WO2016190247A1

WO2016190247A1 - Article having fine uneven structure on surface, and method for producing same

Info

Publication number: WO2016190247A1
Application number: PCT/JP2016/065038
Authority: WO
Inventors: 公介高山; 庄子　習一; 水野　潤
Original assignee: 旭硝子株式会社; 学校法人早稲田大学
Priority date: 2015-05-25
Filing date: 2016-05-20
Publication date: 2016-12-01
Also published as: JPWO2016190247A1; JP6679026B2

Abstract

The purpose of the present invention is to provide a method that makes it easy to produce an article which has on a surface thereof a fine uneven structure and which is superior in abrasion resistance. Provided is a method for producing an article having on a surface thereof a resin pattern 28 (fine uneven structure) that has a plurality of regular projections 22 and bridge sections 26 that each form a link between adjacent projections 22 so as to demarcate bottom sections 24 formed between the projections 22. The method comprises: (a) a step for irradiating a photosensitive resin layer of a substrate equipped with the photosensitive resin layer with light from a light radiating means, via a photomask having a regular dot pattern; and (b) a step for developing the substrate equipped with the photosensitive resin layer, thereby obtaining an article having a resin pattern 28 (fine uneven structure) on a surface thereof. The photomask makes use of the Talbot effect, and the light from the light radiating means has a spread angle in one direction that is broader than a spread angle in another direction.

Description

Article having fine concavo-convex structure on surface and method for producing the same

The present invention relates to an article having a fine concavo-convex structure on its surface and a method for producing the same.

It is known that an article having a fine concavo-convex structure composed of a plurality of protrusions whose period is not more than the wavelength of visible light on the surface is excellent in antireflection performance.
However, the protrusions in the fine concavo-convex structure are easily broken from the base, and the article having the fine concavo-convex structure on the surface is insufficient in scratch resistance.

The following are proposed as articles having a fine concavo-convex structure with improved scratch resistance on the surface.
・ Anti-reflective article in which microprotrusions whose period is equal to or less than the wavelength of visible light are closely arranged, at least a part of the microprotrusions are multimodal microprotrusions having a plurality of vertices, and the rest are unimodal microprotrusions (See Patent Document 1).

The antireflective article of Patent Document 1 is manufactured by a nanoimprint method using a mold having fine holes on the surface corresponding to multimodal microprojections and monomodal microprojections.
However, it is difficult to manufacture a mold having a complicated surface shape. Therefore, the antireflective article of patent document 1 has the problem that it cannot manufacture easily.

JP 2014-029366 A

The present invention provides a method capable of easily producing an article having a fine concavo-convex structure excellent in scratch resistance on the surface; and an article having a fine concavo-convex structure excellent in scratch resistance on the surface.

The present invention has the following aspects.
[1] An article having a fine concavo-convex structure on the surface having a plurality of regular protrusions, a bottom portion formed between the protrusions, and a bridge portion connecting adjacent protrusions so as to divide the bottom portion. (A) by irradiating the photosensitive resin layer of the substrate with the photosensitive resin layer with light from the light irradiation means via a photomask having a regular dot pattern, A step of forming a latent image pattern corresponding to the fine concavo-convex structure on the photosensitive resin layer; and (b) after the step (a), by developing the substrate with the photosensitive resin layer, A resin pattern corresponding to the concavo-convex structure is formed on the surface of the base material, and a step of obtaining an article having the fine concavo-convex structure on the surface, and the photomask is a photomask using a Talbot effect, Light irradiation The light from the step is light having a divergence angle in one direction parallel to the surface of the photomask wider than that in the other direction parallel to the surface of the photomask. A method of manufacturing an article having
[2] (c) After the step (b), the fine concavo-convex structure is directly formed on the surface of the substrate by etching the substrate on which the resin pattern is formed. The method for producing an article having the fine uneven structure according to [1], further comprising a step of obtaining an article having a fine uneven structure on the surface.
[3] The light irradiating means is LED line illumination including a plurality of light emitting diodes (LEDs) arranged in a line and a plano-convex cylindrical lens, and the fine uneven structure according to [1] or [2] is provided on the surface. A method of manufacturing an article having
[4] A method for manufacturing an article having the fine uneven structure according to any one of [1] to [3] on a surface, in which dots in the dot pattern are arranged in a hexagonal lattice pattern.
[5] The light irradiation means and the photomask are arranged so that the direction in which the light spread angle is widest and one direction of the lattice lines of the hexagonal lattice in the dot pattern are orthogonal to each other. ] The manufacturing method of the articles | goods which have the fine concavo-convex structure on the surface.
[6] A direction in which light emitted from the light irradiating means has a divergence angle in one direction parallel to the surface of the photomask of 10 ° to 60 °, and is orthogonal to the direction parallel to the surface of the photomask. A method for producing an article having on its surface a fine concavo-convex structure according to any one of [1] to [5], which is light having a spread angle of 0 to 8 °.
[7] A method for manufacturing an article having the fine concavo-convex structure of any one of [1] to [6] on the surface, wherein the photomask is a phase shift mask using a Talbot effect.
[8] An article having a fine concavo-convex structure on the surface having a plurality of regular protrusions, a bottom formed between the protrusions, and a bridge portion connecting adjacent protrusions so as to divide the bottom.
[9] An article having the fine concavo-convex structure of [8] on the surface, wherein an average height of the bridge portion is lower than an average height of the protrusions.
[10] An article having the fine concavo-convex structure of [8] or [9] on the surface, wherein the protrusions are arranged in a hexagonal lattice pattern.
[11] The bridge portion is formed in line symmetry along the lattice line in the other two directions with respect to the lattice line in one direction among the lattice lines in the three directions of the hexagonal lattice. [10] An article having a fine uneven structure on its surface.

