JP6679026B2 - Article having fine rugged structure on its surface and method for producing the same - Google Patents

Description

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

It is known that an article having a fine concavo-convex structure having a plurality of protrusions whose period is equal to or shorter than the wavelength of visible light on the surface has excellent antireflection performance.
However, the protrusions in the fine concavo-convex structure are easily broken from the root, and the article having the fine concavo-convex structure on the surface has insufficient scratch resistance.

The followings have been proposed as articles having a fine uneven structure with improved scratch resistance on the surface.
An antireflection article in which microprotrusions each having a period equal to or shorter than the wavelength of visible light are closely arranged, at least a part of the microprotrusions is a multimodal microprotrusion, and the rest are monomodal microprotrusions. (See Patent Document 1).

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

JP, 2014-029366, A

  The present invention provides a method for easily producing an article having a fine uneven structure having excellent scratch resistance on the surface; and an article having a fine uneven structure having excellent scratch resistance on the surface.

The present invention has the following aspects.
[1] An article having a fine concavo-convex structure on the surface, which has a plurality of projections having regularity, a bottom portion formed between the projections, and a bridge portion connecting adjacent projections so as to partition the bottom portion. A method of manufacturing, comprising: (a) irradiating light from a light irradiating means onto a photosensitive resin layer of a substrate with a photosensitive resin layer through a photomask having a regular dot pattern, The step of forming a latent image pattern corresponding to the fine concavo-convex structure on the photosensitive resin layer, and (b) the step of (a), by subjecting the substrate with the photosensitive resin layer to a development treatment, A resin pattern corresponding to a 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, the photomask is a photomask utilizing a Talbot effect, Light irradiation The light from the step has a divergence angle in one direction parallel to the surface of the photomask wider than the divergence angle in the other direction parallel to the surface of the photomask. A method for manufacturing an article having the same.
[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 concavo-convex structure on the surface, which further comprises a step of obtaining an article having the fine concavo-convex structure on the surface.
[3] The light irradiation means is an LED line illumination including a plurality of light emitting diodes (LEDs) arranged in a line and a plano-convex cylindrical lens, and the fine concavo-convex structure of [1] or [2] is formed on the surface. A method for manufacturing an article having the same.
[4] The method for producing an article, wherein the dots in the dot pattern are arranged in a hexagonal lattice shape and have the fine concavo-convex structure of any of [1] to [3] on the surface.
[5] The light irradiation means and the photomask are arranged such that a direction in which the spread angle of the light is widest and a direction of a lattice line of a hexagonal lattice in the dot pattern are orthogonal to each other. ] The manufacturing method of the article which has the fine grooving | roughness structure on the surface.
[6] A direction in which 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 is orthogonal to one direction parallel to the surface of the photomask. The method for producing an article having the fine concavo-convex structure of any one of [1] to [5], which is light having a divergence angle of 0 to 8 °.
[7] A method for producing an article, wherein the photomask is a phase shift mask utilizing the Talbot effect, and has the fine uneven structure of any one of [1] to [6] on the surface.
[8] An article having a fine concavo-convex structure on the surface, which has a plurality of projections having regularity, a bottom portion formed between the projections, and a bridging portion connecting adjacent projections so as to partition the bottom portion.
[9] The article having the fine concavo-convex structure of [8] on the surface, wherein the average height of the bridge portion is lower than the average height of the protrusions.
[10] An article having the fine concavo-convex structure of [8] or [9] on the surface, in which the protrusions are arranged in a hexagonal lattice.
[11] Among the three-direction lattice lines of the hexagonal lattice, the bridging portion is formed line-symmetrically along the other two-direction lattice lines with the one-direction lattice line as the axis of symmetry. An article having the fine uneven structure of 1.

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 having excellent scratch resistance and antireflection performance on the surface can be easily produced.
The article having the fine relief structure of the present invention on the surface has excellent scratch resistance of the fine relief structure.

