Barrier film, solar cell, el display device, and method for manufacturing barrier film

Abstract

Provided is a barrier film having a plurality of layers on a substrate, wherein the plurality of layers have at least three layers, i.e. a first silicon nitride layer, a ZAO layer, and a first silicon oxide layer, in the stated order from the substrate side.

Description

Barrier film, solar cell, EL display device, method for manufacturing a barrier film

[0001] This invention relates to a barrier film, a solar cell, an EL display device, and a method for manufacturing a barrier film. This invention claims priority to Japanese Patent Application No. 2024-208724, filed on November 29, 2024, and in designated countries where reference to the present invention is permitted, the contents described in that application are incorporated into this application by reference.

[0002] There is a demand for water vapor barrier films with anti-reflective properties for use in solar cells and EL display devices.

[0003] Japanese Patent Publication No. 2004-291464

[0004] One aspect of the present invention is a barrier film having a plurality of layers on a substrate, wherein the plurality of layers, from the substrate side, consist of at least three layers in this order: a first silicon nitride layer, a ZAO layer, and a first silicon oxide layer.

[0005] Another aspect of the present invention is a barrier film having a plurality of layers on a substrate, wherein the water vapor permeability of the barrier film is 5E －４ g / m ２ The barrier film has a temperature of less than / day and a reflectance of 1% or less for light with wavelengths between 450 nm and 650 nm at an incident angle of 0°.

[0006] Another aspect of the present invention is a solar cell having the barrier film described above.

[0007] Another aspect of the present invention is an EL display device having the barrier film described above.

[0008] Another aspect of the present invention is a method for manufacturing a barrier film, comprising: forming a first silicon nitride layer on a substrate by CVD; forming a ZAO layer on the first silicon nitride layer by sputtering; and forming a first silicon oxide layer on the ZAO layer by CVD.

[0009] This is a schematic cross-sectional view showing barrier film 1 according to this embodiment. This is a schematic cross-sectional view showing barrier film 2 according to this embodiment. This is a schematic cross-sectional view showing barrier film 3 according to this embodiment. This is a schematic cross-sectional view showing barrier film 4 according to this embodiment. This is a graph showing the reflectance (calculated value) of barrier films 1 and 3 according to this embodiment at an incident angle of 0°. This is a graph showing the reflectance (calculated value) of barrier films 2 and 4 according to this embodiment at an incident angle of 0°. This is a graph showing the reflectance (calculated value) of barrier films 1 and 3 according to this embodiment at an incident angle of 45°. This is a graph showing the reflectance (calculated value) of barrier films 2 and 4 according to this embodiment at an incident angle of 45°. This is a graph showing the reflectance (measured value) of barrier film 1 according to this embodiment at an incident angle of 0°. This is a graph showing the water vapor transmittance of barrier film 1 according to this embodiment. This is a graph showing the water vapor transmittance of barrier film 1A according to this embodiment. This is a schematic cross-sectional view showing a solar cell provided with the barrier film according to this embodiment.

[0010] The following describes embodiments of the present invention (hereinafter referred to as "these embodiments"). These embodiments are illustrative examples for explaining the present invention and are not intended to limit the present invention to the following content. The present invention can be implemented by modifying it as appropriate within the scope of its gist.

[0011] This embodiment will be described in detail below.

[0012] <Barrier Film> One embodiment of the barrier film according to this embodiment is a barrier film 1 having a plurality of layers on a substrate (101), wherein the plurality of layers have at least three layers in this order from the substrate (101) side: a first silicon nitride layer (102-1), a ZAO layer (103), and a first silicon oxide layer (104-1). The barrier film 1 is a barrier film having at least three layers as shown in Figure 1. Here, ZAO refers to zinc oxide with aluminum added. This does not preclude the barrier film from having layers other than these three.

