JP7027823B2 - Functional substrate and its manufacturing method, and imprint mold - Google Patents

Description

The present disclosure relates to a functional substrate and a method for manufacturing the same, and an imprint mold manufactured by using the functional substrate.

Nanoimprint technology, which is known as microfabrication technology, uses an imprint mold in which a fine concavo-convex pattern is formed on the surface of a base material, and transfers the fine concavo-convex pattern to a workpiece to increase the size of the fine concavo-convex pattern to the same size. It is a pattern forming technique to be transferred. In particular, with the further miniaturization of wiring patterns and the like in semiconductor devices, nanoimprint technology is drawing attention in the manufacturing process and the like.

As an imprint mold generally used in nanoimprint technology, for example, a base material, a convex structure portion protruding from the surface of the base material, and a fine uneven pattern formed on the upper surface of the convex structure portion are known. ing. By using such an imprint mold and bringing the fine uneven pattern of the imprint mold into contact with the imprint resin as a workpiece supplied on the substrate to be transferred, the fine uneven pattern is filled with the imprint resin. .. Then, by curing the imprint resin in that state, a pattern structure formed by transferring the fine concavo-convex pattern of the imprint mold is formed.

If the supply amount of the imprint resin is insufficient, the imprint resin is not sufficiently filled in the fine concavo-convex pattern, which causes defects (unfilled defects) in the pattern structure. On the other hand, it is extremely difficult to control the supply amount of the imprint resin with high accuracy. If an amount of imprint resin that is too large to cause unfilled defects is supplied to the substrate to be transferred, when the imprint mold is brought into contact with the imprint resin, excess imprint is made on the outside of the convex structure portion of the imprint mold. The printed resin squeezes out and adheres to the side surface of the convex structure. The imprint resin that protrudes to the outside of the convex structure portion and adheres to the side surface is cured at the same time as the imprint resin that is filled in the fine uneven pattern. As a result, a large stress acts when the imprint mold is separated from the imprint resin, which may cause damage to the imprint mold and the pattern structure. Further, when the imprint process is performed by the so-called step-and-repeat method, it is necessary to separate the imprinted area so as not to protrude to the outside of the convex structure portion and overlap with the cured imprint resin. The number of times the imprint process can be performed on the transfer substrate is limited.

In order to solve such a problem, an imprint mold in which a functional layer such as a light-shielding layer is provided in a region surrounding the outer periphery of a pattern region in which a fine concavo-convex pattern is formed is conventionally known (Patent Document 1). , 2).

Japanese Patent No. 4869263 Japanese Unexamined Patent Publication No. 2010-251601

In the imprint mold described in Patent Document 1, a light-shielding layer is provided in a non-pattern region surrounding the outer periphery of the pattern region. As a result, the imprint resin (photocurable resin) protruding to the outside of the pattern region is not irradiated with light, and it is possible to prevent the imprint resin from being cured. However, in Patent Document 1, although it is premised that the light irradiated to the imprint resin via the imprint mold travels in parallel with the thickness direction of the imprint mold, in reality, the imprint There is a problem that the imprint resin protruding to the outside of the pattern region is cured by the light traveling inclining in the thickness direction of the mold. In this regard, in the imprint mold described in Patent Document 1, although a light-shielding film is also provided on the side surface orthogonal to the pattern region, the side surface and the non-pattern region surrounding the outer periphery of the pattern region are connected to the side surface. It is extremely difficult to form a light-shielding film that can exhibit sufficient light-shielding performance by spattering or the like. Therefore, in the imprint mold described in Patent Document 1, there is still a possibility that the imprint resin protruding to the outside of the pattern region will be cured.

Further, in the imprint mold described in Patent Document 2, a material having a continuous first side surface portion and a first step portion on the outer edge of the pattern region and having water repellency or oil repellency on the first side surface portion. A film made of the above is formed, and it is possible to prevent the imprint resin protruding from the pattern region during the imprint process from adhering to the first side surface portion and contaminating the imprint mold. However, like the light-shielding film in Patent Document 1, it is extremely difficult to form a film having a desired function (water-repellent function or oil-repellent function) on the first side surface portion orthogonal to the pattern region. be. Therefore, even in the imprint mold described in Patent Document 2, the imprint resin protruding to the outside of the pattern region may still adhere to the first side surface portion of the imprint mold.

In view of the above problems, the present disclosure discloses a functional substrate capable of exhibiting a desired function by a functional film provided on a plane substantially orthogonal to a predetermined surface, a method for manufacturing the same, and the functionality thereof. One object is to provide an imprint mold having a substrate.

In order to solve the above problems, as one embodiment of the present disclosure, a base material having a first surface and a second surface facing the first surface, and a convex structure protruding from the first surface side of the base material. The convex structure portion is provided with a portion, and the convex structure portion is continuous with an upper surface, a first side surface extending downward along the thickness direction of the base material, and a flat surface continuous with the lower end of the first side surface. A surface and a second side surface continuous with the outer edge of the flat surface and extending in a direction toward the first surface are included, and a first functional film is formed on the first side surface, and the first surface is formed. An imprint mold substrate is provided in which a part including the lower end portion of the functional film is embedded in the convex structure portion.

The first functional film may be made of a material having resistance to an etching solution applicable to the base material, and the base material is made of a material transparent to energy rays having a predetermined wavelength. The first functional film may be made of a material having a light-shielding property against energy rays, and the first functional film may be made of a chromium-based material, a molybdenum-based material, or gold.

The first side surface and the flat surface are continuous via a curved surface located between them, and the curved surface is a predetermined portion of the first functional film formed on the first side surface. It suffices if a continuous second functional film is formed at the position of.

It is sufficient that a third functional film continuous with the second functional film is formed on the flat surface, and the length of the first side surface in the thickness direction of the base material is set to 0.2 μm to 2 μm. can do.

As one embodiment of the present disclosure, a step of preparing a base material having a first surface, a second surface facing the first surface, and a protrusion having a protrusion protruding from the first surface, and in the upper surface of the protrusion. The step of forming a groove portion surrounding the outer periphery of the predetermined region to be included on the upper surface of the protrusion, the step of filling the groove portion with a functional material, and the predetermined region so as to physically include the predetermined region. A step of forming a hard mask pattern having a size larger than that of the above region on the upper surface of the protruding portion, and using the hard mask pattern as an etching mask and using a predetermined etching solution to wet the upper surface of the protruding portion to a predetermined depth. Provided is a method for manufacturing a functional substrate, which includes a step of etching and wet-etches the upper surface of the protruding portion so as to expose a part of the functional material filled in the groove portion but not the entire portion.