It is a top view which shows an example of the article which has the fine grooving | roughness structure of this invention on the surface. FIG. 2 is a sectional view taken along line II-II of FIG. 1. It is a top view which shows the other example of the article which has the fine grooving | roughness structure of this invention on the surface. FIG. 4 is a sectional view taken along line IV-IV of FIG. 3. It is a perspective view for explaining a process (a). It is a figure for demonstrating the spread angle of light. It is a scanning electron microscope image showing an example of a dot arrangement direction of a phase shift mask using the Talbot effect. 8 is an atomic force microscope image showing a resin pattern formed using the phase shift mask utilizing the Talbot effect of FIG. 7. 7 is a scanning electron microscope image showing another example of the dot arrangement direction of the phase shift mask using the Talbot effect. 10 is an atomic force microscope image showing a resin pattern formed by using the phase shift mask utilizing the Talbot effect of FIG. 9. 3 is an atomic force microscope image showing a fine concavo-convex structure on the surface of the article obtained in Example 1. It is the cross-sectional shape of the protrusion in the atomic force microscope image of FIG. FIG. 12 is an atomic force microscope image showing the bridge portion of FIG. 11 (A). It is a cross-sectional shape of the bridge portion in the atomic force microscope image of FIG. 4 is a photograph showing the appearance of the surface of the article obtained in Example 1 after a flannel rubbing test. 4 is a photograph showing the appearance of the surface of the article obtained in Example 1 after a flannel rubbing test. 4 is a photograph showing the appearance of the surface of the article obtained in Example 1 after a flannel rubbing test. 5 is an atomic force microscope image showing a fine concavo-convex structure on the surface of the article obtained in Example 3. It is the cross-sectional shape of the protrusion in the atomic force microscope image of FIG. 5 is a photograph showing the appearance of the surface of the article obtained in Example 3 after the flannel rubbing test. 5 is a photograph showing the appearance of the surface of the article obtained in Example 3 after the flannel rubbing test. 5 is a photograph showing the appearance of the surface of the article obtained in Example 3 after the flannel rubbing test.

The following definitions of terms apply throughout the specification and 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, a mask that can expose the photosensitive resin layer in a pattern when the photosensitive resin layer is irradiated with light therethrough.
The "latent image pattern" is a pattern composed of an exposed portion and an unexposed portion of the photosensitive resin layer. A desired resin pattern is formed by removing either one of the exposed portion and the unexposed portion by the development processing.
The “Talbot effect” refers to a phenomenon in which an interference pattern is formed at a specific distance from the photomask when the photomask having the periodic mask pattern is irradiated with light.
"Phase shift mask using the Talbot effect" is a transparent mask in which parts with different optical path lengths are formed in a pattern, and the phase is partially changed according to the difference in the optical path lengths to diffract the light that emerges. It means a photomask that forms a pattern in a photosensitive resin layer by generating interference (Talbot effect).
The "divergence angle" is defined as the light passing through the pinhole in the photosensitive resin layer arranged at a distance of 9 mm from the pinhole exit by attaching an aperture having a pinhole with a diameter of 1 mm on the emission surface of the light irradiation means. And the photosensitive resin layer is developed to form a pattern (a hole when the photosensitive resin composition is a positive type), and the diameter R2 of the pattern, the diameter R1 (1 mm) of the pinhole, and the 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 that has a shape obtained by dividing a cylinder in the axial direction, and has a curvature in the width direction but no curvature in the longitudinal direction (axial direction of the cylinder). ) And a flat surface facing the cylindrical surface.
"The 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). ) Means that they are 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 the arbitrary dot (or protrusion). It means that 6 dots (or protrusions) that are closest to and equal to the protrusions are arranged. The vertices of the six dots (or protrusions) are arranged at regular intervals of 60 ° centering on the vertices of the arbitrary dots (or protrusions) to form a regular hexagonal lattice.
The “grid line” means a line connecting adjacent grid points.
The “protrusion pitch” means the center-to-center distance between adjacent protrusions in the grid line direction, and the “average pitch of protrusions” means the average value of the pitches of six randomly selected protrusions. .
The “protrusion width” means the maximum length on the bottom surface of the protrusion, and the “average width of the protrusion” means the average value of the widths of 6 randomly selected protrusions.
The "height of the protrusion" means the height from the bottom of the protrusion to the apex, and the "average height of the protrusion" means the average value of the heights of the six randomly selected protrusions. To do.
"Width of the bridging part" means the maximum length in the cross section orthogonal to the lattice line of the bridging part, and "average width of the bridging part" means 6 randomly selected bridges. It means the average value of the width of a part.
"Height of the bridging part" means the height from the bottom of the bridging part to the highest part, and "average height of the bridging part" means 6 randomly selected bridges. It means the average height of the bridge.

