WO2023042438A1 - Light blocking film, multilayer antireflection film, method for producing said light blocking film, method for producing said multilayer antireflection film, and optical member - Google Patents

Abstract

The present invention addresses the problem of providing: a light blocking film and a multilayer antireflection film, each of which has excellent light blocking properties, antireflection properties and chemical stability; a method for producing this light blocking film or this multilayer antireflection film, the method being suppressed in deviation between the design value and the measured value; and an optical member.　The present invention provides a light blocking film which comprises at least a light blocking layer and one or more layers that are in contact with the light blocking layer, and which is characterized in that: the light blocking layer contains chromium and silicon dioxide; and at least one of the one or more layers that are in contact with the light blocking layer contains a compound other than an oxide.

Description

Light-shielding film, multi-layer antireflection film, manufacturing method thereof, and optical member

The present invention relates to a light-shielding film, a multilayer antireflection film, a method for producing them, and an optical member. More specifically, the present invention relates to a light-shielding film and a multilayer anti-reflection film having excellent light-shielding properties and anti-reflection properties, methods for producing them, and optical members.

In recent years, in optical members such as mobile cameras and glass prisms, in order to solve the problem of the occurrence of so-called ghosts and flares, it is required to take measures to prevent light reflection and light shielding on the inner wall surface of the optical members. .
For example, Patent Document 1 discloses an invention in which an inner wall surface of an optical member is coated with a black coating film made of a film-forming resin containing a plurality of fine particles having a plurality of types of shapes.

This is intended to reduce the spectral reflectance and prevent ghosts and flares by applying black ink to optical members using organic substances. Therefore, there is a problem that it is difficult to ensure durability.
In addition, there remains the problem that it is difficult to stabilize the optical properties while reducing the spectral reflectance.

On the other hand, in Patent Document 2, an inorganic material is used for the light shielding film provided in the optical member, and the light shielding film is a combination of a plurality of light absorbing layers and a low refractive index layer having a refractive index of 1.7 or less. By using , not only light incident on the light-shielding film is shielded, but also reflected light from its surface (the substrate side and the surface opposite to the substrate) is reduced.
However, the study by the present inventors has revealed that the light-shielding film disclosed in Patent Document 2 still has room for improvement from the viewpoint of stability.

JP 2011-064737 A JP 2013-148844 A

The present invention has been made in view of the above problems and circumstances, and the problem to be solved is a light-shielding film and a multilayer anti-reflection film that are excellent in light-shielding properties, light anti-reflection properties, and chemical stability, and their design values and An object of the present invention is to provide a manufacturing method and an optical member with little deviation from measured values.

In order to solve the above problems, the present inventors investigated the causes of the above problems, and found that a light shielding film containing chromium and silicon dioxide becomes unstable due to the influence of oxygen. The inventors have discovered that layers affect stability and find ways to improve that stability.
That is, the above problems related to the present invention are solved by the following means.

1. A light-shielding film having at least a light-shielding layer and a layer in contact with the light-shielding layer, wherein the light-shielding layer contains chromium and silicon dioxide, and at least one of the layers in contact with the light-shielding layer contains a compound other than an oxide. A light-shielding film characterized by containing:

2. at least one _of the layers in contact with the light _shielding layer is composed of _MgF2 , _AlF2 , _NdF3 , _LaF3 , YF3 _{, GdF3} , _{YbF3 , PbF2} , _Na3AlF6 , _Na5Al3F14 and _CeF3 2. The light-shielding film according to claim 1, containing any selected fluoride.

3. 3. The light-shielding film according to item 1 or 2, wherein at least one of the layers in contact with the light-shielding layer contains a sulfide.

4. 4. The light shielding film according to item 3, wherein the sulfide is ZnS.

5. The light shielding film according to any one of items 1 to 4, wherein the average spectral transmittance in the wavelength region of 400 to 700 nm is 2% or less.

6. A multilayer antireflection film comprising a light-shielding film, comprising the light-shielding film according to any one of items 1 to 5 as the light-shielding film, and being in contact with at least one of the light-shielding layers. Multilayer antireflection coating characterized by having at least an optical interference layer thereon

7. 7. The multilayer antireflection film according to item 6, further comprising a spectral characteristic adjusting layer between the layer in contact with the light shielding layer and the light interference layer.

8. The multilayer antireflection film according to item 6 or 7, wherein the average spectral reflectance in the wavelength region of 400 to 700 nm is 2% or less.

9. A light-shielding film manufacturing method for manufacturing the light-shielding film according to any one of items 1 to 5, wherein the light-shielding layer is formed by forming a mixture of chromium and silicon dioxide in an argon gas atmosphere. A method for manufacturing a light-shielding film, characterized in that the film is formed by

10. A light-shielding film manufacturing method for manufacturing the light-shielding film according to any one of items 1 to 5, wherein the light-shielding layer is formed by forming a mixture of chromium and silicon dioxide in a nitrogen gas atmosphere. A method for producing a light-shielding film, characterized by forming a film.

11. 9. A method for manufacturing a multilayer antireflection film according to any one of items 6 to 8, comprising: forming the light shielding film; 1. A method for producing a multilayer antireflection coating, comprising the step of laminating an interference layer.

12. An optical member comprising at least a light-shielding film on a substrate, wherein the light-shielding film according to any one of items 1 to 5 is provided as the light-shielding film. Element.

13. 13. The optical member according to item 12, wherein a light interference layer is formed on the light shielding film.

14. 14. The optical member according to item 12 or 13, wherein a light interference layer is formed between the base material and the light shielding film.

By means of the above means of the present invention, a light-shielding film and a multilayer anti-reflection film having excellent light-shielding properties, anti-reflection properties, and chemical stability, and a manufacturing method and an optical member with little deviation between their design values and measured values are provided. be able to.
Although the expression mechanism or action mechanism of the effects of the present invention has not been clarified, it is speculated as follows.

The light shielding layer of the light shielding film of the present invention contains chromium and silicon dioxide.
The inclusion of chromium and silicon dioxide in the light-shielding layer is useful for enhancing the light-shielding properties and antireflection properties of the light-shielding film.
However, when the light-shielding layer is in contact with the oxide, oxygen moves between the light-shielding layer and the oxide, resulting in a change in the chemical properties of the mixture of chromium and silicon dioxide in the light-shielding layer. The present inventor's investigation revealed that the optical properties such as the refractive index and the light absorption coefficient of the light shielding film having the light shielding layer are changed, and the light shielding property and the light antireflection property are deteriorated.
In addition, it has also been clarified that since the light shielding property and the antireflection property are deteriorated, a discrepancy occurs between the originally designed values of these optical properties and the actually measured values after production.
In the present invention, the layer in contact with the light-shielding layer containing chromium and silicon dioxide is a layer containing a compound other than an oxide, thereby preventing the movement of oxygen from the outside of the light-shielding layer and reducing the chemical composition of the light-shielding layer. A light-shielding film is formed which is optically stable without undergoing a thermal change and is excellent in light-shielding properties and light reflectivity. Therefore, it is possible to manufacture a light-shielding film or the like with little divergence between the design value and the actual measurement value.

