JP7671441B2 - Patterned structure and method for producing same - Google Patents

Description

This disclosure relates to patterned structures and methods for manufacturing the same.

Photolithography and imprinting as pattern formation techniques are used in various fields. In imprinting, a relief pattern formed on a mold is transferred to a molding material such as resin. The mold used in imprinting may be formed from a resin substrate or a quartz substrate. The relief pattern of the mold can be formed, for example, by cutting using a lathe, laser processing, 3D printing, or photolithography.

In imprinting, stress can occur in the mold, particularly at the material interface, when a pattern is transferred to the molding material, when the material is cured with heat or ultraviolet light after transfer, and when the mold is separated from the molding material. The mold can also shrink depending on the temperature and humidity, and is affected by the linear expansion coefficient of the material. These factors can cause distortion in the concave-convex pattern transferred by imprinting. Therefore, various techniques have been proposed to properly transfer concave-convex patterns in imprinting (for example, Patent Document 1).

JP 2022-190892 A

For example, if a metal film is patterned onto the concave-convex pattern formed by imprinting, the use and functionality of the resulting component with the concave-convex pattern can be expanded by mixing two types of materials, for example.

Here, the patterning of the metal film may be performed by photolithography. However, if the concave-convex pattern transferred by imprinting is distorted, the relative position between the concave-convex pattern and the exposure pattern from the reticle used in photolithography will be shifted. As a result, a situation may arise in which the metal film cannot be formed in the correct position. Therefore, it has been difficult to provide a suitable member that has additional functions in addition to the concave-convex pattern, particularly a fine pattern.

The present disclosure has been made in light of the above circumstances, and its objective is to provide a patterned structure and a method for manufacturing the same that can appropriately expand uses and functions.

Embodiments of the present disclosure relate to the following [1] to [10].

[1] A substrate having a pattern including a plurality of recesses;
A patterned structure comprising: a functional layer that is provided in each of the recesses without extending beyond each of the recesses, the functional layer including a metal and/or an inorganic material.

[2] The patterned structure described in [1], in which the functional layer is in the form of a film and is provided in a state in which the recess does not fill the recess and is aligned along the inner surface of the recess.

[3] The patterned structure according to [1] or [2], further comprising a cap portion that overlaps the functional layer in the recess and contains a resin.

[4] The patterned structure according to any one of [1] to [3], wherein the recess includes a step portion recessed from the surface of the substrate and a concave pattern portion recessed from the step portion.

[5] The patterned structure described in [4], in which the functional layer is provided in the concave pattern portion and the step portion.

[6] The patterned structure described in [4] or [5], in which the step portion includes a first surface parallel to the surface of the substrate and a second surface extending from the first surface to the surface of the substrate, and the functional layer is provided at least on the concave pattern portion and the first surface of the step portion.

[7] preparing a substrate having a pattern including a plurality of recesses;
providing a film-like functional material layer containing a metal and/or an inorganic material on the substrate so as to cover each of the recesses and a portion of the substrate where the recesses are not present;
providing a photosensitive resist material on the functional material layer;
a step of exposing the resist material to light from a light source while moving a light source that irradiates light for melting or hardening the resist material and/or the base material on which the resist material is laminated, and removing the melted or unhardened portions of the resist material to form a resist pattern from the resist material that covers the entire recess via the functional material layer;
and removing a portion of the functional material layer other than a portion covered with the resist pattern.

[8] The method for producing a patterned structure according to [7] further comprises a step of forming the substrate having the pattern from the resin composition by imprinting, which involves contacting a mold with a resin composition and curing the resin composition.

[9] The recess includes a step portion recessed from a surface of the base material and a concave pattern portion recessed from the step portion,
the resist pattern is formed so as to cover the recessed pattern portion and the step portion,
The method for manufacturing a patterned structure according to [7] or [8], wherein the functional material layer is left in the concave pattern portion and the step portion.

[10] The method for manufacturing a patterned structure according to any one of [7] to [9], further comprising a step of exposing and/or baking the resist pattern to form a cap portion by hardening the resist pattern.