The upper surface of the protruding portion may be wet-etched so that the lower end of the functional material filled in the groove is located in the base material , and the functional material has resistance to the etching solution. A material can be used, the base material is made of a material transparent to an energy ray having a predetermined wavelength, and a material having a light shielding performance against the energy ray may be used as the functional material. It suffices to further include a step of forming a functional material film on the surface of the base material surrounding the outside of the groove, which appears when the upper surface of the protrusion is wet-etched, and the upper surface of the protrusion may be formed. The groove may be formed by etching the upper surface of the protrusion through a formed mask pattern having an opening corresponding to the groove, or the groove may be formed by cutting the upper surface of the protrusion. It may be formed, and the opening size of the groove can be 50 nm or more.

As an embodiment of the present invention, there is provided an imprint mold including the imprint mold substrate and an uneven pattern formed in a pattern region set on the upper surface of the convex structure portion.

According to the present disclosure, a functional substrate capable of exhibiting a desired function by a functional film provided on a plane substantially orthogonal to a predetermined plane, a method for manufacturing the same, and an imprint having the functional substrate. A print mold can be provided.

FIG. 1 is a cut end view showing a schematic configuration of an aspect of an imprint mold according to an embodiment of the present disclosure. FIG. 2 is a partially enlarged cut end view showing a schematic configuration of a portion A in the imprint mold shown in FIG. 1. FIG. 3 is a partially enlarged cut end view showing a schematic configuration of a portion B in the imprint mold shown in FIG. 2. FIG. 4 is a partially enlarged cut end view illustrating the operation of the imprint mold as a comparison for showing the operation and effect of the imprint mold according to the embodiment of the present disclosure. FIG. 5 is a partially enlarged cut end view for explaining the operation of the imprint mold according to the embodiment of the present disclosure. FIG. 6 is a top view showing a schematic configuration of an imprint mold according to an embodiment of the present disclosure. FIG. 7 is a process flow chart showing each process of the imprint mold manufacturing method according to the embodiment of the present disclosure. FIG. 8 is a process flow chart following FIG. 7, showing each process of the imprint mold manufacturing method according to the embodiment of the present disclosure. FIG. 9 is a process flow chart following FIG. 8 showing each process of the imprint mold manufacturing method according to the embodiment of the present disclosure. FIG. 10 is a partially enlarged cut end view showing an initial stage of a wet etching step in the method for manufacturing an imprint mold according to an embodiment of the present disclosure. FIG. 11 is a partially enlarged cut end view showing a step following FIG. 10 in the wet etching step in the method for manufacturing an imprint mold according to an embodiment of the present disclosure. FIG. 12 is a partially enlarged cut end view showing a step following FIG. 11 in the wet etching step in the method for manufacturing an imprint mold according to an embodiment of the present disclosure. FIG. 13 is a process flow chart showing each step of the imprint method using the imprint mold according to the embodiment of the present disclosure on the cut end face. 14 is an exploded cross-sectional view (FIG. 14 (A)) and a sectional view (FIG. 14 (B)) showing a schematic configuration of an imprint mold according to another embodiment of the present disclosure. FIG. 15 is a cut end view showing a schematic configuration of an imprint mold substrate that can be used in the imprint mold manufacturing method according to another embodiment of the present disclosure.

Embodiments of the present disclosure will be described with reference to the drawings.
In the drawings, in order to facilitate understanding, the shape, scale, aspect ratio, etc. of each part may be changed or exaggerated from the actual product. The numerical range represented by using "-" in the present specification and the like means a range including each of the numerical values described before and after "-" as a lower limit value and an upper limit value. In the present specification and the like, terms such as "film", "sheet", and "board" are not distinguished from each other based on the difference in designation. For example, "board" is a concept that includes members that can be generally called "sheet" or "film".

[Imprint mold]
FIG. 1 is a cut end view showing a schematic configuration of one aspect of an imprint mold according to the present embodiment, and FIG. 2 is a partially enlarged cut end view showing a schematic configuration of part A in FIG. 1. FIG. Is a partially enlarged cut end view showing a schematic configuration of a portion B in FIG. 2.

As shown in FIGS. 1 to 3, the imprint mold 1 according to the present embodiment has a base material 2 having a first surface 2A and a second surface 2B facing the first surface 2A, and a first surface of the base material 2. It includes a convex structure portion 3 protruding from the surface 2A, a concave-convex pattern 4 formed on the upper surface 31 of the convex structure portion 3, and a recessed portion 5 formed on the second surface 2B side.

The base material 2 is a general substrate for imprint molding, for example, quartz glass substrate, soda glass substrate, fluorite substrate, calcium fluoride substrate, magnesium fluoride substrate, barium borosilicate glass, aminoborosilicate glass. , Glass substrate such as non-alkali glass substrate such as aluminosilicate glass, resin substrate such as polycarbonate substrate, polypropylene substrate, polyethylene substrate, polymethylmethacrylate substrate, polyethylene terephthalate substrate, and two or more substrates arbitrarily selected from these. A transparent substrate such as a laminated substrate made by laminating the above can be used. In the present embodiment, "transparent" means that light having a wavelength that can cure the imprint resin can be transmitted, and that the transmittance of light having a wavelength of 150 nm to 400 nm is 60% or more. However, it is preferably 90% or more, and particularly preferably 95% or more.

The plan view shape of the base material 2 is not particularly limited, and examples thereof include a substantially rectangular shape and a substantially circular shape. When the base material 2 is made of a quartz glass substrate generally used for optical imprinting, the plan view shape of the base material 2 is usually substantially rectangular.

The size of the base material 2 (the size in a plan view) is not particularly limited, but when the base material 2 is made of the quartz glass substrate, for example, the size of the base material 2 is about 152 mm × 152 mm. .. Further, the thickness of the base material 2 can be appropriately set in the range of, for example, about 300 μm to 10 mm in consideration of strength, handling suitability and the like.