According to the method for producing an article having a fine concavo-convex structure on the surface of the present invention, an article having a fine concavo-convex structure on the surface which is excellent in scratch resistance and excellent in antireflection performance can be easily produced.
The article having the fine concavo-convex structure of the present invention on the surface is excellent in scratch resistance of the fine concavo-convex structure.

It is a top view which shows an example of the article | item which has the fine concavo-convex structure of this invention on the surface. FIG. 2 is a sectional view taken along the line II-II in FIG. It is a top view which shows the other example of the articles | goods which have the fine concavo-convex structure of this invention on the surface. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. It is a perspective view for demonstrating a process (a). It is a figure for demonstrating the spreading angle of light. It is a scanning electron microscope image which shows an example of the arrangement direction of the dot of the phase shift mask using the Talbot effect. It is an atomic force microscope image which shows the resin pattern formed using the phase shift mask using the Talbot effect of FIG. It is a scanning electron microscope image which shows the other example of the arrangement direction of the dot of the phase shift mask using the Talbot effect. It is an atomic force microscope image which shows the resin pattern formed using the phase shift mask using the Talbot effect of FIG. 2 is an atomic force microscope image showing a fine uneven structure on the surface of an article obtained in Example 1. FIG. It is the cross-sectional shape of the protrusion in the atomic force microscope image of FIG. It is an atomic force microscope image which shows the bridge part of FIG. It is a cross-sectional shape of the bridge part in the atomic force microscope image of FIG. 2 is a photograph showing the surface state of the article obtained in Example 1 after a flannel rubbing test. 2 is a photograph showing the surface state of the article obtained in Example 1 after a flannel rubbing test. 2 is a photograph showing the surface state of the article obtained in Example 1 after a flannel rubbing test. 4 is an atomic force microscope image showing a fine uneven structure on the surface of an article obtained in Example 3. FIG. It is the cross-sectional shape of the protrusion in the atomic force microscope image of FIG. 6 is a photograph showing the surface state of a product obtained in Example 3 after a flannel rubbing test. 6 is a photograph showing the surface state of a product obtained in Example 3 after a flannel rubbing test. 6 is a photograph showing the surface state of a product obtained in Example 3 after a flannel rubbing test.

The following definitions of terms apply throughout this specification and the claims.
“Light” is a general term for ultraviolet rays, γ-rays, X-rays, electron beams, and the like.
The “photomask” means a pattern original plate in photolithography, that is, one that can expose the photosensitive resin layer in a pattern when the photosensitive resin layer is irradiated with light.
The “latent image pattern” is a pattern composed of an exposed portion and an unexposed portion in the photosensitive resin layer. A desired resin pattern is formed by removing one of the exposed portion and the unexposed portion by the development process.
The “Talbot effect” means a phenomenon in which an interference pattern is formed at a specific distance from a photomask when light is irradiated onto the photomask having a periodic mask pattern.
A “phase shift mask that uses the Talbot effect” is a transparent mask in which parts with different optical path lengths are formed in a pattern. The phase is partially changed by the difference in optical path length, and is diffracted into the emitted light. It means a photomask that forms a pattern in a photosensitive resin layer by generating interference (Talbot effect).
“Diverging angle” refers to light that has passed through a pinhole on a photosensitive resin layer that is disposed at a distance of 9 mm from the pinhole exit by attaching an aperture having a 1 mm diameter pinhole formed on the exit surface of the light irradiation means. , The photosensitive resin layer is developed to form a pattern (a hole when the photosensitive resin composition is positive), a pattern diameter R2, a pinhole diameter R1 (1 mm), and a pinhole It means the angle θ obtained by the following formula from the distance D (9 mm) from the exit to the photosensitive resin layer.
θ = tan ⁻¹ [{(R2-R1) / 2} / D]
A “plano-convex cylindrical lens” is a lens having a cylindrical shape divided in the axial direction, and has a cylindrical surface (cylindrical surface) that has a curvature in the width direction but no curvature in the longitudinal direction (axial direction of the cylinder). ) And a plane opposite to the cylindrical surface.
“Dots (or protrusions) are arranged in a hexagonal lattice (or tetragonal lattice)” means that the dots (or protrusions) are located at the lattice points of the hexagonal lattice (or tetragonal lattice). ) Is arranged.
“The dots (or protrusions) are periodically arranged in a regular hexagonal lattice” means that any dot (or protrusion) other than the outermost dot (or protrusion) is surrounded by any dot (or protrusion). This means that six dots (or projections) that are closest and equal in distance from the projection) are arranged. The vertices of the six dots (or protrusions) are arranged at an equal pitch at an interval of 60 ° around the vertex of the arbitrary dot (or protrusion) to constitute a regular hexagonal lattice.
“Lattice line” means a line connecting adjacent lattice points.
“Protrusion pitch” means the distance between the centers of adjacent protrusions in the lattice line direction, and “protrusion average pitch” means the average value of the pitches of six randomly selected protrusions. .
“Protrusion width” means the maximum length of the bottom surface of the protrusion, and “average width of the protrusion” means an average value of the widths of six randomly selected protrusions.
“Protrusion height” means the height from the bottom of the protrusion to the apex, and “Average protrusion height” means the average height of six randomly selected protrusions. To do.
“Bridge width” means the maximum length of the cross section perpendicular to the grid line of the bridge, and “average width of the bridge” means 6 bridges selected at random. Means the average width of the part.
“The height of the bridge” means the height from the bottom of the bridge to the highest part, and the “average height of the bridge” means six randomly selected bridges Means the average height of the bridge.

