 or Nb2O5 and the second low refractive index film layer 202 containing SiO2 in sequence from the substrate S side.

[0057] From the viewpoint of further reducing the film stress of the dielectric multilayer film, the total number of layers of the first high refractive index film layer, the first low refractive index film layer, the second high refractive index film layer and the second low refractive index film layer in the dielectric multilayer film is preferably 4 to 12 layers. In addition, the total number of layers is more preferably 4 layers or more, and more preferably 6 layers or more, and more preferably 10 layers or less, and more preferably 8 layers or less. The total number of layers is particularly preferably 6 layers.

[0058] In addition, from the viewpoint of further reducing the film stress of the dielectric multilayer film, the total number of layers of the first high refractive index film layer 101 and the first low refractive index film layer 102 in the first dielectric stacked film 10 is preferably 2 to 8 layers. In addition, the total number of layers is more preferably 2 or more, and more preferably 6 or less. The total number of layers is particularly preferably 4 layers.

[0059] In addition, from the viewpoint of further reducing the film stress of the dielectric multilayer film, the total number of layers of the second high refractive index film layer 201 and the second low refractive index film layer 202 in the second dielectric laminated film 20 is preferably 2 to 8 layers. In addition, the total number of layers is more preferably 2 or more, more preferably 8 or less, more preferably 6 or less, and more preferably 4 or less. The total number of layers is particularly preferably 2 layers.

[0060] In addition, in the substrate with a dielectric multilayer film according to the embodiment of the present invention, the thickness of the first low refractive index film layer 102 (1022) farthest from the substrate S in the first dielectric stacked film 10 is 30 nm or more. From the viewpoint of further reducing the film stress of the dielectric multilayer film, it is preferably 30 nm to 50 nm. The above thickness is more preferably 45 nm or less, and further preferably 40 nm or less.

[0061] It should be noted that the “first low-refractive index film layer farthest from the substrate S” means, in other words, the “first low-refractive index film layer in contact with the second dielectric stacked film”.

[0062] In addition, in this specification, the refractive index and film thickness that can be reproduced by the reflection spectrum can be obtained by computer based on the actual reflection spectrum, with the refractive index dispersion and film thickness as variables. The above can be implemented using commercially available software, for example, TF-Calc (manufactured by HULINKS) and OptiLayer (manufactured by K1) can also be used. In addition, the film thickness can also be estimated by observing the cross-sectional structure using a scanning electron microscope and measuring the thickness of layers of different contrast. In this case, since the resolution is very important, it is preferred to measure in a manner that the viewing angle can confirm the entire stacked structure, using the average value of the measurements at multiple points or more. It is more preferred to use the average value of the measurements at 5 points or more.

[0063] In addition, from the viewpoint of further reducing the film stress of the dielectric multilayer film, the second low refractive index film layer (described later) farthest from the substrate S in the second dielectric multilayer film 20 is preferably Figure 2 In the embodiment of the present invention, the thickness of the low refractive index film layer b3) is preferably 75 nm to 105 nm. The thickness is more preferably 80 nm or more, more preferably 100 nm or less, and further preferably 95 nm or less.

[0064] In addition, from the viewpoint of further reducing the film stress of the dielectric multilayer film, the first high refractive index film layer (described later) farthest from the substrate S in the first dielectric multilayer film 10 is Figure 2 In the embodiment of the invention, the thickness T1 of the high refractive index film layer a2) is equal to the thickness T2 of the second high refractive index film layer (described later) closest to the substrate in the second dielectric laminate film. Figure 2 In the embodiment of the invention, the ratio (T1 / T2) of the thickness T2 of the high refractive index film layer a3) is preferably 0.7 to 1.4. The above ratio (T1 / T2) is more preferably 1 or more, further preferably 1.2 or more, and further preferably 1.3 or more.

[0065] In addition, in vacuum film formation for forming dielectric multilayer films, the increase in the number of layers and film thickness increases the production time, resulting in increased production costs. From the perspective of suppressing production costs, the total film thickness of the dielectric multilayer film is preferably 300 nm or less, more preferably 250 nm or less.

[0066] In this method, the reason why the film stress of the dielectric multilayer film is suppressed is not clear, but it is speculated to be the following reasons. That is, the internal stress of the dielectric film changes according to the gas pressure during film formation, but from the perspective of the density of the film, it is necessary to lower the pressure of the sputtering gas (generally Ar) during film formation. As a result, most films are generally formed at a pressure of about 0.1 Pa, so the residual stress component after film formation causes compression on the film surface. Therefore, the dielectric film is basically compressive stress, but the magnitude of the stress varies depending on the type of material. A stress difference is applied in the form of an action force and a reaction force by stacking a material with a smaller compressive stress on a material with a larger compressive stress. Therefore, stresses of opposite signs are applied to the film interface, and the stress of the entire laminated film is suppressed. Such an effect is further increased by combining multiple materials for use as a dielectric film. Therefore, according to this embodiment, it is presumed that the film stress of the dielectric multilayer film is suppressed by providing a first high refractive index film layer containing TiO2 with high compressive stress on the substrate side and stacking a second high refractive index film layer containing Ta2O5 or Nb2O5 with low compressive stress in a direction away from the substrate. It should be noted that the present invention is not limited in any way by this reason.