The convex structure portion 3 protruding from the first surface 2A of the base material 2 is provided substantially in the center of the base material 2 in a plan view. The shape of the convex structure portion 3 in a plan view may be, for example, a substantially rectangular shape, but is not limited thereto, and may be any substantially polygonal shape such as a substantially octagon, a substantially circular shape, a substantially elliptical shape, or the like. It may be in shape. The size of the convex structure portion 3 is appropriately set according to the product or the like manufactured through the imprint process using the imprint mold 1, and is, for example, a substantially rectangular shape of 33 mm ± 1 μm × 26 mm ± 1 μm. The convex structure portion 3 of the above can be mentioned.

The protruding height of the convex structure portion 3 (the length along the thickness direction of the base material 2 between the first surface 2A of the base material 2 and the upper surface 31 of the convex structure portion 3) is the imprint mold according to the present embodiment. As long as 1 can serve the purpose of including the convex structure portion 3, it is not particularly limited and may be set to, for example, about 10 μm to 100 μm.

The convex structure portion 3 is continuous with the upper surface 31 having the pattern region PA on which the uneven pattern 4 is formed and the outer peripheral edge portion of the upper surface 31, and is substantially orthogonal to the upper surface 31 (substantially in the thickness direction of the base material 2). A first side surface portion 32 (which is substantially parallel), a curved surface 33 continuous with the lower end portion of the first side surface portion 32, a flat surface 34 continuous with the curved surface 33 and substantially parallel to the upper surface 31, and a flat surface. It has a second side surface portion 35 continuous with the outer peripheral edge of 34.

The length T ₃₂ of the first side surface portion 32 in the thickness direction of the base material 2 may be, for example, about 0.2 μm to 2 μm, preferably about 0.5 μm to 1 μm. If the length T ₃₂ exceeds 2 μm, the etching process in the manufacturing process of the imprint mold 1 takes too much time, and the manufacturing cost of the imprint mold 1 may be significantly increased. The difference in height position between the upper surface 31 and the flat surface 34 along the thickness direction of the base material 2 is uneven on the imprint resin 101 on the transfer substrate 100 (see FIG. 13A) during the imprint processing. It suffices if the flat surface 34 is set so as not to come into contact with the transfer substrate 100 when the pattern 4 is pressed against it.

The imprint mold 1 according to the present embodiment has a functional film 6 that covers the first side surface portion 32, the curved surface 33, and the flat surface 34. The functional film 6 includes a first functional film 61 that covers the first side surface portion 32, a second functional film 62 that covers the curved surface 33 and is continuous in the middle of the first functional film 61, and a flat surface. 34 is covered with a third functional film 63 which is continuous with the second functional film 62.

Functions that can be performed by the functional membranes 6 (first to third functional membranes 61 to 63) include, for example, a light-shielding function, a light absorption (absorbency) function, a low reflection function, a water-repellent / oil-repellent function, and the like. Be done. When the functional film 6 exerts a light-shielding function, it shields energy rays (UV, etc.) traveling in a direction inclined with respect to the thickness direction of the base material 2 of the imprint mold 1, and the energy rays (UV, etc.) are emitted. It is possible to prevent the imprint resin protruding outward from the upper surface 31 (pattern region PA) of the convex structure portion 3 of the imprint mold 1 from being irradiated. Further, when the functional film 6 exerts a light absorption (absorption) function, the imprint mold 1 is accompanied by energy rays (UV or the like) that travel in a direction inclined with respect to the thickness direction of the base material 2 of the imprint mold 1. It is possible to absorb the reflected light reflected by a part of the energy rays (UV, etc.) that have passed through and reached the substrate to be transferred, and those energy rays (UV, etc.) are the convex structure portion 3 of the imprint mold 1. It is possible to prevent the imprint resin protruding outward from the upper surface 31 (pattern region PA) of the above surface 31 from being irradiated again. Further, since the functional film 6 exhibits a low reflection function, a part of the energy rays (UV, etc.) transmitted through the imprint mold 1 and reached the transfer substrate is reflected by the transfer substrate, but the functional film is used. 6 can suppress the reflection of the reflected light, and can prevent the imprint resin protruding outward from the upper surface 31 (pattern region PA) of the convex structure portion 3 of the imprint mold 1 from being cured. Furthermore, the functional film 6 exhibits water and oil repellency functions, so that the imprint resin protruding outward from the upper surface 31 (pattern region PA) of the convex structure portion 3 of the imprint mold 1 becomes the imprint mold 1. It becomes difficult to adhere, and it is possible to prevent the imprint mold 1 from being contaminated.

The first functional film 61 is provided on the first side surface portion 32 so that the lower end portion thereof is embedded in the base material 2 (convex structure portion 3) (see FIG. 3). As will be described later, the first to third functional films 63 are, for example, a chemical vapor deposition method (CVD method) such as a normal pressure CVD method, a reduced pressure CVD method, and a plasma CVD method; a vacuum vapor deposition method, an ion plating method. , Is formed on the first side surface portion 32, the curved surface 33 and the flat surface 34 by a physical vapor deposition method (PVD method) such as a sputtering method, but it is difficult to form uniformly on the curved surface 33. In particular, the film thickness of the portion of the second functional film 62 located near the first side surface portion 32 is relatively thin. Therefore, in the vicinity of the second functional film 62 provided on the curved surface 33, particularly the portion continuous with the first functional film 61, the function of the second functional film 62 may not be sufficiently performed. ..

For example, the functional films 6 (first to third functional films 61 to 63) are light-shielding films having a light-shielding function, and the imprint resin is irradiated with energy rays (UV or the like) via the imprint mold 1. In this case, the energy rays (UV, etc.) generally travel in a direction inclined with respect to the energy rays UV1 and UV4 traveling in parallel with the thickness direction of the imprint mold 1 and the thickness direction of the imprint mold 1. Energy rays UV2 and UV3 are included (see FIGS. 4 and 5).

The energy ray UV1 passes through the upper surface 31 (pattern region PA) of the convex structure portion 3, but the energy ray UV2 is shielded by the first functional film 61 and the energy ray UV4 is shielded by the third functional film 63. (See Figures 4 and 5). On the other hand, when the lower end portion of the first functional film 61 is not embedded in the base material 2 (convex structure portion 3), the energy ray UV3 passes through the second functional film 62 (see FIG. 4). However, as in the present embodiment, since the lower end portion of the first functional film 61 is embedded in the base material 2 (convex structure portion 3), the energy ray UV3 is generated by the base material 2 (convex structure portion 3). The lower end of the first functional film 61 embedded in the film is shielded from light (see FIG. 5).