[0013] Another embodiment of the barrier film according to this embodiment is a barrier film 2 having a plurality of layers on a substrate (201), wherein the plurality of layers have at least three layers in this order from the substrate (201) side: a first silicon nitride layer (202-1), a ZAO layer (203), and a first silicon oxide layer (204-1), and further, between the substrate (201) and the first silicon nitride layer (202-1), there are at least two layers in this order from the substrate (201) side: a second silicon nitride layer (202-2) and a second silicon oxide layer (204-2). The barrier film 2 is a barrier film having at least five layers as shown in Figure 2. This does not preclude the barrier film having layers other than these five layers.

[0014] Another embodiment of the barrier film according to this embodiment is a barrier film 3 having a plurality of layers on a substrate (301), wherein the plurality of layers, from the substrate (301) side, consist of at least three layers in this order: a first silicon nitride layer (302-1), a ZAO layer (303), and a first silicon oxide layer (304-1), and further having a third silicon nitride layer (302-3) between the ZAO layer (303) and the first silicon oxide layer (304-1). The barrier film 3 is a barrier film having at least four layers as shown in Figure 3. This does not preclude the barrier film having layers other than these four.

[0015] Another embodiment of the barrier film according to this embodiment is a barrier film 4 having a plurality of layers on a substrate (401), wherein the plurality of layers have at least three layers in this order from the substrate (401) side: a first silicon nitride layer (402-1), a ZAO layer (403), and a first silicon oxide layer (404-1), and further, between the substrate (401) and the first silicon nitride layer (402-1), there are at least two layers in this order from the substrate (401) side: a second silicon nitride layer (402-2) and a second silicon oxide layer (404-2). Furthermore, there is a third silicon nitride layer (402-3) between the ZAO layer (403) and the first silicon oxide layer (404-1). The barrier film 4 is a barrier film having at least six layers as shown in Figure 4. This does not negate the possibility of having layers other than these six layers as a barrier film.

[0016] The substrates (101, 201, 301, 401) of barrier films 1 to 4 are organic resin substrates or film substrates. Examples of substrate materials include cycloolefin polymer (COP), polyimide (PI), colorless polyimide (CPI: transparent), polyethylene naphthalate (PEN), and polyethylene terephthalate (PET). The thickness of the substrates (101, 201, 301, 401) is 25 μm to 150 μm. When colorless polyimide is used as the substrate material, it is known that adhesion to the layer placed on the substrate cannot be achieved and peeling occurs. Therefore, when using colorless polyimide as the substrate, it is preferable to form a SiCN film in contact with the colorless polyimide and then provide the layer configuration shown for barrier films 1 to 4. This prevents the first silicon nitride layer or the second silicon nitride layer from peeling off from the colorless polyimide. The SiCN film can be obtained, for example, by CVD deposition with nitrogen mixed in organic silane gas. The thickness of the SiCN film is preferably 5 nm to 30 nm.

[0017] The barrier film according to this embodiment has an organic resin substrate or a film substrate, and if the stress on the barrier film is high, it may not maintain its flatness and may warp. Therefore, the stress on the barrier film according to this embodiment must be within a predetermined range to prevent warping. In addition, the barrier film according to this embodiment is required to have water vapor barrier performance or anti-reflective performance. The stress on the barrier film is adjusted by controlling the film type and film thickness of each layer. The water vapor barrier performance of the barrier film is adjusted by controlling the film type and film thickness. The anti-reflective performance of the barrier film is adjusted by controlling the refractive index and film thickness of each layer. Since film thickness affects all three properties (stress, water vapor barrier performance, and anti-reflective performance), for example, it is desirable to increase the film thickness to improve water vapor barrier performance, but increasing the film thickness also increases the stress on the barrier film. Therefore, it is important to control the film type and film thickness of each layer so that these three properties (stress, water vapor barrier performance, and anti-reflective performance) can be obtained.

[0018] In the barrier film 1, which has a basic three-layer structure, the first silicon nitride layer (102-1) and the ZAO layer (103) provide water vapor barrier performance. Furthermore, by providing the first silicon oxide layer (104-1), the refractive indices of the first silicon nitride layer (102-1), the ZAO layer (103), and the first silicon oxide layer (104-1) are arranged in order from medium, high, and low from the substrate side. In addition, the film thickness of each layer is adjusted. In this way, anti-reflective performance can be given to the barrier film, and the barrier film can be adjusted to a predetermined stress.