[0067] Figure 2 This is a cross-sectional view schematically showing a substrate with a dielectric multilayer film according to an embodiment of the present invention in the above-mentioned particularly preferred mode.

[0068] exist Figure 2 In the figure, the substrate 2 with a dielectric multilayer film is formed by stacking a first dielectric stack film 10 and a second dielectric stack film 20 in sequence on a substrate S, and the first dielectric stack film 10 is stacked in sequence from the substrate S side with a first high refractive index film layer a1 containing TiO2, a first low refractive index film layer b1 containing SiO2, a first high refractive index film layer a2 containing TiO2, and a first low refractive index film layer b2 containing SiO2.

[0069] The second dielectric laminate film 20 is formed by laminating a second high refractive index film layer a3 containing Ta 2 O 5 or Nb 2 O 5 and a second low refractive index film layer b3 containing SiO 2 in this order from the substrate S side.

[0070] In addition, the thickness of the first low-refractive-index film layer b2 which is farthest from the substrate S in the first dielectric multilayer film 10 is 30 nm or more.

[0071] Figure 2The substrate 2 with dielectric multilayer films shown in FIG. 1 has a total of six dielectric multilayer films disposed on a substrate S. Figure 2 The above-described embodiment is particularly preferred from the viewpoint that the film stress of the dielectric multilayer film can be further reduced and the light reflectance (SCI Y) can also be reduced.

[0072] Figure 2 In the embodiment shown, the thickness of the first high refractive index film layer a1 containing TiO2 is preferably 20 nm or less, more preferably 3 nm to 15 nm. The thickness of the first high refractive index film layer a1 is further preferably 10 nm or less.

[0073] The thickness of the first low refractive index film layer b1 containing SiO2 is preferably 30 nm to 50 nm. The thickness of the first low refractive index film layer b1 is more preferably 35 nm or more, more preferably 45 nm or less, and further preferably 40 nm or less.

[0074] The thickness of the first high refractive index film layer a2 containing TiO2 is preferably 10 nm to 50 nm. The thickness of the first high refractive index film layer a2 is more preferably 15 nm or more, further preferably 20 nm or more, and more preferably 45 nm or less, further preferably 40 nm or less.

[0075] The film thickness of the first low-refractive index film layer b2 containing SiO2 is preferably 30nm to 50nm. The film thickness of the above-mentioned first low-refractive index film layer b2 is preferably more than 30nm, and is preferably less than 50nm, more preferably less than 45nm, and further preferably less than 40nm. It should be noted that the first low-refractive index film layer b2 containing SiO2 is equivalent to the first low-refractive index film layer farthest from the substrate.

[0076] The thickness of the second high refractive index film layer a3 containing Ta2O5 or Nb2O5 is preferably 15nm to 50nm. The thickness of the second high refractive index film layer a3 is more preferably 20nm or more, further preferably 30nm or more, and more preferably 45nm or less, further preferably 40nm or less.

[0077] The thickness of the second low refractive index film layer b3 containing SiO2 is preferably 75 nm to 105 nm. The thickness of the second low refractive index film layer b3 is more preferably 80 nm or more, more preferably 100 nm or less, and further preferably 95 nm or less.

[0078] <Substrate>

[0079] The substrate of this method can use any previously known substrate such as glass and resin film. When the substrate with a dielectric multilayer film of this method is used as an anti-reflection film, the refractive index of the substrate is preferably 1.4 to 1.7. If the refractive index of the substrate is in the above range, the reflection of the bonding surface can be fully suppressed when optically bonded to a display, a touch panel, etc. The refractive index of the substrate is more preferably 1.45 or more, more preferably 1.47 or more, and more preferably 1.65 or less, and more preferably 1.6 or less.

[0080] The substrate preferably includes at least any one of glass and resin.

[0081] When the substrate includes glass, the type of glass is not particularly limited, and glasses having various compositions can be used. Among them, the glass preferably includes quartz and sodium, and preferably has a composition that can be molded and strengthened by chemical strengthening treatment. Specifically, for example, quartz glass, aluminosilicate glass, soda-lime glass, borosilicate glass, alkali-free glass, lead glass, alkaline barium glass, aluminoborosilicate glass, etc. can be cited. It should be noted that in this specification, when the substrate includes glass, the substrate is also referred to as a glass substrate.

[0082] The thickness of the glass substrate is not particularly limited, but is usually preferably 5 mm or less, more preferably 3 mm or less, and further preferably 1.5 mm or less. In addition, it is usually 0.2 mm or more.

[0083] The glass substrate is preferably a chemically strengthened glass that has been chemically strengthened. Thus, the strength of the substrate with a dielectric multilayer film is improved. It should be noted that when an anti-glare layer described later is provided on the glass substrate, chemical strengthening is performed before the dielectric multilayer film (multilayer film) is formed after the anti-glare layer is provided.

