JP2020017591A - Substrate for imprint mold, master mold, method for manufacturing imprint mold using them, and method for manufacturing master mold - Google Patents

Abstract

To provide a substrate for an imprint mold in which high-precision alignment is possible, and that has a removable alignment mark, a master mold capable of high-accuracy alignment with the imprint mold substrate, and a manufacturing method of an imprint mold using them, and a manufacturing method of the master mold.SOLUTION: A substrate for an imprint mold includes a base material having a first surface and a second surface facing the first surface, and a convex structure portion projecting from the first surface of the base material and having an upper surface portion, and on the upper surface portion of the convex structure portion, a pattern region in which a concavo-convex pattern can be formed and a non-pattern region that a region other than the pattern region are set, and an alignment mark is provided in at least a part of the non-pattern region, and the alignment mark is a concavo-convex pattern structure made of a material having a predetermined contrast difference with respect to the base material, and is configured to be removable from the base material.SELECTED DRAWING: Figure 1

Description

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

  Nanoimprint technology, which is known as microfabrication technology, uses an imprint mold in which a fine uneven pattern is formed on the surface of a substrate, and transfers the fine uneven pattern to the workpiece to magnify the fine uneven pattern. This is a pattern forming technology for transferring. In particular, with further miniaturization of wiring patterns and the like in semiconductor devices, nanoimprint technology has been attracting attention in its manufacturing process and the like.

  A mold having a fine concavo-convex pattern used in such a nanoimprint technique can be manufactured by, for example, electron beam (EB) lithography or the like. The mold manufactured in this way has a high accuracy in the shape and dimensions of the fine uneven pattern, but increases the manufacturing cost. Defects may occur in the transfer pattern formed on the print resin or the like, or the fine uneven pattern of the mold may be damaged.

  In the case where a defect of the transfer pattern or damage of the fine concave / convex pattern of the mold occurs as described above, if the mold is replaced with a new one, the cost of a product manufactured through the nanoimprint process is increased. Therefore, when performing a nanoimprint process on an industrial scale, generally, a mold manufactured by electron beam (EB) lithography or the like as described above is used as a master mold, and a replica mold manufactured by nanoimprint lithography using the master mold is used. Etc. are used.

  The replica mold prepares a substrate for imprint molding having a substrate and a convex structure projecting from the surface of the substrate, and a fine irregular pattern of a master mold is formed on the upper surface of the convex structure of the substrate for imprint molding. It is manufactured by transferring. When transferring the fine concavo-convex pattern of the master mold onto the upper surface of the convex structure portion of the imprint mold substrate, it is important to position the imprint mold substrate and the master mold with high accuracy. By performing these alignments with high accuracy, it is possible to improve the positional accuracy on the upper surface of the convex structure portion of the fine uneven pattern.

  Generally, the alignment between the imprint mold substrate and the master mold is performed using alignment marks provided on both. Conventionally, as an alignment mark for aligning both, an alignment mark formed from a dielectric material having a refractive index different from that of the imprint mold (see Patent Document 1), and the imprint resin cannot be filled. An alignment mark having a concave-convex structure having a concave portion with a depth (see Patent Document 2), an alignment mark made of a material different from that of the imprint mold and capable of being imaged by an image pickup device (see Patent Document 3), and a non-transfer region of the mold An alignment mark formed of a structure lower than the height of the mesa structure having the transfer region as the upper surface (see Patent Document 4) is known.

JP 2011-97051 A JP 2011-29642 A JP 2008-100507 A JP 2012-134319 A

  The imprint mold described in Patent Document 4 has a non-transfer area around a mesa structure 3 'on a substrate, and an alignment mark 5' made of a convex structure is formed in the non-transfer area. . In manufacturing the imprint mold, a master mold 20 'provided with an alignment mark 23' and an imprint mold substrate having a mesa structure 3 'and an alignment mark 5' formed in a non-transfer area. 1 ′ is prepared, and both alignment marks 5 ′ and 23 ′ are observed from the back side of the master mold 20 ′ using the image sensor 70 and the like, so that the master mold 20 ′ and the imprint mold substrate 1 ′ Positioning can be performed with high accuracy (see FIG. 21).

  In recent years, with the miniaturization of patterns and the increase in the number of pattern layers in products manufactured using nanoimprint technology, the upper surface of the fine uneven pattern formed on the upper surface of the mesa structure 3 ′ of the imprint mold substrate 1 ′. There is a demand for further improving the positional accuracy in. In order to further improve the positional accuracy of the fine concavo-convex pattern, it is desirable to observe the alignment mark 23 'of the master mold 20' and the alignment mark 5 'of the imprint mold substrate 1' closer to each other. .

  However, in the imprint mold substrate 1 'for producing an imprint mold described in Patent Document 4, an alignment mark 5' lower than the mesa structure 3 'is provided in a non-transfer region one step lower than the mesa structure 3'. Since it is formed, there is a problem that it is physically difficult to reduce the distance between the master mold 20 'and the alignment mark 23'.

  In order to make the alignment mark 23 'of the master mold 20' closer to the alignment mark 5 'of the imprint mold substrate 1', the alignment mark 5 'is formed on the upper surface of the mesa structure 3' of the imprint mold substrate 1 '. It is desirable to form an alignment mark 23 'on the master mold 20' so as to correspond to the alignment mark 5 '. However, when an alignment mark 5 'made of a structure is formed on the upper surface of the mesa structure 3', when a pattern is formed on a transfer target substrate using an imprint mold manufactured from the imprint mold substrate 1 ', A pattern corresponding to the alignment mark 5 'is also formed on the transferred substrate. In a case where a separate pattern needs to be formed in a subsequent step in a region on the transfer target substrate facing the alignment mark 5 ′ at the time of imprinting, even though the region needs to be a flat surface, There is a problem that a pattern corresponding to the alignment mark 5 'is formed.

  The alignment marks 5 'and 23' are visually recognized because the refractive index of the base material and the refractive index of the imprint resin constituting each of the master mold 20 'and the imprint mold substrate 1' are substantially the same. For this purpose, the alignment between the two is performed while the imprint resin is not filled in the recesses of the alignment marks 23 'of the master mold 20' (see Patent Document 2). The supply amount of the imprint resin onto the mesa structure 3 'of the imprint mold substrate 1' is controlled so that the recess of the alignment mark 23 'is not filled with the imprint resin. Since it is difficult to completely control the flow of imprint resin or the like between the mesa structure 3 ', the amount of imprint resin filled into the recess of the alignment mark 23' increases or decreases. Sometimes. As a result, the required amount of imprint resin for transferring the pattern located around the alignment mark 23 'may be insufficient or excessive. If the imprint resin is cured in this state, problems such as the formation of unnecessary patterns and defective structures may occur when the imprint mold substrate 1 'is etched using the cured imprint resin as a mask.

  In view of the above problems, the present disclosure is capable of high-accuracy alignment, and has an imprint mold substrate having a removable alignment mark, and a master capable of high-accuracy alignment with the imprint mold substrate. An object of the present invention is to provide a mold, a method of manufacturing an imprint mold using the same, and a method of manufacturing the master mold.

  In order to solve the above-mentioned subject, as one embodiment of the present disclosure, a base having a first surface and a second surface opposed to the first surface, and protruding from the first surface of the base, And a non-pattern region that is a region other than the pattern region in which a concave-convex pattern can be formed on the upper surface portion of the convex structure portion. An alignment mark is provided in at least a part of the region, and the alignment mark is an uneven pattern structure formed of a material having a predetermined contrast difference with respect to the base material, An imprint mold substrate configured to be removable from the substrate is provided.

  The base material is made of a transparent material, and a material containing a metal can be used as a material forming the pattern structure as the alignment mark, and at least the pattern of the upper surface portion of the convex structure portion can be used. It is sufficient that a hard mask layer is provided in the region, and the material forming the hard mask layer and the material forming the alignment mark may be the same material. As a material forming the alignment mark and the hard mask, a material containing chromium (Cr) can be given.