[0019] The refractive index of a layer is controlled by the type of film and the manufacturing method. Even films made of the same material will have different refractive indices depending on whether the film is sparse or dense.

[0020] Barrier film 2 has a second silicon nitride layer (202-2) and a second silicon oxide layer (204-2) added to the structure of barrier film 1. Compared to barrier film 1, barrier film 2 can broaden the wavelength range of its anti-reflective performance.

[0021] Barrier film 3 includes a third silicon nitride layer (302-3) to strengthen the adhesion between the ZAO layer 303 and the first silicon oxide layer (304-1). Similarly, barrier film 4 includes a third silicon nitride layer (402-3) to strengthen the adhesion between the ZAO layer 403 and the first silicon oxide layer (404-1).

[0022] In barrier films 1 to 4, the refractive indices of the first silicon nitride layer (102-1, 202-1, 302-1, 402-1) and the first silicon oxide layer (104-1, 204-1, 304-1, 404-1) are each smaller than the refractive indices of the ZAO layer (103, 203, 303, 403).

[0023] In barrier films 1 to 4, the refractive indices of the first silicon oxide layers (10⁴-1, 20⁴-1, 30⁴-1, 40⁴-1) are each smaller than the refractive indices of the first silicon nitride layers (10⁂-1, 20⁂-1, 30⁂-1, 40⁂-1).

[0024] In barrier films 2 and 4, the refractive index of the second silicon oxide layer (204-2, 404-2) is smaller than that of the second silicon nitride layer (202-2, 402-2), respectively.

[0025] Another aspect of the barrier film according to this embodiment is a barrier film having a plurality of layers on a substrate, wherein the water vapor transmission rate of the barrier film is 5E －４ g / m ２ / day or less, and the reflectance with respect to light having a wavelength of 450 nm or more and 650 nm or less at an incident angle of 0° is 1% or less.

[0026] The water vapor transmission rate of the barrier film according to this embodiment is 5E －４ g / m ２ / day or less. The upper limit of the water vapor transmission rate is preferably 1E －４ g / m ２ / day, more preferably 8E －５ g / m ２ / day.

[0027] The reflectance of the barrier film according to this embodiment with respect to light having a wavelength of 450 nm or more and 650 nm or less at an incident angle of 0° is 1% or less. The upper limit of the reflectance at an incident angle of 0° is preferably 0.6%, more preferably 0.5%, and even more preferably 0.4%.

[0028] The reflectance of the barrier film according to this embodiment with respect to light having a wavelength of 450 nm or more and 650 nm or less at an incident angle of 45° is 3% or less. The upper limit of the reflectance at an incident angle of 45° is preferably 2.6%, more preferably 2%, and even more preferably 1.9%.

[0029] If the compressive stress of the barrier film is large, film peeling may occur at the interface between the substrate and the layer on the substrate, or the barrier film may break. The stress of the barrier film is determined by the film type and the film thickness. In this specification, the stress value of the barrier film is the value of the stress of the entire barrier film.

[0030] The film thickness of the first silicon nitride layer (102-1, 202-1, 302-1, 402-1) of the barrier films 1 to 4 is 50 nm or more and 60 nm or less. Since the first silicon nitride layer is responsible for the water vapor barrier performance of the barrier film, its film thickness is made thicker than those of the second and third silicon nitride layers.

[0031] The film thickness of the second silicon nitride layer (202-2, 402-2) of the barrier films 2 and 4 is 10 nm or more and 20 nm or less.

[0032] The film thickness of the third silicon nitride layer (302-3, 402-3) of the barrier films 3 and 4 is 5 nm or more and 20 nm or less. Since the third silicon nitride layer may function as an adhesion layer between the ZAO layer and the first silicon oxide layer, the film thickness can be made thinner than that of the first silicon nitride layer and the second silicon nitride layer.