[0084] When the substrate includes a resin, the type of resin is not particularly limited, and resins with various compositions can be used. Among them, the above-mentioned resin is preferably a thermoplastic resin or a thermosetting resin, for example, polyvinyl chloride resin, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl acetate resin, polyester resin, polyurethane resin, cellulose resin, acrylic resin, AS (acrylonitrile-styrene) resin, ABS (acrylonitrile-butadiene-styrene) resin, fluorine resin, thermoplastic elastomer, polyamide resin, polyimide resin, polyacetal resin, polycarbonate resin, modified polyphenylene ether resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polylactic acid resin, cyclic polyolefin resin, polyphenylene sulfide resin, etc. Among them, cellulose resin is preferred, and cellulose triacetate resin, polycarbonate resin, polyethylene terephthalate resin, etc. can be mentioned. These resins can be used alone or in combination of two or more. The resin particularly preferably includes at least one resin selected from the group consisting of polyethylene terephthalate, polycarbonate, acrylic, silicone, and cellulose triacetate.

[0085] In addition, in this specification, when a substrate contains a resin, the substrate is also referred to as a resin substrate.

[0086] The shape of the resin substrate is not particularly limited, and may be a film, a plate, etc., and is preferably a film from the perspective of preventing scattering. When the shape of the resin substrate is a film, that is, a resin film, its thickness is not particularly limited, preferably 20 to 250 μm, and more preferably 40 to 188 μm. When the shape of the resin substrate is a plate, that is, a resin plate, its thickness is not particularly limited, and is usually preferably 5 mm or less, more preferably 3 mm or less, and further preferably 1.5 mm or less. In addition, it is usually 0.2 mm or more.

[0087] When the transparent substrate includes both glass and resin, for example, a form in which the resin substrate is provided on the glass substrate may be adopted.

[0088] <Sealing layer>

[0089] In the present invention, an adhesion layer may be provided between the substrate and the dielectric multilayer film.

[0090] The type of the adhesion layer is not particularly limited, and the adhesion layer may be an organic layer composed of a resin or the like, or an inorganic layer. Each case will be described in detail below.

[0091] (Organic layer)

[0092] As the organic layer, a resin layer containing a prescribed resin is preferred. The type of resin forming the resin layer is not particularly limited, and for example, silicone resin, polyimide resin, acrylic resin, polyolefin resin, polyurethane resin, or fluorine resin can be cited. It is also possible to mix several types of resins for use. Among them, silicone resin, polyimide resin, and fluorine resin are preferred.

[0093] The thickness of the organic layer is not particularly limited, but is preferably 1 to 100 μm, more preferably 5 to 30 μm, and further preferably 7 to 20 μm. When the thickness of the organic layer is within the above range, adhesion between the substrate and the dielectric multilayer film is sufficient.

[0094] In order to improve the flatness of the organic layer, a leveling agent may be contained in the organic layer. The type of the leveling agent is not particularly limited, and typical examples thereof include fluorine-based leveling agents.

[0095] (Inorganic layer)

[0096] The material constituting the inorganic layer is not particularly limited, but preferably contains at least one selected from oxides, nitrides, oxynitrides, carbides, carbonitrides, silicides, and fluorides, for example.

[0097] Examples of the oxide (preferably metal oxide), nitride (preferably metal nitride) and oxynitride (preferably metal oxynitride) include oxides, nitrides and oxynitrides of one or more elements selected from Si, Hf, Zr, Ta, Ti, Y, Nb, Na, Co, Al, Zn, Pb, Mg, Bi, La, Ce, Pr, Sm, Eu, Gd, Dy, Er, Sr, Sn, In and Ba. More specifically, silicon oxynitride (SiN x O y ), titanium oxide (TiO2), indium oxide (IN2O3), indium cerium oxide (ICO), tin oxide (SnO2), zinc oxide (ZnO), gallium oxide (Ga2O3), indium tin oxide (ITO), indium zinc oxide (IZO), zinc tin oxide (ZTO), gallium-doped zinc oxide (GZO), etc.

[0098] Examples of carbides (preferably metal carbides) and carbonitrides (preferably metal carbonitrides) include carbides, carbonitrides, and carbon oxides of one or more elements selected from Ti, W, Si, Zr, and Nb. Examples include silicon carbide oxide (SiCO) and the like.

[0099] The carbide may be a so-called carbon raw material, for example, a carbide obtained by sintering a resin component such as a phenol resin.

[0100] Examples of the silicide (preferably metal silicide) include silicides of one or more elements selected from the group consisting of Mo, W, and Cr.

[0101] Examples of the fluoride (preferably a metal fluoride) include fluorides of one or more elements selected from the group consisting of Mg, Y, La, and Ba. Examples thereof include magnesium fluoride (MgF2).