In order to exert such an effect more effectively, the length of the embedded portion 611 (of the base material 2) embedded in the base material 2 (convex structure portion 3) of the first functional film 61. The length along the thickness direction) is the direction from the region facing the upper surface 31 (pattern region PA) of the convex structure portion 3 on the second surface 2B side of the base material 2 toward the second functional film 62 (base material 2). The energy rays (UV, etc.) traveling in the direction of inclination with respect to the thickness direction of the above may be set to such an extent that they can be shielded from light (see FIG. 5), and may be set to, for example, about 0.1 μm to 1 μm. When the length of the embedded portion 611 is less than 0.1 μm, the region facing the upper surface 31 (pattern region PA) of the convex structure portion 3 on the second surface 2B side of the base material 2 becomes the second functional film 62. There is a possibility that the energy rays (UV, etc.) traveling in the direction of the direction cannot be sufficiently shielded from light, and the imprint protruding from the upper surface 31 (pattern region PA) of the convex structure portion 3 during the imprint process using the imprint mold 1. There is a risk of curing the print resin. On the other hand, if the length of the embedded portion 611 exceeds 1 μm, the etching process in the manufacturing process of the imprint mold 1 takes too much time, and the manufacturing cost of the imprint mold 1 may increase significantly. .. Further, if the length of the buried portion 611 exceeds 1 μm, it takes too much time to fill the buried portion 611 with the material constituting the first functional film 61, or the material is likely to be unfilled. There is also a risk of doing so. The length of the embedded portion 611 can be measured, for example, from a cross section along the thickness direction of the imprint mold 1 using a scanning electron microscope (SEM) or the like.

The film thickness of the functional film 6 may be a film thickness that can exert a desired function. For example, when the function exerted by the functional film 6 is a light-shielding function, the film thickness may be about 10 nm to 100 nm. , It is preferably about 15 nm to 80 nm. As will be described later, the lower limit of the film thickness of the first functional film 61, which can also function as an etching stopper in the manufacturing process of the imprint mold 1, may be about 50 nm, preferably about 100 nm. ..

The material constituting the functional membrane 6 (first to third functional membranes 61 to 63) may be any material that can exhibit a desired function. For example, when the functional films 6 (first to third functional films 61 to 63) have a light-shielding function, the materials thereof include chromium-based materials such as chromium, chromium oxide, chromium nitride, and chromium oxynitride. Molybdenum-based materials such as molybdenum and molybdenum silicide; gold and the like can be used. When the functional film 6 (first to third functional films 61 to 63) has a light absorption (absorbency) function, the material may be an inorganic material such as zirconium dioxide or cerium oxide, or a triazine compound. , Benzophenone-based, benzotriazole-based, benzoate-based and other organic materials may be used, or two or more of these organic materials may be combined and laminated, or zinc oxide may be used. , A fine particle-containing resin material or the like in which fine particles such as titanium oxide are contained in the binder resin may be used. Further, when the functional film 6 (first to third functional films 61 to 63) exhibits a low reflection function, magnesium fluoride, silicon oxide, aluminum oxide, titanium oxide or the like should be used as the material. Can be done. Furthermore, when the functional films 6 (first to third functional films 61 to 63) have water-repellent and oil-repellent functions, fluorine or the like can be used as the material.

In this embodiment, an adhesion layer is provided at least between the base material 2 and the first functional film 61 for the purpose of improving the adhesion of the first functional film 61 to the base material 2. May be good. Needless to say, an adhesion layer may be provided between the second functional film 62 and the third functional film 63 and the base material 2.

As will be described later, the first functional film 61 functions as an etching stopper in the manufacturing process of the imprint mold 1 according to the present embodiment (progresses in the in-plane direction toward the pattern region PA of the imprint mold substrate 10). It can also fulfill the function of stopping etching). Therefore, as the material constituting at least the first functional film 61, it is preferable to use a material having resistance to the etching solution, depending on the material constituting the base material 2 and the corresponding etching solution. For example, when the material constituting the base material 2 is quartz glass and hydrofluoric acid is used as the etching solution, a chromium-based material, a molybdenum-based material, gold, or the like is used as the material constituting the first functional film 61. Is preferable.

The shape, dimensions, etc. of the uneven pattern 4 formed on the upper surface of the convex structure portion 3 depend on the shape, dimensions, etc. required for the product or the like manufactured by using the imprint mold 1 according to the present embodiment. It can be set as appropriate. For example, examples of the shape of the uneven pattern 4 include a line-and-space shape, a pillar shape, a hole shape, a grid shape, and the like. Further, the dimensions of the uneven pattern 4 can be set to, for example, about 10 nm to 200 nm.

A recess 5 having a predetermined size may be formed on the second surface 2B of the base material 2. Since the recessed portion 5 is formed, the imprint mold 1 according to the present embodiment is used during the imprint process, particularly when in contact with the imprint resin 101 (see FIG. 13B) or when the imprint mold 1 is formed. The upper surface of the base material 2, particularly the convex structure portion 3, can be curved at the time of peeling. As a result, when the upper surface 31 of the convex structure portion 3 and the imprint resin 101 are brought into contact with each other, gas is sandwiched between the uneven pattern 4 formed on the upper surface 31 of the convex structure portion 3 and the imprint resin 101. It is possible to prevent the imprint mold 1 from being squeezed, and the imprint mold 1 can be easily peeled off from the transfer pattern in which the uneven pattern 4 is transferred to the imprint resin 101.

The plan view shape of the recess 5 is preferably a substantially circular shape. Due to the substantially circular shape, the imprint mold is formed during the imprint process, particularly when the upper surface 31 of the convex structure portion 3 is brought into contact with the imprint resin 101 or when the imprint mold 1 is peeled off from the imprint resin 101. The upper surface 31 of the convex structure portion 3 of 1 can be curved substantially uniformly in the plane.

As shown in FIG. 6, the size of the recessed portion 5 in a plan view is such that the convex structure portion 3 is included in the projection region in which the recessed portion 5 is projected onto the first surface 2A side of the base material 2. As long as it is, there are no particular restrictions. If the projection region has a size that cannot include the convex structure portion 3, the entire upper surface of the convex structure portion 3 of the imprint mold 1 may not be effectively curved.