[0033] The thickness of the ZAO layer (103, 203, 303, 403) of the barrier films 1 to 4 is 75 nm or more and 110 nm or less. ZAO is zinc oxide to which aluminum is added. The content rate of aluminum is 2% or more and 7% or less in terms of the atomic ratio of Al / (Zn + Al). Note that the ZAO layer only needs to have zinc oxide to which aluminum is added as the main component, and may contain other components such as niobium and titanium at the impurity level. Since the ZAO layer is responsible for the water vapor barrier performance of the barrier film, the film thickness is made thick among the layers constituting the barrier layer.

[0034] The thickness of the first silicon oxide layer (104-1, 204-1, 304-1, 404-1) of the barrier films 1 to 4 is 70 nm or more and 95 nm or less. Since the first silicon oxide layer is responsible for the antireflection performance, the film thickness is made thick among the layers constituting the barrier film.

[0035] The thickness of the second silicon oxide layer (104-2, 404-2) of the barrier films 2 and 4 is 20 nm or more and 35 nm or less.

[0036] In the barrier films 1 to 4, the film thickness of the ZAO layer (103, 203, 303, 403) or the first silicon oxide layer (104-1, 204-1, 304-1, 404-1) is the thickest.

[0037] From the above, in the barrier film according to the present embodiment, among the layers constituting the barrier film, the film thickness of the ZAO layer or the first silicon oxide layer becomes the thickest.

[0038] The stress (compressive stress) of the barrier film according to this embodiment is -100 MPa or more and 0 Pa or less. The lower limit of the compressive stress is preferably -75 MPa, more preferably -50 MPa, and even more preferably -20 MPa.

[0039] The barrier film according to this embodiment can be used as a water vapor barrier film, an anti-reflective film, or both a water vapor barrier film and an anti-reflective film. Furthermore, the barrier film according to this embodiment can be used in solar cells, EL display devices, and the like. Products such as solar cells and EL display devices using the barrier film according to this embodiment are also included in the present invention.

[0040] <Method for manufacturing a barrier film> The method for manufacturing the barrier film 1 (three-layer structure) according to this embodiment includes: forming a first silicon nitride layer (102-1) on a substrate (101) by CVD (Chemical Vapor Deposition); forming a ZAO layer (103) on the first silicon nitride layer (102-1) by sputtering; and forming a first silicon oxide layer (104-1) on the ZAO layer (103) by CVD using an inorganic material.

[0041] A method for manufacturing the barrier film 2 (5-layer structure) according to this embodiment includes: forming a second silicon nitride layer (202-2) on a substrate (201) by CVD; forming a second silicon oxide layer (204-2) on the second silicon nitride layer (202-2) by CVD; forming a first silicon nitride layer (202-1) on the second silicon oxide layer (204-2) by CVD; forming a ZAO layer (203) on the first silicon nitride layer (202-1) by sputtering; and forming a first silicon oxide layer (204-1) on the ZAO layer (203) by CVD using an inorganic material.

[0042] The method for manufacturing the barrier film 3 (four-layer structure) according to this embodiment includes: forming a first silicon nitride layer (302-1) on a substrate (301) by CVD; forming a ZAO layer (303) on the first silicon nitride layer (302-1) by sputtering; forming a third silicon nitride layer (302-3) on the ZAO layer (303) by CVD; and forming a first silicon oxide layer (304-1) on the third silicon nitride layer (302-3) by CVD using an organic silane.

[0043] The method for manufacturing the barrier film 4 according to this embodiment includes: forming a second silicon nitride layer (402-2) on a substrate (401) by CVD; forming a second silicon oxide layer (404-2) on the second silicon nitride layer (402-2) by CVD; forming a first silicon nitride layer (402-1) on the second silicon oxide layer (404-2) by CVD; forming a ZAO layer (403) on the first silicon nitride layer (402-1) by sputtering; forming a third silicon nitride layer (402-3) on the ZAO layer (403) by CVD; and forming a first silicon oxide layer (404-1) on the third silicon nitride layer (402-3) by CVD using an organic silane.