[0102] The thickness of the inorganic layer is not particularly limited, but is preferably 5 to 5000 nm, more preferably 10 to 500 nm, from the viewpoint of adhesion between the substrate and the dielectric multilayer film.

[0103] The surface roughness (Ra) of the inorganic layer in contact with the dielectric multilayer film is preferably 2.0 nm or less, more preferably 1.0 nm or less. The lower limit is not particularly limited, but most preferably 0. Within the above range, the adhesion with the dielectric multilayer film becomes better.

[0104] Ra is measured in accordance with JIS B 0601 (revised in 2001).

[0105] The adhesion layer may be a plasma polymerized film. When the adhesion layer is a plasma polymerized film, materials for forming the plasma polymerized film include fluorocarbon monomers such as CF4, CHF3, and CH3F, hydrocarbon monomers such as methane, ethane, propane, ethylene, propylene, acetylene, benzene, toluene, and C4H8, hydrogen, and SF6. A plasma polymerized film composed of a fluorocarbon monomer or a hydrocarbon monomer is particularly preferred. These may be used alone or in combination of two or more.

[0106] The thickness of the plasma polymerized film is preferably 1 to 100 nm, more preferably 1 to 50 nm, and even more preferably 1 to 10 nm, from the viewpoint of scratch resistance.

[0107] (Anti-glare layer, hard coating)

[0108] At least one of an anti-glare layer and a hard coating layer may be provided on the side of the surface of the substrate of the present embodiment where the dielectric multilayer film is provided.

[0109] The anti-glare layer generates external scattering or internal scattering due to the concavo-convex shape on one side, thereby increasing the haze value and imparting anti-glare properties. The anti-glare layer can use a conventionally known anti-glare layer, for example, it can be composed of an anti-glare layer composition in which at least a granular substance having anti-glare properties is dispersed in a solution in which a polymer resin serving as a binder is dissolved. The anti-glare layer can be formed by applying the anti-glare layer composition to, for example, one main surface of a substrate.

[0110] As granular substances having anti-glare properties, for example, in addition to inorganic fine particles such as silica, clay, talc, calcium carbonate, calcium sulfate, barium sulfate, aluminum silicate, titanium oxide, synthetic zeolite, alumina, and montmorillonite, organic fine particles containing styrene resins, polyurethane resins, benzoguanamine resins, silicone resins, acrylic resins, etc. can also be mentioned.

[0111] The hard coat layer may be a conventionally known hard coat layer, and may be composed of, for example, a hard coat layer composition containing a polymer resin described below. The hard coat layer may be formed by applying the hard coat layer composition to one main surface of a transparent substrate such as a substrate.

[0112] In addition, polymer resins such as polyester resins, acrylic resins, acrylic urethane resins, polyester acrylate resins, urethane acrylate resins, epoxy acrylate resins, and polyurethane resins can be used as the binder of the anti-glare layer and the hard coat layer.

[0113] (Anti-fouling film)

[0114] From the viewpoint of protecting its outermost surface, the substrate with a dielectric multilayer film in this embodiment may further have an antifouling film (also referred to as an "anti-fingerprint coating (AFP) film") on the above-mentioned dielectric multilayer film. The antifouling film may be composed of, for example, a fluorinated organosilicon compound. As a fluorinated organosilicon compound, as long as it can impart antifouling properties, water repellency, and oil repellency, it can be used without particular limitation. For example, a fluorinated organosilicon compound having one or more groups selected from a polyfluoropolyether group, a polyfluoroalkylene group, and a polyfluoroalkyl group may be cited. It should be noted that a polyfluoropolyether group refers to a divalent group having a structure formed by alternating bonding of a polyfluoroalkylene group and an etheric oxygen atom.

[0115] In addition, as commercially available fluorinated silicone compounds having one or more groups selected from a polyfluoropolyether group, a polyfluoroalkylene group and a polyfluoroalkyl group, KP-801 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), KY178 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), KY-130 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), KY-185 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), Optool (registered trademark) DSX and Optool AES (both trade names, manufactured by Daikin Corporation) and the like can be preferably used.

[0116] In the present embodiment, when the substrate with the dielectric multilayer film has an antifouling film, the antifouling film is provided on the dielectric multilayer film. When the dielectric multilayer film is provided on both sides of the two main surfaces of the substrate, the antifouling film may be formed on the two dielectric multilayer films, or the antifouling film may be laminated only on one main surface side. This is because the antifouling film can be provided in a place where it may be touched by a human hand, etc., and can be selected according to its use, etc.

[0117] (Adhesive layer)

[0118] The substrate with dielectric multilayer film in this mode can be provided with an adhesive layer on the main surface of the side where the dielectric multilayer film is not provided among the two main surfaces of the transparent substrate. The substrate with dielectric multilayer film is attached to, for example, an image display device via the adhesive layer. The adhesive layer can use a conventionally known adhesive composition, and optically transparent adhesives (OCA: Optical Clear Adhesive), optically transparent resins (OCR: Optical Clear Resin) such as UV curing resins can be cited. As OCA and OCR, for example, polymers such as acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyvinyl ethers, vinyl acetate / vinyl chloride copolymers, modified polyolefins, epoxy systems, fluorine systems, natural rubber, synthetic rubbers, and other rubber systems can be cited. In particular, it is preferred to use acrylic polymers from the perspective of showing appropriate adhesive properties such as wettability, cohesion and adhesion, and excellent transparency, weather resistance, heat resistance, solvent resistance, etc., and a wide range of adhesive force.