<Article>
The article having a fine concavo-convex structure on the surface of the present invention (hereinafter, also simply referred to as an article) is a plurality of regular projections, bottoms formed between the projections, and adjacent projections that partition the bottom. The surface has a fine concavo-convex structure having a bridging portion connecting between them.

(First embodiment)
1 is a top view showing a first embodiment of the article of the present invention, and FIG. 2 is a sectional view taken along line II-II of 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 has a plurality of protrusions 22 having regularity, a bottom portion 24 formed between the protrusions 22, and a wall-shaped bridging portion 26 that connects adjacent protrusions 22 so as to partition the bottom portion 24. It consists of a fine relief structure.

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

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

  Examples of the organic material include fluororesin, 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 material may be used because of its excellent adhesion to the resin pattern 28. Examples of the surface treatment include primer coating treatment, UV ozone treatment, and plasma etching treatment. Examples of the primer include polymethylmethacrylate, silane coupling agent, silazane, polyvinyl alcohol and the like.

  The resin pattern 28 is a pattern formed by removing an unnecessary portion from a 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 shell shape (bell shape) as shown in the drawing, and may be a cylindrical shape, a prismatic shape, a conical shape, a pyramidal 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 portion 24 may have a residue of the photosensitive resin layer that cannot be completely removed.

  The bridging portion 26 is a wall-shaped portion that connects the protrusions 22 that are adjacent to each other in the grid line direction so as to divide the bottom portion 24. The bridging portion 26 is a portion that extends 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, more preferably 160 to 400 nm. When the average pitch of the protrusions 22 is equal to or more 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 excellent. 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 concavo-convex 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 more than the lower limit value, the protrusions 22 are more difficult to break, the scratch resistance of the fine concavo-convex structure is further excellent, and the flat bottom portion 24 can be reduced, so that the antireflection effect can be enhanced. If the average width of the protrusions 22 is equal to or less than the upper limit value, the bridging 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. When the average height of the projections 22 is equal to or more than the lower limit value, sufficient antireflection performance due to the fine uneven structure can be obtained. When the average height of the protrusions 22 is equal to or less than the upper limit value, the protrusions 22 are more difficult to break, and the scratch resistance of the fine concavo-convex structure is further excellent.

  The average width of the bridging portion 26 is preferably 40 to 300 nm, more preferably 100 to 200 nm. When the average width of the bridging portion 26 is equal to or more than the lower limit value, the bridging portion 26 is less likely to be broken, and the scratch resistance of the fine uneven structure is further excellent. When the average width of the bridging portion 26 is not more than the upper limit value, sufficient antireflection performance due to the fine concavo-convex structure can be obtained.

  The average height of the bridging 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 bridging portion 26 is lower than the average height of the protrusions 22, sufficient antireflection performance due to the fine concavo-convex structure can be obtained. When the average height of the bridging portion 26 is 30% or more of the height of the protrusions 22, the protrusions 22 are less likely to be broken, and the scratch resistance of the fine concavo-convex structure is further excellent.

  The protrusions 22 may be arranged in a hexagonal lattice or may be arranged in a tetragonal lattice. It is preferable that the protrusions 22 are arranged in a hexagonal lattice, and the protrusions 22 are periodically arranged in a regular hexagonal lattice, 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.

  In the bridging portion 26, the projections 22 are less likely to be broken, the scratch resistance of the fine concavo-convex structure is further excellent, and the bridging portion 26 is easily formed. Among these, it is preferable that the lattice lines in the X direction are symmetrically formed along the lattice lines in the other two directions. When the bridging portions 26 are formed parallel to each other along only one direction of the grid lines, the scratch resistance of the fine concavo-convex structure is inferior to that of the illustrated example. When the bridging portions 26 are formed along all the grid lines in three directions, the area occupied by the valleys in the fine concavo-convex structure is reduced, and it becomes difficult to obtain sufficient antireflection performance.