[0044] In the manufacturing method for barrier films 1 and 2, a first silicon oxide layer (104-1, 204-1) is formed using an inorganic silicon source. To ensure the water vapor barrier performance and anti-reflective performance of barrier films 1 and 2, the first silicon oxide layer needs to have a thickness above a certain value. However, as the film thickness increases, the film stress also increases, making it difficult to keep the stress of the barrier film within a predetermined range.

[0045] Therefore, in the manufacturing method for barrier films 3 and 4, in order to reduce the compressive stress of the first silicon oxide layer compared to barrier films 1 and 2, the first silicon oxide layer (304-1, 404-1) is formed using an organic silicon source. By using an organic silicon source instead of an inorganic silicon source, the compressive stress (negative stress) of barrier films 3 and 4 is reduced, thereby reducing the stress of the barrier films.

[0046] In the method for manufacturing barrier film 3, the compressive stress of barrier film 3 can be reduced compared to barrier film 1 by forming the first silicon oxide layer (304-1) using an organic silicon source. However, as a side effect, it was found that the adhesion between the ZAO layer (303) and the first silicon oxide layer (304-1) was lower than that of barrier film 1. Therefore, a third silicon nitride layer (302-3) is provided between these two layers to ensure adhesion.

[0047] In the manufacturing method of barrier film 4, the compressive stress of barrier film 4 can be reduced compared to barrier film 2 by forming the first silicon oxide layer (404-1) using an organic silicon source. On the other hand, similar to barrier film 3, barrier film 4 also exhibits lower adhesion between the ZAO layer and the first silicon oxide layer compared to barrier film 2. Therefore, by providing a third silicon nitride layer (402-3) between the first silicon oxide layer (404-1) and the ZAO layer (403), adhesion between each layer of ZAO layer (403), third silicon nitride layer (402-3), and first silicon oxide layer (404-1) is ensured.

[0048] The third silicon nitride layer only needs to function as an adhesion layer, so its thickness can be in the range of 5 nm to 25 nm.

[0049] In the manufacturing method of barrier films 1 and 2, the silicon source of the inorganic material for the first silicon oxide layer (104-1, 204-1) is, for example, a carbon-free inorganic silane, and monosilane (SiH ４ ), disilane (Si ２ H ６ ) etc.

[0050] In the manufacturing method of barrier films 3 and 4, the silicon source of the organic material for the first silicon oxide layer (304-1, 404-1) is, for example, an organic silane such as hexamethyldisiloxane (HMDSO), hexamethyldisilazane (HMDS), or tetraethoxysilane (TEOS).

[0051]

[0052] In barrier films 3 and 4, forming the first silicon oxide layer using an organic material reduces film stress compared to forming it using an inorganic material. This is thought to be due to the carbon contained in the silicon source of the organic material. On the other hand, since an organic material is used as the material for the first silicon oxide layer in barrier films 3 and 4, carbon remains in the first silicon oxide layer, raising concerns about optical performance. However, the amount of carbon in the first silicon oxide was extremely small, so it did not affect the optical properties, which are the anti-reflective properties.

[0053] Furthermore, in the manufacturing method of barrier films 1 to 4 in this embodiment, each ZAO layer and each silicon oxide layer has compressive stress. Therefore, when these layers are formed by heating, thermal stress compression is added, further increasing the compressive stress of each layer. Also, when the substrate is heated, it expands, and when it cools, it contracts, generating thermal stress. Consequently, when each ZAO layer and each silicon oxide layer is formed by heating, the compressive stress of the barrier film becomes even stronger. Therefore, by forming each ZAO layer and each silicon oxide layer without heating, the compression of thermal stress due to heat deposition is eliminated, and the warping of the barrier film can be prevented.

[0054] <Method for Manufacturing Solar Cells> Figure 12 shows a solar cell with a barrier film. The solar cell has a pair of electrodes on both sides of the photoelectric conversion layer. The barrier film is provided on the electrode side opposite to the photoelectric conversion layer side via an adhesive layer. In this case, the barrier film is provided so that the substrate of the barrier film is in contact with the adhesive layer. In other words, the barrier film is provided so that the first silicon oxide layer becomes the light incident surface. In Figure 12, barrier films are provided on both sides of the solar cell, but if light is incident on only one side, the barrier film may be provided only on the light incident side. By providing the barrier film of this embodiment to the solar cell, the amount of light incident on the photoelectric conversion layer can be increased. Also, if the solar cell is made of a material that is sensitive to water, the intrusion of moisture can be prevented. Also, if the solar cell is flexible, the amount of light incident and the intrusion of moisture can be prevented without hindering the flexibility. In particular, the barrier film of this embodiment is in the form of a film and has excellent flexibility, making it suitable for application to water-sensitive perovskite solar cells and the like.