A conceptual diagram showing the simplest configuration of the light shielding film of the present invention. Conceptual diagram of an example showing the configuration of a multilayer antireflection film having surface antireflection effects Conceptual diagram of an example showing the configuration of a multilayer antireflection film having a back-surface antireflection effect Conceptual diagram of an example showing the configuration of a multilayer antireflection film having antireflection effects on both the front and back surfaces Conceptual diagram showing an example of the configuration of a multilayer antireflection film having a front-surface antireflection effect and a multilayer antireflection film having a rear-surface antireflection effect with adjusted spectral characteristics. Conceptual diagram of spectral reflectance of each optical member Conceptual diagram of spectral transmittance of each optical member Flowchart showing an example of the flow of the manufacturing process of the light shielding film Flowchart showing an example of the flow of a manufacturing process for a multilayer antireflection coating having surface antireflection effects Flowchart showing an example of the manufacturing process flow of a multi-layer antireflection film having a back-surface antireflection effect Flowchart showing an example of the manufacturing process flow of a multilayer antireflection film having antireflection effects on both the front and back surfaces Schematic diagram showing an example of a vacuum deposition apparatus Spectral reflectance of sample optical member A1 Spectral reflectance of sample optical member A2 Spectral reflectance of sample optical member A3

The light-shielding film of the present invention is a light-shielding film having at least a light-shielding layer and a layer in contact with the light-shielding layer, wherein the light-shielding layer contains chromium and silicon dioxide, and at least one of the layers in contact with the light-shielding layer is , containing a compound other than an oxide.
This feature is a technical feature common to or corresponding to each of the following embodiments (aspects).

As an embodiment of the present invention, at least one of the layers in contact with the light shielding layer is _MgF2 , _AlF2 , NdF3, _LaF3 , _YF3 , _{GdF3 , YbF3 , PbF2} , _Na3AlF6 , _Na5. From the viewpoint of stabilizing the chemical properties of the light-shielding film, it is preferable to contain any one of fluorides selected from Al ₃ F ₁₄ and CeF ₃ .

From the viewpoint of stabilizing the chemical properties of the light shielding film, it is preferable that at least one of the layers in contact with the light shielding layer contains a sulfide.

From the viewpoint of stabilizing the chemical properties of the light shielding film, it is more preferable that the sulfide is ZnS.

From the viewpoint of light shielding properties, the average spectral transmittance in the wavelength region of 400 to 700 nm is preferably 2% or less.

From the viewpoint of antireflection properties, it is preferable that the multilayer antireflection film comprising the light shielding film of the present invention has at least a light interference layer on at least one layer in contact with the light shielding layer.

From the viewpoint of light shielding properties and antireflection properties, it is preferable that the multilayer antireflection film has a spectral characteristic adjusting layer between the layer in contact with the light shielding layer and the light interference layer.

From the viewpoint of antireflection properties, it is preferable that the average spectral reflectance of the multilayer antireflection film in the wavelength region of 400 to 700 nm is 2% or less.

The light-shielding film is preferably manufactured by forming the light-shielding layer by forming a film of a mixture of chromium and silicon dioxide in an argon gas atmosphere.

The light-shielding film is preferably manufactured by forming the light-shielding layer by forming a film of a mixture of chromium and silicon dioxide in a nitrogen gas atmosphere.

The manufacturing process of the multilayer antireflection film includes a step of forming a light shielding film and a step of laminating at least a light interference layer on the light shielding film, so that the multilayer antireflection film is preferably manufactured.

An optical member having at least a light shielding film on a substrate preferably includes the light shielding film of the present invention as the light shielding film.

The optical member preferably has a light interference layer formed on the light shielding film from the viewpoint of antireflection properties.

From the viewpoint of antireflection properties, it is preferable that the optical member has a light interference layer formed between the base material and the light shielding film.

The following is a detailed description of the present invention, its components, and the forms and modes for carrying out the present invention. In the present application, "-" is used to mean that the numerical values before and after it are included as the lower limit and the upper limit.

1. Light-shielding film The light-shielding film of the present invention is a light-shielding film having at least a light-shielding layer and a layer in contact with the light-shielding layer, wherein the light-shielding layer contains chromium and silicon dioxide, and at least the layer in contact with the light-shielding layer is One is characterized by containing compounds other than oxides.

FIG. 1 is a conceptual diagram showing the simplest structure of the light shielding film of the present invention.
As shown in FIG. 1, the light-shielding film of the present invention has a light-shielding layer having excellent light-shielding properties and antireflection properties on a substrate, and in order to stabilize the chemical properties of the light-shielding layer, The effects of the present invention are exhibited by forming the layer in contact with the light shielding layer to be a layer containing a compound other than an oxide.

(1.1) Substrate The substrate for use in the present invention is not particularly limited, and resins such as cycloolefin copolymers (COC), cycloolefin polymers (COP) and polyester resins can be mentioned.

(1.2) Light-Shielding Layer The light-shielding layer constituting the light-shielding film of the present invention contains chromium and silicon dioxide.
The film-forming material used for forming the light-shielding layer is not particularly limited as long as it contains chromium and silicon _dioxide . 3mm Patinal (a mixture of Cr (45%) + SiO ₂ (50-60%), hereinafter the product name is referred to as "BlackA").

(1.3) Layer in Contact with Light-Shielding Layer The inclusion of chromium and silicon dioxide in the light-shielding layer is useful for enhancing the light-shielding properties and antireflection properties of the light-shielding film.
However, when the light-shielding layer is in contact with the oxide, oxygen moves between the light-shielding layer and the oxide, resulting in a change in the chemical properties of the mixture of chromium and silicon dioxide in the light-shielding layer. Optical properties such as the refractive index and light absorption coefficient of the light-shielding film having the light-shielding layer are changed, and the light-shielding properties and anti-reflection properties are deteriorated.
Therefore, by using a layer containing a compound other than an oxide as at least one of the layers in contact with the light-shielding layer, that is, the adjacent layers, it is possible to suppress the change in the optical properties of the light-shielding layer due to the movement of oxygen.

At least one of the layers in contact with the light-shielding layer must be formed of a compound film-forming material other than an oxide, but the other layer can also use an oxide as a film-forming material.
Film-forming materials _that are compounds other than _oxides include, for example, _MgF2 , _AlF2 , _NdF3 , _LaF3 , _YF3 , _GdF3 , _YbF3 , _{PbF2 , Na3AlF6} , _Na5Al3F14 , _CeF3 , ZnS, etc. are mentioned.
At least one of the layers in contact with _the light _shielding layer is made _{of MgF2} , _AlF2 , _NdF3 , LaF3, _YF3 , _GdF3 , _YbF3 , _{PbF2 , Na3AlF6} , _Na5Al3F14 , _CeF3 Containing any selected fluoride is preferable from the viewpoint of stabilizing the chemical properties of the light-shielding film.

It is also preferable that at least one of the layers in contact with the light shielding layer contains sulfide from the viewpoint of stabilizing the chemical properties of the light shielding film.

Further, it is more preferable that the sulfide is ZnS from the viewpoint of stabilizing the chemical properties of the light shielding film.

(1.4) Average Spectral Transmittance The average spectral transmittance of the light shielding film in the wavelength region of 400 to 700 nm is preferably 2% or less from the viewpoint of light shielding properties.
Here, "transmittance" means the ratio of transmitted radiant flux or luminous flux to incident radiant flux or luminous flux under given conditions (New Color Chemistry Handbook 2nd edition Ed., page 222), the unit is "1".
However, "spectral transmittance" in the present invention means transmittance (%) for light of a specific wavelength in the above definition of "transmittance".
Further, the "average spectral transmittance" according to the present invention means the average value of the spectral transmittance at each wavelength measured within the spectral wavelength range of 400 to 700 nm.