[0119] The light transmittance of the adhesive layer measured by a spectrophotometer in accordance with JIS Z 8709 (1999) is preferably 90% or more, preferably 91% or more, and more preferably 92% or more. The transmittance of the adhesive layer in the above range does not impair visibility of, for example, an image display device.

[0120] (Light reflectivity: SCI Y)

[0121] The light reflectance (SCI Y) of the outermost surface of the dielectric multilayer film of the substrate with a dielectric multilayer film of this embodiment is preferably 4% or less. If the light reflectance (SCI Y) is within the above range, when used in an image display device, the effect of preventing external light from being reflected into the screen is high. The light reflectance (SCI Y) is further preferably 2% or less, and particularly preferably 1% or less.

[0122] By adjusting the balance of the film thickness of the high refractive index film layer and the low refractive index film layer to generate optical interference and suppress reflected light, the light reflectivity (SCI Y) can be reduced.

[0123] In addition, the said light reflectance (SCI Y) is measured by the method described in the Example mentioned later.

[0124] (use)

[0125] The substrate with a dielectric multilayer film of this embodiment can be suitably used as an antireflection film or the like for displays, touch panels, and the like.

[0126] <Method for producing a substrate with a dielectric multilayer film>

[0127] The method for manufacturing a substrate with a dielectric multilayer film according to an embodiment of the present invention is as follows:

[0128] A dielectric multilayer film composed of a first dielectric stacked film and a second dielectric stacked film is provided on a substrate.

[0129] The manufacturing method comprises: alternately stacking the same number of first high refractive index film layers containing TiO2 and first low refractive index film layers containing SiO2 on the substrate to form a first dielectric stacked film, and

[0130] The second dielectric stacked film is formed by alternately stacking the same number of second high refractive index film layers containing Ta2O5 or Nb2O5 and second low refractive index film layers containing SiO2 on the above-mentioned first dielectric stacked film.

[0131] The lamination of the above-mentioned layers can be carried out by known film forming methods such as dry film forming processes such as CVD method, sputtering method, vacuum evaporation method, and wet film forming processes such as spraying method and immersion method. From the viewpoint of easily obtaining a high refractive index film layer of a thin film layer, a dry film forming process is preferred, and among them, sputtering method is more preferred.

[0132] Examples of the sputtering method include magnetron sputtering, pulse sputtering, AC sputtering, and digital sputtering.

[0133] For example, magnetron sputtering is a method in which a magnet is placed on the back side of a dielectric material serving as a matrix to generate a magnetic field, whereby gas ion atoms collide with the surface of the dielectric material and are knocked out to form a film by sputtering with a thickness of several nanometers. This method can form a continuous film of the dielectric material's oxide or nitride, i.e., a dielectric.

[0134] In addition, for example, digital sputtering is different from the usual magnetron sputtering method. It is a method of forming a thin film of metal oxide by repeatedly performing the process of first forming an extremely thin film of metal by sputtering and then irradiating oxygen plasma or oxygen ions or oxygen free radicals to oxidize in the same chamber. In this case, the film-forming molecules are metal when attached to the substrate, so it is presumed that it has ductility compared to the case of attaching the film with metal oxide. Therefore, it is believed that even with the same energy, the rearrangement of the film-forming molecules is easy to occur, and as a result, a compact and smooth film can be formed.

[0135] As described above, this specification discloses the following matters.

[0136] (1) A substrate with a dielectric multilayer film, comprising a dielectric multilayer film on the substrate,

[0137] The dielectric multilayer film is composed of a first dielectric multilayer film and a second dielectric multilayer film stacked in order from the substrate side.

[0138] The first dielectric laminate film is formed by alternately laminating the first high refractive index film layer containing TiO2 and the first low refractive index film layer containing SiO2 in the same number starting from the substrate side.

[0139] The second dielectric laminate film is alternately laminated in the same number of second high refractive index film layers containing Ta2O5 or Nb2O5 and second low refractive index film layers containing SiO2 in order from the substrate side.

[0140] The thickness of the first low-refractive-index film layer farthest from the substrate in the first dielectric stack film is 30 nm or more.

[0141] (2) A substrate with a dielectric multilayer film according to (1) above, wherein the ratio (T1 / T2) of the thickness T1 of the first high refractive index film layer farthest from the substrate in the first dielectric multilayer film to the thickness T2 of the second high refractive index film layer closest to the substrate in the second dielectric multilayer film is 0.7 to 1.4.