[0055] <Method for Manufacturing an EL Display Device> The barrier film of this embodiment is provided on the display surface of an EL (Electro-Luminescence) display device via an adhesive layer. An adhesive layer is formed on the display surface of the EL display device, and the barrier film is provided so that the adhesive layer and the substrate of the barrier film are directly bonded. By providing the barrier film of this embodiment to the EL display device, it is possible to prevent moisture from entering the EL element, which is sensitive to moisture. It is also possible to prevent the display from becoming difficult to see due to light reflection on the display surface. Furthermore, if the EL display device is flexible, it is possible to prevent moisture from entering and provide a clear display without hindering its flexibility.

[0056] Examples and comparative examples of the present invention will be described below. However, the present invention is not limited to the following examples. In Figure 7, the notation aEn means a × 10 ｎ This represents the following: For example, 1.0E - 03 = 1.0 × 10 －３ That is the case.

[0057] <Manufacturing of Barrier Film 1> 1. On a cycloolefin polymer (COP), which is the film-forming substrate for the first silicon nitride layer, SiH ４ A silicon nitride film was deposited using CVD at 150°C. At this point, the silicon nitride layer had tensile stress. The heat resistance temperatures of the other substrates were 230°C or less for polyimide (PI) and colorless polyimide (CPI), 150°C or less for cycloolefin polymer (COP) and polyethylene naphthalate (PEN), and 100°C or less for polyethylene terephthalate (PET). The refractive index of the first silicon nitride layer was 1.83.

[0058] 2. Deposition of the ZAO layer A ZAO layer was deposited on the first silicon nitride layer. The ZAO layer was formed by pulsed DC sputtering or RF sputtering using ZAO-Nb ２ O ｘ The film was deposited without heating using the target. The deposition gas was Ar and O ２ In the mixture, the partial pressure ratio is Ar:O ２A ratio of approximately 10:0.5 to 10:1.5 is preferable. At this point, the combined stress of the first silicon nitride layer and the ZAO layer becomes compressive stress. For water vapor barrier performance, a ZAO layer thickness of 100 nm or more is preferable, but it may be less than 100 nm to also function as an anti-reflective coating. The refractive index of the ZAO layer was 2.1.

[0059] 3. Formation of the first silicon oxide layer (inorganic silicon source) A first silicon oxide layer is formed on the ZAO layer. The silicon oxide layer is SiH ４ A CVD film was deposited using gas without heating. At this point, the combined stress of the first silicon nitride layer, the ZAO layer, and the first silicon oxide layer was compressive stress. Through the above process, barrier film 1 was formed. The refractive index of the first silicon oxide layer was 1.45.

[0060] <Manufacturing of Barrier Film 2> 4. Formation of the second silicon nitride layer The second silicon nitride layer was formed in the same manner as the first silicon nitride layer of barrier film 1. The refractive index of the second silicon nitride layer was 1.83.

[0061] 5. The second silicon oxide layer was formed using the same method as the first silicon oxide layer of the barrier film 1. The refractive index of the second silicon oxide layer was 1.45.

[0062] The method for forming the other layers is the same as that for barrier film 1.

[0063] <Manufacturing of Barrier Film 3> 6. Formation of the Third Silicon Nitride Layer After forming the first silicon nitride layer and the ZAO layer using the same manufacturing method as for barrier film 1, a third silicon nitride layer was formed on the ZAO layer using the same method as for the first silicon nitride layer of barrier film 1. The refractive index of the third silicon nitride layer was 1.83.