<Article>
An article having a fine concavo-convex structure on a surface thereof (hereinafter, also simply referred to as an article) of the present invention includes a plurality of regular protrusions, a bottom formed between the protrusions, and a protrusion adjacent to the bottom. It has a fine concavo-convex structure on the surface, which has a bridge portion connecting between them.

(First embodiment)
FIG. 1 is a top view showing a first embodiment of the article of the present invention, and FIG. 2 is a cross-sectional view taken along the line II-II in FIG. The broken lines in FIG. 1 are hexagonal lattice lines.
The article 1 has a base material 10 and a resin pattern 28 formed on the surface of the base material 10. The resin pattern 28 includes a plurality of regular protrusions 22, a bottom part 24 formed between the protrusions 22, and a wall-like bridge part 26 that connects adjacent protrusions 22 so as to divide the bottom part 24. It consists of a fine relief structure.

The substrate 10 may be appropriately selected according to the type of the target product, and is not particularly limited. Examples of the material of the substrate 10 include inorganic materials and organic materials.

Examples of the inorganic material include glass, quartz, silicon wafer, metal (aluminum, nickel, copper, etc.), metal oxide (sapphire, indium tin oxide, etc.), gallium nitride, silicon nitride, aluminum nitride, lithium niobate, and the like. .

Examples of the organic material include fluorine resin, silicone resin, acrylic resin, polycarbonate, polyester (polyethylene terephthalate, etc.), polyamide, polyimide, polypropylene, polyethylene, nylon resin, polyphenylene sulfide, triacetyl cellulose, cyclic polyolefin, and the like.

As the base material 10, a surface-treated one may be used in terms of excellent adhesion to the resin pattern 28. Examples of the surface treatment include primer coating treatment, UV ozone treatment, plasma etching treatment, and the like. Examples of the primer include polymethyl methacrylate, silane coupling agent, silazane, polyvinyl alcohol and the like.

The resin pattern 28 is a pattern formed by removing unnecessary portions from the photosensitive resin layer described later, and including a portion where the resin is not removed and a portion where the resin is removed.

The protrusions 22 are formed so as to be separated from each other via the bridge portion 26. The shape of the protrusion 22 is not limited to the bullet shape (bell shape) as shown in the illustrated example, and may be a cylindrical shape, a prism shape, a conical shape, a pyramid shape, a semicircular shape, or the like.

The bottom portion 24 is a substantially flat portion formed between the protrusions 22. Usually, it is the surface of the base material 10. The bottom 24 may contain a residue of the photosensitive resin layer that could not be removed.

The bridge portion 26 is a wall-like portion that connects the adjacent protrusions 22 in the lattice line direction so as to divide the bottom portion 24. The bridge portion 26 is a portion extending radially from the center of the protrusion 22, and is clearly distinguished from the protrusion 22.

The average pitch of the protrusions 22 is preferably 80 to 700 nm, and more preferably 160 to 400 nm. If the average pitch of the protrusions 22 is equal to or greater than the lower limit value, the width of the protrusions 22 can be sufficiently secured, so that the protrusions 22 are more difficult to break and the scratch resistance of the fine concavo-convex structure is further improved. When the average pitch of the protrusions 22 is equal to or less than the upper limit value, sufficient antireflection performance due to the fine uneven structure can be obtained.

The average width of the protrusions 22 is preferably 50% or more of the average pitch, and more preferably 60% or more and 90% or less of the average pitch. When the average width of the protrusions 22 is equal to or greater than the lower limit, the protrusions 22 are more difficult to break, the scratch resistance of the fine uneven structure is further improved, and the flat bottom 24 can be reduced, so that the antireflection effect can be increased. If the average width of the protrusions 22 is equal to or less than the upper limit value, the bridge portion 26 can be formed.

The average height of the protrusions 22 is preferably 50% or more and 300% or less of the average pitch, and more preferably 70% or more and 250% or less of the average pitch. If the average height of the protrusions 22 is equal to or greater than the lower limit, sufficient antireflection performance due to the fine uneven structure can be obtained. If the average height of the protrusions 22 is equal to or less than the upper limit, the protrusions 22 are more difficult to break, and the scratch resistance of the fine concavo-convex structure is further improved.

The average width of the bridge portion 26 is preferably 40 to 300 nm, and more preferably 100 to 200 nm. If the average width of the bridge portion 26 is equal to or greater than the lower limit value, the bridge portion 26 is not easily broken, and the scratch resistance of the fine uneven structure is further improved. If the average width of the bridge portion 26 is equal to or less than the upper limit value, sufficient antireflection performance due to the fine uneven structure can be obtained.

The average height of the bridge portion 26 is preferably lower than the average height of the protrusions 22, and more preferably 30 to 60% of the average height of the protrusions 22. If the average height of the bridge portion 26 is lower than the average height of the protrusions 22, sufficient antireflection performance due to the fine uneven structure can be obtained. If the average height of the bridge portion 26 is 30% or more of the height of the protrusion 22, the protrusion 22 is more difficult to break, and the scratch resistance of the fine concavo-convex structure is further improved.