Specifically, the spectral transmittance of the light-shielding film is measured with a spectrophotometer U-4100 manufactured by Hitachi, Ltd., and the average value of the spectral transmittances at 31 points at intervals of 10 nm in the spectral wavelength range of 400 to 700 nm is taken.
The value of the average spectral transmittance is obtained by the following formula (1).

Formula (1):
Average spectral transmittance (%)=( _T400 + _T410 +...+ _T690 + _T700 )/31
Here, for example, T ₄₀₀ indicates a spectral transmittance value (%) at a light wavelength of 400 nm, T ₄₁₀ indicates a spectral transmittance value (%) at a light wavelength of 410 nm, and so on.

(1.5) Refractive index “Refractive index” is the value of the ratio of the speed of light in a vacuum to the speed of light in a substance, that is, (speed of light in a vacuum)/(speed of light in a substance). It is a value that describes how light travels in matter.
Since the speed of light in a substance changes with the wavelength of the light, the refractive index also changes with the wavelength of the light.
Refractions described herein are refractive indices for the d-line of helium (wavelength 587.56 nm), unless otherwise specified.
In addition, the refractive index according to the present invention is a measured value at room temperature (25° C.).
It should be noted that the refractive index of a substance is an important controlling factor affecting the reflection, absorption, and transmission of light when incident light.
Therefore, the refractive index of the film-forming material of each layer constituting the light-shielding film and the multilayer anti-reflection film is greatly related to the light-reflecting property.

The refractive index of the material used for the light shielding film or antireflection film according to the present invention is preferably in the range of 1.33 to 2.5.
Examples of film forming materials having a refractive index within the above range include BlackA, MgF ₂ , YF ₃ , SiO ₂ , AlF ₂ , H ₄ (LaTiO ₃ ), NdF ₃ and LaF, which are used in the light shielding layer and adjacent layers. ₃ , _{GdF3 , YbF3 , PbF2} , _Na3AlF6 , _Na5Al3F14 , CeF3 _, ZnS _{, Al2O3} , _ZrTiO4 and the like.

2. Multilayer Antireflection Film The multilayer antireflection film of the present invention is a multilayer antireflection film comprising a light-shielding film, wherein the light-shielding film of the present invention is provided as the light-shielding film, and at least one of the light-shielding layers includes: It is characterized by having at least an optical interference layer on the contacting layer.
The multilayer antireflection film of the present invention preferably has one or more layers, and is preferably formed on a substrate.
Specifically, it has a light shielding film composed of two or more layers, has at least an optical interference layer, and has at least one low refractive index layer and at least one high refractive index layer as its configuration. and the uppermost layer farthest from the substrate is preferably the low refractive index layer.

Here, in the present invention, the "low refractive index layer" refers to a layer formed by using a film-forming material having a refractive index of less than 1.6, and the high refractive index layer refers to a layer having a refractive index of 1.9. It refers to a layer formed by using the film-forming materials described above.

Although the number of layers is not particularly limited, it is preferably 30 layers or less from the viewpoint of obtaining an optical interference layer while maintaining high productivity.
That is, the number of layers depends on the required optical performance, but by laminating about 2 to 26 layers, the reflectance of the entire visible light region can be reduced, and the upper limit is 30 layers or less. This is preferable in that it can prevent peeling of the film due to an increase in the stress of the film.

There are various forms of the multilayer antireflection film according to the present invention, and FIG. 2 is a conceptual diagram showing one example of the configuration of a multilayer antireflection film having a surface antireflection effect, which is one of them.

In the present invention, the “surface” means “the surface on the side opposite to the substrate side when viewed from the light shielding film”, and the “surface antireflection effect” means “on the side of the substrate when viewed from the light shielding film. The effect of preventing reflection of light incident from the opposite surface.

In the structure of the multilayer antireflection film shown in FIG. 2, the light interference layer is formed on the light shielding film and serves to prevent reflection of light incident from the surface. The performance of the multilayer antireflection coating of the invention is further enhanced.

(2.1) Light Interference Layer The multilayer antireflection film of the present invention is provided with a light shielding film, and from the viewpoint of antireflection properties, it is necessary to have at least a light interference layer on a layer in contact with at least one light shielding layer. preferable.
The "light interference layer" according to the present invention means that the reflected light, i.e. A layer that has the function of reducing the combined light of the reflected light reflected by each layer.
As the structure of the light interference layer, various modes of structure can be adopted, but it is preferable to have a structure in which layers having different refractive indexes, for example, low refractive index layers and high refractive index layers are alternately laminated.

Oxides can also be used as the film-forming material used for the optical interference layer according to the present invention. and an oxidized compound that is a combination of
In addition, film-forming materials that are compounds other than oxides can also be used, such as _MgF2 , _AlF2 , _NdF3 , LaF3, _YF3 , _GdF3 , _{YbF3 , PbF2 , Na3AlF6} , and _Na5. Al ₃ F ₁₄ , CeF ₃ , ZnS and the like are included.
The light interference layer according to the present invention can add a function of reducing the reflectance of the entire visible light region by stacking a plurality of different film forming materials as described above.

The thickness of the light interference layer according to the present invention (total thickness when multiple layers are laminated) is preferably in the range of 50 to 3000 nm. If the thickness is 50 nm or more, anti-reflection optical properties can be exhibited, and if the thickness is 3000 nm or less, surface deformation due to the film stress of the multilayer film itself can be prevented.
Preferably, it is in the range of 60-2000 nm.

(2.2) Spectral characteristic adjustment layer In the multilayer antireflection film, a spectral characteristic adjustment layer may be provided between the layer in contact with the light shielding layer and the light interference layer from the viewpoint of light shielding properties and light antireflection properties. good.

FIG. 3 is a conceptual diagram showing an example of the configuration of a multilayer antireflection film having a back-surface antireflection effect among various forms of the multilayer antireflection film according to the present invention.

In the present invention, the "back surface" means "the surface on the substrate side when viewed from the light shielding film", and the "antireflection effect on the back surface" means "the effect of light entering from the substrate side when viewed from the light shielding film. The effect of preventing the reflection of

In the structure of the multi-layer antireflection film shown in FIG. 3, the spectral characteristic adjustment layer is formed between the light interference layer and the light shielding film, maintains the function of the light interference layer, and prevents reflection from the rear surface of the light shielding film. adjustment layer.

In order to further enhance the effect of the multilayer antireflection film according to the present invention, it is preferable that a layer having an antireflection effect is formed on both sides of the light shielding film.
FIG. 4A shows a conceptual diagram of an example of an optical member having multilayer antireflection coatings on both sides of a substrate.

In the multilayer antireflection film of the present invention, the layer structure shown in FIG. 4A further enhances the light shielding property and the light antireflection property. From the viewpoint of light shielding properties and antireflection properties, a spectral characteristic adjusting layer may be provided between the layers.

By adopting the configuration shown in FIG. 4B, the multi-layer antireflection coating simultaneously satisfies the role of preventing reflection of light incident from the surface and the role of maintaining and enhancing the function of the light interference layer, thereby further enhancing the effect of the invention. be able to.