[0064] 7. Formation of the first silicon oxide layer (organosilicon source) The first silicon oxide layer was formed on the third silicon nitride layer using hexamethyldisilazane (HMDS) without heating via CVD.

[0065] The stress of barrier film 3 was -58 MPa. In contrast, a barrier film with the same four-layer structure as barrier film 3, but in which the first silicon oxide layer was deposited using silane, an inorganic silicon source, had a stress of -93 MPa. It was found that depositing the first silicon oxide layer using an organic material relieved the stress of the barrier film by approximately 35 MPa.

[0066] <Manufacturing of Barrier Film 4> A second silicon nitride layer and a second silicon oxide layer were deposited on the substrate, a cycloolefin polymer (COP), in the same manner as for barrier film 2. On the second silicon oxide layer, the layers from the first silicon nitride layer onward were deposited in the same manner as for barrier film 3. The stress of barrier film 4 was -90 MPa.

[0067] In contrast, a barrier film with the same six-layer structure as barrier film 4, but in which the first silicon oxide layer was deposited using silane, an inorganic silicon source, had a stress of -125 MPa. It was found that depositing the first silicon oxide layer using an organic material relieved the stress of the barrier film by approximately 35 MPa.

[0068] Table 1 shows the layer structure, film thickness, and stress of barrier films 3 and 4 of the example barrier films 1 to 4.

[0069]

[0070] <Evaluation of Anti-Reflection Performance> The reflectance of each barrier film 1 to 4 was calculated at wavelengths from 380 nm to 780 nm. Calculations were performed at incident angles of 0° and 45° (Figures 5 to 8). At both incident angles of 0° and 45°, barrier films 3 and 4 were able to broaden the wavelength range over which the reflectance was low compared to barrier films 1 and 2. This is thought to be due to the presence of a second silicon nitride layer and a second silicon oxide layer. Figures 7 and 8 show that by broadening the wavelength range in barrier films 3 and 4, the incident angle characteristics improved, making them less likely to appear red when viewed from an oblique angle.

[0071] In Figures 5 and 6, at an incident angle of 0°, the maximum reflectivity of barrier film 1 was 0.47% at a wavelength of 526 nm, the maximum reflectivity of barrier film 2 was 0.51% at a wavelength of 520 nm, the maximum reflectivity of barrier film 3 was 0.30% at a wavelength of 520 nm, and the maximum reflectivity of barrier film 4 was 0.34% at a wavelength of 518 nm. The reflectivity of all barrier films 1 to 4 for light with wavelengths between 450 nm and 650 nm at an incident angle of 0° was 1% or less.

[0072] In the case of an incident angle of 45° shown in Figures 7 and 8, the maximum reflectance values ​​of barrier films 1 to 4 at a wavelength of 650 nm were 2.4%, 2.6%, 1.8%, and 1.9%, respectively. Therefore, the reflectance of all barrier films 1 to 4 for light with wavelengths between 450 nm and 650 nm at an incident angle of 45° was 3% or less.

[0073] Figure 9 shows the measured reflectance of barrier film 1 at an incident angle of 0°. Similar to the calculated values ​​in Figure 5, the measured values ​​in Figure 9 also showed a reflectance of 1% or less for light with wavelengths between 450 nm and 650 nm. The maximum reflectance in the wavelength range of 450 nm to 650 nm was 0.63% at a wavelength of 650 nm. Therefore, it can be inferred that the calculated reflectances of barrier films 2 to 4 are similar to the measured values.

[0074] <Evaluation of water vapor prevention performance> Using barrier film 1, the water vapor transmission rate was measured, and the water vapor transmission rate was 9.0 × 10⁻⁶. －５ (g / m ２ It was confirmed that the value was / day (Figure 10). The water vapor transmission rate was measured using a WVTR (Water Vapor Transmission Rate, manufactured by TI Corporation). The measurement method was the differential pressure method using a quadrupole mass spectrometer (QMS).