[Manufacturing method of imprint mold]
An example of a method for manufacturing the imprint mold 1 having the above-described configuration will be described. 7 and 8 are process flow charts showing each process of the imprint mold manufacturing method according to the present embodiment on the cut end face.

[Board preparation process]
First, the imprint mold substrate 10 is prepared. As shown in FIG. 7A, the imprint mold substrate 10 has a base material 2 having a first surface 2A and a second surface 2B facing the first surface 2A, and a plan view of the base material 2 on the first surface 2A side. It is provided with a protruding portion 30 located in the central portion and protruding from the first surface 2A, and a recessed portion 5 formed in a substantially central portion in a plan view on the second surface 2B side of the base material 2. In the imprint mold substrate 10, the same components as those of the imprint mold 1 according to the present embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The size of the protruding portion 30 can be appropriately set according to the size of the convex structure portion 3 of the imprint mold 1 according to the present embodiment. For example, the size of the substantially rectangular convex structure portion 3 ( For example, the length of one side may be larger by about 200 μm or more than 33 mm ± 1 μm × 26 mm ± 1 μm).

In the present embodiment, the first hard mask layer 70 is formed on the first surface 2A of the base material 2 of the imprint mold substrate 10 and the upper surface of the protruding portion 30. Examples of the material constituting the first hard mask layer 70 include metals such as chromium, titanium, tantalum, silicon, and aluminum; chromium-based compounds such as chromium nitride, chromium oxide, and chromium nitride, tantalum oxide, and tantalum nitride. Tantalum compounds such as tantalum oxide and tantalum oxynitride, titanium nitride, silicon nitride, silicon oxynitride and the like can be used alone or in combination of two or more arbitrarily selected.

The first hard mask layer 70 is patterned in a step described later (see FIG. 7 (D)), and a substantially rectangular annular groove portion 301 (see FIG. 7 (E)) is provided in the protruding portion 30 of the imprint mold substrate 10. It is used as a mask when it is formed by etching. Therefore, it is preferable to select the constituent material of the first hard mask layer 70 in consideration of the etching selection ratio and the like according to the type of the imprint mold substrate 10. For example, when the imprint mold substrate 10 is a quartz glass substrate, a chromium oxide film or the like can be preferably selected as the first hard mask layer 70.

The thickness of the first hard mask layer 70 is the etching selection ratio according to the type of the imprint mold substrate 10 and the length of the first functional film 61 in the manufactured imprint mold 1 (in the thickness direction of the substrate). It is set appropriately in consideration of the length along the line) and the like. For example, when the substrate 10 for imprint molding is a quartz glass substrate and the first hard mask layer 70 is a chromium oxide film, the thickness of the first hard mask layer 70 is appropriately within the range of about 1 nm to 20 nm. Can be set.

The method for forming the first hard mask layer 70 on the first surface 2A of the base material 2 of the substrate 10 for imprint molding and the upper surface of the projecting portion 30 is not particularly limited, and is not particularly limited, for example, sputtering or PVD (Physical). Examples thereof include known film forming methods such as Vapor Deposition) and CVD (Chemical Vapor Deposition).

[First resist pattern forming step]
Next, the first photoresist layer 71 is formed by a spin coating method or the like so as to cover the first surface 2A of the imprint mold substrate 10 and the first hard mask layer 70 on the protrusion 30 (FIG. 7 (FIG. 7). B)), an opening corresponding to a substantially rectangular annular groove 301 (see FIG. 7E) formed in the protrusion 30 by subjecting the first photoresist layer 71 to exposure / development processing. The first resist pattern 72 is formed (see FIG. 7 (C)). The material constituting the first photoresist layer 71 is not particularly limited, and for example, a negative type or a positive type photosensitive material can be used, but a positive type photosensitive material is preferably used. ..

The film thickness of the first resist pattern 72, that is, the film thickness of the first photoresist layer 71 is not particularly limited, but in the present embodiment, a substantially rectangular annular groove portion 301 (FIG. 7 (FIG. 7). E) After the formation), the first resist pattern 72 remains. Therefore, the film thickness of the first resist pattern 72 (the film thickness of the first photoresist layer 71) can be appropriately set according to the depth of the substantially rectangular annular groove portion 301 and the amount of film loss of the first resist pattern 72. ..

In the present embodiment, the convex structure of the imprint mold 1 is formed by the formation position of the substantially rectangular annular groove portion 301 (see FIG. 7 (E)) formed by the step described later, that is, the opening portion of the first resist pattern 72. The size of the pattern region PA of the upper surface 31 of the portion 3 is determined. Therefore, the pattern region PA on the upper surface 31 of the convex structure portion 3 of the imprint mold 1 can be formed with high accuracy. Further, the film thickness of the first functional film 61 in the imprint mold 1 is determined by the dimension (width in the lateral direction) of the opening of the first resist pattern 72. Therefore, the size of the opening of the first resist pattern 72 is set to, for example, 50 nm or more, preferably 100 nm or more, depending on the film thickness of the first functional film 61, whereby the film thickness of the first functional film 61 is set. Can be controlled with high precision.

[First hard mask pattern forming step]
The first resist pattern 72 formed as described above is used as an etching mask, and the first hard mask layer 70 exposed from the opening is dry-etched using, for example, a chlorine-based (Cl ₂ + O ₂ ) etching gas. As a result, the first hard mask pattern 73 is formed on the protruding portion 30 of the imprint mold substrate 10 (see FIG. 7 (D)).

[Groove forming process]
By performing a dry etching process on the imprint mold substrate 10 using the first hard mask pattern 73 formed as described above as an etching mask, a substantially rectangular annular groove portion 301 is formed on the protruding portion 30 (FIG. 7). See (E)). In forming the groove 301, the correlation between the formation conditions (etching conditions, etc.) of the groove 301 and the depth of the groove 301 is obtained in advance so that the depth of the groove 301 is within a desired range. The formation conditions (etching conditions, etc.) of the above may be set. In the above correlation, a groove is formed on the sample substrate (a substrate made of the same material as the substrate 10 for imprint molding) under predetermined conditions (etching conditions, etc.), and the cross section of the sample substrate (cross section along the thickness direction). Is obtained by observing with a scanning electron microscope (SEM) or the like and determining the depth of the groove.