[0142] (3) The substrate with a dielectric multilayer film according to (1) or (2) above, wherein the total film thickness of the dielectric multilayer film is 300 nm or less.

[0143] (4) A substrate with a dielectric multilayer film according to any one of (1) to (3) above, wherein the thickness of the second low refractive index film layer farthest from the substrate in the second dielectric multilayer film is 75 nm to 105 nm.

[0144] (5) A substrate with a dielectric multilayer film according to any one of (1) to (4) above, wherein the total number of layers of the first high refractive index film layer, the first low refractive index film layer, the second high refractive index film layer and the second low refractive index film layer in the above dielectric multilayer film is 6 to 12 layers.

[0145] (6) The dielectric multilayer film-attached substrate according to (5) above, wherein the total number of layers is 6.

[0146] (7) A substrate with a dielectric multilayer film according to (6) above, wherein the dielectric multilayer film comprises, in order from the substrate side, a first high refractive index film layer a1 containing TiO2, a first low refractive index film layer b1 containing SiO2, a first high refractive index film layer a2 containing TiO2, a first low refractive index film layer b2 containing SiO2, a second high refractive index film layer a3 containing Ta2O5 or Nb2O5, and a second low refractive index film layer b3 containing SiO2.

[0147] (8) A substrate with a dielectric multilayer film according to (6) above, wherein the dielectric multilayer film comprises, in order from the substrate side, a first high refractive index film layer a1 containing TiO2 with a film thickness of less than 20 nm, a first low refractive index film layer b1 containing SiO2 with a film thickness of 30 nm to 50 nm, a first high refractive index film layer a2 containing TiO2 with a film thickness of 10 nm to 50 nm, a first low refractive index film layer b2 containing SiO2 with a film thickness of 30 nm to 50 nm, a second high refractive index film layer a3 containing Ta2O5 or Nb2O5 with a film thickness of 15 nm to 50 nm, and a second low refractive index film layer b3 containing SiO2 with a film thickness of 75 nm to 105 nm.

[0148] (9) The substrate with a dielectric multilayer film according to any one of (1) to (8) above, wherein the substrate includes at least one of glass and resin.

[0149] (10) The substrate with a dielectric multilayer film according to any one of (1) to (9) above, further comprising an adhesion layer between the substrate and the dielectric multilayer film.

[0150] (11) A method for manufacturing a substrate with a dielectric multilayer film, the substrate with a dielectric multilayer film comprising a first dielectric multilayer film and a second dielectric multilayer film on the substrate,

[0151] The manufacturing method comprises the following steps:

[0152] The first dielectric laminate film is formed by alternately laminating the same number of first high refractive index film layers containing TiO2 and first low refractive index film layers containing SiO2 on the substrate, and

[0153] The second dielectric laminate film is formed by alternately laminating the same number of second high refractive index film layers containing Ta2O5 or Nb2O5 and second low refractive index film layers containing SiO2 on the first dielectric laminate film.

[0154] The thickness of the first low-refractive-index film layer farthest from the substrate in the first dielectric laminate film is set to be 30 nm or more.

[0155] Example

[0156] Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto. Examples 1 to 3 are Examples, and Examples 4 to 8 are Comparative Examples.

[0157] <Film thickness measurement>

[0158] The reflectance at each wavelength was measured using a spectrophotometer (manufactured by Shimadzu Corporation, trade name: SolidSpec 3700), and the film thickness was determined from the obtained actual reflection spectrum using TF-Calc (manufactured by HULINKS) with refractive index dispersion and film thickness as variables.

[0159] <Measurement of membrane stress>

[0160] The following Stoney equation was used to determine the change in the warpage amount before and after film formation measured by the following method.

[0161] (Changes in warpage before and after film formation)

[0162] As a laser displacement meter, Dyvoce 3000 manufactured by Kamitsu Seiki Co., Ltd. was used to measure the height direction positions of the outer and inner sides of the substrate, and the difference was calculated as the warpage. The warpage was measured before and after film formation, and the difference was used as the contribution of residual stress caused by film formation.

[0163] (Stoney formula)

[0164] Membrane stress = ED 2 / 6(1-v)tR

[0165] E = Young's modulus of the substrate

[0166] v = Poisson's ratio of the substrate

[0167] D=Substrate thickness

[0168] t=Film thickness

[0169] R = Radius curvature change

[0170] <Light reflectance (SCI Y)>

[0171] The light reflectance (SCI Y) was measured on the outermost surface of the dielectric multilayer film using a spectrophotometer (manufactured by Shimadzu Corporation, trade name: SolidSpec 3700) according to the method specified in JIS Z 8722 (2009).

[0172] (Example 1)

[0173] The substrate with a dielectric multilayer film of Example 1 was prepared by the following method. The substrate with a dielectric multilayer film of Example 1 has Figure 2That is, the substrate 2 with a dielectric multilayer film has a first dielectric multilayer film 10 and a second dielectric multilayer film 20 stacked in this order on a substrate S.