(Second embodiment)
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 the line IV-IV of FIG. The broken line in FIG. 3 is a hexagonal lattice line.
The article 2 corresponds to the article 1 obtained by etching the article 1 according to the first embodiment.
The article 2 is composed of the base material 10 having the fine concavo-convex structure 18 directly formed on the surface thereof. The fine concavo-convex structure 18 includes a plurality of protrusions 12 having regularity, a bottom portion 14 formed between the protrusions 12, and a wall-shaped bridging portion 16 that connects adjacent protrusions 12 so as to partition the bottom portion 14. Have.
Hereinafter, detailed description of the same configuration as the article 1 according to the first embodiment will be omitted.

  The shape, size, arrangement, etc. of the projections 12, the bottom portion 14, and the bridging portion 16 are the same as the shape, size, arrangement, etc. of the projection 22, the bottom portion 24, and the bridging 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 the bridging portion that connects the adjacent protrusions, the bridging portion reinforces the protrusion in the lateral direction. Therefore, the protrusions in the fine concavo-convex structure are unlikely to be broken from the root, and the scratch resistance of the fine concavo-convex structure is excellent.

(Other forms)
The article of the present invention has, on the surface, a fine concavo-convex structure having a plurality of regular projections, a bottom formed between the projections, and a bridging portion connecting adjacent projections so as to partition the bottom. What is necessary is to have it, and it is not limited to the article 1 according to the first embodiment and the article 2 according to the second embodiment in the illustrated example.

<Method of manufacturing article>
A method for producing an article having a fine concavo-convex structure on its surface (hereinafter, also simply referred to as an article production method) includes a plurality of regular protrusions, a bottom portion formed between the protrusions, and a bottom portion. A method for producing an article having a fine concavo-convex structure on its surface, which has a bridging portion that connects adjacent protrusions so as to divide the process, comprising the following step (a), step (b), and optionally step ( Including c).

(A) By irradiating the photosensitive resin layer of the substrate with the photosensitive resin layer with the light from the light irradiation means through the photomask having the dot pattern having the regularity, the latent image corresponding to the fine concavo-convex structure is formed. A step of 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 base material, 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) A 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 having the resin pattern formed on the surface after the step (b), if necessary. A step of obtaining an article having a surface (corresponding to the article according to the second embodiment of the present invention).

(Step (a))
As shown in FIG. 5, a substrate having a photosensitive resin layer 20 formed on the surface of the substrate 10 has a photosensitive resin layer 20 side surface, and a photo having a regular dot pattern is formed on the surface of the substrate. The mask 30 is placed. The light irradiation means 40 is arranged above the photomask 30 so that the longitudinal direction is the Y direction. Irradiating the light from the light irradiation means 40 to the photosensitive resin layer 20 of the base material 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 irradiation with light in photolithography. Examples of the material for forming the photosensitive resin layer 20 include known photosensitive resin compositions such as photoresist. The photosensitive resin composition may be a positive type or a negative type.

  The photomask 30 is a photomask that uses the Talbot effect. Examples of the photomask utilizing the Talbot effect include a phase shift mask utilizing the Talbot effect.

  The photomask 30 has a regular dot pattern for forming a plurality of protrusions having a fine concavo-convex structure formed on the surface of the finally obtained article. In the case of a phase shift mask using the Talbot effect, the photomask 30 has portions having different optical path lengths in a dot shape. 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 always one-to-one.

Examples of the photomask 30 include those in which the dots in the dot pattern are arranged in a hexagonal lattice shape, those in which the dots are arranged in a tetragonal lattice shape, and the like. The protrusions in the finally obtained article are more difficult to break, and from the viewpoint that 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 of 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 emit light.