The protrusions 22 may be arranged in a hexagonal lattice shape or a tetragonal lattice shape. The protrusions 22 are preferably arranged in a hexagonal lattice form and are periodically arranged in a regular hexagonal lattice form in that the protrusions 22 are more difficult to break and the scratch resistance of the fine concavo-convex structure is further excellent. Is more preferable.

The bridge portion 26 has three-way lattice lines of a hexagonal lattice as shown in the example from the point that the protrusions 22 are more difficult to break, the scratch resistance of the fine concavo-convex structure is further excellent, and the bridge portion 26 is easily formed. Of these, it is preferable that the lattice lines in the X direction are symmetrical with respect to the lattice lines in the other two directions with respect to the lattice lines in the X direction. When the bridge portions 26 are formed in parallel with each other along only lattice lines in one direction, the scratch resistance of the fine concavo-convex structure is inferior to that of the illustrated example. When the bridge portion 26 is formed along all the lattice lines in the three directions, the area between the valleys in the fine concavo-convex structure is reduced, so that it is difficult to obtain sufficient antireflection performance.

(Second Embodiment)
FIG. 3 is a top view showing a second embodiment of the article of the present invention, and FIG. 4 is a sectional view taken along line IV-IV in FIG. The broken lines in FIG. 3 are hexagonal lattice lines.
The article 2 corresponds to that obtained by etching the article 1 according to the first embodiment.
The article 2 includes a base material 10 on which a fine uneven structure 18 is directly formed on the surface. The fine concavo-convex structure 18 includes a plurality of regular protrusions 12, a bottom part 14 formed between the protrusions 12, and a wall-like bridge part 16 that connects adjacent protrusions 12 so as to divide the bottom part 14. Have.
Hereinafter, detailed description of the same configuration as the article 1 according to the first embodiment is omitted.

The shape, size, arrangement, and the like of the protrusion 12, the bottom portion 14, and the bridge portion 16 are the same as the shape, size, arrangement, and the like of the protrusion 22, the bottom portion 24, and the bridge portion 26 according to the first embodiment. It is the same.

(Mechanism of action)
In the article of the present invention described above, since the fine concavo-convex structure has a bridge portion that connects adjacent protrusions, the bridge portion reinforces the protrusion from the lateral direction. Therefore, the protrusions in the fine concavo-convex structure are not easily broken from the base, and the scratch resistance of the fine concavo-convex structure is excellent.

(Other forms)
The article of the present invention has a fine concavo-convex structure having a plurality of regular protrusions, a bottom formed between the protrusions, and a bridge portion connecting adjacent protrusions so as to divide the bottom on the surface. What is necessary is just to have, and it is not limited to the goods 1 which concern on 1st Embodiment of illustration example, and the goods 2 which concern on 2nd Embodiment.

<Production method>
A method for manufacturing an article having a fine concavo-convex structure on a surface thereof according to the present invention (hereinafter, also simply referred to as an article manufacturing method) includes a plurality of regular protrusions, a bottom formed between the protrusions, and the bottom. A method of manufacturing an article having a fine concavo-convex structure on the surface having a bridge portion that connects adjacent protrusions so as to divide, and includes the following step (a), step (b), and, if necessary, step ( c).

(A) The light corresponding to the fine concavo-convex structure is irradiated by irradiating the photosensitive resin layer of the substrate with the photosensitive resin layer with light from the light irradiation means through a photomask having a regular dot pattern. Forming an image pattern on the photosensitive resin layer;
(B) After the step (a), by developing the substrate with the photosensitive resin layer, a resin pattern corresponding to the fine concavo-convex structure is formed on the surface of the substrate, and the surface has a fine concavo-convex structure. A step of obtaining an article (corresponding to the article according to the first embodiment of the present invention).
(C) If necessary, after the step (b), the fine concavo-convex structure in which the fine concavo-convex structure is directly formed on the surface of the substrate by etching the substrate on which the resin pattern is formed on the surface. A step of obtaining an article having a surface thereof (corresponding to an article according to the second embodiment of the present invention).

(Process (a))
As shown in FIG. 5, a photo having a regular dot pattern on the surface of the substrate with the photosensitive resin layer 20 having the photosensitive resin layer 20 formed on the surface of the substrate 10 on the surface of the photosensitive resin layer 20. A mask 30 is disposed. The light irradiation means 40 is disposed above the photomask 30 so that the longitudinal direction is the Y direction. Irradiating the photosensitive resin layer 20 of the substrate with the photosensitive resin layer through the photomask 30 while moving the light irradiation means 40 in the X direction orthogonal to the Y direction. Thus, a latent image pattern corresponding to the fine concavo-convex structure is formed on the photosensitive resin layer 20.

The photosensitive resin layer 20 is not particularly limited as long as it can form a latent image pattern by light irradiation in photolithography. Examples of the material for forming the photosensitive resin layer 20 include known photosensitive resin compositions such as a photoresist. The photosensitive resin composition may be a positive type or a negative type.

The photomask 30 is a photomask using the Talbot effect. Examples of the photomask using the Talbot effect include a phase shift mask using the Talbot effect.

The photomask 30 has a regular dot pattern for forming a plurality of projections having a fine concavo-convex structure formed on the surface of an article finally obtained. In the case of a phase shift mask using the Talbot effect, the photomask 30 has dots having different optical path lengths. When the Talbot effect is used, the arrangement of the dot pattern of the photomask and the arrangement of the plurality of protrusions of the finally obtained article are not necessarily one-to-one.