This disclosure makes it possible to provide patterned structures that can appropriately expand their uses and functions.

1 is a perspective view of a patterned structure according to a first embodiment; 2 is a cross-sectional view of the patterned structure shown in FIG. 1; 2A to 2C are diagrams illustrating an example of a method for manufacturing the patterned structure shown in FIG. 1, and are diagrams illustrating an imprint process. 2A to 2C are diagrams illustrating an example of a method for manufacturing the patterned structure shown in FIG. 1, and are diagrams illustrating an imprint process. 2A to 2C are diagrams illustrating an example of a method for manufacturing the patterned structure shown in FIG. 1, and are diagrams illustrating an imprint process. 2 is a diagram for explaining an example of a method for manufacturing the patterned structure shown in FIG. 1, and is a diagram for explaining a functional material layer forming step. FIG. FIG. 2 is a diagram for explaining an example of the patterned structure shown in FIG. 1 and is a diagram for explaining a resist material application step. 2A to 2C are diagrams for explaining an example of a method for manufacturing the patterned structure shown in FIG. 1, and are diagrams for explaining a resist pattern forming step. 2A to 2C are diagrams for explaining an example of a method for manufacturing the patterned structure shown in FIG. 1, and are diagrams for explaining a resist pattern forming step. 2A to 2C are diagrams for explaining an example of a method for manufacturing the patterned structure shown in FIG. 1, and are diagrams for explaining a patterning step. 2A to 2C are diagrams for explaining an example of a method for manufacturing the patterned structure shown in FIG. 1, and are diagrams for explaining a resist pattern removing step. FIG. 11 is a cross-sectional view of a patterned structure according to a second embodiment. FIG. 13 is a cross-sectional view of a patterned structure according to a third embodiment. FIG. 13 is a plan view of a patterned structure according to a fourth embodiment. 15 is a cross-sectional view of the patterned structure shown in FIG. 14. 11A to 11C are cross-sectional views of a modified example of the first embodiment. 13A to 13C are cross-sectional views of a modified example of the third embodiment. 1A and 1B are diagrams illustrating an application example of a patterned structure according to an embodiment.

Each embodiment will be described below with reference to the drawings.

In this specification, the terms "sheet," "film," "plate," and the like are not distinguished from one another solely on the basis of differences in name. Thus, for example, "sheet" is a concept that includes members that may also be called films or plates.

First Embodiment
A patterned structure 1 according to a first embodiment and a method for manufacturing the same will be described below. Fig. 1 is a perspective view of the patterned structure 1. Fig. 2 is a cross-sectional view of the patterned structure 1.

(Configuration of patterned structures)
1 and 2, the patterned structure 1 includes a substrate 10 and a functional layer 20 provided on the substrate 10. The patterned structure 1 may be in the form of a film, a sheet, or a plate, and is in the form of a film in this embodiment. The substrate 10 has a pattern 12 including a plurality of recesses 11. The functional layer 20 is provided in each recess 11 in the pattern 12 without protruding from each recess 11.

The substrate 10 may contain a resin. In this case, the substrate 10 may contain a resin as a main component or may be made of a resin. In this case, the resin contained in the substrate 10 may be polymethyl methacrylate, epoxy, polycarbonate, polyimide, polyolefin, polyethylene terephthalate, polyethylene naphthalate, polyvinyl butyral, or two or more of these. The main component means a component that is contained in a volume ratio of 50% or more of the entire substance among multiple components that constitute a certain substance, or a component that is contained in the largest amount. The substrate 10 may also contain an inorganic material. The substrate 10 may be, for example, a quartz substrate, a glass substrate, a sapphire substrate, a silicon substrate, a silicon carbide substrate, an alumina (Al2O3) substrate, an aluminum nitride (AlN) substrate, a zirconia oxide (ZrO2) substrate, a lithium niobate substrate, a tantalum niobate substrate, or the like. The substrate 10 may also include two or more of a quartz substrate, a glass substrate, a sapphire substrate, a silicon substrate, a silicon carbide substrate, an alumina (Al2O3) substrate, an aluminum nitride (AlN) substrate, a zirconia (ZrO2) substrate, a lithium niobate substrate, a tantalum niobate substrate, and a resin substrate.