  As one embodiment of the present disclosure, a master mold used for forming an uneven pattern in the pattern region of the imprint mold substrate, the master mold having a pattern forming surface and a facing surface facing the pattern forming surface A transfer pattern having a concave portion and a convex portion corresponding to the concave-convex pattern to be formed in the pattern region of the imprint mold substrate, the substrate being provided on the pattern forming surface of the master substrate, and An alignment pattern used for alignment with the substrate for imprint molding, the alignment pattern is configured by an uneven structure including a convex portion and a concave portion, the bottom surface of the concave portion of the concave and convex structure, A high control made of a material having a predetermined contrast difference with respect to the master base material. Strike film is provided, the top surface of the convex portion, the master mold which is located on the opposite surface side of the pattern surface along the thickness direction of the master substrate is provided.

  The interval between the plane including the pattern forming surface and the top surface of the convex portion along the thickness direction of the master substrate may be any depth as long as it is equal to or greater than the depth of the concave portion of the transfer pattern. And the depth of the concave portion of the concavo-convex structure as the positioning pattern may be substantially the same.

  The pitch of the concavo-convex structure as the alignment pattern may be different from the pitch of the concavo-convex pattern structure as the alignment mark of the imprint mold substrate, or the alignment of the imprint mold substrate. The pitch may be the same as the pitch of the concave / convex pattern structure as a mark.

  The high-contrast film only needs to have a film thickness capable of transmitting active energy rays to such an extent that the active energy ray-curable imprint resin can be cured during imprint processing using the master mold.

  As an embodiment of the present disclosure, a method for manufacturing an imprint mold, a preparation step of preparing the imprint mold base material and the master mold, and a method of manufacturing the imprint mold base material, A resin supply step of supplying an active energy ray-curable imprint resin to the upper surface portion; and bringing the pattern forming surface of the master mold into contact with the active energy ray-curable imprint resin; A contact step of filling a line-curable imprint resin, a curing step of curing the active energy ray-curable imprint resin contacted with the pattern forming surface of the master mold, and the cured active energy ray curing Separate the master mold from the functional imprint resin Mold step, in the contacting step, the alignment pattern of the master mold and the alignment mark of the imprint mold substrate, the opposite side of the master mold or the imprint mold substrate of the By observing from the second surface side, a method for manufacturing an imprint mold for aligning the master mold and the imprint mold substrate is provided.

  In the resin supply step, the active energy ray-curable imprint resin may be supplied to such an extent that the transfer pattern and the alignment pattern can be filled, and the volume of the transfer pattern and the alignment pattern is considered. The active energy ray-curable imprint resin may be supplied in a supply amount.

  A hard mask layer is provided on at least the pattern region of the upper surface portion of the convex structure portion of the substrate for imprint molding, and a resin pattern formed on the upper surface portion of the convex structure portion by the release process Forming a hard mask pattern by etching the hard mask layer with the mask as a mask, and etching the base material for imprint molding using the hard mask pattern as a mask, thereby forming the upper surface portion of the convex structure portion. The method may further include a step of forming an uneven pattern in the pattern region, and a step of removing the hard mask pattern and the alignment mark remaining on the upper surface of the convex structure.

  As one embodiment of the present disclosure, a method of manufacturing a master mold, a substrate forming step of preparing a master substrate having a pattern forming surface and a facing surface facing the pattern forming surface, A transfer pattern forming step of forming a transfer pattern including a convex portion and a concave portion in a transfer pattern region set on the pattern forming surface, and a transfer pattern region of the master substrate other than the transfer pattern region on the pattern forming surface. A positioning pattern forming step of forming a positioning pattern formed by a concavo-convex structure including a convex portion and a concave portion in a positioning pattern region set at least in part, and a process other than the positioning pattern region A mask pattern forming step of forming a mask pattern in the region of An etching step of etching the alignment pattern region; and a high contrast formed of a material having a predetermined contrast difference with respect to the master base material on the bottom surface of the concave portion of the concave-convex structure forming the alignment pattern. A method of manufacturing a master mold including a step of forming a film and a high contrast film.

  In the etching step, the alignment pattern region may be etched at an etching depth equal to or greater than the depth of the concave portion of the transfer pattern, and has an opening corresponding to each of the transfer pattern and the alignment pattern. By forming an etching mask on the pattern formation surface and performing an etching process on the master base material using the etching mask, the transfer pattern forming step and the alignment pattern forming step may be performed simultaneously.

  According to the present disclosure, a highly accurate alignment is possible, and a substrate for imprint molding having a removable alignment mark, a master mold capable of performing alignment with the imprint molding substrate with high accuracy, and A method for manufacturing the imprint mold used and a method for manufacturing the master mold can be provided.

FIG. 1 is a cut end view illustrating a schematic configuration of an imprint mold substrate according to an embodiment of the present disclosure. FIG. 2 is a partially enlarged cut end view showing a schematic configuration of the convex structure portion in the substrate for imprint molding according to an embodiment of the present disclosure. FIG. 3 is a side view illustrating a schematic configuration of the convex structure portion in the imprint mold substrate according to the embodiment of the present disclosure. FIG. 4 is a plan view illustrating a schematic configuration of one mode (part 1) of the alignment mark on the imprint mold substrate according to the embodiment of the present disclosure. FIG. 5 is a plan view illustrating a schematic configuration of one mode (part 2) of the alignment mark on the imprint mold substrate according to the embodiment of the present disclosure. FIG. 6 is a plan view illustrating a schematic configuration of one mode (part 3) of the alignment mark on the imprint mold substrate according to the embodiment of the present disclosure. FIG. 7A is a plan view illustrating a schematic configuration of one mode (part 1) of each of an alignment mark and a master mold alignment mark in the imprint mold substrate according to an embodiment of the present disclosure. FIG. 7B is a plan view showing a schematic configuration of an aspect (part 1) in which both alignment marks overlap. FIG. 8A is a plan view illustrating a schematic configuration of one mode (part 2) of each of an alignment mark and a master mold alignment mark in the imprint mold substrate according to an embodiment of the present disclosure. FIG. 8B is a plan view illustrating a schematic configuration of a mode (part 2) in which both alignment marks overlap each other. FIG. 9 is a process flow diagram illustrating each step of the method for manufacturing a substrate for imprint molding according to an embodiment of the present disclosure using a partially enlarged cut end surface. FIG. 10 is a cut end view illustrating a schematic configuration of a master mold according to an embodiment of the present disclosure. FIG. 11 is a partially enlarged cut end view showing a schematic configuration near the alignment mark of the master mold according to an embodiment of the present disclosure. FIG. 12 is a plan view illustrating a schematic configuration of an aspect (part 3) in which the alignment mark and the alignment mark of the master mold overlap on the imprint mold substrate according to the embodiment of the present disclosure. FIGS. 13A and 13B are schematic configurations of an aspect in which an alignment mark and an alignment mark of a master mold overlap on an imprint mold substrate according to an embodiment of the present disclosure (parts 4 and 5). FIG. FIGS. 14A to 14C are process flow diagrams illustrating each step of the method for manufacturing a master mold according to an embodiment of the present disclosure, with partially enlarged cut end faces. 15 (A) to 15 (C) are each a process flow diagram of a method of manufacturing a master mold according to an embodiment of the present disclosure, the process subsequent to FIG. 14 being a partially enlarged cut end surface. FIGS. 16A to 16D are process flow charts showing each step of the method for forming a high-contrast film according to an embodiment of the present disclosure by using cut end faces. 17 (A) to 17 (C) are process flow diagrams illustrating each step of the method of manufacturing a replica mold according to an embodiment of the present disclosure by using cut end faces. 18 (A) to 18 (C) are each a process flow diagram of a method of manufacturing a replica mold according to an embodiment of the present disclosure, showing a process subsequent to FIG. 17 as a cut end surface. FIGS. 19A to 19E are process flow charts for explaining the operation and effect based on the relationship between the depth of the alignment region of the master mold and the depth of the concave portion of the transfer pattern according to an embodiment of the present disclosure. 20 (A) to 20 (E) are process flow diagrams for describing the operation and effect based on the relationship between the depth of the alignment region of the master mold and the depth of the concave portion of the transfer pattern according to an embodiment of the present disclosure. FIG. 21 is a cross-sectional end view schematically illustrating a conventional alignment method using a master mold and an imprint mold substrate.