[First functional film forming step]
The substantially rectangular annular groove portion 301 formed as described above is filled with a material (for example, a chromium-based material, a molybdenum-based material, gold, etc.) constituting the first functional film 61, and the first functional film 61 is filled. (See FIG. 8 (A)). It is preferable to fill the material so that the upper end portion of the first functional film 61 is substantially flush with the first hard mask pattern 73 on the protrusion 30. When the material is filled in the substantially rectangular annular groove portion 301, the material is also laminated on the remaining first resist pattern 72. The material laminated on the first resist pattern 72 can be removed at the same time when the first resist pattern 72 is removed in the step described later.

The first functional film 61 functions as an etching stopper when the protruding portion 30 is wet-etched in a step described later. Therefore, as the material constituting the first functional film 61, a material having resistance to the etching solution in the step described later (for example, chromium-based material, molybdenum-based material, gold, etc.) is preferably used.

The substantially rectangular annular groove portion 301 formed by the groove portion forming step (see FIG. 7E) has dimensions corresponding to the dimensions of the first hard mask pattern 73 (dimensions of the opening of the first resist pattern 72). Formed by. Then, the first hard mask pattern 73 (the opening of the first resist pattern 72) is formed with dimensions corresponding to the film thickness of the first functional film 61. Therefore, the first functional film 61 formed by filling the substantially rectangular annular groove portion 301 is formed with a desired film thickness.

Prior to filling the groove 301 with the material constituting the first functional film 61, an adhesion layer capable of improving the adhesion between the first functional film 61 and the imprint mold substrate 10 is formed on the surface of the groove 301. You may. In the wet etching step described later, the imprint mold substrate 10 is subjected to wet etching treatment until the first functional film 61 is exposed. At this time, the gap between the first functional film 61 and the imprint mold substrate 10 is applied. If the etching solution infiltrates into the surface, the surface of the imprint mold substrate 10 (the interface with the first functional film 61) may be roughened. If the surface of the imprint mold substrate 10 is roughened, the functional film 6 (particularly the first functional film 61) may be peeled off from the imprint mold 1. However, since the adhesion layer is formed, the etching solution is less likely to penetrate into the gap between the first functional film 61 and the imprint mold substrate 10, and the surface of the imprint mold substrate 10 is less likely to be roughened. Therefore, it is possible to prevent the functional film 6 from peeling off from the imprint mold 1.

[Second resist pattern forming step]
After the material constituting the first functional film 61 is filled in the substantially rectangular annular groove portion 301, the first resist pattern 72 and the material 61'(which constitutes the first functional film 61) laminated on the first resist pattern 72. The material) is removed to form a second photoresist layer 74 on top of the first hardmask pattern 73 and the first functional film 61 (see FIG. 8B). As the material constituting the second photoresist layer 74, the same material as the material constituting the first photoresist layer 71 may be used. Then, the second photoresist layer 74 is exposed and developed to form the second resist pattern 75 (see FIG. 8C).

In the present embodiment, the second resist pattern 75 is formed so as to include the first functional film 61 formed by filling the substantially rectangular annular groove portion 301 in a plan view. That is, in a plan view, the second resist pattern 75 is formed so that the outer peripheral edge of the second resist pattern 75 surrounds the first functional film 61 having a substantially rectangular ring shape.

[Second hard mask pattern forming step]
The second resist pattern 75 formed as described above is used as an etching mask, and the exposed first hard mask pattern 73 is dry-etched using, for example, a chlorine-based (Cl ₂ + O ₂ ) etching gas. A second hard mask pattern 76 is formed on the protruding portion 30 of the substrate 10 for imprint molding (see FIG. 8D).

[Wet etching process]
Using the second hard mask pattern 76 formed as described above as an etching mask, the imprint mold substrate 10 is subjected to wet etching treatment (see FIG. 8E). As the etching solution in the wet etching treatment, for example, hydrofluoric acid or the like is preferably used.

At the beginning of the wet etching process, etching progresses downward (in the thickness direction of the imprint mold substrate 10) from the outer edge of the second hard mask pattern 76 (see FIG. 10), and gradually becomes the first functional film 61. Etching proceeds toward (in-plane direction of the imprint mold substrate 10) (see FIG. 11). That is, the etching proceeds isotropically. When the etching proceeds until the first functional film 61 is exposed, the etching toward the in-plane direction of the imprint mold substrate 10 stops, and only the etching toward the thickness direction of the imprint mold substrate 10 proceeds (FIG. 12). reference). Then, the wet etching process is completed in a state where the lower end portion of the first functional film 61 is embedded in the imprint mold substrate 10. As a result, the upper surface 31 and the first side surface portion 32 that is continuous with the outer peripheral edge portion of the upper surface 31 and substantially orthogonal to the upper surface portion 31, the curved surface 33 continuous with the lower end portion of the first side surface portion 32, and the curved surface. The convex structure portion 3 having a flat surface 34 continuous with 33 and substantially parallel to the upper surface 31 and a second side surface portion 35 continuous with the outer peripheral edge of the flat surface 34 is the first imprint mold substrate 10. It is formed so as to protrude from the surface 2A. As a result, the base material 2 having the first surface 2A and the second surface 2B facing the first surface 2A, and the convex structure portion 3 integrally projecting from the first surface 2A side of the base material 2 are provided, and the first side surface is provided. A first functional film 61 is formed in the portion 32, and a functional substrate 1'where a part including the lower end portion of the first functional film 61 is located in the convex structure portion 3 (base material 2) is manufactured. be able to. The second functional film 62 and the third functional film 63 may be formed on the curved surface 33 and the flat surface 34 of the convex structure portion 3 of the functional substrate 1'.

[Concavo-convex pattern forming process]
After the convex structure portion 3 is formed as described above, the third hard mask pattern 77 corresponding to the uneven pattern 4 is formed on the upper surface 31 (pattern region PA) of the convex structure portion 3 of the functional substrate 1'. (See FIG. 9 (A)). Then, the imprint mold 1 is manufactured by performing a dry etching process on the imprint mold substrate 10 using the third hard mask pattern 77 as a mask to form the uneven pattern 4 on the upper surface of the convex structure portion 3 (FIG. FIG. 9 (B)). Dry etching of the functional substrate 1'can be performed by appropriately selecting an etching gas according to the type of the constituent material of the functional substrate 1'. As the etching gas, for example, a fluorine-based gas or the like can be used.