The substrate 10 includes a surface 10A and a back surface 10B located opposite the surface 10A. The pattern 12 is formed on the surface 10A. The pattern 12 includes a plurality of recesses 11 that are spaced apart in one direction and extend in another direction that intersects with the one direction and is perpendicular to the other direction in this example. The plurality of recesses 11 form a striped pattern in the pattern 12. In this embodiment, the surface 10A and the back surface 10B extend parallel to a plane that includes the one direction and the other direction. In this embodiment, the surface 10A of the substrate 10 refers to a flat surface of the substrate 10 on which the recesses 11 are not formed.

In this embodiment, the recess 11 includes a step portion 13 recessed from the surface 10A of the substrate 10, and a concave pattern portion 14 recessed further from the step portion 13. The step portion 13 includes a first surface 13A parallel to the surface 10A of the substrate 10, and a second surface 13B extending from the first surface 13A to the surface 10A of the substrate 10. In this embodiment, the first surface 13A extends parallel to the surface 10A of the substrate 10, but may be inclined with respect to the surface 10A. In this case, the first surface 13A may be a flat surface or a folded surface including multiple element surfaces. The second surface 13B extends in the thickness direction perpendicular to the surface 10A of the substrate 10, but may be inclined with respect to the surface 10A.

The cross-sectional shape of the concave pattern portion 14 in a direction perpendicular to the longitudinal direction of the recess 11 (corresponding to the other directions mentioned above) is rectangular as shown in FIG. 2. However, the cross-sectional shape of the concave pattern portion 14 is not particularly limited, and may be rectangular, trapezoidal, triangular, semicircular, arcuate, or a combination of these. The recess 11 may also be cylindrical, square prism-shaped, cone-shaped, etc. extending in the thickness direction.

The dimensions of the recess 11, that is, the depth D and width W, can be set appropriately depending on the application of the patterned structure 1. The pattern 12 may be formed together with the recess 11 by imprinting, particularly nanoimprinting, and the pattern 12 may be a fine pattern. In this case, the depth D of the recess 11 may be, for example, 0.1 μm or more and 100 μm or less. The width W of the recess 11 may be, for example, 0.1 μm or more and 100 μm or less. The width W of the recess 11 here is the distance between the parts facing each other at the edge of the recess 11. The application of the patterned structure 1 may be a wiring board, an optical member, etc.

The depth D1 of the step portion 13 may be, for example, 0.1 μm or more and 5 μm or less. The width W1 of the step portion 13, which is the shortest distance from the edge of the concave pattern portion 14 connected to the step portion 13 to the edge of the step portion 13 connected to the surface 10A of the substrate 10, may be, for example, 0.1 μm or more and 10 μm or less. The depth D2 of the concave pattern portion 14 may be, for example, 0.1 μm or more and 100 μm or less. The width W2 of the concave pattern portion 14 may be, for example, 1 μm or more and 100 μm or less, 1 μm or more and 80 μm or less, 1 μm or more and 60 μm or less, 1 μm or more and 40 μm or less, 1 μm or more and 20 μm or less, or 1 μm or more and 10 μm or less. The width W2 may be 1 μm or less. The width W2 may be 0.1 μm or more. Width W1 may be 1/20 or more and 1/2 or less of width W2.

The illustrated pattern 12 is an example, and the shape of the pattern 12 is not particularly limited. The pattern 12 may be a pattern in which the recesses are formed in a dot shape, or a pattern in which the recesses are formed randomly. The pattern 12 may be formed by photolithography, pressing, cutting, ablation, injection molding, or 3D printing, and the formation method is not particularly limited.

The functional layer 20 is in the form of a film, and is provided so as not to fill the recess 11 but to fit along the inner surface of the recess 11. The thickness of the functional layer 20 is not particularly limited, but may be, for example, 10 nm or more and 500 nm or less. The functional layer 20 may be one that fills the recess 11.