An embodiment 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, and the like of each part may be changed or exaggerated from the real thing in some cases. In this specification and the like, a numerical range represented by using “to” means a range including the numerical values described before and after “to” as the lower limit and the upper limit, respectively. In this specification and the like, terms such as “film”, “sheet”, and “plate” are not distinguished from one another based on a difference in name. For example, “plate” is a concept that also includes members that can be generally called “sheets” and “films”.

[Substrate for imprint mold]
FIG. 1 is a cut end view showing a schematic configuration of the imprint mold substrate according to the present embodiment, and FIG. 2 is a partially enlarged cut end view showing a schematic configuration of a portion A in the imprint mold substrate shown in FIG. FIG. 3 is a plan view showing a schematic configuration of the convex structure portion of the imprint mold substrate according to the present embodiment.

  As shown in FIGS. 1 and 2, an imprint mold substrate 1 according to the present embodiment includes a substrate 2 having a first surface 2A and a second surface 2B opposite to the first surface 2A, And a depression 4 formed on the second surface 2B side.

  The substrate 2 is a general substrate for imprint molding, for example, a quartz glass substrate, a soda glass substrate, a fluorite substrate, a calcium fluoride substrate, a magnesium fluoride substrate, a barium borosilicate glass, an aminoborosilicate glass A glass substrate such as a non-alkali glass substrate such as aluminosilicate glass, a polycarbonate substrate, a polypropylene substrate, a polyethylene substrate, a polymethyl methacrylate substrate, a resin substrate such as a polyethylene terephthalate substrate, and two or more substrates arbitrarily selected from these. May be used, a metal substrate such as a nickel substrate, a titanium substrate, and an aluminum substrate; and a semiconductor substrate such as a silicon substrate and a gallium nitride substrate. However, in the replica mold manufacturing method and the imprint method using the replica mold described below, if light irradiation is performed from the base material 2 side to cure the imprint resin, the base material 2 is formed of the imprint resin. It is necessary to have light transmittance so that it can be cured. In this embodiment, “transparent” means that light having a wavelength capable of curing 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 at least 90%, particularly preferably at least 95%.

  The shape of the substrate 2 in plan view is not particularly limited, and may be, for example, a substantially rectangular shape. When the substrate 2 is made of a quartz glass substrate generally used for optical imprinting, the substrate 2 usually has a substantially rectangular shape in a plan view.

  The size (size in plan view) of the base material 2 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. . In addition, the thickness of the substrate 2 can be appropriately set in a range of, for example, about 300 μm to 10 mm in consideration of strength, handling suitability, and the like.

  The convex structure 3 protruding from the first surface 2A of the substrate 2 is provided substantially at the center of the substrate 2 in plan view. The shape of the convex structure portion 3 in a plan view is substantially rectangular. The size of the convex structure portion 3 is appropriately set according to a product manufactured through imprint processing using the substrate 1 for imprint molding, and is set to, for example, about 30 mm × 25 mm.

  The protrusion height of the convex structure 3 (the length along the thickness direction of the substrate 2 between the first surface 2A of the substrate 2 and the upper surface 3A of the convex structure 3) is the imprint according to the present embodiment. There is no particular limitation as long as the molding substrate 1 can fulfill the purpose of including the convex structure portion 3, and may be set to, for example, about 10 μm to 100 μm.

  The upper surface portion 3A of the convex structure portion 3 is located substantially at the center, and includes a pattern region PA in which the uneven pattern 11 is formed, and a non-pattern region NA surrounding the periphery of the pattern region PA. The hard mask layer 6 is formed in the pattern area PA. Examples of the material constituting the hard mask layer 6 include metals such as chromium, titanium, tantalum, silicon, and aluminum; chromium-based compounds such as chromium nitride, chromium oxide, and chromium oxynitride; tantalum oxide; tantalum oxynitride; Tantalum compounds such as tantalum oxide and tantalum oxynitride, titanium nitride, silicon nitride, silicon oxynitride and the like. One of these may be used alone or in combination of two or more selected arbitrarily. Can be. The non-pattern area NA includes at least one (four in the illustrated example) alignment mark area AA, and the alignment mark 5 is formed in the alignment mark area AA.

  The alignment mark 5 has a concavo-convex pattern structure and is made of a material having a predetermined contrast difference with respect to the substrate 2. Since the alignment mark 5 is made of a material having a predetermined contrast difference with respect to the base material 2, the master mold 20 (see FIG. 10) is formed on the upper surface 3 </ b> A of the convex structure 3 of the imprint mold substrate 1. At the time of positioning the master mold 20 and the imprint mold substrate 1 when transferring the transfer pattern 22, the alignment marks 5 can be easily visually recognized. When the base material 2 is made of a transparent substrate, for example, chromium, (Cr), molybdenum (Mo), tantalum (Ta), tungsten (W), zirconium (Zr) ), Titanium (Ti) and the like. The material forming the alignment mark 5 is a material that can function as an etching mask when etching the base material 2 in relation to the material forming the base material 2 and that does not damage the base material 2. 5 is a material that can be removed. For example, the material forming the alignment mark 5 is a material having an etching selectivity with respect to the substrate 2, and by using a predetermined etchant, only the alignment mark 5 can be etched without etching the substrate 2. Such a material may be used. Since the alignment mark 5 is made of a material having an etching selectivity with respect to the base material 2, in the process of manufacturing the replica mold 10 from the imprint mold substrate 1, the uneven pattern 11 is formed on the upper surface 3 A of the convex structure 3. Is formed, the alignment area AA in which the alignment mark 5 is formed is not etched. As a result, after a pattern is formed on the substrate to be transferred (for example, a silicon wafer or the like) using the replica mold 10, the pattern on the substrate to be transferred corresponding to the area (the alignment area AA of the substrate 1 for imprint molding) in the replica mold 10 is formed. , A separate pattern can be formed in the region. Further, since the alignment mark 5 is made of a material that can be removed, the non-pattern area NA (alignment area AA) in the replica mold 10 can be made up of a flat surface.

  The material forming the alignment mark 5 and the material forming the hard mask layer 6 may be the same or different. If the material forming the hard mask layer 6 and the material forming the alignment mark 5 are the same, the hard mask layer 6 and the alignment mark 5 may be simultaneously formed or removed in manufacturing the imprint mold substrate 1. It becomes possible. Even if both are of the same material, if the thickness of the hard mask layer 6 and the thickness of the alignment mark 5 are different, each may be formed separately.

  The shape in plan view of the projection 51 of the concavo-convex pattern structure forming the alignment mark 5 can be appropriately set in accordance with the shape of the alignment mark 23 of the master mold 20 described later. 4), a substantially cross shape (see FIG. 5), a substantially square shape (see FIG. 6), and the like.

  The size of the protrusion 51 of the concavo-convex pattern structure forming the alignment mark 5 may be any size that allows the alignment mark 5 to be visually recognized by an image sensor or the like. For example, the length of the convex portion 51 of the concavo-convex pattern structure forming the alignment mark 5 in the lateral direction may be about 100 nm to 1000 nm.