Examples of the photomask 30 include those in which dots in a dot pattern are arranged in a hexagonal lattice, and those in which a dot is arranged in a tetragonal lattice. From the point that the protrusions in the finally obtained article are more difficult to break and the scratch resistance of the fine concavo-convex structure is further excellent, it is preferable that the dots in the dot pattern are arranged in a hexagonal lattice, and the dots are in a regular hexagonal lattice Those arranged periodically are more preferable.
The shape of the photomask 30 is not limited to the planar shape in the illustrated example, and may be a roll shape, a belt shape, or the like.

In the light irradiation means 40, the spread angle in one direction (for example, the Y direction) parallel to the surface of the photomask 30 is made wider than the spread angle in the other direction (for example, the X direction) parallel to the surface of the photomask 30. It can irradiate light.

As shown in FIG. 6, the light spread angle is an angle θ that indicates how much the light diameter at a predetermined distance from the light irradiation means 40 spreads with respect to the exit diameter of the exit surface of the light irradiation means 40. Specifically, an aperture (not shown) with a pinhole having a diameter of 1 mm is attached to the exit surface of the light irradiation means 40, and a photosensitive resin layer (not shown) disposed at a distance of 9 mm from the pinhole outlet. Is irradiated with light that has passed through the pinhole, the photosensitive resin layer is developed to form a pattern, the pattern diameter R2, the pinhole diameter R1 (1 mm), and from the pinhole exit to the photosensitive resin layer The angle θ obtained by the following equation from the distance D (9 mm).
θ = tan ⁻¹ [{(R2-R1) / 2} / D]

The light irradiation means 40 is not limited to the line-shaped illumination in the illustrated example, and may be a planar illumination or the like. The light irradiation means includes a normal light source (high pressure mercury lamp, light emitting diode (LED), xenon lamp, mercury xenon lamp, metal halide lamp, deuterium lamp, electrodeless light source, etc.) and optical member (concave mirror, condenser lens) And a combination with a collimation lens (such as a cylindrical lens).

As the light irradiation means 40, from the point that a light source can be introduced into a small space, an LED line array in which a plurality of LEDs (light emitting diodes) are arranged in a line in one direction, and a plano-convex having the same length as the LED line array LED line illumination comprising a cylindrical lens, in which the LED line array and the plano-convex cylindrical lens are arranged in parallel to each other and so that light emitted from the LED line array enters from the plane side of the plano-convex cylindrical lens is preferable. . According to the LED line illumination, light is collimated in the width direction of the LED line illumination so that the light approaches a parallel state, and light that diffuses without being collimated can be irradiated in the longitudinal direction of the LED line illumination.

In conventional photolithography, it is common sense to use substantially collimated light in any direction within the surface to be irradiated as light to be irradiated in terms of resolution. On the other hand, in the present invention, the light to be irradiated is collimated to light whose divergence angle in one direction is wider than the divergence angle in the other direction, for example, one direction (that is, a collimating direction, for example, the X direction). In the direction perpendicular to the direction (that is, the diffusion direction, for example, the Y direction), diffused anisotropic light is used.

When exposure is performed by combining a two-tone binary mask composed of a normal light shielding part and a light transmitting part and anisotropic light, light in the diffusion direction enters the light shielding part. Therefore, in the case of a combination of a binary mask having a dot-shaped light shielding portion and a positive photosensitive resin composition, elliptical dots eroded in the light diffusion direction are formed in the resin pattern. In the case of a combination of a binary mask having a dot-like light transmission portion and a negative photosensitive resin composition, elliptical dots extended in the light diffusion direction are formed in the resin pattern. On the other hand, when a photomask that uses the Talbot effect (more specifically, a phase shift mask that uses the Talbot effect) and anisotropic light is used for exposure, what is the case of a binary mask? In contrast, the present inventors have found that a bridge portion is formed in the resin pattern so that dots are connected in the light diffusion direction due to a complicated light interference phenomenon.

The light divergence angle in the collimating direction (for example, the X direction) is preferably 0 to 8 ° and more preferably 0 to 6 ° from the viewpoint of easily forming a bridge portion.
The spread angle of light in the diffusion direction (for example, Y direction) is preferably 10 to 60 °, more preferably 20 to 45 °, from the viewpoint of easily forming a bridge portion.

The light irradiation means 40 and the photomask 30 are preferably arranged so that the direction in which the light spread angle is the widest and one direction of the lattice lines of the hexagonal lattice in the dot pattern are orthogonal to each other. Specifically, as shown in FIG. 5, the light irradiation means 40 whose longitudinal direction is the light diffusion direction and whose width direction is the light collimation direction is used, and the longitudinal direction of the light irradiation means 40 (that is, light 7 is the Y direction, as shown in FIG. 7, the light irradiation means so that one direction of the lattice lines of the hexagonal lattice in the dot pattern of the photomask 30 is the X direction orthogonal to the Y direction. 40 and a photomask 30 are arranged.

As shown in FIG. 7, when the diffusion direction (Y direction) of the light irradiated from the light irradiation means 40 and one direction (X direction) of the lattice lines of the hexagonal lattice in the dot pattern of the photomask 30 are orthogonal, As shown in FIG. 8, in the resin pattern, dots are connected in the light diffusion direction (Y direction), and the bridge portion is symmetrically lined along the lattice line in the other two directions with the lattice line in the X direction as the axis of symmetry. Is formed. In FIG. 8, the black portion represents the bottom.