As shown in FIG. 6, the spread angle of light is an angle θ indicating how much the light diameter at a predetermined distance from the light irradiation means 40 spreads with respect to the exit diameter of the emission surface of the light irradiation means 40. Specifically, an aperture (not shown) having a pinhole with a diameter of 1 mm is attached to the emission surface of the light irradiation means 40, and a photosensitive resin layer (not shown) arranged at a distance of 9 mm from the pinhole outlet. Irradiate the light passing through the pinhole, and develop the photosensitive resin layer to form a pattern, and the diameter R2 of the pattern, the diameter R1 of the pinhole (1 mm), and the pinhole exit to the photosensitive resin layer. And the distance D (9 mm) of the angle .theta.
θ = tan ⁻¹ [{(R2-R1) / 2} / D]

  The light irradiation means 40 is not limited to the linear illumination shown in the figure, and may be planar illumination or the like. As the light irradiation means, an ordinary 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) , A collimation lens (such as a cylindrical lens)) in combination.

  As the light irradiating means 40, from the viewpoint 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 An LED line illumination including a cylindrical lens, in which the LED line array and the plano-convex cylindrical lens are arranged in parallel with each other and 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, in the width direction of the LED line illumination, light is collimated so as to approach a parallel state, and in the longitudinal direction of the LED line illumination, light that is not collimated and diffuses can be emitted.

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

  When exposure is performed by combining an anisotropic light and a binary mask of two gradations including a normal light shielding portion and a light transmitting portion, light in the diffusion direction also enters the light shielding portion. 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-shaped light transmitting portion and a negative photosensitive resin composition, elliptical dots extending in the light diffusion direction are formed in the resin pattern. On the other hand, when exposure is performed by combining a photomask that uses the Talbot effect (more specifically, a phase shift mask that uses the Talbot effect) and anisotropic light, the case of using a binary mask Differently, the present inventors have found that due to a complicated light interference phenomenon, a bridge portion is formed in the resin pattern so that dots are connected in the light diffusion direction.

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

  The light irradiation means 40 and the photomask 30 are preferably arranged so that the direction in which the spread angle of light is widest and the one direction of the lattice line 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 collimating direction is used. 7) is the Y direction, the light irradiating means is arranged so that one direction of the grid lines of the hexagonal lattice in the dot pattern of the photomask 30 is the X direction orthogonal to the Y direction, as shown in FIG. 40 and the photomask 30 are arranged.

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

  On the other hand, as shown in FIG. 9, the diffusion direction (Y direction) of the light emitted from the light irradiation unit 40 and one direction (Y direction) of the lattice lines of the hexagonal lattice in the dot pattern of the photomask 30 match. In this case, as shown in FIG. 10, in the resin pattern, dots are connected in the light diffusion direction (Y direction), and bridging portions are formed in parallel with each other along only the lattice lines in the Y direction. In FIG. 10, the black portion represents the bottom portion.

  Compared to the fine concavo-convex structure in which the bridging portions are formed in parallel with each other along the grid lines in only one direction, the fine concavo-convex structure in which the bridging portions are formed in line symmetry along the grid lines in two directions is scratch-resistant. Excellent in performance.

  When the photosensitive resin composition is a positive type, it is preferable that the integrated light amount is less than an 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%, and more preferably 75 to 85% of the appropriate light amount.

  When the photosensitive resin composition is a negative type, it is preferable that the integrated light amount is a light amount larger than an appropriate light amount, that is, overexposure, 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% of the appropriate light amount, and more preferably 120 to 130%.

  Here, the appropriate light amount means the median value of the light amount range where the height of the formed photoresist protrusion is the highest.

(Step (b))
After step (a), the photosensitive resin layer-provided substrate is subjected to a development treatment to form a resin pattern corresponding to the fine uneven structure on the surface of the substrate as shown in FIG. 8, for example. An article having a surface (corresponding to the article according to the first embodiment of the present invention) is obtained.

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

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

The etching treatment is performed, for example, by bringing a plasma-forming etching gas into contact with the surface of the base material having the resin pattern formed on its surface on the side having the resin pattern formed thereon.
The etching gas may be appropriately selected depending on the material of the base material 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.
The surface of the base material after the etching treatment may be treated with a known surface treatment agent such as a slipperiness imparting agent.