In this embodiment, the functional layer 20 is provided on the concave pattern portion 14 and the step portion 13. More specifically, the functional layer 20 is provided on the inner surface of the concave pattern portion 14, and the first surface 13A and second surface 13B of the step portion 13. Note that the functional layer 20 only needs to be provided on the concave pattern portion 14 and the first surface 13A of the step portion 13, and does not have to be provided on the second surface 13B of the step portion 13.

The functional layer 20 is formed as a hardened layer containing a metal and/or an inorganic material. More specifically, the functional layer 20 contains a metal and/or an inorganic material as a main component. The metal contained in the functional layer 20 may be aluminum, nickel, zinc, titanium, platinum, gold, silver, copper, iron, chromium, palladium, indium, tungsten, two or more of these, one or more oxides of these, or an alloy containing one or more of these. The inorganic material contained in the functional layer 20 may be nitrogen oxide, silicon oxide, titanium oxide, glass beads, calcium carbonate, aluminum powder, mica, graphite, carbon black, carbon fiber, or two or more of these.

The functional layer 20 as described above is formed by patterning a film formed by, for example, sputtering, vapor deposition, ion plating, electrolytic plating, or electroless plating. The functional layer 20 may be, for example, conductive, light reflecting, or light diffusing. When the functional layer 20 is conductive, it may be used as a seed electrode layer for electrolytic plating of the recess 11. In such applications, the electrical resistance of the functional layer 20 is preferably 1 Ω/□ or less in terms of sheet resistance. Since it is difficult to measure the sheet resistance after patterning, it is measured immediately after film formation using Loresta-AX MCP-T370 manufactured by Nitto Seiko Analytech Co., Ltd.
Having a light reflecting function means that the visible light reflectance is 50% or more. The visible light reflectance is specified as the average value of the total light reflectance at each wavelength when measured at an incident angle of 45° every 1 nm within a measurement wavelength range of 380 nm to 780 nm using a "UV-3100PC" manufactured by Shimadzu Corporation. Also, having a light diffusing function means that the diffuse transmittance is 10% or more. The diffuse transmittance may be 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, or 90% or more. Also, the diffuse transmittance may be 90% or less, 80% or less, 70% or less, 60% or less, or 50% or more. The numerical range of the diffuse transmittance may be configured by combining any one of the upper limit value candidates listed above with any one of the lower limit value candidates. The diffuse transmittance is measured by a haze meter, product number HM-150, manufactured by Murakami Color Research Laboratory.

(Method of manufacturing a patterned structure)
Next, an example of a method for manufacturing the patterned structure 1 will be described with reference to FIGS.

First, the substrate 10 is formed. At this time, as shown in FIG. 3, a mold 100 and a molding material 200 are prepared. The mold 100 has a pattern 102 including a protruding portion 101. The protruding portion 101 is a portion that forms the recessed portion 11 in the pattern 12 of the substrate 10, and in this example, is formed in a multi-step shape. The molding material 200 contains a resin, and the resin contained in the molding material 200 may be, for example, a photosensitive resin. In this example, the molding material 200 contains a photocurable resin that is cured by irradiation with ultraviolet light or the like as the resin. The molding material 200 may also be a thermosetting resin.

After the mold 100 and molding material 200 are prepared as described above, imprinting is performed. That is, as shown in FIG. 4, the pattern 102 of the mold 100 is brought into contact with the molding material 200, and the inverted pattern of the pattern 102 is transferred to the molding material 200. The molding material 200 is then cured by irradiating it with light, and the substrate 10 is formed from the molding material 200. The substrate 10 is then removed from the mold 100 as shown in FIG. 5. This completes the imprinting process, and the substrate 10 having the pattern 12 including the recess 11 is formed and prepared.