(2.3) Average Spectral Reflectance The average spectral reflectance of the multilayer antireflection film in the wavelength region of 400 to 700 nm is preferably 2% or less from the viewpoint of antireflection properties.
Here, "reflectance" means the ratio of reflected radiant flux or luminous flux to incident radiant flux or luminous flux under given conditions. Ed., page 222), the unit is "1".
However, "spectral reflectance" in the present invention means reflectance (%) for light of a specific wavelength in the above definition of "reflectance".
Further, the "average spectral reflectance" according to the present invention means the average value of the spectral reflectance at each wavelength measured within the spectral wavelength range of 400 to 700 nm.

In the multilayer antireflection film according to the present invention, light may be incident from the front surface or from the back surface. were calculated as necessary for both measurements.
Specifically, the spectral reflectance is measured with a microscopic spectrophotometer USPM-RU III manufactured by Olympus, and the average value of the spectral reflectance at 31 points at intervals of 10 nm in the spectral wavelength region of 400 to 700 nm is taken.
The value of average spectral reflectance is obtained by the following formula (1).

Formula (1) Average spectral reflectance (%)=( _R400 + _R410 +...+ _R690 + _R700 )/31

Here, for example, R ₄₀₀ indicates a spectral reflectance value (%) at a light wavelength of 400 nm, R ₄₁₀ indicates a spectral reflectance value (%) at a light wavelength of 410 nm, and so on.

3. Deviation between Design Values and Measured Values In the present invention, as described above, by preventing the movement of oxygen from the outside to the light-shielding layer, the components of the light-shielding layer are optically stabilized. It is possible to reduce the range of divergence between the design values of the film's ideal optical characteristics and the measured values when the film is actually used after production.

(3.1) Deviation of Spectral Reflectance Values In terms of spectral reflectance, if the divergence between the preset design value and the actually measured value is small, the effect of oxygen is reduced and the material is chemically stable. As a result, it can be seen that the antireflection effect is excellent.

Judgment of whether the divergence width between the design value and the actual measurement value is large is made when the design value and the actual measurement value are graphed within the light wavelength range of 400 to 700 nm and the spectral reflectance is separated by 1% or more. This was done by determining whether the area covered by the graph occupied 50% or more of the line on the graph.

The design value of the spectral reflectance is calculated with the thin film calculation software TF-CALC (Software Spectra, Inc), the reflectance Target (400-700 nm, set to 0.5%) is input, and the film configuration and Calculated by optimizing the film thickness.

In addition, the measured value of the spectral reflectance is calculated by measuring the spectral reflectance for light incident from the normal direction using the Olympus microspectrophotometer USPM-RU III.

FIG. 5 shows the relationship between the spectral reflectance value R _ref required for a conventional light-shielding film and the measured spectral reflectance value D _ref of the light-shielding film of the present invention when Black A is used as the film forming material. It is a conceptual diagram representing.

That is, the measured value D _ref of the spectral reflectance of the light shielding film of the present invention, in the light wavelength range of 400 to 700 nm, is the spectral reflectance required for the conventional light shielding film according to the graph shape shown in FIG. below the value R _ref .

(3.2) Deviation of Spectral Transmittance Values In terms of spectral transmittance, if the range of divergence from the preset design value is small, it is found that the influence of oxygen is reduced and the product is chemically stable. As a result, it can be seen that the antireflection effect is excellent.

Judgment as to whether or not the divergence width between the design value and the actual measurement value is large is made when the design value and the actual measurement value are graphed within the light wavelength range of 400 to 700 nm and the spectral transmittance is separated by 1% or more. This was done by determining whether the area covered by the graph occupied 50% or more of the line on the graph.

The design value of the spectral transmittance is calculated with the thin film calculation software TF-CALC (Software Spectra, Inc), the transmittance Target (400-700 nm, set to 0.5%) is input, and the film configuration and Calculated by optimizing the film thickness.

Also, the measured value of the spectral transmittance is calculated using a spectrophotometer U4100 (manufactured by Hitachi High-Technologies Corporation).

FIG. 6 shows the relationship between the spectral transmittance value R _tra required for a conventional light shielding film and the measured spectral transmittance value D _tra of the light shielding film of the present invention when Black A is used as the film forming material. It is a conceptual diagram representing.

That is, the measured value D _tra of the spectral transmittance of the light shielding film of the present invention, in the light wavelength range of 400 to 700 nm, corresponds to the spectral transmittance required for the conventional light shielding film according to the graph shape shown in FIG. below the value _Rtra .

4. Optical Member The optical member of the present invention is an optical member including at least a light-shielding film on a base material, and is characterized in that the light-shielding film of the present invention is provided as the light-shielding film.

It is preferable that the optical member has a light interference layer formed on the light shielding film from the viewpoint of antireflection property.
From the viewpoint of antireflection properties, it is preferable that the optical member has a light interference layer formed between the substrate and the light shielding film.
The optical member of the present invention is preferably used as a light shielding member for mobile cameras and camera optical systems.
Examples of the optical member of the present invention include an optical member having a layer structure as shown in FIGS. 1 to 4 described above.
Substrates according to the present invention include, but are not limited to, resins such as cycloolefin copolymers (COC), cycloolefin polymers (COP) and polyester resins.

5. Method for Producing Light-Shielding Film and Multi-Layer Antireflection Film The method for producing a light-shielding film of the present invention is a method for producing the above-described light-shielding film, wherein the light-shielding layer is formed in an argon gas or nitrogen gas atmosphere with chromium and It is preferably formed by depositing a mixture of silicon dioxide.
Further, the method for producing a multilayer antireflection film of the present invention is a method for producing the above-described multilayer antireflection film of the present invention, comprising: forming the light shielding film; It is preferable to have a step of laminating at least an optical interference layer on the substrate.

(5.1) Method for Forming Each Constituent Layer in Manufacturing Light-Shielding Films and Multilayer Antireflection Films It is preferably manufactured by depositing and forming a mixture of chromium and silicon dioxide below.
The multi-layer anti-reflection film is preferably manufactured by including the step of forming a light-shielding film and the step of laminating at least a light interference layer on the light-shielding film.

Various known methods can be used as a method for forming the light shielding layer, the layer in contact with the light shielding layer, the light interference layer, and the spectral characteristic adjusting layer on the substrate. magnetron cathode sputtering, flat plate magnetron sputtering, bipolar AC flat plate magnetron sputtering, bipolar AC rotating magnetron sputtering, including reactive sputtering methods), vapor deposition methods (e.g. resistance heating vapor deposition, electron beam vapor deposition, ion beam vapor deposition, plasma assisted deposition, and vacuum deposition using the IAD method), thermal CVD method, catalytic chemical vapor deposition method (Cat-CVD), capacitively coupled plasma CVD method (CCP-CVD), optical CVD method, plasma CVD method (PE- CVD), an epitaxial growth method, a chemical vapor deposition method such as an atomic layer deposition method, or the like to form the layer.

_The film-forming materials used in _{the production} of the light-shielding film and _the multilayer antireflection film of the present invention are as described above _. , GdF ₃ , YbF ₃ , PbF ₂ , Na ₃ AlF ₆ , Na ₅ Al ₃ F ₁₄ and CeF _3, etc.), the IAD method or the like is used because the metal fluoride is decomposed by ion irradiation during film formation. preferably not.