If the plan view shape of the convex portion 51 of the concavo-convex pattern structure constituting the alignment mark 5 is a line-shaped (see FIG. 4), the pitch P ₅ of the relief pattern structure, the unevenness of the alignment marks 23 of the master mold 20 to be described later it may be the same as the pitch P ₂₃ of the structure (see FIG. 7 (a)), may be different (see FIG. 8 (a)). By the pitch P ₅ of the concavo-convex pattern structure of the alignment mark 5 is identical to a pitch P ₂₃ of the concavo-convex structure of the alignment mark 23 of the master mold 20, superposing the master mold 20 and the substrate imprint mold 1, the imaging device As a result, when observing the alignment marks 5 and 23, linear patterns at substantially equal intervals are observed (see FIG. 7B). Based on the shape of the linear pattern, highly accurate positioning between the master mold 20 and the imprint mold substrate 1 can be performed. On the other hand, the pitch P ₅ of the concavo-convex pattern structure of the alignment mark 5 is different from the pitch P ₂₃ of the concavo-convex structure of the alignment mark 23 of the master mold 20, superposing the master mold 20 and the substrate imprint mold 1, the imaging device Thus, when observing the alignment marks 5 and 23, a bright and dark striped pattern, that is, a moire pattern is observed (see FIG. 8B). In this moiré pattern, the position of the light and dark stripes changes depending on the relative positional relationship between the alignment marks 5 and 23. Therefore, based on the positions of the light and dark stripes, highly accurate alignment between the master mold 20 and the imprint mold substrate 1 can be performed.

Pitch P ₅ of the concavo-convex pattern structure of the alignment mark 5 in the imprint mold substrate 1, in relation to the pitch P ₂₃ of the concavo-convex structure of the alignment mark 23 of the master mold 20, the master mold 20 and the imprint mold substrate 1 May be set appropriately so that the alignment marks 5 and 23 when are aligned are observed as a moire pattern by the image sensor.

The height T ₅₁ of the convex portion 51 of the alignment marks 5 may be set as the height difference contrast can be obtained with the recess of the alignment mark 5, the refractive index and extinction coefficient of the material constituting the alignment mark 5 Can be set accordingly. On the other hand, in the relationship between the depth D ₂₁₃ of the alignment mark region 213 where the alignment mark 23 on the master mold 20 to be described later is formed, the height T ₅₁ may be any depth D ₂₁₃ or less. If the height T ₅₁ of the convex portion 51 of the alignment mark 23 is greater than the depth D _213, when subjected to imprinting imprint mold substrate 1 by using the master mold 20, the alignment mark 5 is the master mold 20 May come into contact with the alignment mark area 213 to damage the master mold 20 or generate foreign matter.

  A depression 4 having a predetermined size is formed on the second surface 2B of the base material 2. Due to the formation of the depressions 4, the imprint resin using the replica mold 10 (see FIG. 18C) manufactured from the imprint mold substrate 1 according to the present embodiment, The substrate 2, in particular, the upper surface portion 3 </ b> A of the convex structure portion 3 can be curved at the time of contact with the substrate or at the time of peeling of the replica mold 10. As a result, when the upper surface portion 3A of the convex structure portion 3 is brought into contact with the imprint resin, gas is interposed between the uneven pattern 11 formed on the upper surface portion 3A of the convex structure portion 3 and the imprint resin. The replica mold 10 can be easily peeled from the pattern in which the concave and convex pattern 11 is transferred to the imprint resin.

  The shape of the depression 4 in a plan view is preferably substantially circular. Due to the substantially circular shape, the protrusion of the replica mold 10 during the imprinting process, particularly when the upper surface portion 3A of the convex structure 3 is brought into contact with the imprint resin or when the replica mold 10 is peeled off from the imprint resin. The upper surface portion 3A of the structure portion 3 can be substantially uniformly curved in the plane.

  The size of the depression 4 in a plan view is not particularly limited as long as the projection 4 is included in a projection area where the depression 4 is projected on the first surface 2A side of the base material 2. It is not something to be done. If the projection area has a size that cannot cover the convex structure 3, the entire upper surface 3 </ b> A of the convex structure 3 of the replica mold 10 may not be able to be effectively curved.

  According to the imprint mold substrate 1 having the above-described configuration, since the alignment mark 5 is made of a material having a contrast difference with respect to the base material 2, the imprint mold 5 and the alignment mark 23 of the master mold 20 have an imprint. Even when the print resin is completely filled, the alignment marks 5 and 23 can be easily visually recognized at the time of alignment with the master mold 20, so that the alignment with the master mold 20 can be performed with high accuracy. As a result, it is possible to form the concavo-convex pattern 11 on the upper surface portion 3A of the convex structure portion 3 of the imprint mold substrate 1 with high positional accuracy. In the imprint mold substrate 1 according to the present embodiment, the replica mold 10 is manufactured from the imprint mold substrate 1 because the alignment mark 5 is made of a material having an etching selectivity with respect to the base material 2. In the process, when forming the concavo-convex pattern 11 on the upper surface portion 3A of the convex structure portion 3, there is an effect that the alignment area AA where the alignment mark 5 is formed is not etched. Further, since the alignment mark 5 is made of a material that can be removed, the non-pattern area NA (alignment area AA) in the replica mold 10 can be made of a flat surface. As a result, after a pattern is formed on the substrate to be transferred (for example, a silicon wafer or the like) using the replica mold 10, the pattern on the substrate to be transferred corresponding to the area (the alignment area AA of the substrate 1 for imprint molding) in the replica mold 10 is formed. , A separate pattern can be formed in the region.

[Method of manufacturing imprint mold substrate]
A method for manufacturing the above-described substrate for imprint molding will be described. FIG. 9 is a process flow chart showing each step of the method for manufacturing an imprint mold substrate according to the present embodiment by a partially enlarged cut end face near the convex structure portion.

  First, a base material having a first surface, a second surface opposed to the first surface, and having a convex structure portion 3 protruding from the first surface and a concave portion formed on the second surface side is prepared. Then, a metal-containing layer 6 'is formed on the upper surface 3A of the convex structure 3 (see FIG. 9A).

  As the substrate, a general substrate for an imprint mold, for example, a quartz glass substrate, a soda glass substrate, a fluorite substrate, a calcium fluoride substrate, a magnesium fluoride substrate, a barium borosilicate glass, an amino borosilicate glass, A glass substrate such as an alkali-free glass substrate such as aluminosilicate glass, a polycarbonate substrate, a polypropylene substrate, a polyethylene substrate, a polymethyl methacrylate substrate, a resin substrate such as a polyethylene terephthalate substrate, and two or more substrates arbitrarily selected from these. A transparent substrate such as a laminated substrate formed by lamination can be used.

  The shape of the substrate in plan view is not particularly limited, and may be, for example, a substantially rectangular shape. When the substrate is made of a quartz glass substrate that is generally used for optical imprinting, the shape of the substrate 2 in plan view is generally a substantially rectangular shape.

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

  The material forming the metal-containing layer 6 ′ may be any material that forms the alignment mark 5 and the hard mask layer 6 in the imprint mold substrate 1, such as chromium, (Cr), molybdenum (Mo), and tantalum. One of (Ta), tungsten (W), zirconium (Zr), titanium (Ti) and the like can be used alone or in combination of two or more selected arbitrarily.

The thickness of the metal-containing layer 6 ′ is appropriately set according to the height T ₅₁ of the projection 51 of the alignment mark 5 on the imprint mold substrate 1. The height T ₅₁ of the convex portion 51 of the alignment marks 5 may be set as the height difference contrast can be obtained with the recess of the alignment mark 5, the refractive index and extinction coefficient of the material constituting the alignment mark 5 It can be set appropriately as needed. For example, the thickness of the metal-containing layer 6 ′ can be appropriately set within a range of about 5 nm to 30 nm.

  The method for forming the metal-containing layer 6 'on the first surface of the base material is not particularly limited, and for example, a known film formation such as sputtering, PVD (Physical Vapor Deposition), CVD (Chemical Vapor Deposition), or the like. Method.