[Imprint method]
An imprint method using the imprint mold 1 having the above-described configuration will be described. FIG. 13 is a process flow chart showing each step of the imprint method in the present embodiment on the cut end face.

First, the imprint mold 1 and the transfer substrate 100 having the first surface 100A and the second surface 100B facing the first surface 100A are prepared (see FIG. 13A). The transfer substrate 100 includes, for example, a quartz glass substrate, a soda glass substrate, a calcium fluoride substrate, a magnesium fluoride substrate, an acrylic glass, or the like, or two or more substrates arbitrarily selected from these are laminated. Transparent substrates such as laminated substrates; metal substrates such as nickel substrates, titanium substrates, and alnium substrates; semiconductor substrates such as silicon substrates and gallium nitride substrates can be mentioned.

Next, the imprint resin 101 is supplied to the first surface 100A side of the transfer substrate 100 (see FIG. 13B). As the imprint resin 101, a conventionally known ultraviolet curable resin or the like can be used. The supply amount of the imprint resin 101 depends on the residual film thickness of the pattern structure 102 (see FIG. 13 (D)) produced by the imprint method in the present embodiment, the volume of the uneven pattern 4 of the imprint mold 1, and the like. Can be calculated and determined as appropriate. At this time, in order to prevent defects (unfilled defects) from occurring in the pattern structure 102 due to insufficient supply of the imprint resin 101, the supply amount of the imprint resin 101 is the residual film thickness of the pattern structure 102 and the remaining film thickness of the pattern structure 102. The amount can be determined to be slightly larger than the amount calculated according to the volume of the uneven pattern 4 of the imprint mold 1.

Subsequently, the uneven pattern 4 (pattern area PA) of the imprint mold 1 is brought into contact with the imprint resin 101, and the first surface 100A of the substrate 100 to be transferred and the uneven pattern 4 (pattern area PA) of the imprint mold 1 are brought into contact with each other. The imprint resin 101 is developed in the meantime. Then, in that state, the imprint resin 101 is irradiated with energy rays (UV or the like) via the imprint mold 1 to cure the imprint resin 101 (see FIG. 13C).

In the present embodiment, the supply amount of the imprint resin 101 is slightly larger than the amount calculated according to the residual film thickness of the pattern structure 102, the volume of the uneven pattern 4 of the imprint mold 1, and the like. Therefore, when the imprint resin 101 is developed between the first surface 100A of the transfer substrate 100 and the uneven pattern 4 (pattern region PA) of the imprint mold 1, the convex structure portion 3 of the imprint mold 1 The imprint resin 101 protrudes from the outside of the upper surface 31 (pattern region PA). When energy rays (UV or the like) are irradiated through the imprint mold 1 to cure the imprint resin 101, the upper surface 31 (pattern region PA) of the convex structure portion 3 on the second surface 2B side of the imprint mold 1 is exposed. Energy rays (UV, etc.) also travel from the facing regions in a direction inclined with respect to the thickness direction of the imprint mold 1 (direction toward the protruding imprint resin 101) (see FIG. 5). However, since this energy ray (UV or the like) is shielded from light by the first functional film 61 of the imprint mold 1, it is possible to prevent the protruding imprint resin 101 from being cured.

Finally, the imprint mold 1 is peeled off from the cured imprint resin 101 (see FIG. 13 (D)). As a result, the pattern structure 102 in which the uneven pattern 4 of the imprint mold 1 is transferred onto the first surface 100A of the substrate 100 to be transferred can be manufactured.

The embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

In the above embodiment, the functional film 6 is the first functional film 61 provided on the first side surface portion 32 of the convex structure portion 3, the second functional film 62 provided on the curved surface 33, and the flat surface. Although the embodiment including the third functional film 63 provided in 34 has been described as an example, the present invention is not limited to this embodiment. For example, the functional film 6 provided in the imprint mold 1 or the functional substrate 1'may include at least the first functional film 61 provided on the first side surface portion 32, and is a second functional film. The 62 and the third functional film 63 may not be included, or the second functional film 62 may be included, but the third functional film 63 may not be included.

In the above embodiment, the first to third functional membranes 61 to 63 have been described by exemplifying an embodiment in which all of them have the same function, but the present invention is not limited to this embodiment. For example, one of the first to third functional membranes 61 to 63 may have different functions, or all of them may have different functions from each other. In this case, the first functional film 61 may function as an etching stopper in the manufacturing process of the imprint mold 1. Further, one of the first to third functional films 61 to 63 may be made of different materials, or all of them may be made of different materials.

In the above embodiment, an embodiment in which each of the first to third functional membranes 61 to 63 is composed of one layer has been described as an example, but the present invention is not limited to this embodiment, and the present invention is not limited to this embodiment. It may be composed of a laminated body. For example, the first to third functional films 61 to 63 may be formed by laminating a functional film having a water-repellent / oil-repellent function on a functional film having a light-shielding function, or may be a light-absorbing film. A functional film having a low reflection function may be laminated on a functional film having a (absorbency) function, and if desired, a functional film having a water-repellent / oil-repellent function may be laminated.

In the above embodiment, the embodiment in which the convex structure portion 3 integrally protrudes from the first surface 2A of the base material 2 has been described as an example, but the present invention is not limited to this embodiment. For example, the convex structure portion 3 separate from the base material 2 may be bonded directly to the first surface 2A of the base material 2 or via an adhesive or the like. Further, as shown in FIGS. 14A and 14B, a thin plate portion 22 having a hollow cylindrical support portion 21, a first surface 22A and a second surface 22B facing the first surface 22A, and a first thin plate portion 22. The support portion has a convex structure portion 3 protruding from the surface 22A and a concavo-convex pattern 4 formed on the upper surface 31 of the convex structure portion 3 so as to close the opening end 51 of the support portion 22 with the second surface 22B. The thin plate portion 22 may be joined to the 21. The recessed portion 5 is formed by joining the thin plate portion 22 to the support portion 21. In the embodiment shown in FIGS. 14A and 14B, the functional film 6 (first) covering the first side surface portion 32, the curved surface 33 and the flat surface 34 of the convex structure portion 3 of the thin plate portion 22. The imprint mold 1 can be manufactured by forming the third functional film 61 to 63) and joining the thin plate portion 22 to the support portion 21.