When vacuum deposition is employed as the formation condition of each layer, the degree of pressure reduction in the chamber is usually 1×10 ⁻⁴ to 1×10 ⁻¹ Pa, preferably 1×10 ⁻³ to 3×10 ⁻² Pa. and the film formation rate ^is in the range of 1 to 10 Å/sec. It is preferable to form each layer at a film-forming speed suitable for each film-forming material.

Examples of the form of the light shielding film and the multilayer antireflection film formed on the substrate include the forms shown in FIGS. Each layer of the light-shielding film and the multilayer antireflection film is formed in order from the substrate side according to "Method for Forming Each Constituent Layer".

When forming each layer of the light-shielding film and multilayer anti-reflection film, the deposition source of the vapor deposition device used is appropriately loaded with the film-forming material, but when forming the light-shielding layer, the vapor deposition source of the vapor deposition device used contains chromium and silicon dioxide. A film forming material containing a compound other than an oxide is loaded into the vapor deposition source of the vapor deposition apparatus to be used when forming a layer in contact with the light shielding layer.

(5.2) Flow of Manufacturing Process FIG. 7 is a flow chart showing an example of the flow of the manufacturing process of the light-shielding film, and FIG. 9 is a flow chart showing an example of the manufacturing process flow of a multilayer antireflection film having a back-surface antireflection effect, and FIG. 4 is a flow chart showing an example of the flow of a membrane manufacturing process.

7 shows the flow of the manufacturing process for producing the light shielding film of FIG. 1, FIG. 8 shows the flow of the manufacturing process for producing the multilayer antireflection film of FIG. 2, and FIG. FIG. 9 shows the flow of the manufacturing process for fabricating the membrane.
In FIG. 10, the steps from D1 for forming the front-surface antireflection optical interference layer to D2 for forming the rear-surface antireflection spectral characteristic adjustment layer are not collective steps, but are performed between D1 and D2. D3 includes the step of taking out the multilayer anti-reflection film being formed from the film forming apparatus and setting the optical member on the mask jig for forming the light shielding film in the atmosphere. to start film formation again.

(5.3) Vapor Deposition Apparatus FIG. 11 is a schematic diagram showing an example of a vacuum deposition apparatus.
A vacuum deposition apparatus 1 comprises a dome 3 in a chamber 2 along which a substrate 4 is arranged.
The vapor deposition source 5 is provided with an electron gun or a resistance heating device for evaporating the vapor deposition material.
When the IAD method is used, the substrate is irradiated with an ion beam 8 from an IAD ion source 7, and the high kinetic energy of the ions is applied during the film formation to form a dense film, or to increase the adhesion of the film. to increase
An example of the substrate 4 is glass.

A plurality of deposition sources 5 may be arranged at the bottom of the chamber 2 .
Although one vapor deposition source is shown as the vapor deposition source 5 here, the number of vapor deposition sources 5 may be plural.
A deposition material 6 is generated from the deposition material (evaporation material) of the deposition source 5 by an electron gun, and the deposition material is scattered and adhered to a substrate 4 (for example, a glass plate) installed in the chamber 2 to form a film. A layer of material is deposited on the substrate 4 .

In addition, the chamber 2 is provided with an evacuation system (not shown), which evacuates the inside of the chamber 2 .
The degree of pressure reduction in the chamber is usually 1×10 ⁻⁴ to 1×10 ⁻¹ Pa, preferably 1×10 ⁻³ to 3×10 ⁻² Pa.

The dome 3 holds at least one holder (not shown) that holds the substrate 4, and is also called a vapor deposition umbrella.
The dome 3 has an arcuate cross section, and has a rotationally symmetrical shape that passes through the center of a chord connecting both ends of the arc and rotates about an axis perpendicular to the chord.
When the dome 3 rotates around the axis at a constant speed, for example, the substrate 4 held by the dome 3 via the holder revolves around the axis at a constant speed.

The dome 3 can hold a plurality of holders side by side in the rotation radial direction (revolution radial direction) and the rotation direction (revolution direction).
As a result, it is possible to form films simultaneously on a plurality of substrates 4 held by a plurality of holders, thereby improving the manufacturing efficiency of the device.

The IAD ion source 7 is a device that introduces argon gas or oxygen gas into its main body, ionizes them, and irradiates the substrate 4 with the ionized gas molecules (ion beam 8 ).
As the ion source, a Kaufmann type (filament), a hollow cathode type, an RF type, a bucket type, a duoplasmatron type, or the like can be applied.
By irradiating the substrate 4 with the above gas molecules from the IAD ion source 7, the molecules of the film-forming material evaporated from, for example, a plurality of evaporation sources can be pressed against the substrate 4, and a film with high adhesion and high density can be formed on the substrate. 4 can be deposited.
The IAD ion source 7 is installed at the bottom of the chamber 2 so as to face the substrate 4, but may be installed at a position shifted from the facing axis.

The ion beam used in the IAD method tends to be used in a lower degree of vacuum and at a lower acceleration voltage than the ion beam used in the ion beam sputtering method.
For example, an ion beam with an acceleration voltage of 100 to 2000 V and an ion beam with a current density of 1 to 120 μA/cm ² can be used.
The ion beam used in the film formation process can be an oxygen ion beam, an argon ion beam, or an ion beam of a mixed gas of oxygen and argon.
For example, it is preferable to set the amount of oxygen gas to be introduced in the range of 30 to 60 sccm and the amount of argon gas to be introduced in the range of 0 to 10 sccm.

A monitor system (not shown) monitors the wavelength characteristics of the layers formed on the substrate 4 by monitoring the layers that evaporate from the vapor deposition sources 5 and adhere to themselves during vacuum film formation. .
With this monitor system, it is possible to grasp the optical properties of the layers formed on the substrate 4 (for example, spectral transmittance, spectral reflectance, optical layer thickness, etc.).
The monitoring system also includes a quartz layer thickness monitor to monitor the physical layer thickness of layers deposited on the substrate 4 .
This monitor system also functions as a control unit that controls ON/OFF switching of the plurality of evaporation sources 5, ON/OFF switching of the IAD ion source 7, etc., according to the layer monitoring results.

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these. In the examples, "parts" or "%" are used, but "mass parts" or "mass%" are indicated unless otherwise specified.

(Outline of formation of optical member, film-forming material and film-forming conditions)
Using a vapor deposition apparatus BES-1300DN (manufactured by Syncron Co., Ltd.), using H-ZF52GT (nd = 1.8467, manufactured by Chengdu Guangming Co., Ltd.) as a glass substrate, each layer on one side of the substrate. Various optical members were formed by sequentially forming from the side.

(Measurement of layer thickness)
The layer thickness of each layer was measured by the following method.

(1) A layer to be measured is formed in advance on a base material with a layer thickness of 1/4λ (λ=550 nm), and the spectral reflectance is measured.

(2) Each layer is formed on the layer formed in (1) under the film formation conditions shown in Table I below, the spectral reflectance is measured, and the refractive index and layer thickness of the layer are calculated from the amount of change. .
The film-forming materials used in the examples are as follows.