Next, referring to FIG. 6, a process (functional material layer formation process) is performed in which a film-like functional material layer 210 containing a metal and/or inorganic material is provided on the substrate 10 so as to cover each recess 11 in the pattern 12 and the portion of the substrate 10 where there are no recesses 11 (surface 10A). In this example, the functional material layer 210 is formed by sputtering. The functional material layer 210 is a layer for forming the functional layer 20. In this example, the functional material layer 210 is provided on the entire inner surface of the recess 11 and the entire surface 10A of the substrate 10.

Next, as shown in FIG. 7, a resist material 220, which is, for example, a photosensitive photocurable resin and whose uncured portion is soluble in an alkaline aqueous solution or the like, is provided so as to cover the functional material layer 210 (resist material application process). The resist material 220 may be a negative resist or a positive resist. In this example, a negative resist is used as the resist material 220.

Next, a resist pattern forming process is performed in which a resist pattern 220P is formed from the resist material 220 (see Figures 8 and 9). Figure 8 shows an exposure process in the resist pattern forming process. In the exposure process, the resist material 220 is exposed to light L from the light source 120 while moving the light source 120 that irradiates light L to melt or harden the resist material 220 and/or the substrate 10 on which the resist material 220 is laminated.

In this example, since the resist material 220 is a negative resist, the resist material 220 hardens when irradiated with light L. The resist pattern 220P to be formed covers the entire recess 11 in the thickness direction via the functional material layer 210. Therefore, the area of the resist material 220 above the recess 11 indicated by the symbol Ta in FIG. 8 is exposed to light. Meanwhile, the portion of the resist material 220 other than the area Ta is in a semi-hardened state in which it is not completely hardened by exposure, or is exposed to an extent that it is not hardened and maintains its solubility in the developer. In this way, the unhardened portion of the resist material 220 is removed to form the resist pattern 220P as shown in FIG. 9.

In this example, the light source 120 is fixed, and the substrate 10 is moved by an XYZ stage (not shown) that holds the substrate 10. The light source 120 is part of an exposure device, which is, for example, a proximity exposure device, but is not limited to a particular type. The exposure position of the resist material 220 is adjusted based on an image of the laminate including the substrate 10 and the resist material 220 captured by the imaging device 121 (see FIG. 8).

As is clear from the above description, in the formation of the resist pattern in this embodiment, a reticle (photomask) is not used. Therefore, it is possible to reduce costs and work time. In addition, when a reticle is not used, even if the pattern 12 on the substrate 10 is distorted, the resist pattern 220P can be formed appropriately in a state where it covers the recess 11 by adjusting the light irradiation position according to the distortion to form the resist pattern 220P, which is advantageous. This allows the shape of the functional layer 20 to be formed appropriately. In other words, if exposure is performed through a reticle when the pattern 12 on the substrate 10 is distorted, the exposure pattern from the reticle does not match the distorted pattern 12, so a situation may occur in which a resist pattern is formed in an undesired position, for example, a position outside the recess 11. According to the present disclosure, such a situation can be avoided, and therefore the functional layer 20 can be formed appropriately.

In addition, in this embodiment, the resist material 220 can be laminated on the step portion 13 in the recess 11 via the functional material layer 210. This allows the resist pattern 220P to be stably formed on the step portion 13, thereby preventing the functional material layer 210 on the step portion 13 from being undesirably etched and causing a disturbance in its shape. Even if the light irradiation position is shifted and the resist material 220 on the step portion 13 is melted, the resist material 220 has a large thickness, so that the resist pattern 220P can be stably formed on the step portion 13. Therefore, similarly to the above, the functional material layer 210 on the step portion 13 is prevented from being undesirably etched and causing a disturbance in its shape.

Next, as shown in FIG. 10, a patterning process is performed to remove the functional material layer 210 except for the portion not covered by the resist pattern 220P. The partial removal of the functional material layer 210 is performed with an etching solution. As a result, the functional material layer 210 is left in the concave pattern portion 14 and the step portion 13 to form the functional layer 20. The type of etching can be selected by the user as long as a selectivity between the functional material layer 210 and the resist material 220 is obtained, and is not particularly limited. The etching may be plasma etching or wet etching.