On the other hand, as shown in FIG. 9, the diffusion direction (Y direction) of the light irradiated from the light irradiation means 40 and the one direction (Y direction) of the hexagonal lattice lines in the dot pattern of the photomask 30 coincide. In this case, as shown in FIG. 10, in the resin pattern, dots are connected in the light diffusion direction (Y direction), and bridge portions are formed in parallel to each other only along the grid lines in the Y direction. In FIG. 10, the black part represents the bottom part.

The fine concavo-convex structure in which the bridge part is formed symmetrically along the lattice line in two directions is more resistant to scratches than the fine concavo-convex structure in which the bridge part is formed in parallel with each other only along the lattice line in one direction. Excellent in properties.

When the photosensitive resin composition is a positive type, it is preferable that the integrated light amount is less than the appropriate light amount, that is, underexposure from the viewpoint of easily forming a bridge portion. When the photosensitive resin composition is a positive type, the integrated light amount is preferably 70 to 90% of the appropriate light amount, and more preferably 75 to 85%.

When the photosensitive resin composition is a negative type, it is preferable that the integrated light amount is more than the appropriate light amount, that is, overexposed, from the viewpoint of easily forming a bridge portion. When the photosensitive resin composition is a negative type, the integrated light amount is preferably 115 to 135%, more preferably 120 to 130% of the appropriate light amount.

Here, the proper light amount means the median value of the light amount range in which the height of the photoresist protrusion to be formed is the highest.

(Process (b))
After the step (a), by developing the substrate with the photosensitive resin layer, for example, as shown in FIG. 8, a fine uneven structure in which a resin pattern corresponding to the fine uneven structure is formed on the surface of the substrate. Is obtained on the surface (corresponding to the article according to the first embodiment of the present invention).

The development process is performed, for example, by bringing the photosensitive resin layer on which the latent image pattern is formed into contact with the developer.
The developer is not particularly limited as long as it can remove either the exposed part or the unexposed part in the step (a).

(Process (c))
After the step (b), the substrate with the resin pattern (photoresist pattern) formed on the surface is etched to obtain a fine concavo-convex structure as shown in FIGS. 11 (A) and 11 (B), for example. Is formed directly on the surface of the substrate, and an article having a fine concavo-convex structure on the surface (corresponding to the article according to the second embodiment of the present invention) is obtained.

The etching process is performed, for example, by bringing a plasma etching gas into contact with the surface of the substrate on which the resin pattern is formed on the surface on which the resin pattern is formed.
The etching gas may be appropriately selected according to the material of the substrate and the material of the resin pattern.

When the resin pattern remains on the surface of the base material after the etching treatment, the base material may be treated with a stripping solution or the like.
You may process the surface of the base material after an etching process with well-known surface treatment agents, such as a slipperiness | lubricity imparting agent.

(Mechanism of action)
In the method for producing an article of the present invention described above, in step (a), a photomask using a Talbot effect having a regular dot pattern and a unidirectional spread angle parallel to the surface of the photomask. However, the photosensitive resin layer is exposed in combination with light that is wider than the spread angle in the other direction parallel to the surface of the photomask. Therefore, not only a latent image pattern corresponding to a plurality of protrusions of an article finally obtained due to a complicated light interference phenomenon, but also a bridge that connects adjacent protrusions so as to divide the bottom formed between the protrusions. A latent image pattern corresponding to the bridge portion is also formed. As a result, by developing the photosensitive resin layer on which the latent image pattern is formed in the step (b), the plurality of regular protrusions, the bottom formed between the protrusions, and the bottom are separated. The resin pattern which consists of a fine concavo-convex structure which has a bridge part which connects between adjacent protrusions is formed.

(Other forms)
In the method for producing an article of the present invention, (a) the photosensitive resin layer of the substrate with the photosensitive resin layer is irradiated with light from the light irradiation means through a photomask having a regular dot pattern. A step of forming a latent image pattern corresponding to the fine concavo-convex structure on the photosensitive resin layer, and (b) after the step (a), by developing the substrate with the photosensitive resin layer, the fine concavo-convex structure And a step of obtaining an article having a fine concavo-convex structure on the surface, wherein the photomask is a photomask using the Talbot effect, Any light may be used as long as the spread angle in one direction parallel to the surface of the photomask is wider than the spread angle in the other direction parallel to the surface of the photomask. Limited to methods There.

In addition, by applying the method for producing an article of the present invention, a mold having a reversal structure of a fine concavo-convex structure formed on the surface is produced, and the reversal structure is applied to the surface of a substrate to be transferred by an imprint method using the mold. By transferring, an article having a fine concavo-convex structure on the surface may be obtained. Specifically, by performing electroforming or nanoimprinting on the surface of the fine concavo-convex structure produced by steps (a) and (b), a plurality of holes and a flat portion formed between the holes, Then, it is possible to produce a mold having a reverse structure formed on the surface having a groove portion connecting adjacent holes so as to divide the flat portion.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
Examples 1 and 2 are examples, and example 3 is a comparative example.