  Next, a resist layer is formed by spin coating or the like so as to cover the metal-containing layer 6 'on the upper surface 3A of the convex structure 3 of the base material. Then, the resist layer is subjected to an electron beam drawing process and a developing process, or an exposure process and a developing process through a photomask (not shown) having a predetermined opening to the resist layer, thereby forming a resist corresponding to the alignment mark 5. The pattern 7 is formed on the metal-containing layer 6 '(see FIG. 9B).

  The material constituting the resist layer is not particularly limited as long as it is an electron beam-sensitive resist and a light-sensitive resist.For example, a negative or positive photosensitive material can be used. It is preferable to use a mold-type photosensitive material. The thickness of the resist layer is not particularly limited, and can be appropriately set according to a selection ratio or the like according to a constituent material of the metal-containing layer 6 ′.

Using the resist pattern 7 formed as described above as an etching mask, the metal-containing layer 6 ′ exposed from the opening is dry-etched using, for example, a chlorine-based (Cl ₂ + O ₂ ) etching gas to remain. The resist pattern 7 is removed. By adjusting the etching amount of the metal-containing layer 6 ′, the alignment mark 5 and the hard mask layer 6 are simultaneously formed on the upper surface 3A of the convex structure 3 of the base material (see FIG. 9C). Thus, the imprint mold substrate 1 according to the present embodiment is manufactured. After the alignment mark 5 is formed by etching the metal-containing layer 6 ′, the metal-containing layer 6 ′ remaining in a region other than the alignment region AA (eg, the pattern region PA) is completely removed by etching, and the region ( For example, the hard mask layer 6 may be formed in the pattern area PA).

[Master mold]
The master mold in the present embodiment will be described. FIG. 10 is a cut end view showing a schematic configuration of a master mold in the present embodiment, and FIG. 11 is a partially enlarged cut end view showing a schematic configuration of an alignment mark of the master mold in the present embodiment.

  The master mold 20 according to the present embodiment includes a base 21 having a first surface 21A and a second surface 21B opposed to the first surface 21A, and a transfer pattern provided in a pattern region 211 on the first surface 21A of the base 21. 22 and an alignment mark 23 provided in a non-pattern area 212 surrounding the pattern area 211 on the first surface 21A of the base 21. The master mold 20 is used for manufacturing the replica mold 10 by forming the concavo-convex pattern 11 formed by transferring the transfer pattern 22 on the upper surface portion 3A of the convex structure portion 3 of the imprint mold substrate 1 described above. It is.

  The base 21 is a general substrate for imprint molding, for example, a quartz glass substrate, a soda glass substrate, a fluorite substrate, a calcium fluoride substrate, a magnesium fluoride substrate, a barium borosilicate glass, an aminoborosilicate glass, A glass substrate such as an alkali-free glass substrate such as aluminosilicate glass, a polycarbonate substrate, a polypropylene substrate, a polyethylene substrate, a polymethyl methacrylate substrate, a resin substrate such as a polyethylene terephthalate substrate, and two or more substrates arbitrarily selected from these. A transparent substrate such as a laminated substrate may be used.

  The shape of the base 21 in plan view is not particularly limited, and may be, for example, a substantially rectangular shape. When the base 21 is made of a quartz glass substrate generally used for optical imprinting, the shape of the base 21 in a plan view is generally a substantially rectangular shape.

  The size of the base 21 (the size in plan view) is not particularly limited, but when the base 21 is made of the quartz glass substrate, for example, the size of the base 21 is about 152 mm × 152 mm. In addition, the thickness of the base 21 can be appropriately set in a range of, for example, about 300 μm to 10 mm in consideration of strength, handling suitability, and the like.

  The shape, dimensions, and the like of the transfer pattern 22 are the shapes, dimensions, and the like required for the replica mold 10 (product manufactured using the replica mold 10) manufactured from the imprint mold substrate 1 according to the present embodiment. May be set as appropriate. For example, the shape of the transfer pattern 22 includes a line and space shape, a pillar shape, a hole shape, a grid shape, and the like. Further, the size of the transfer pattern 22 can be set, for example, to about 10 nm to 200 nm.

  The alignment mark 23 has an uneven structure formed in the alignment mark area 213 in the non-pattern area 212 on the first surface 21A. The alignment mark area 213 is an area that is recessed from the first surface 21A of the base 21 toward the second surface 21B, and the bottom surface of the alignment mark area 213 that is recessed from the first surface 21A has irregularities forming the alignment mark 23. A structure is formed.

  A high-contrast film 24 made of a material having a predetermined contrast difference with respect to the base 21 is formed on the bottom surface of the concave portion 231 of the concavo-convex structure constituting the alignment mark 23. Since the high contrast film 24 is made of a material having a predetermined contrast difference with respect to the base 21, the transfer pattern 22 of the master mold 20 is formed on the upper surface 3A of the convex structure 3 of the substrate 1 for imprint molding. At the time of alignment between the master mold 20 and the imprint mold substrate 1 at the time of transfer, the alignment marks 23 can be easily visually recognized. When the base 21 is made of a transparent substrate, the high contrast film 24 may be made of, for example, chromium, (Cr), molybdenum (Mo), tantalum (Ta), tungsten (W), zirconium (Zr). ), Titanium (Ti) and the like.

  The shape of the concave portion 231 of the concavo-convex structure constituting the alignment mark 23 in a plan view can be appropriately set according to the shape of the alignment mark 5 of the imprint mold substrate 1. When the plan view shape of the projection 51 of the concavo-convex pattern structure of the alignment mark 5 is linear (see FIG. 4), for example, the plan view shape of the concavity 231 of the concavo-convex structure forming the alignment mark 23 is also linear. can do. When the projection 51 of the concave-convex pattern structure of the alignment mark 5 has a substantially cross shape in plan view (see FIG. 5), for example, the planar shape of the concave portion 231 of the concave-convex structure forming the alignment mark 23 is substantially The cross-shaped alignment mark 5 can be formed in a substantially rectangular shape that can be physically included (see FIG. 12). Further, in the case of a substantially square shape (see FIG. 6), for example, the planar view shape of the concave portion 231 of the concavo-convex structure constituting the alignment mark 23 is physically included in the substantially square shape alignment mark 5. It can be formed in a substantially cross shape, a substantially square shape, or the like (see FIGS. 13A and 13B).

If the plan view shape of the concavo-convex structure constituting the alignment mark 23 is linear, the pitch P ₂₃ of the relief structure, there the same as a pitch P ₅ of the concavo-convex pattern structure of the alignment mark 5 imprint mold substrate 1 (See FIG. 7A) or may be different (see FIG. 8A). By the pitch P ₂₃ of the concavo-convex structure of the alignment mark 23 is identical to the pitch P ₅ of the concavo-convex pattern structure of the alignment mark 5 imprint mold substrate 1 are overlapped and a master mold 20 and the substrate imprint mold 1 When the alignment marks 5 and 23 are observed by the image pickup device, a line-like pattern at substantially equal intervals is observed (see FIG. 7B). Based on the shape of the linear pattern, highly accurate positioning between the master mold 20 and the imprint mold substrate 1 can be performed. On the other hand, by the pitch P ₂₃ of the concavo-convex structure of the alignment mark 23 is different from the pitch P ₅ of the concavo-convex pattern structure of the alignment mark 5 imprint mold substrate 1 are overlapped and a master mold 20 and the imprint mold substrate 1 When the alignment marks 5 and 23 are observed by the image sensor, a bright and dark stripe pattern, that is, a moiré pattern is observed (see FIG. 8B). In this moiré pattern, the position of the light and dark stripes changes depending on the relative positional relationship between the alignment marks 5 and 23. Therefore, based on the positions of the light and dark stripes, highly accurate alignment between the master mold 20 and the imprint mold substrate 1 can be performed.