[0174] The first dielectric multilayer film 10 is stacked in order from the substrate S side with a first high refractive index film layer a1 containing TiO2, a first low refractive index film layer b1 containing SiO2, a first high refractive index film layer a2 containing TiO2, and a first low refractive index film layer b2 containing SiO2. The second dielectric multilayer film 20 is stacked in order from the substrate S side with a second high refractive index film layer a3 containing Ta2O5 and a second low refractive index film layer b3 containing SiO2. The substrate 2 with dielectric multilayer film of Example 1 is formed by providing a total of 6 layers of dielectric multilayer films on the substrate S.

[0175] The following is a detailed description.

[0176] As the substrate S, a quartz substrate (synthetic recyclable material, manufactured by Sanei-Opt Co., Ltd.) having a refractive index of 1.46 and a size of Φ150 mm×0.5 mmt was used.

[0177] The quartz substrate was fully evacuated to a pre-evacuation pressure of 10 －4 Pa or less, and during film formation, a first high refractive index film layer a1 containing TiO2 with a thickness of 10 nm was formed by reactive sputtering using DC magnetron and oxygen in an Ar gas pressure atmosphere of 0.1 Pa.

[0178] Next, the first high refractive index film layer a1 is fully evacuated to a pre-evacuation pressure of 10 －4 Pa or less, and during film formation, a first low refractive index film layer b1 containing SiO2 with a thickness of 40 nm was formed by reactive sputtering using DC magnetron and oxygen in an Ar gas pressure atmosphere of 0.1 Pa.

[0179] Next, the first low refractive index film layer b1 is fully evacuated to a pre-evacuation pressure of 10 －4 Pa or less, and during film formation, a first high refractive index film layer a2 containing TiO2 with a thickness of 30 nm is formed by reactive sputtering based on DC magnetron and oxygen in an Ar gas pressure atmosphere of 0.1 Pa.

[0180] Next, the first high refractive index film layer a2 is fully evacuated to a pre-evacuation pressure of 10 －4 Pa or less, and during film formation, a first low refractive index film layer b2 containing SiO2 with a thickness of 30 nm was formed by reactive sputtering using DC magnetron and oxygen in an Ar gas pressure atmosphere of 0.1 Pa.

[0181] In this way, the first dielectric stacked film 10 is provided.

[0182] Next, the first low-refractive-index film layer b2 in the first dielectric laminate film 10 is fully evacuated to a pre-evacuation pressure of 10 －4 Pa or less, and during film formation, a second high refractive index film layer a3 containing Ta2O5 with a thickness of 30 nm is provided by reactive sputtering based on DC magnetron and oxygen in an Ar gas pressure atmosphere of 0.1 Pa.

[0183] Next, the second high refractive index film layer a3 is fully evacuated to a pre-evacuation pressure of 10 －4 Pa or less, and during film formation, a second low refractive index film layer b3 containing SiO2 with a thickness of 85 nm is provided by reactive sputtering based on DC magnetron and oxygen in an Ar gas pressure atmosphere of 0.1 Pa.

[0184] In this way, the second dielectric stack film 20 is provided on the first dielectric stack film 10, and the substrate with a dielectric multilayer film of Example 1 is manufactured.

[0185] (Example 2)~(Example 8)

[0186] In Example 1, except that the layer structure and film thickness of the dielectric multilayer film were changed as described in Table 1, Example 1 was repeated.

[0187] The results are shown in Table 1. In addition, the film thickness of the dielectric multilayer film is shown in Figure 3 The results of the film stress measurements are shown in Figure 4 .

[0188] [Table 1]

[0189]

[0190] According to the results in Table 1, it can be seen that since the substrates with dielectric multilayer films in Examples 1 to 3 are formed by stacking the first dielectric stacked film and the second dielectric stacked film in sequence on the substrate, the first dielectric stacked film is stacked alternately from the substrate side with the first high refractive index film layer containing TiO2 and the first low refractive index film layer containing SiO2, and the number of the first high refractive index film layer and the first low refractive index film layer in the first dielectric stacked film is the same, and the second dielectric stacked film is stacked alternately from the substrate S side with the second high refractive index film layer containing Ta2O5 or Nb2O5 and the second low refractive index film layer containing SiO2, and the number of the second high refractive index film layer and the second low refractive index film layer in the second dielectric stacked film is the same, and the thickness of the first low refractive index film layer farthest from the substrate in the first dielectric stacked film is more than 30nm, so the film stress is reduced, and warping and peeling can be fully suppressed.

[0191] On the other hand, in Example 4, since the second high refractive index film layer containing Ta2O5 or Nb2O5 is not provided, the film stress increases.

[0192] In Example 5, since the first high refractive index film layer containing TiO2 is not provided, the film stress increases.

[0193] In Example 6, since the first low-refractive-index film layer is not provided on the side farthest from the substrate in the first dielectric stack film, the film stress increases.

[0194] In Examples 7 and 8, since the thickness of the first low-refractive-index film layer farthest from the substrate is less than 30 nm, the film stress increases.