(Spread angle)
Attaching an aperture with a 1 mm diameter pinhole to the LED line illumination exit surface, and passing the light through the pinhole to the photosensitive resin layer disposed at a distance of 9 mm from the pinhole exit (a) ), The photosensitive resin layer is developed under the same conditions as in step (b) to form a pattern, the pattern diameter R2, the pinhole diameter R1 (1 mm), and the pinhole From the distance D (9 mm) from the exit to the photosensitive resin layer, the light spread angle θ was determined by the following equation. The spread angle of light was calculated | required about the width direction (X direction) of LED line illumination, and the longitudinal direction (Y direction) of LED line illumination.
θ = tan ⁻¹ [{(R2-R1) / 2} / D]

(Atomic force microscope image)
An atomic force microscope image of the fine concavo-convex structure on the surface of the article was obtained using a scanning probe microscope (S-I Nano Technology, L-trace / Nanoavi). As the cantilever, Point Probe Plus-NCHR manufactured by Nanoworld was used.

(Nell cloth rubbing test)
Using a surface property tester (manufactured by Shinto Kagaku Co., Ltd., Tribogear TYPE: 38), the surface of the article on the fine uneven structure side was rubbed with flannel cloth under the following conditions, and the appearance of the surface was observed.
Temperature: room temperature (25 ° C),
Weight: 750g,
Number of rubbing: 100 round trips
Speed: 1200mm / min,
Distance: 30 mm.

(Example 1)
Step (a):
A synthetic quartz substrate (manufactured by AGC Electronics, diameter 100 mm, thickness: 1 mm) having a thickness of 1 mm was prepared as a base material.

1,1,1,3,3,3-hexamethyldisilazane (Tokyo Ohka Kogyo Co., Ltd., OAP) is dropped on the center of the surface of the synthetic quartz substrate, and a spin coater (Mikasa Co., Ltd., 1H-DX2) is used. Then, spin coating was performed at 25 ° C. and 3000 rpm for 20 seconds. The synthetic quartz substrate was heated on a hot plate at 130 ° C. for 180 seconds to obtain a surface-treated synthetic quartz substrate.

A positive-type photoresist (AZ Electronics, AZ-7904) is dropped on the center of the surface of the surface-treated synthetic quartz substrate, and the spin coater (Mikasa, 1H-DX2) is used at 25 ° C. and 3000 rpm. Spin coating was performed for 20 seconds. The synthetic quartz substrate was heated on a hot plate at 90 ° C. for 180 seconds to obtain a synthetic quartz substrate with a photoresist film having a thickness of 430 nm (base material with a photosensitive resin layer).

A phase shift mask using the Talbot effect shown in FIG. 7 on the surface of the synthetic quartz substrate with a photoresist film (dot arrangement: regular hexagonal lattice, dot pitch: 600 nm, dot diameter: 300 nm) Are arranged such that one direction of the hexagonal lattice line in the dot pattern is the X direction. Above the phase shift mask using the Talbot effect, LED line illumination (manufactured by ITEC System, main wavelength: 365 nm, light spreading angle in the width direction (X direction, collimating direction): 6 °, longitudinal direction (Y direction, The light spread angle in the diffusion direction (45 °) was arranged so that the longitudinal direction was the Y direction. The distance from the exit surface of the LED line illumination to the photoresist film was 9 mm.

By moving the LED line illumination in the X direction and irradiating the photoresist film of the synthetic quartz substrate with the photoresist film with ultraviolet rays from the LED line illumination through a phase shift mask using the Talbot effect, a latent image is obtained. A pattern was formed on the photoresist film. The integrated light quantity was 27 mJ / cm ² .

Step (b):
The exposed synthetic quartz substrate with a photoresist film was immersed in a developer (AZ300MIF DEV. (2.38), manufactured by AZ Electronics Co., Ltd.) at 25 ° C. for 30 seconds. The synthetic quartz substrate was rinsed with pure water and dried by air blow to obtain a synthetic quartz substrate with a photoresist pattern shown in FIG.

The average pitch of the protrusions in the resist pattern is 600 nm, the average width of the protrusions is 370 nm, the average height of the protrusions is 450 nm, the average width of the bridge portion is 150 nm, and the average height of the bridge portion is It was 200 nm.

Step (c):
A synthetic quartz substrate with a photoresist pattern is set in a high-density plasma etching apparatus (NLD-500 manufactured by ULVAC, Inc.), using a mixed gas of 50 sccm of Ar and 10 sccm of SF ₆ , pressure: 1000 Pa, RF power: 1000 W, Etching time: The synthetic quartz substrate with a photoresist pattern was etched under the condition of 60 seconds.
The synthetic quartz substrate after the etching treatment was immersed in a resist stripping solution (manufactured by Tokyo Ohka Kogyo Co., Ltd., stripping solution 106) for 10 minutes at room temperature. The synthetic quartz substrate is rinsed with pure water, dried by air blow, and the article having the fine concavo-convex structure shown in FIGS. 11 (A), 11 (B), 12 (A), and 12 (B) on the surface Got.

The average pitch of the protrusions in the fine concavo-convex structure is 600 nm, the average width of the protrusions is 350 nm, the average height of the protrusions is 330 nm, the average width of the bridge portion is 130 nm, and the average height of the bridge portion Was 180 nm.

The obtained article was immersed in a treatment solution obtained by diluting a surface treatment agent (manufactured by Daikin Industries, Ltd., OPTOOL DSX) to 0.1% by mass with perfluorohexane at room temperature for 1 minute. After pulling up the article, it was allowed to stand for 1 hour under conditions of 60 ° C. and 90% RH to obtain an article for a flannel rubbing test. Three such articles were prepared, and a flannel rubbing test was performed in each of the X direction, the Y direction, and the oblique direction. The results are shown in FIGS. 13 (A), 13 (B), and 13 (C). No streak-like scratches appeared in the rubbing direction.