(Deposition material)
(1) BlackA powder less than 0.3mm Patinal (manufactured by Merck, a mixture of Cr [45%] + SiO ₂ [50-60%], hereinafter the product name is referred to as "BlackA".)
(2) Magnesium fluoride granules about 1-2.5mm ( _MgF2 ) Patinal (manufactured by Merck, hereinafter the product name is referred to as " _MgF2 ")
(3) Substance H4 granules about 0.1-2 mm Patinal (manufactured by Merck, LaTiO ₃ [99%], hereinafter the product name is referred to as "H4".)
(4) YF ₃ (manufactured by Merck)
(5) Silicon dioxide granules about 1-4 mm (SiO ₂ ) Patinal (manufactured by Merck, hereinafter the product name is referred to as “SiO ₂ ”)
(6) _AlF2 (manufactured by Merck)
(7) _NdF3 (manufactured by Merck)
(8) LaF ₃ (manufactured by Merck)
(9) _GdF3 (manufactured by Merck)
(10) _YbF3 (manufactured by Merck)
(11) _PbF2 (manufactured by Merck)
(12) Na ₃ AlF ₆ (manufactured by Merck)
₍ 13) _Na5Al3F14 ( _manufactured by Merck)
(14) _CeF3 (manufactured by Merck)
(15) ZnS (manufactured by Merck)
(16) _{Al2O3 (} manufactured by Merck)
(17) _ZrTiO4 (manufactured by Merck)

First, Table I shows the film forming conditions when each layer was formed using each film forming material.
In Table I, for example, when AlF ₂ is used as a film forming material when forming each layer, each layer is formed under the <conditions (AlF ₂ )> shown in Table I, and when YbF ₃ is used, Each layer is formed under <Conditions (YbF ₃ )> shown in Table I.
Hereinafter, in the description of the examples, the description of "a layer of the th layer counting from the base material" will be referred to as "the th layer".
For example, the description of "the third layer counted from the base material" is referred to as "the third layer".

(Confirmation of deviation width between design value and actual measurement value of spectral reflectance and spectral transmittance of light shielding film)
Before preparing the optical members in the examples, first, when the light-shielding film was formed, the spectral reflectance and the spectral transmittance were measured depending on whether the layer in contact with the light-shielding layer contained an oxide or a layer other than an oxide. Sample optical members A1, A2, and A3 were produced according to the following procedure in order to confirm the effects on the design values and actual measurement values.
As the sample optical member, one having the layer structure shown in FIG. 1 was produced.

(1) Production of Optical Members for Each Sample Various optical members were produced according to the film formation conditions shown in Table I above.
[Preparation of sample optical member A1]
A light shielding layer containing chromium and silicon dioxide and having a thickness of 1500 nm was formed on the substrate under <Conditions (BlackA)> shown in Table I above.
Next, a layer containing a compound other than an oxide having a thickness of 114 nm (a layer in contact with the light-shielding layer) was formed on the light-shielding layer under <Conditions (MgF ₂ )> shown in Table I above. An optical member A1 was produced.

[Production of sample optical member A2]
A light shielding layer containing chromium and silicon dioxide and having a thickness of 1500 nm was formed on the substrate under <Conditions (BlackA)> shown in Table I above.
Next, under the <conditions (SiO ₂ )> shown in Table I, a layer containing an oxide having a thickness of 188 nm (a layer in contact with the light shielding layer) was formed on the light shielding layer, thereby forming a sample optical member. A2 was produced.

[Production of sample optical member A3]
A light shielding layer containing chromium and silicon dioxide and having a thickness of 1500 nm was formed on the substrate under <Conditions (BlackA)> shown in Table I above.
Next, a layer containing an oxide having a thickness of 114 nm (layer in contact with the light-shielding layer) was formed on the light-shielding layer under <Condition (H4)> shown in Table I, thereby forming a sample optical member A3. was made.

(2) Deviation range between design values and actual measurement values For the sample optical members A1 to A3 obtained above, design values and actual measurement values of spectral reflectance and spectral transmittance within the light wavelength range of 400 to 700 nm were calculated. .
FIG. 12 shows a graph of the spectral reflectance of the sample optical members A1 to A3.

Regarding the spectral transmittance, since there was almost no difference between the design value and the measured value for each optical member, the graph is omitted.

As can be seen from FIG. 12, with respect to the spectral reflectance, the sample optical member A1 has a smaller divergence width between the design value and the measured value than the sample optical members A2 and A3. The optical member containing the compound in the layer in contact with the light-shielding layer is less affected by oxygen and is chemically more stable than the optical member containing the oxide in the layer in contact with the light-shielding layer. It can be seen that the antireflection effect is excellent.

A. Preparation of Optical Member Equipped with Light-Shielding Film [Optical member No. Production of 1]
(A.1) Formation of light-shielding film (A.1.1) Formation of light-shielding layer (first layer) Light-shielding with a thickness of 1500 nm on the base material under <conditions (BlackA)> shown in Table I above formed a layer.

(A.1.2) Formation of a layer (second layer) in contact with the light shielding layer A thickness of 81.2 nm on the light shielding layer (first layer) under <Conditions (MgF ₂ )> shown in Table I above. layer (layer in contact with the light shielding layer) was formed.

(A.2) Fabrication of optical member Optical member No. 1 provided with a light-shielding film having a layer structure shown in Table II through the above steps. 1 was produced.

[Optical member No. Preparation of 2 and 3]
The film forming materials and layer thicknesses of the first layer and the second layer were changed as shown in Table II, and the conditions in Table I were applied according to each film forming material. 2 and 3 were made.

B. Production of Optical Member Equipped with Multilayer Antireflection Film Having Surface Antireflection Effect As described above, in the present invention, the "surface" means "the side opposite to the substrate side when viewed from the light shielding film". , "surface antireflection effect" means "effect of preventing reflection of light incident from the surface opposite to the substrate side when viewed from the light shielding film".

[Optical member No. Production of 4]
(B.1) Formation of light-shielding film (B.1.1) Formation of light-shielding layer (first layer) Light-shielding with a thickness of 1500 nm on the base material under <conditions (BlackA)> shown in Table I above formed a layer.

(B.1.2) Formation of a layer (second layer) in contact with the light-shielding layer Under <conditions (MgF ₂ )> shown in Table I above, the thickness is 8.0 nm on the light-shielding layer (first layer). layer (layer in contact with the light shielding layer) was formed.

(B.2) Formation _of multilayer antireflection film (B.2.1) Formation of light interference layer (3rd to 8th layers) )> was applied according to the layer order shown in Table III, and each layer was formed on the layer (second layer) in contact with the light shielding layer to form a light interference layer.

(B.3) Fabrication of optical member Optical member No. 1 provided with a multi-layer antireflection film having a surface antireflection effect formed with the layer structure shown in Table III by the above steps. 4 was produced.

[Optical member No. Production of 5]
[Optical member No. 4] in (B.1.1) Formation of the light shielding layer (first layer), <Condition (BlackA)> shown in Table I above is changed to <Condition (BlackA: Ar)> to form the light shielding layer. Except that argon (Ar) gas was sometimes introduced as an inert gas, the deposition materials and layer thicknesses of the 1st to 8th layers (light-shielding layer, layer in contact with the light-shielding layer, and light interference layer) were as shown in Table III. , and applying the conditions in Table I in accordance with each film forming material, the optical member No. 5 was produced.
By introducing argon (Ar) gas as an inert gas when forming the light shielding layer as described above, the oxidation of the light shielding film BlackA is suppressed and the refractive index and light absorption coefficient of the light shielding layer are increased.
Since the absorption coefficient of the light shielding film is increased, even if the thickness of the light shielding layer is thin, the same transmittance can be ensured. It became possible to obtain results equivalent to those of 4.
Although argon (Ar) gas r is introduced as an inert gas in the above manufacturing method, the same effect can be obtained even if nitrogen (N ₂ ) gas is used instead of argon (Ar) gas.