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

(Other forms)
In the method for producing an article of the present invention, (a) irradiating light from a light irradiation means onto a photosensitive resin layer of a substrate with a photosensitive resin layer through a photomask having a regular dot pattern. To form a latent image pattern corresponding to the fine concavo-convex structure on the photosensitive resin layer, and (b) after the step (a), the substrate with the photosensitive resin layer is subjected to a development treatment to obtain the fine concavo-convex structure. A resin pattern corresponding to is formed on the surface of the substrate, a step of obtaining an article having a fine uneven structure on the surface, the photomask is a photomask utilizing the Talbot effect, Any method may be used as long as the light is light whose divergence angle in one direction parallel to the surface of the photomask is wider than divergence angle in the other direction parallel to the surface of the photomask. Limited to methods There.

  Further, by applying the method for producing an article of the present invention, a mold having an inverted structure of a fine concavo-convex structure formed on the surface is produced, and the inverted structure is formed on the surface of the transferred substrate by an imprint method using the mold. It may be transferred to obtain an article having a fine relief structure on its surface. Specifically, a plurality of holes and a flat portion formed between the holes are formed by performing electroforming or nanoimprinting on the surface of the fine concavo-convex structure manufactured by the steps (a) and (b). It is possible to manufacture a mold in which a reversal structure having a groove portion that connects adjacent holes so as to divide the flat portion is formed on the surface.

Hereinafter, the present invention will be specifically described 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)
An aperture having a pinhole with a diameter of 1 mm was attached to the emitting surface of the LED line illumination, and the light passing through the pinhole was applied to the photosensitive resin layer arranged at a distance of 9 mm from the pinhole exit. ) And the photosensitive resin layer is developed under the same conditions as in step (b) to form a pattern, and the diameter R2 of the pattern, the diameter R1 of the pinhole (1 mm), and the pinhole From the distance D (9 mm) from the exit to the photosensitive resin layer, the spread angle θ of light was calculated by the following formula. The divergence angle of light was obtained in the width direction (X direction) of the LED line illumination and the longitudinal direction (Y direction) of the 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 by using a scanning probe microscope (L-trace / Nonavi, manufactured by SII Nanotechnology Inc.). As the cantilever, Point Probe Plus-NCHR manufactured by Nanoworld was used.

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

(Example 1)
Process (a):
As a base material, a synthetic quartz substrate (made by AGC Electronics, diameter 100 mm, thickness 1 mm) having a thickness of 1 mm was prepared.

  1,1,1,3,3,3-hexamethyldisilazane (manufactured by Tokyo Ohka Kogyo Co., Ltd., OAP) was dropped on the center of the surface of the synthetic quartz substrate, and a spin coater (manufactured by Mikasa Corp., 1H-DX2) was used. Spin coating was performed at 3000 rpm for 20 seconds at 25 ° C. 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 photoresist (AZ Electronics, AZ-7904) was dropped on the center of the surface of the surface-treated synthetic quartz substrate, and a spin coater (Mikasa, 1H-DX2) was used at 25 ° C. at 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 430 nm-thick synthetic quartz substrate with a photoresist film (base material with a photosensitive resin layer).

  A phase shift mask utilizing the Talbot effect shown in FIG. 7 (dot arrangement: regular hexagonal lattice, dot pitch: 600 nm, dot diameter: 300 nm) on the surface of the synthetic quartz substrate with a photoresist film on the photoresist film side. Were arranged so that one direction of the hexagonal lattice lines in the dot pattern was the X direction. Above the phase shift mask using the Talbot effect, LED line illumination (manufactured by Aitec System Co., Ltd., main wavelength: 365 nm, light spread angle in width direction (X direction, collimate direction): 6 °, longitudinal direction (Y direction, The light divergence angle (diffusion direction: 45 °) was arranged so that the longitudinal direction was the Y direction. The distance from the emitting 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 utilizing the Talbot effect, a latent image is obtained. A pattern was formed on the photoresist film. The integrated light amount was 27 mJ / cm ² .

Step (b):
The exposed synthetic quartz substrate with a photoresist film was immersed in a developing solution (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 portions is 150 nm, and the average height of the bridge portions is It was 200 nm.