(Example 2)
A synthetic quartz substrate with a photoresist pattern shown in FIG. 10 in the same manner as in Example 1 except that the phase shift mask using the Talbot effect is arranged so that one direction of the hexagonal lattice line in the dot pattern is the Y direction. Got.

The average pitch of the protrusions in the resist pattern is 600 nm, the average width of the protrusions is 350 nm, the average height of the protrusions is 450 nm, the average width of the bridge portion is 180 nm, and the average height of the bridge portion is It was 230 nm.

(Example 3)
The LED line illumination of Example 1 is a UV exposure apparatus (manufactured by Quintel, UL-7000, main wavelength: 365 nm, light spread angle in the width direction (X direction): 4 °, light spread angle in the longitudinal direction (Y direction) : 4 °), and an article having a fine concavo-convex structure shown in FIGS. 14 (A) and 14 (B) was obtained in the same manner as in Example 1 except that the integrated light quantity was changed to 17 mJ / cm ² . .

The average pitch of the protrusions in the fine concavo-convex structure was 600 nm, the average width of the protrusions was 335 nm, and the average height of the protrusions was 450 nm. No bridge was formed.

The article was etched and surface-treated in the same manner as in Example 1 to obtain an article for a fretting rub test. Three such articles were prepared, and a flannel rubbing test was performed in each of the X direction, the Y direction, and the oblique direction. The results are shown in FIGS. 15 (A), 15 (B), and 15 (C). A streak-like scratch appeared in the rubbing direction.

The article having the fine concavo-convex structure of the present invention on the surface is useful as an antireflection member, a light extraction member, a heat radiating member, a surface catalyst, a hydrophilic member, a water repellent member, an antifouling member, and the like.
The entire contents of the description, claims, drawings, and abstract of Japanese Patent Application No. 2015-105247 filed on May 25, 2015 are incorporated herein as the disclosure of the present invention. .

1: article, 2: article, 10: base material, 12: protrusion, 14: bottom, 16: bridge, 18: fine uneven structure, 20: photosensitive resin layer, 22 protrusion, 24: bottom, 26: bridge Bridge part, 28: resin pattern, 30: photomask, 40: light irradiation means.

Claims

A method for producing an article having a fine concavo-convex structure on the surface, having a plurality of regular protrusions, a bottom formed between the protrusions, and a bridge portion connecting adjacent protrusions so as to divide the bottom Because
(A) By irradiating the light from the light irradiation means to the photosensitive resin layer of the substrate with the photosensitive resin layer through a photomask having a regular dot pattern, it corresponds to the fine concavo-convex structure. Forming a latent image pattern on the photosensitive resin layer;
(B) The fine concavo-convex structure in which a resin pattern corresponding to the fine concavo-convex structure is formed on the surface of the substrate by developing the substrate with the photosensitive resin layer after the step (a). Obtaining an article having a surface thereof;
Have
The photomask is a photomask using the Talbot effect,
The fine concavo-convex structure in which the light from the light irradiating means is light in which a spread angle in one direction parallel to the surface of the photomask is wider than a spread angle in another direction parallel to the surface of the photomask A method for manufacturing an article having a surface thereof.
(C) After the step (b), the fine concavo-convex structure in which the fine concavo-convex structure is directly formed on the surface of the base material by etching the base material on which the resin pattern is formed on the surface. The manufacturing method of the articles | goods which have the fine uneven | corrugated structure on the surface of Claim 1 which further has the process of obtaining the articles | goods which have on the surface.
The article having the fine concavo-convex structure on the surface according to claim 1 or 2, wherein the light irradiation means is LED line illumination including a plurality of light emitting diodes (LEDs) arranged in a line and a plano-convex cylindrical lens. Production method.
The method for producing an article having a fine concavo-convex structure on the surface according to any one of claims 1 to 3, wherein the dots in the dot pattern are arranged in a hexagonal lattice pattern.
The light irradiation means and the photomask are arranged so that a direction in which the light spread angle is widened and a direction of hexagonal lattice lines in the dot pattern are orthogonal to each other. A method for producing an article having a fine concavo-convex structure on its surface.
The light emitted from the light irradiation means has a divergence angle in one direction parallel to the surface of the photomask of 10 ° to 60 °, and a divergence angle in a direction perpendicular to the one direction parallel to the surface of the photomask. The method for producing an article having a fine concavo-convex structure on a surface thereof according to any one of claims 1 to 5, wherein the light is light set at 0 to 8 °.
The method for producing an article having a fine concavo-convex structure on a surface according to any one of claims 1 to 6, wherein the photomask is a phase shift mask using a Talbot effect.
An article having on the surface a fine concavo-convex structure having a plurality of regular protrusions, a bottom formed between the protrusions, and a bridge portion connecting adjacent protrusions so as to divide the bottom.
The article having a fine concavo-convex structure on the surface according to claim 8, wherein an average height of the bridge portion is lower than an average height of the protrusions.
The article having a fine uneven structure according to claim 8 or 9, wherein the protrusions are arranged in a hexagonal lattice pattern.
11. The bridge according to claim 10, wherein among the three-direction lattice lines of the hexagonal lattice, the bridging portion is formed line-symmetrically along another two-direction lattice line with the lattice line in one direction as a symmetry axis. Articles having a fine relief structure on the surface.