Next, as shown in FIG. 11, the resist pattern 220P is removed (resist pattern removal process). The removal may be performed by ashing or wet stripping. This results in the formation of the patterned structure 1.

The patterned structure 1 according to the present embodiment described above includes a substrate 10 having a pattern 12 including a plurality of recesses 11, and a functional layer 20 including a metal and/or an inorganic material, which is provided in each recess 11 without protruding from each recess 11. In such a patterned structure 1, the functional layer 20 made of a material different from that of the substrate 10 is provided in the recess 11, thereby expanding the uses and functions of the patterned structure 1. In particular, since the functional layer 20 is provided without protruding from the recess 11, the functional layer 20 does not affect the functions of the portion of the substrate 10 where the functional layer 20 is not provided (surface 10A). This allows the function of the patterned structure 1 to be properly and effectively exerted. Therefore, according to the patterned structure 1 according to the present embodiment, the uses and functions can be properly expanded.

In this embodiment, the recess 11 includes a step portion 13 recessed from the surface 10A of the substrate 10, and a concave pattern portion 14 recessed from the step portion 13. In this case, by checking the state of the step portion 13, it becomes easier to grasp the state of the functional layer 20. For example, it becomes easier to check whether the functional layer 20 protrudes from the step portion 13 based on the step portion 13. In this embodiment, the functional layer 20 is provided in the concave pattern portion 14 and the step portion 13, and by checking the state of the functional layer 20 on the step portion 13, it is possible to check, for example, whether the functional layer 20 has been etched excessively or insufficiently. This makes it possible, for example, to correct the functional layer 20 or change the manufacturing conditions, thereby increasing, for example, the yield rate.

Moreover, the patterned structure 1 according to this embodiment is generally manufactured through the following manufacturing steps (1) to (5).
(1) A step of preparing a substrate 10 having a pattern 12 including a plurality of recesses 11, which in this example includes a resin.
(2) A step of providing a film-like functional material layer 210 on the substrate 10 so as to cover each recess 11 of the pattern 12 on the substrate 10 and the portion of the substrate 10 where there are no recesses 11 (surface 10A).
(3) providing a photosensitive resist material 220 on the functional material layer 210;
(4) A process of exposing the resist material 220 to light from the light source 120 while moving the light source 120 that irradiates light to melt or harden the resist material 220 and/or the substrate 10 on which the resist material 220 is laminated, and removing the melted or unhardened portions of the resist material 220, thereby forming a resist pattern 220P from the resist material 220 that covers the entire recess 11 via the functional material layer 210.
(5) A step of removing the portions of the functional material layer 210 other than the portions covered with the resist pattern 220P.

In the above manufacturing process, a reticle (photomask) is not used in forming the resist pattern 220P. This makes it possible to reduce costs and work time. In addition, what is noteworthy about this manufacturing method is that even if the pattern 12 on the substrate 10 is distorted, the resist pattern 220P can be properly formed in a state where it covers the recess 11 by adjusting the light irradiation position according to the distortion. This allows the shape of the functional layer 20 to be properly formed. In other words, if exposure is performed through a reticle when the pattern 12 on the substrate 10 is distorted, the exposure pattern from the reticle does not match the distorted pattern 12, so a situation may occur in which a resist pattern is formed in an undesired position, for example, a position outside the recess 11. According to the present disclosure, such a situation can be avoided, so that the functional layer 20 can be properly formed.

Second Embodiment
Next, a patterned structure 2 according to a second embodiment will be described with reference to Fig. 12. Fig. 12 is a cross-sectional view of the patterned structure 2. Components in this embodiment that are the same as those in the first embodiment are given the same reference numerals, and duplicated descriptions will be omitted.

As shown in FIG. 12, in addition to the substrate 10 and the functional layer 20, the patterned structure 2 further includes a cap portion 30 that overlaps the functional layer 20 in the recess 11 and contains a resin. The cap portion 30 is laminated on the functional layer 20 and fills the recess 11. The surface of the cap portion 30 exposed from the recess 11 is flush with the surface 10A of the substrate 10. However, the surface of the cap portion 30 may be recessed or protruded relative to the surface 10A of the substrate 10.