Step (c):
A synthetic quartz substrate with a photoresist pattern was set in a high-density plasma etching device (NLD-500 manufactured by ULVAC, Inc.), a mixed gas of 50 sccm of Ar and 10 sccm of SF ₆ was used, pressure: 1000 Pa, RF power: 1000 W, The synthetic quartz substrate with the photoresist pattern was etched under the condition of etching time: 60 seconds.
The synthetic quartz substrate after the etching treatment was immersed in a resist stripping solution (Tokyo Ohka Kogyo Co., Ltd. stripping solution 106) at room temperature for 10 minutes. Articles having a synthetic quartz substrate rinsed with pure water and dried by air blow, and having the fine uneven 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 portions is 130 nm, and the average height of the bridge portions is Was 180 nm.

  The above-obtained article was immersed for 1 minute at room temperature in a treatment liquid prepared by diluting a surface treatment agent (Optool DSX manufactured by Daikin Industries, Ltd.) with perfluorohexane to 0.1% by mass. After pulling up the article, it was left under conditions of 60 ° C. and 90% RH for 1 hour to obtain an article for flannel rubbing test. Three such articles were prepared and subjected to a flannel rubbing test in 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 utilizing the Talbot effect was arranged so that one direction of the lattice lines of the hexagonal lattice in the dot pattern was 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 portions is 180 nm, and the average height of the bridge portions is It was 230 nm.

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

  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. The bridge was not formed.

  The article was etched and surface treated as in Example 1 to give an article for flannel rub testing. Three such articles were prepared and subjected to a flannel rubbing test in the X direction, the Y direction, and the oblique direction. The results are shown in FIGS. 15 (A), 15 (B), and 15 (C). Streak-like scratches appeared in the rubbing direction.

The article having the fine uneven structure on the surface of the present invention is useful as an antireflection member, a light extraction member, a heat dissipation member, a surface catalyst, a hydrophilic member, a water repellent member, an antifouling member, and the like.
The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2005-105247 filed on May 25, 2015 are cited herein and incorporated as disclosure of the present invention. .

  1: Article, 2: Article, 10: Substrate, 12: Projection, 14: Bottom part, 16: Bridging part, 18: Fine uneven structure, 20: Photosensitive resin layer, 22 Projection, 24: Bottom part, 26: Bridge Hanging part, 28: resin pattern, 30: photomask, 40: light irradiation means.

Claims (7)

Method for producing an article having on its surface a fine concavo-convex structure having a plurality of regular projections, a bottom formed between the projections, and a bridge connecting the adjacent projections so as to partition the bottom And
(A) Corresponding to the fine concavo-convex structure by irradiating the photosensitive resin layer of the substrate with the photosensitive resin layer with the light from the light irradiation means through the photomask having the dot pattern having regularity. 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 base material by developing the base material with the photosensitive resin layer after the step (a). A step of obtaining an article having a
Have
The photomask is a photomask utilizing the Talbot effect,
A fine concavo-convex structure in which the light from the light irradiating means has a divergence angle in one direction parallel to the surface of the photomask wider than a divergence angle in another direction parallel to the surface of the photomask. A method for producing an article having a surface.   (C) 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 having the resin pattern formed on the surface after the step (b). The method for producing an article having the fine concavo-convex structure on the surface according to claim 1, further comprising the step of obtaining an article having the surface.   The article having a fine concavo-convex structure on a surface according to claim 1 or 2, wherein the light irradiation means is an 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 of manufacturing an article having the fine concavo-convex structure on the surface according to claim 1, wherein the dots in the dot pattern are arranged in a hexagonal lattice.   The light irradiation means and the photomask are arranged so that a direction in which the spread angle of the light is widest and a direction of a lattice line of a hexagonal lattice in the dot pattern are orthogonal to each other. A method for producing an article having the fine uneven structure on the surface thereof.   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 orthogonal to one direction parallel to the surface of the photomask. Is the light set to 0 to 8 °, The method for producing an article having the fine concavo-convex structure on the surface according to any one of claims 1 to 5.   The method for producing an article having a fine concavo-convex structure on its surface according to claim 1, wherein the photomask is a phase shift mask utilizing the Talbot effect.

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