[Optical member No. Preparation of 6 to 25]
The deposition materials and layer thicknesses of the 1st to 8th layers (light-shielding layer, layer in contact with the light-shielding layer, and light interference layer) were changed as shown in Tables III to VI. Applying the conditions, the optical member No. 6-25 were made.

C. Production of Optical Member Equipped with Multilayer Antireflection Film Having Backside Antireflection Effect As described above, in the present invention, the “back surface” means “the surface on the substrate side when viewed from the light shielding film”, and the “back surface” The term "antireflection effect" means "the effect of preventing reflection of light incident from the substrate side when viewed from the light shielding film".

[Optical member No. 26]
(C.1) Formation of multilayer antireflection film (C.1.1) Formation of light interference layers (1st to 8th layers) <condition (H4)> or <condition (MgF _{2 )} shown in Table I )> were applied according to the layer order of Table VII to form the optical interference layers (1st to 8th layers).

(C.2) Fabrication of optical member Optical member No. 1 provided with a multilayer antireflection film having an antireflection effect on the back surface and formed with the layer structure shown in Table VII through the above steps. 26 was made.

[Optical member No. 27]
(C.3) Formation of multilayer antireflection film (C.3.1) Formation of optical interference layers (1st to 7th layers) <condition (H4)> or <condition (MgF _{2 )} shown in Table I above )> were applied according to the layer order of Table VII to form the optical interference layers (1st to 7th layers).

(C.4) Formation of light shielding film (C.4.1) Formation of layer ( _8th layer) in contact with light shielding layer A layer having a thickness of 94.1 nm (a layer in contact with the light shielding layer) was formed.

(C.4.2) Formation of Light-Shielding Layer A light-shielding layer having a thickness of 1500 nm was formed on the layer (eighth layer) in contact with the light-shielding layer under <Conditions (BlackA)> shown in Table I above.

(C.5) Fabrication of optical member Optical member No. 1 provided with a multilayer antireflection film having a back-surface antireflection effect and formed with the layer structure shown in Table VII through the above steps. 27 was made.

[Optical member No. Preparation of 28]
(C.6) Formation of multilayer antireflection film (C.6.1) Formation of optical interference layers (1st to 8th layers) <condition (H4)> or <condition (MgF _{2 )} shown in Table I above )> were applied according to the layer order of Table VII to form the optical interference layers (1st to 8th layers).

(C.6.2) Formation of spectral characteristic adjustment layers (9th to 17th layers) <Condition (H4)> or <Condition (MgF ₂ )> shown in Table I above according to the layer order in Table VII Then, spectral characteristic adjustment layers (9th to 17th layers) were formed on the optical interference layers (1st to 8th layers).

(C.7) Formation of light-shielding film (C.7.1) Formation of layer (18th layer) in contact with light-shielding layer Under <Conditions (MgF ₂ )> shown in Table I above, the spectral characteristic adjustment layer ( A layer having a thickness of 8.0 nm (a layer in contact with the light-shielding layer) was formed on the 9th to 17th layers).

(C.7.2) Formation of a light-shielding layer (19th layer) A light-shielding layer with a thickness of 1500 nm on the layer (18th layer) in contact with the light-shielding layer under <Condition (BlackA)> shown in Table I above. formed.

(C.8) Fabrication of optical member Optical member No. 1 provided with a multi-layered antireflection film having an antireflection effect on the rear surface and formed with the layer structure shown in Table VII through the above steps. 28 was made.

[Optical member No. Preparation of 29]
(C.9) Formation of multilayer antireflection coating (C.9.1) Formation of light interference layers (1st to 8th layers) <condition (H4)> or <condition (MgF _{2 )} shown in Table I )> were applied according to the layer order of Table VII to form the optical interference layers (1st to 8th layers).

(C.9.2) Formation of spectral characteristic adjustment layers (9th to 16th layers) <Condition (H4)> or <Condition (MgF ₂ )> shown in Table I above according to the layer order in Table VII Then, spectral characteristics adjusting layers (9th to 16th layers) were formed on the 8th layer.

(C.10) Formation of light-shielding film (C.10.1) Formation of layer (17th layer) in contact with light-shielding layer Under <conditions (MgF ₂ )> shown in Table I above, the spectral characteristic adjustment layer ( A layer (a layer in contact with the light-shielding layer) having a thickness of 40.7 nm was formed on the 9th to 16th layers).

(C.10.2) Formation of a light-shielding layer (18th layer) A light-shielding layer with a thickness of 1500 nm on the layer (17th layer) in contact with the light-shielding layer under <Condition (BlackA)> shown in Table I above. formed.

(C.11) Fabrication of optical member Optical member No. 1 provided with a multilayer antireflection film having a back-surface antireflection effect and formed with the layer structure shown in Table VII through the above steps. 29 was made.

D. Multilayer antireflection film having antireflection effects on both front and back surfaces [Optical member No. Production of 30]
(D.1) Formation of a layer having an antireflection effect on the rear surface of the multilayer antireflection film (D.1.1) Formation of the light interference layer (1st to 8th layers) )> or <Conditions (MgF ₂ )> were applied according to the layer order in Table VIII to form optical interference layers (1st to 8th layers).
After that, the optical member was temporarily removed from the film forming apparatus, and the optical member in the process of production was set on a mask jig for forming a light shielding film in the atmosphere.

(D.1.2) Formation of spectral characteristic adjustment layers (9th to 17th layers) <Condition (H4)> or <Condition (MgF ₂ )> shown in Table I above according to the layer order in Table VIII Then, spectral characteristic adjustment layers (9th to 17th layers) were formed on the optical interference layers (1st to 8th layers).

(D.1.3) Formation of a layer (eighteenth layer) in contact with a light-shielding layer formed in a step of forming a spectral characteristic adjustment layer and a batch process Under <conditions (MgF ₂ )> shown in I, a layer (a layer in contact with the light-shielding layer) having a thickness of 8.0 nm was formed on the spectral characteristic adjustment layers (9th to 17th layers).

(D.2) Formation of light-shielding film (D.2.1) Formation of layer (18th layer) in contact with light-shielding layer As the next step, formation of a light shielding layer was started.

(D.2.2) Formation of Light-Shielding Layer (19th Layer) After returning the optical member on which the above layer was formed to the film-forming apparatus, under <Condition (BlackA)> shown in Table I above, , a light shielding layer having a thickness of 1500 nm was formed on the layer (18th layer) in contact with the light shielding layer.

(D.2.3) Formation of a layer (20th layer) in contact with the light-shielding layer Under <conditions (MgF ₂ )> shown in Table I above, the thickness is 8.0 nm on the light-shielding layer (19th layer). layer (layer in contact with the light shielding layer) was formed.

(D.3) Formation of layer having surface antireflection effect of multilayer antireflection film (D.3.1) Formation of light interference layer (21st to 26th layers) )> or <Condition (MgF ₂ )> according to the order of layers shown in Table VIII, and each layer was formed on the layer (20th layer) in contact with the light shielding layer to form a light interference layer.

(D.4) Fabrication of optical member Optical member No. 1 was provided with a multilayer antireflection film having an antireflection effect on both the front surface and the back surface, which was formed with the layer structure shown in Table VIII by the above steps. 30 was made.