Pitch P ₂₃ of the concavo-convex structure of the alignment mark 23 on the master mold 20, in relation to the pitch P ₅ of the concavo-convex pattern structure of the alignment mark 5 imprint mold substrate 1, the master mold 20 and the imprint mold substrate 1 May be set appropriately so that the alignment marks 5 and 23 when are aligned are observed as a moire pattern by the image sensor.

As described later, in the manufacturing process of the master mold 20 in the present embodiment, the transfer pattern 22 and the alignment mark 23 are formed by an etching process performed at the same time. Therefore, the depth D ₂₃₁ of the concave portion 231 of the concavo-convex structure constituting the alignment mark 23 is substantially the same as the depth D ₂₂₁ of the concave portion 221 of the transfer pattern 22.

The depth D ₂₁₃ of the alignment mark area 213 is not less than the height T ₅₁ of the projection 51 of the uneven pattern structure forming the alignment mark 5 of the imprint mold substrate 1 and the depth of the recess 221 of the transfer pattern 22. D ₂₂₁ or more. If the depth D ₂₁₃ of the alignment mark region 213 is less than the height T ₅₁ of the convex portion 51 of the alignment marks 5 imprint mold substrate 1, imprinting the imprint mold substrate 1 by using the master mold 20 When applying, the alignment mark area 213 and the alignment mark 5 of the imprint mold substrate 1 come into contact with each other, and the master mold 20 may be damaged. The relative position of the depth D ₂₁₃ of the alignment mark region 213 is less than the depth D ₂₂₁ of the recess 221 of the transfer pattern 22, a concavo-convex pattern structure forming the uneven structure and the alignment marks 5 constituting the alignment mark 23 When the positions of the convex portions and the concave portions (positions in the thickness direction of the base material 2 and the base portion 21 during the imprint process) do not match, the alignment mark of the imprint mold substrate 1 is not obtained. There is a possibility that the base material 2 located below 5 is processed (etched).

According to the master mold 20 having the above structure, the alignment depth D ₂₁₃ of the mark region 213 is more than the height T ₅₁ of the convex portion 51 of the concavo-convex pattern structure constituting the alignment mark 5 of the imprint mold substrate 1, In addition, since the depth of the concave portion 221 of the transfer pattern 22 is equal to or more than the depth D ₂₂₁ , even when the relative positions of the concave and convex structure forming the alignment mark 23 and the concave and convex pattern structure forming the alignment mark 5 do not coincide with each other. Thus, the replica mold 10 in which the non-pattern area NA is a flat surface can be manufactured without processing (etching) the base material 2 located below the alignment mark 5 of the imprint mold substrate 1.

[Manufacturing method of master mold]
An example of a method for manufacturing the above-described master mold 20 will be described. FIG. 14 and FIG. 15 are process flow diagrams showing each step of the method for manufacturing a master mold in the present embodiment by partially enlarged cut end faces.

A base 21 having a first surface 21A and a second surface 21B opposed to the first surface 21A and having a hard mask layer 25 provided on the first surface 21A is prepared (see FIG. 14A). A resist pattern corresponding to the concavo-convex structure of the transfer pattern 22 and the alignment mark 23 is formed on the mask layer 25. Then, using the resist pattern as a mask, the hard mask layer 25 is dry-etched using a chlorine-based (Cl ₂ + O ₂ ) etching gas or the like to form the hard mask pattern 26 on the first surface 21A ( FIG. 14B).

  The base 21 is a general substrate for imprint molding, for example, a quartz glass substrate, a soda glass substrate, a fluorite substrate, a calcium fluoride substrate, a magnesium fluoride substrate, a barium borosilicate glass, an aminoborosilicate glass, A glass substrate such as an alkali-free glass substrate such as aluminosilicate glass, a polycarbonate substrate, a polypropylene substrate, a polyethylene substrate, a polymethyl methacrylate substrate, a resin substrate such as a polyethylene terephthalate substrate, and two or more substrates arbitrarily selected from these. A transparent substrate such as a laminated substrate may be used.

  The shape of the base 21 in plan view is not particularly limited, and may be, for example, a substantially rectangular shape. When the base 21 is made of a quartz glass substrate generally used for optical imprinting, the shape of the base 21 in a plan view is generally a substantially rectangular shape.

  The size of the base 21 (the size in plan view) is not particularly limited, but when the base 21 is made of the quartz glass substrate, for example, the size of the base 21 is about 152 mm × 152 mm. In addition, the thickness of the base 21 can be appropriately set in a range of, for example, about 300 μm to 10 mm in consideration of strength, handling suitability, and the like.

  Examples of the material constituting the hard mask layer 25 include metals such as chromium, titanium, tantalum, silicon, and aluminum; chromium-based compounds such as chromium nitride, chromium oxide, and chromium oxynitride; tantalum oxide; tantalum oxynitride; Tantalum compounds such as tantalum oxide and tantalum oxynitride, titanium nitride, silicon nitride, silicon oxynitride and the like. One of these may be used alone or in combination of two or more selected arbitrarily. Can be.

  The hard mask layer 25 is formed by patterning in a later-described step, and forms a hard mask pattern 26 used as a mask for forming the transfer pattern 22 and the uneven structure forming the alignment mark 23 by etching. Therefore, it is preferable to select the constituent material of the hard mask layer 25 in consideration of the etching selectivity and the like according to the constituent material of the base 21. For example, when the base 21 is a quartz glass substrate, a chromium oxide film or the like can be suitably selected as the hard mask layer 25.

  The thickness of the hard mask layer 25 is appropriately set in consideration of an etching selectivity and the like according to a constituent material of the base 21. For example, when the base 21 is a quartz glass substrate and the hard mask layer 25 is a chromium oxide film, the thickness of the hard mask layer 25 can be appropriately set within a range of about 1 nm to 20 nm.

  The method for forming the hard mask layer 25 on the first surface 21A of the base 21 is not particularly limited. For example, a known film formation method such as sputtering, PVD (Physical Vapor Deposition), or CVD (Chemical Vapor Deposition) is used. Method.

  The material constituting the resist pattern formed on the hard mask layer 25 is not particularly limited. For example, a negative or positive electron beam sensitive resist material or the like can be used. The thickness of the resist pattern is not particularly limited, and can be appropriately set according to a selection ratio or the like according to a constituent material of the hard mask layer 25. The resist pattern can be formed by performing an electron beam drawing process and a developing process on the resist layer provided on the hard mask layer 25.

  Next, a dry etching process is performed on the first surface 21A of the base 21 using the hard mask pattern 26 as a mask, thereby forming an uneven structure of the transfer pattern 22 and the alignment mark 23 (see FIG. 14C). The dry etching of the base 21 can be performed by appropriately selecting an etching gas according to the type of the constituent material of the base 21. As the etching gas, for example, a fluorine-based gas or the like can be used.

  Subsequently, a resist layer made of a negative or positive photosensitive material or the like is formed on the first surface 21A of the base 21 on which the concave / convex structure of the transfer pattern 22 and the alignment mark 23 is formed. By performing exposure and development processing, a resist pattern 28 having an opening corresponding to the alignment mark area 213 is formed (see FIG. 15A).

  Then, the first surface 21A of the base 21 is subjected to dry etching using the resist pattern 28 as a mask, so that the first surface 21A of the base 21 is depressed from the first surface 21A toward the second surface 21B, thereby forming an alignment mark 23 on the bottom surface. An alignment mark region 213 in which an uneven structure is formed can be formed (see FIG. 15B).