In this embodiment, the cap portion 30 is formed by subjecting the resist pattern 220P shown in FIG. 9 to additional exposure and/or baking and hardening. Therefore, the cap portion 30 includes a photosensitive resin. More specifically, the cap portion 30 includes a hardened photosensitive resin. When making the surface of the cap portion 30 flush with the surface 10A of the substrate 10, the surface of the hardened resist pattern 220P may be polished. In addition, when the resist pattern 220P is formed from a positive resist, the thickness of the resist pattern 220P on the recess 11 can be adjusted by adjusting the amount of exposure to the resist material 220. By adjusting the amount of exposure in this way, the surface of the hardened cap portion 30 may be controlled to be flush with the surface 10A of the substrate 10.

When the cap portion 30 that covers the functional layer 20 is provided as in this embodiment, the durability of the functional layer 20 can be improved. Specifically, the corrosion resistance and scratch resistance of the functional layer 20 can be improved. In addition, since the cap portion 30 is formed using the resist pattern 220P, the cap portion 30 can be formed easily and efficiently.

Third Embodiment
Next, a patterned structure 3 according to a third embodiment will be described with reference to Fig. 13. Fig. 13 is a cross-sectional view of the patterned structure 3. Components in this embodiment that are the same as those in the first and second embodiments are given the same reference numerals, and duplicated descriptions will be omitted.

As shown in FIG. 13, the patterned structure 3 includes a substrate 10 and a functional layer 20. However, the recess 11 in the pattern 12 of the substrate 10 on which the functional layer 20 is provided does not include a step portion 13.

When the recess 11 does not have a step portion 13 as in this embodiment, the function of the functional layer 20 located in the recess 11 and the function of the surface of the substrate 10 are prevented from affecting each other, so that the function of the patterned structure 3 can be effectively exerted.

<Fourth embodiment>
Next, a patterned structure 4 according to a fourth embodiment will be described with reference to Fig. 14. Fig. 14 is a plan view of the patterned structure 4. Fig. 15 is a cross-sectional view of the patterned structure 4. Components in this embodiment that are the same as those in the first to third embodiments are given the same reference numerals, and duplicated descriptions will be omitted.

As shown in FIG. 14, a pattern 12 including a plurality of recesses 11 formed in a dot-like distribution is formed on the substrate 10 in the patterned structure 4. The patterned structure 4 further includes a functional layer 20 provided in the recess 11 so as not to extend beyond the recess 11, and a cap portion 30 that covers the functional layer 20. The recess 11 includes a step portion 13 and a recessed pattern portion 14, and the functional layer 20 is provided in the recessed pattern portion 14 and the step portion 13.

The concave pattern portion 14 is cylindrical, but may instead be rectangular prism-shaped, pyramidal, etc. In this embodiment, the functional layer 20 is provided over the entire concave pattern portion 14, but for example, the functional layer 20 may not be provided on the bottom surface of the concave pattern portion 14, but may be provided only on the side surface. The multiple recesses 11 may be formed randomly in the substrate 10.

The patterned structure 4 is also formed in the same manner as the procedures shown in Figures 3 to 10. Therefore, even if distortion occurs in the pattern 12, the resist pattern 220P (see Figure 10) can be formed by adjusting the light irradiation position according to the distortion, so that the resist pattern 220P can be properly formed in a state where it covers the recesses 11. This allows the functional layer 20 to be properly formed. When there are a large number of recesses 11, as in the patterned structure 4, stress is likely to occur in the mold, and the pattern 12 may be easily distorted. Therefore, the manufacturing method according to the present disclosure is beneficial for the form shown in Figure 14.

<Modification>
Modifications of the embodiment will be described below. Figures 16(A) to (C) are cross-sectional views of modifications of the first embodiment. In the modification of Figure 16(A), the cross-sectional shape of the concave pattern portion 14 in a direction perpendicular to the longitudinal direction of the recess 11 is a trapezoid. In the modification of Figure 16(B), the cross-sectional shape of the concave pattern portion 14 in a direction perpendicular to the longitudinal direction of the recess 11 is a semicircle. In the modification of Figure 16(C), the cross-sectional shape of the concave pattern portion 14 in a direction perpendicular to the longitudinal direction of the recess 11 is a triangle. Note that the shape of the concave pattern portion 14 may be other shapes.