<<Spectral reflectance and spectral transmittance>>
(1) Spectral reflectance <design value>
The obtained optical member sample No. 1 to No. The design value of the spectral reflectance of No. 29 was calculated with thin film calculation software TF-CALC (Sotfware Spectra, Inc).
For the thin film design, the reflectance Target (400 to 700 nm, set to 0.5%) was input, and the film configuration and film thickness were optimized based on the needle method.
At that time, the performance of each optical member was evaluated by extracting spectral reflectance values for each 10 nm from 400 to 700 nm and graphing them, and evaluating the deviation width between the design value and the actual measurement value of each optical member.
At the same time, the design value of the average spectral reflectance was calculated according to the calculation method described above.

<Measured value>
Using a microspectrophotometer USPM-RU III manufactured by Olympus Corporation, the spectral reflectance with respect to incident light from the normal direction was measured.
At that time, the performance of each optical member was evaluated by extracting spectral reflectance values for each 10 nm from 400 to 700 nm and graphing them, and evaluating the divergence width between the design value and the actual measurement value of each optical member.
At the same time, the actual measurement value of the average spectral reflectance was calculated according to the calculation method described above.

<Evaluation method>
The deviation width between the design value and the actual measurement value of each optical member was evaluated according to the following criteria.
In the following criteria, "large divergence between design value and actual measurement value" means, for example, optical members A2 and A3 in FIG. When graphed, the area where the two values are separated by 1% or more in terms of spectral reflectance occupies 50% or more of the line on the graph. The range of deviation from the actual measurement value is small.”

(Evaluation criteria)
○: When the design value and the measured value of the spectral reflectance are graphed, the range of divergence between the two values is small, and there is no problem in practical use.
x: When the design value and the measured value of the spectral reflectance are graphed, the range of divergence between the two values is large, and the level causes problems in practice.

(2) Spectral transmittance <design value>
The obtained optical member sample No. 1 to No. The design value of the spectral reflectance of No. 29 was calculated with thin film calculation software TF-CALC (Sotfware Spectra, Inc).
At that time, spectral transmittance values were extracted for each 10 nm from 400 to 700 nm and graphed, and the performance of each optical member was evaluated by evaluating the deviation width between the design value and the actual measurement value of each optical member.
At the same time, the design value of the average spectral transmittance was calculated according to the calculation method described above.
Design values for the spectral transmittance of each optical member are graphed.

<Measured value>
The spectral transmittance was measured using a spectrophotometer U4100 (manufactured by Hitachi High-Technologies Corporation).
At that time, spectral transmittance values were extracted for each 10 nm from 400 to 700 nm and graphed, and the performance of each optical member was evaluated by evaluating the deviation width between the design value and the actual measurement value of each optical member.
At the same time, the design value of the average spectral transmittance was calculated according to the calculation method described above.

<Evaluation method>
The deviation width between the design value and the actual measurement value of each optical member was evaluated according to the following criteria.
In the following criteria, "the range of divergence between the design value and the measured value is large" means that when the design value and the measured value are graphed within the light wavelength range of 400 to 700 nm, both values are spectral transmittance. The case where the area separated by 1% or more occupies 50% or more of the line on the graph is defined as "the divergence width between the design value and the actual measurement value is small" when this is not the case.

(Evaluation criteria)
◯: When the design value and the measured value of the spectral transmittance are graphed, the range of divergence between the two values is small, and there is no problem in practical use.
x: When the design value and the measured value of the spectral transmittance are graphed, the range of divergence between the two values is large, and the level is problematic in practice.

(3) Evaluation of each optical member Each optical member produced in Examples and Comparative Examples was evaluated according to the above evaluation criteria.
Evaluation results are shown in Tables II to VIII.

(4) Conclusion From the above, unlike the optical members of the comparative examples, the optical members of the examples have a small divergence from the preset design values in terms of spectral reflectance and spectral transmittance. It was found that a light-shielding film and a multilayer anti-reflection film having excellent light-shielding properties, light anti-reflection properties, and chemical stability can be obtained.

It is possible to provide a light-shielding film and a multilayer anti-reflection film that are excellent in light-shielding properties, anti-reflection properties, and chemical stability, and a manufacturing method and an optical member that have little deviation between their design values and actual measurement values.

REFERENCE SIGNS LIST 1 vacuum deposition apparatus 2 chamber 3 dome 4 substrate 5 deposition source 6 deposition material 7 IAD ion source 8 ion beam L (1) light shielding layer L (2) layer in contact with light shielding layer L _R light interference layer L _a spectral characteristic adjustment layer R _ref Value of spectral reflectance required for conventional light-shielding film D _ref Measured value of spectral reflectance R _tra Value of spectral transmittance required for conventional light-shielding film D _tra Measured spectral transmittance

Claims (14)

1. A light-shielding film having at least a light-shielding layer and a layer in contact with the light-shielding layer,
   The light shielding layer contains chromium and silicon dioxide,
   A light-shielding film, wherein at least one of the layers in contact with the light-shielding layer contains a compound other than an oxide.
2. at least one _of the layers in contact with the light _shielding layer is composed of _MgF2 , _AlF2 , _NdF3 , _LaF3 , YF3 _{, GdF3} , _{YbF3 , PbF2} , _Na3AlF6 , _Na5Al3F14 and _CeF3 2. The light-shielding film according to claim 1, containing any selected fluoride.
3. 3. The light-shielding film according to claim 1, wherein at least one of the layers in contact with the light-shielding layer contains sulfide.
4. 4. The light shielding film according to claim 3, wherein said sulfide is ZnS.
5. 5. The light shielding film according to any one of claims 1 to 4, wherein the average spectral transmittance in the wavelength region of 400 to 700 nm is 2% or less.
6. A multilayer antireflection film comprising a light shielding film,
   The light shielding film according to any one of claims 1 to 5 is provided as the light shielding film, and at least a light interference layer is provided on a layer in contact with at least one of the light shielding layers. Multilayer anti-reflection coating.
7. 7. The multi-layer antireflection film according to claim 6, further comprising a layer for adjusting spectral characteristics between the layer in contact with the light shielding layer and the light interference layer.
8. 8. The multilayer antireflection film according to claim 6, wherein the average spectral reflectance in the wavelength region of 400 to 700 nm is 2% or less.
9. A light-shielding film manufacturing method for manufacturing the light-shielding film according to any one of claims 1 to 5,
   A method for producing a light-shielding film, wherein the light-shielding layer is formed by depositing a mixture of chromium and silicon dioxide in an argon gas atmosphere.
10. A light-shielding film manufacturing method for manufacturing the light-shielding film according to any one of claims 1 to 5,
    A method for producing a light-shielding film, wherein the light-shielding layer is formed by forming a film of a mixture of chromium and silicon dioxide in a nitrogen gas atmosphere.
11. A method for manufacturing a multilayer antireflection film according to any one of claims 6 to 8, comprising:
    A method for manufacturing a multi-layer antireflection film, comprising the steps of: forming the light shielding film; and laminating at least a light interference layer on the light shielding film.
12. An optical member comprising at least a light shielding film on a substrate,
    An optical member comprising the light shielding film according to any one of claims 1 to 5 as the light shielding film.
13. 13. The optical member according to claim 12, further comprising a light interference layer formed on the light shielding film.
14. 14. The optical member according to claim 12, wherein a light interference layer is formed between the base material and the light shielding film.

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