[0075] In the above embodiment, the barrier film 1 was formed by CVD deposition of the first silicon nitride layer at 150°C. However, Figure 11 shows the water vapor transmission rate of barrier film 1A in which the first silicon nitride layer was formed by CVD deposition without heating. The thickness of each layer of barrier film 1A is the same as that of barrier film 1. The water vapor transmission rate of barrier film 1A is 7.8 × 10⁻⁶. －５ (g / m ２It was / day).

[0076] <Stress Evaluation> Stress was measured using a thin-film stress measuring device (FLX).

[0077] Based on the above, it was confirmed that barrier films 1 to 4 possess the desired water vapor barrier performance, anti-reflective performance, and film stress properties.

[0078] 1... Barrier film (3-layer structure) 2... Barrier film (5-layer structure) 3... Barrier film (4-layer structure) 4... Barrier film (6-layer structure) 101, 201, 301, 401... Substrate 102-1, 202-1, 302-1, 402-1... First silicon nitride layer 202-2, 402-2... Second silicon nitride layer 302-3, 402-3... Third silicon nitride layer 103, 203, 303, 403... ZAO layer 104-1, 204-1, 304-1, 404-1... First silicon oxide layer 204-2, 404-2... Second silicon oxide layer

Claims

1. A barrier film having a plurality of layers on a substrate, wherein the plurality of layers, from the substrate side, consist of at least three layers in this order: a first silicon nitride layer, a ZAO layer, and a first silicon oxide layer.

2. The barrier film according to claim 1, wherein between the substrate and the first silicon nitride layer, there are at least two layers in this order, from the substrate side: a second silicon nitride layer and a second silicon oxide layer.

3. The barrier film according to claim 1 or 2, having a third silicon nitride layer between the ZAO layer and the first silicon oxide layer.

4. The barrier film according to claim 2, wherein the refractive index of the second silicon oxide layer is smaller than the refractive index of the second silicon nitride layer.

5. The barrier film according to any one of claims 1 to 4, wherein the refractive index of the first silicon nitride layer and the refractive index of the first silicon oxide layer are smaller than the refractive index of the ZAO layer, and the refractive index of the first silicon oxide layer is smaller than the refractive index of the first silicon nitride layer.

6. The barrier film according to any one of claims 1 to 5, wherein the ZAO layer or the first silicon oxide layer has the thickest film thickness.

7. Water vapor transmission rate is 5E －４ g / m ２ A barrier film according to any one of claims 1 to 6, wherein the duration is less than or equal to one day.

8. The barrier film according to any one of claims 1 to 7, wherein the reflectance for light with a wavelength of 450 nm to 650 nm at an incident angle of 0° is 1% or less.

9. A barrier film having multiple layers on a substrate, wherein the water vapor permeability of the barrier film is 5E －４ g / m ２ A barrier film having a temperature of less than / day and a reflectance of 1% or less for light with wavelengths between 450 nm and 650 nm at an incident angle of 0°.

10. The barrier film according to any one of claims 1 to 9, wherein the reflectance for light with a wavelength of 450 nm to 650 nm at an incident angle of 45° is 3% or less.

11. The barrier film according to any one of claims 1 to 10, wherein the compressive stress is 0 Pa or more and 100 MPa or less.

12. The barrier film according to any one of claims 1 to 11, wherein the barrier film is a water vapor barrier film, an anti-reflective film, or a water vapor barrier film and an anti-reflective film.

13. A solar cell having a barrier film according to any one of claims 1 to 12.

14. An EL display device having a barrier film according to any one of claims 1 to 12.

15. A method for manufacturing a barrier film, comprising: forming a first silicon nitride layer on a substrate by CVD; forming a ZAO layer on the first silicon nitride layer by sputtering; and forming a first silicon oxide layer on the ZAO layer by CVD.

16. A method for manufacturing a barrier film according to claim 15, comprising: forming a second silicon nitride layer on the substrate by CVD before forming the first silicon nitride layer; and forming a second silicon oxide layer on the second silicon nitride layer by CVD.

17. A method for producing a barrier film according to claim 15 or 16, comprising: forming a third silicon nitride layer on the ZAO layer by CVD; and forming the first silicon oxide layer on the third silicon nitride layer by CVD using an organic silane.

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