In the above embodiment, an embodiment in which a substantially rectangular annular groove portion 301 is formed by a dry etching process using the first hard mask pattern 73 as a mask has been described as an example, but the present invention is not limited to this embodiment. For example, a substantially rectangular annular groove portion 301 may be formed by cutting the protruding portion 30.

In the above embodiment, an embodiment in which the film thickness of the first resist pattern 72 is set so that the first resist pattern 72 remains even after the substantially rectangular annular groove portion 301 is formed by dry etching is given as an example. Although described, the present invention is not limited to this aspect. For example, the first resist pattern 72 may be formed with a thickness such that the first resist pattern 72 does not remain after the substantially rectangular annular groove portion 301 is formed by dry etching treatment, or the first hard mask pattern 73 may be formed. After forming the first resist pattern 72, a substantially rectangular annular groove portion 301 may be formed by a dry etching process using the first hard mask pattern 73 as a mask. In this case, prior to filling the substantially rectangular annular groove portion 301 with the material constituting the first functional film 61, a resist pattern or the like having an opening corresponding to the substantially rectangular annular groove portion 301 may be formed.

In the above embodiment, an imprint mold substrate 10 having a protrusion 30 protruding from the first surface 2A is prepared (see FIG. 7A), and the imprint mold substrate 10 is used to prepare a functional substrate 1'. (See FIGS. 7 (B) to 8 (E)), and finally, an embodiment in which the imprint mold 1 is manufactured by forming the uneven pattern 4 on the upper surface 31 of the convex structure portion 3 will be described as an example. However, it is not limited to this aspect (see FIG. 9). For example, an imprint mold substrate in which a concavo-convex pattern 4 is formed on the upper surface of the protrusion 30, and a protective film (resist film or the like) 70'that protects the concavo-convex pattern 4 and a first hard mask layer 70 are formed in this order. A step of preparing the functional substrate 1'(see FIGS. 7 (B) to 8 (E)) is carried out by preparing the 10'(see FIG. 15) and using the imprint mold substrate 10'. Therefore, the imprint mold 1 may be manufactured. In the imprint mold substrate 10'shown in FIG. 15, a protective film (resist film or the like) 70'is formed between the first surface 2A of the base material 2 and the first hard mask layer 70 on the outside of the protrusion 30. It may be formed.

1 ... Imprint mold 1'... Functional substrate 2 ... Base material 2A ... First surface 2B ... Second surface 3 ... Convex structure part 31 ... Top surface 32 ... First side surface part 33 ... Curved surface 34 ... Flat surface 35 ... First 2 Side surface 6 ... Functional film 61 ... 1st functional film 62 ... 2nd functional film 63 ... 3rd functional film

Claims (16)

A base material having a first surface and a second surface facing the first surface,
A convex structure portion protruding from the first surface side of the base material is provided.
The convex structure portion has a first side surface that is continuous with the upper surface and the outer edge of the upper surface and extends downward along the thickness direction of the base material, a flat surface that is continuous with the lower end of the first side surface, and the flat surface. Includes a second side surface that is continuous with the outer edge of the surface and extends in the direction towards the first surface.
A first functional film is formed on the first side surface.
A part including the lower end portion of the first functional membrane is embedded in the convex structure portion.
Imprint mold substrate. The substrate for imprint molding according to claim 1, wherein the first functional film is made of a material having resistance to an etching solution applicable to the substrate. The base material is made of a material that is transparent to energy rays of a predetermined wavelength.
The imprint mold substrate according to claim 1 or 2, wherein the first functional film is made of a material having a light-shielding property against energy rays. The imprint mold substrate according to any one of claims 1 to 3, wherein the first functional film is made of a chromium-based material, a molybdenum-based material, or gold. The first side surface and the flat surface are continuous via a curved surface located between them.
The imprint according to any one of claims 1 to 4, wherein a continuous second functional film is formed on the curved surface at a predetermined position of the first functional film formed on the first side surface. Substrate for print mold . The imprint molding substrate according to claim 5, wherein a third functional film continuous with the second functional film is formed on the flat surface. The imprint mold substrate according to any one of claims 1 to 6, wherein the length of the first side surface in the thickness direction of the base material is 0.2 μm to 2 μm. A step of preparing a base material having a first surface, a second surface facing the first surface, and a protrusion protruding from the first surface.
A step of forming a groove portion surrounding the outer periphery of a predetermined region included in the upper surface of the protrusion on the upper surface of the protrusion.
The process of filling the groove with a functional material and
A step of forming a hard mask pattern having a size larger than the predetermined region on the upper surface of the protrusion so as to physically include the predetermined region.
The hard mask pattern is used as an etching mask, and a step of wet-etching the upper surface of the protrusion to a predetermined depth using a predetermined etching solution is included.
Wet etching the upper surface of the protrusion so as to expose a part of the functional material filled in the groove but not the whole.
Manufacturing method of substrate for imprint mold . The method for manufacturing an imprint mold substrate according to claim 8, wherein the upper surface of the protruding portion is wet-etched so that the lower end portion of the functional material filled in the groove portion is embedded in the base material . The method for manufacturing an imprint mold substrate according to claim 8 or 9, wherein the functional material is a material having resistance to the etching solution. The base material is made of a material that is transparent to energy rays of a predetermined wavelength.
The method for manufacturing an imprint mold substrate according to any one of claims 8 to 10, wherein the functional material is a material having a light-shielding property against energy rays. The inn according to any one of claims 8 to 11, further comprising a step of forming a functional material film on the surface of the base material surrounding the outside of the groove, which appears by wet etching the upper surface of the protrusion. Manufacturing method of substrate for print mold . The invention according to any one of claims 8 to 12, wherein the groove is formed by etching the upper surface of the protrusion through a mask pattern formed on the upper surface of the protrusion and having an opening corresponding to the groove. Manufacturing method of substrate for imprint mold . The method for manufacturing an imprint mold substrate according to any one of claims 8 to 12, wherein the groove is formed by cutting the upper surface of the protrusion. The method for manufacturing an imprint mold substrate according to any one of claims 8 to 14, wherein the opening size of the groove is 50 nm or more. The imprint mold substrate according to any one of claims 1 to 7.
An imprint mold comprising a concavo-convex pattern formed in a pattern region set on the upper surface of the convex structure portion.

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