In forming the alignment mark area 213, the depth D ₂₁₃ of the alignment mark area 213 is determined based on the concavo-convex pattern structure of the alignment mark 5 of the imprint mold substrate 1 to which the transfer pattern 22 of the master mold 20 is to be transferred. the height T ₅₁ or more posts 51, and so that the depth D ₂₂₁ or more recesses 221 of the transfer pattern 22 is subjected to dry etching on the first surface 21A of the base portion 21. If the depth D ₂₁₃ of the alignment mark region 213 is less than the height T ₅₁ of the convex portion 51 of the alignment marks 5 imprint mold substrate 1, imprinting the imprint mold substrate 1 by using the master mold 20 When applying, the alignment mark area 213 and the alignment mark 5 of the imprint mold substrate 1 come into contact with each other, and the master mold 20 may be damaged. The relative position of the depth D ₂₁₃ of the alignment mark region 213 is less than the depth D ₂₂₁ of the recess 221 of the transfer pattern 22, a concavo-convex pattern structure forming the uneven structure and the alignment marks 5 constituting the alignment mark 23 If the positions of the convex portions and the concave portions (positions when viewed in the thickness direction of the base material 2 and the base portion 21 during the imprint process) do not match, the alignment mark 5 of the imprint mold substrate 1 is not aligned. There is a possibility that the base material 2 located below is processed (etched).

  Finally, a high-contrast film 24 made of a material having a predetermined contrast difference with respect to the base 21 is formed on the bottom surface of the concave / convex portion 231 constituting the alignment mark 23 (see FIG. 15C). When the base 21 is made of a transparent substrate, the high contrast film 24 may be made of, for example, chromium, (Cr), molybdenum (Mo), tantalum (Ta), tungsten (W), zirconium (Zr). ), Titanium (Ti) and the like. Thus, the master mold 20 according to the present embodiment is manufactured.

The high-contrast film 24 can be manufactured, for example, by the process shown in FIG.
First, the base 21 (see FIG. 15B) on which the alignment mark area 213 is formed is prepared, and the concave and convex structure forming the transfer pattern 22 on the first surface 21A of the base 21 by using a technique such as a sputtering method. A material forming the high contrast film 24 is formed on the bottom surface of the concave portion and the bottom surface of the concave portion 231 of the concave / convex structure forming the alignment mark 23 to form the high refractive film 241 (see FIG. 16A).

  Next, a resist film 27 is formed thereon, and the step substrate is pressed against the resist film 27 so that the film thickness of the region where the alignment mark 23 is formed is larger than the film thickness of the region where the transfer pattern 22 is formed. Then, the resist film 27 is deformed (see FIG. 16B). Note that the resist film 27 having such a step structure may be formed by an imprint process using an imprint mold having a structure corresponding to the step structure.

  After that, the resist film 27 is dry-etched by a predetermined thickness to leave the resist film 27 only inside the concave portion 231 of the concavo-convex structure constituting the alignment mark 23 (see FIG. 16C). Next, the high refraction film 241 exposed from the resist film 27 is removed by dry etching, and finally, the resist film 27 inside the concave portion 231 of the concavo-convex structure forming the alignment mark 23 is removed, so that the alignment mark 23 is removed. The high-contrast film 24 can be formed on the bottom surface of the concave portion 231 having the concave-convex structure (see FIG. 16D).

[Replica mold manufacturing method]
A method for manufacturing a replica mold using the master mold 20 and the imprint mold substrate 1 in the present embodiment will be described. FIG. 17 and FIG. 18 are process flow charts showing the respective steps of the method of manufacturing a replica mold in the present embodiment by cutting end faces.

  First, the master mold 20 and the substrate 1 for imprint molding in this embodiment are prepared, and the imprint resin 40 is supplied to the upper surface 3A of the convex structure 3 of the substrate 1 for imprint molding (see FIG. 17A). ).

  The imprint resin 40 (resist material) is not particularly limited, and a resin material generally used for imprint processing (for example, an ultraviolet curable resin, a thermosetting resin, or the like) can be used. The imprint resin 40 includes a release agent for easily separating the master mold 20 and an adhesive for improving adhesion to the upper surface portion 3A (the hard mask layer 6) of the convex structure portion 3 of the substrate 1 for imprint molding. An adhesive or the like may be included.

  The supply amount of the imprint resin 40 to the upper surface portion 3A of the convex structure portion 3 may be an amount capable of completely filling the transfer pattern 22 and the alignment mark 23 of the master mold 20 with the imprint resin 40.

  Next, the transfer pattern 22 formed on the first surface 21A of the master mold 20 is brought into contact with the imprint resin 40 supplied to the upper surface portion 3A of the convex structure portion 3, and the first surface 21A of the master mold 20 is brought into contact with the imprint resin 40. The imprint resin 40 is developed between the imprint resin and the upper surface 3A of the convex structure 3 of the imprint mold substrate 1, and the transfer pattern 22 and the alignment mark 23 are completely filled with the imprint resin 40 (FIG. 17B). reference). In this state, the alignment between the master mold 20 and the imprint mold substrate 1 is performed by observing the alignment marks 23 of the master mold 20 and the alignment marks 5 of the imprint mold substrate 1 with an image sensor or the like.

  Since the alignment mark 5 is made of a material having a predetermined contrast difference with respect to the base material 2 and the high contrast film 24 is formed on the bottom surface of the concave portion 231 of the uneven structure of the alignment mark 23, the alignment mark 5 The alignment mark 23 can be easily visually recognized, and the alignment between the two can be performed with high accuracy.

The projection 51 of the concavo-convex pattern structure forming the alignment mark 5 has a linear shape in plan view (see FIG. 4), and the concavo-convex structure of the alignment mark 23 has a linear shape in plan view. If the pitch P ₅ of the pattern structure is identical to the pitch P ₂₃ of the concavo-convex structure of the alignment mark 23 (FIG. 7 (a) reference), superposing the master mold 20 and the substrate imprint mold 1, the alignment by the image sensor When the marks 5 and 23 are observed, line-like patterns at substantially equal intervals are observed (see FIG. 7B). Based on the shape of the linear pattern, highly accurate positioning between the master mold 20 and the imprint mold substrate 1 can be performed. On the other hand, if the pitch P ₅ of the concavo-convex pattern structure of the alignment mark 5 is different from the pitch P ₂₃ of the concavo-convex structure of the alignment marks 23 are overlapped and a master mold 20 and the substrate imprint mold 1, the alignment marks 5 by the image pickup device, When observing No. 23, a bright and dark striped pattern, that is, a moire pattern is observed (see FIG. 8B). In this moiré pattern, the position of the light and dark stripes changes depending on the relative positional relationship between the alignment marks 5 and 23. Therefore, based on the positions of the light and dark stripes, highly accurate alignment between the master mold 20 and the imprint mold substrate 1 can be performed.

  After the alignment of the two is completed, the imprint resin 40 is irradiated with light to be cured, and then the master mold 20 is released. Thus, a resist pattern 41 obtained by transferring the transfer pattern 22 is formed on the upper surface 3A of the convex structure 3 of the imprint mold substrate 1 (see FIG. 17C).

Subsequently, the remaining film of the resist pattern 41 is removed (see FIG. 18A), and the resist pattern 41 is used as a mask, for example, by dry etching using a chlorine-based (Cl ₂ + O ₂ ) etching gas. The hard mask layer 6 formed on the upper surface portion 3A of the convex structure portion 3 of the print mold substrate 1 is etched to form a hard mask pattern 61 (see FIG. 18B).

  Then, the substrate 1 for imprint molding is subjected to dry etching using the hard mask pattern 61 as a mask to form the concavo-convex pattern 11 on the upper surface 3A of the convex structure 3. Thereafter, the hard mask pattern 61 and the alignment mark 5 remaining on the upper surface 3A of the convex structure 3 are removed to manufacture the replica mold 10 (see FIG. 18C). The dry etching of the imprint mold substrate 1 can be performed by appropriately selecting an etching gas according to the type of the constituent material of the imprint mold substrate 1. As the etching gas, for example, a fluorine-based gas or the like can be used.

  Since the alignment mark 5 of the imprint mold substrate 1 in the present embodiment is made of a removable material, the replica mold 10 in which the non-pattern area NA of the upper surface 3A of the convex structure 3 is a flat surface. Can be manufactured. In particular, since the alignment mark 5 is made of the same material as the hard mask pattern 61 (the hard mask layer 6), an effect is obtained that the alignment mark 5 can be removed simultaneously with the hard mask pattern 61.