[0195] In the above, various embodiments are described with reference to the accompanying drawings, but the present invention is certainly not limited to the above examples. It can be understood that for those skilled in the art, various variations or modifications can be thought of within the scope of the scope of the patent claim, and these certainly also belong to the technical scope of the present invention. In addition, the various constituent elements in the above embodiments can also be arbitrarily combined within the scope of the invention without departing from the main purpose of the invention.

[0196] It should be noted that the present application is based on the Japanese patent application (Japanese Patent Application No. 2022-133627) filed on August 24, 2022, and the contents thereof are incorporated herein by reference.

[0197] Explanation of symbols

[0198] 1.2 Substrate with dielectric multilayer film

[0199] 101st dielectric laminate film

[0200] 20 Second dielectric laminate film

[0201] 101, a1, a2 The first high refractive index film layer containing TiO2

[0202] 102, b1, b2 The first low refractive index film layer containing SiO2

[0203] 201, a3 A second high refractive index film layer containing Ta2O5 or Nb2O5

[0204] 202, b3 The second low refractive index film layer containing SiO2

[0205] S substrate

Claims

1. A substrate with a dielectric multilayer film, comprising a dielectric multilayer film on the substrate, The dielectric multilayer film includes a first dielectric multilayer film and a second dielectric multilayer film stacked in order from the substrate side. The first dielectric laminate film is alternately laminated in order from the substrate side with the same number of first high refractive index film layers containing TiO2 and first low refractive index film layers containing SiO2, The second dielectric laminate film is alternately laminated in the same number of second high refractive index film layers containing Ta2O5 or Nb2O5 and second low refractive index film layers containing SiO2 in order from the substrate side. The thickness of the first low-refractive-index film layer farthest from the substrate in the first dielectric stack film is 30 nm or more.

2. The substrate with a dielectric multilayer film according to claim 1, wherein: The ratio T1 / T2 of the thickness T1 of the first high refractive index film layer farthest from the substrate in the first dielectric stack film to the thickness T2 of the second high refractive index film layer closest to the substrate in the second dielectric stack film is 0.7 to 1.

4.

3. The substrate with a dielectric multilayer film according to claim 1 or 2, wherein: The total film thickness of the dielectric multilayer film is 300 nm or less.

4. The substrate with a dielectric multilayer film according to claim 1 or 2, wherein: The thickness of the second low refractive index film layer farthest from the substrate in the second dielectric stack film is 75 nm to 105 nm.

5. The substrate with a dielectric multilayer film according to claim 1 or 2, wherein: The total number of layers of the first high refractive index film layer, the first low refractive index film layer, the second high refractive index film layer, and the second low refractive index film layer in the dielectric multilayer film is 6 to 12 layers.

6. The substrate with a dielectric multilayer film according to claim 5, wherein: The total number of layers is 6.

7. The substrate with a dielectric multilayer film according to claim 6, wherein: The dielectric multilayer film comprises, from the substrate side, in sequence: a first high refractive index film layer a1 containing TiO2, a first low refractive index film layer b1 containing SiO2, a first high refractive index film layer a2 containing TiO2, a first low refractive index film layer b2 containing SiO2, a second high refractive index film layer a3 containing Ta2O5 or Nb2O5, and a second low refractive index film layer b3 containing SiO2.

8. The substrate with a dielectric multilayer film according to claim 6, wherein: The dielectric multilayer film comprises, from the substrate side, in sequence: a first high refractive index film layer a1 containing TiO2 with a film thickness of less than 20nm, a first low refractive index film layer b1 containing SiO2 with a film thickness of 30nm to 50nm, a first high refractive index film layer a2 containing TiO2 with a film thickness of 10nm to 50nm, a first low refractive index film layer b2 containing SiO2 with a film thickness of 30nm to 50nm, a second high refractive index film layer a3 containing Ta2O5 or Nb2O5 with a film thickness of 15nm to 50nm, and a second low refractive index film layer b3 containing SiO2 with a film thickness of 75nm to 105nm.

9. The substrate with a dielectric multilayer film according to claim 1 or 2, wherein: The substrate includes at least any one of glass and resin.

10. The substrate with a dielectric multilayer film according to claim 1 or 2, wherein: An adhesion layer is provided between the substrate and the dielectric multilayer film.

11. A method for manufacturing a substrate with a dielectric multilayer film, wherein the substrate with a dielectric multilayer film comprises a dielectric multilayer film composed of a first dielectric stacked film and a second dielectric stacked film on the substrate, the method comprising the following steps: The first dielectric laminate film is formed by alternately stacking the same number of first high refractive index film layers containing TiO2 and first low refractive index film layers containing SiO2 on the substrate, and The second dielectric laminate film is formed by alternately laminating the same number of second high refractive index film layers containing Ta2O5 or Nb2O5 and second low refractive index film layers containing SiO2 on the first dielectric laminate film, The thickness of the first low-refractive-index film layer farthest from the substrate in the first dielectric stack film is set to be greater than or equal to 30 nm.

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