Figures 17(A) to (C) are cross-sectional views of modified examples of the third embodiment. In the modified example of Figure 17(A), the cross-sectional shape of the recess 11 in a direction perpendicular to the longitudinal direction of the recess 11 is trapezoidal. In the modified example of Figure 17(B), the cross-sectional shape of the recess 11 in a direction perpendicular to the longitudinal direction of the recess 11 is semicircular. In the modified example of Figure 17(C), the cross-sectional shape of the recess 11 in a direction perpendicular to the longitudinal direction of the recess 11 is triangular. Note that the shape of the recess 11 may be other shapes.

<Application Examples>
18A and 18B are diagrams for explaining application examples of the patterned structure according to the embodiment. FIG. 18A shows an example in which the patterned structure 1 according to the first embodiment is used as an optical film. In this example, the substrate 10 is transparent and transmits visible light. The functional layer 20 contains diffusing particles made of silica as an inorganic material. The portion of the substrate 10 that is not covered by the functional layer 20 transmits, for example, straight light S1 without refracting it. The functional layer 20 diffuses the light S2 when, for example, light S2 inclined with respect to the straight light S1 is incident. Such a patterned structure 1 can exhibit optical functions different from those of a structure without the functional layer 20.

Figure 18 (B) shows an example in which the patterned structure 3 according to the third embodiment is used as a wiring substrate. In this example, the wiring layer 40 provided on the surface 10A of the substrate 10 is electrically connected to the functional layer 20, which functions as an electrode, via the pad 41. The pad 41 connects to a portion of the functional layer 20 located on the step portion 13, thereby improving the reliability of the connection. The pad 41 is passed through a hole formed in the cap portion 30. In the configuration shown in Figure 18 (B), the cap portion 30 does not have to be provided.

Although several embodiments and variations of the present disclosure have been described above, various modifications may be made to the above-described embodiments. Such other variations may also fall within the technical scope of the present disclosure.

Reference Signs List 1, 2, 3, 4...Patterned structure 10...Substrate 10A...Front surface 10B...Back surface 11...Recess 12...Pattern 13...Step portion 13A...First surface 13B...Second surface 14...Recessed pattern portion 20...Functional layer 30...Cap portion 40...Wiring layer 100...Mold 101...Protruding portion 102...Pattern 120...Light source 200...Molding material 210...Functional material layer 220...Resist material 220P...Resist pattern

Claims (3)

preparing a substrate having a pattern including a plurality of recesses and transmitting visible light;
providing a functional material layer including a metal and/or an inorganic material on the substrate so as to cover each of the recesses and a portion of the substrate that does not have the recesses;
providing a photosensitive resist material on the functional material layer;
a step of exposing the resist material to light from a light source while moving a light source that irradiates light for melting or hardening the resist material and/or the base material on which the resist material is laminated, and removing the melted or unhardened portions of the resist material to form a resist pattern from the resist material that covers the entire recess via the functional material layer;
removing a portion of the functional material layer other than a portion covered with the resist pattern;
the recess includes a step portion recessed from a surface of the base material and a concave pattern portion recessed from the step portion, the step portion including a first surface and a second surface extending from the first surface to the surface of the base material,
the resist pattern is formed so as to cover the recessed pattern portion and the step portion,
A method for manufacturing an optical member, wherein the functional material layer is left at least in the concave pattern portion and on the first surface of the step portion. The method for producing an optical member according to claim 1 , further comprising the step of forming the substrate having the pattern from a resin composition by imprinting, which involves contacting a mold with a resin composition and curing the resin composition. The method for producing an optical member according to claim 1 , further comprising the step of exposing and/or baking the resist pattern to form a cap portion by hardening the resist pattern.