The depth D ₂₁₃ of the alignment mark region 213 of the master mold 20 in the present embodiment, it is the depth D ₂₂₁ or more recesses 221 of the transfer pattern 22 is exerted an effect as described below.

The relative positions of the alignment marks 23 of the master mold 20 and the concavo-convex pattern structure of the alignment marks 5 of the imprint mold substrate 1 (the positions of the protrusions and the positions of the recesses (the thickness direction of the base material 2 and the base 21 during imprint processing). 19) (see FIG. 19A), after the transfer pattern 22 of the master mold 20 is transferred to the imprint resin 40 to form the resist pattern 41 (FIG. 19). (See FIG. 19B), and the remaining film 411 of the resist pattern 41 is removed (see FIG. 19C). When the residual film 411 is removed, the thin film portion 412 of the resist pattern 41 remains on the convex portion of the concave / convex pattern structure portion of the alignment mark 5, and the resist pattern 41 having a sufficient thickness also remains on the concave portion. As shown in FIG. 19C, the alignment mark 5 is masked by the resist pattern 41 during the etching of the hard mask layer 6. As a result, the film thickness of the alignment mark 5 hardly decreases (see FIG. 19D). Therefore, when the imprint mold substrate 1 is subsequently etched, the non-pattern area NA of the upper surface portion 3A of the convex structure portion 3 is masked by the alignment mark 5 and is not etched. That is, the depth D ₂₁₃ of the alignment mark region 213 of the master mold 20, that is the depth D ₂₂₁ or more recesses 221 of the transfer pattern 22, the non-pattern region NA is the constructed replica mold 10 by the flat surface It can be manufactured (see FIG. 19E).

On the other hand, the depth D ₂₁₃ of the alignment mark region 213 of the master mold 20, the transfer be less than the depth D221 of the recess 221 of the pattern 22, the uneven structure imprint alignment of the mold substrate 1 of the alignment mark 23 of the master mold 20 When the relative position of the mark 5 with respect to the concavo-convex pattern structure (the position of the convex portions and the position of the concave portions (the position when viewed in the thickness direction of the base material 2 and the base 21 during the imprint process)) does not match ( After the transfer pattern 22 of the master mold 20 is transferred to the imprint resin 40 to form the resist pattern 41 (see FIG. 20B), the remaining film 411 of the resist pattern 41 is removed. (See FIG. 20C), the resist pattern on the convex portion of the concave / convex pattern structure portion of the alignment mark 5 is formed. Since the thin film portion 412 of 41 disappears and the thickness of the resist pattern 41 on a part of the concave portion becomes insufficient (see FIG. 20C), the alignment mark 5 A part of the resist pattern 41 masking the concave portion disappears. As a result, part of the alignment mark 5 is etched away and disappears, or part of the alignment mark 5 becomes extremely thin (see FIG. 20D). Therefore, in the subsequent etching of the substrate 1 for imprint molding, a part of the non-pattern area NA of the upper surface portion 3A of the convex structure portion 3 is not sufficiently masked by the alignment mark 5 and is etched (see FIG. )reference).

As described above, according to the present embodiment, the depth D ₂₁₃ of the alignment mark region 213 of the master mold 20 is _{equal to} or greater than the depth D ₂₂₁ of the concave portion 221 of the transfer pattern 22, so that the upper surface portion of the convex structure 3 The replica mold 10 in which the non-pattern area NA in 3A is constituted by a flat surface 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.

DESCRIPTION OF SYMBOLS 1 ... Imprint mold board | substrate 2 ... Base material 2A ... 1st surface 2B ... 2nd surface 3 ... convex structure part 3A ... upper surface part 32 ... side surface part 5 ... alignment mark 6 ... hard mask layer 10 ... replica mold 11 ... unevenness Pattern 20 Master mold 21 Base 22 Transfer pattern 23 Alignment mark 24 High contrast film

Claims (18)

A base material having a first surface and a second surface facing the first surface;
Protruding from the first surface of the base material, comprising a convex structure portion having an upper surface portion,
In the upper surface portion of the convex structure portion, a pattern region in which a concavo-convex pattern can be formed and a non-pattern region that is a region other than the pattern region are set,
An alignment mark is provided in at least a part of the non-pattern area,
The substrate for imprint molding, wherein the alignment mark is a concavo-convex pattern structure made of a material having a predetermined contrast difference with respect to the base material, and is configured to be removable from the base material. The base material is made of a transparent material,
The substrate for imprint molding according to claim 1, wherein a material forming the pattern structure as the alignment mark is a material containing a metal. The imprint mold substrate according to claim 1, wherein a hard mask layer is provided on at least the pattern region of the upper surface of the convex structure. 4. The imprint mold substrate according to claim 3, wherein a material forming the hard mask layer and a material forming the alignment mark are the same. The imprint mold substrate according to claim 1, wherein the alignment mark is made of a material containing chromium. A master mold used to form an uneven pattern in the pattern region of the imprint mold substrate according to any one of claims 1 to 5,
A master substrate having a pattern forming surface and a facing surface facing the pattern forming surface,
A transfer pattern having concave portions and convex portions corresponding to the concave / convex pattern to be formed in the pattern region of the imprint mold substrate, which is provided on the pattern forming surface of the master substrate, and for the imprint mold. A positioning pattern used for positioning with the substrate,
The alignment pattern is configured by an uneven structure including a convex portion and a concave portion,
On the bottom surface of the concave portion of the concave-convex structure, a high-contrast film made of a material having a predetermined contrast difference with respect to the master base material is provided.
A master mold wherein a top surface of the convex portion is located closer to the facing surface side than the pattern forming surface along a thickness direction of the master base material. The master mold according to claim 6, wherein an interval between a plane including the pattern forming surface and a top surface of the convex portion along a thickness direction of the master substrate is equal to or greater than a depth of a concave portion of the transfer pattern. . 8. The master mold according to claim 6, wherein a depth of the concave portion of the transfer pattern and a depth of the concave portion of the concave-convex structure as the alignment pattern are substantially the same. The master mold according to claim 6, wherein a pitch of the concave-convex structure as the alignment pattern is different from a pitch of the concave-convex pattern structure as the alignment mark of the imprint mold substrate. The master mold according to any one of claims 6 to 8, wherein a pitch of the concave-convex structure as the alignment pattern is the same as a pitch of the concave-convex pattern structure as the alignment mark of the imprint mold substrate. . The high-contrast film according to any one of claims 6 to 10, wherein the high-contrast film has a thickness capable of transmitting active energy rays to an extent that the active energy ray-curable imprint resin can be cured during imprint processing using the master mold. The described master mold. A method for producing an imprint mold, comprising:
A preparation step for preparing the imprint mold substrate according to any one of claims 1 to 5 and the master mold according to any one of claims 6 to 11,
A resin supply step of supplying an active energy ray-curable imprint resin to the upper surface of the convex structure portion of the imprint mold substrate,
A contact step of contacting the pattern forming surface of the master mold with the active energy ray-curable imprint resin, and filling at least the transfer pattern with the active energy ray-curable imprint resin.
A curing step of curing the active energy ray-curable imprint resin that has contacted the pattern forming surface of the master mold,
A mold release step of separating the master mold from the cured active energy ray-curable imprint resin,
In the contacting step, the alignment pattern of the master mold and the alignment mark of the imprint mold substrate are observed from the opposite surface side of the master mold or the second surface side of the imprint mold substrate. A method of manufacturing an imprint mold for performing positioning of the master mold and the imprint mold substrate. 13. The method of manufacturing an imprint mold according to claim 12, wherein in the resin supply step, the active energy ray-curable imprint resin is supplied to such an extent that the transfer pattern and the alignment pattern can be filled. 14. The method of manufacturing an imprint mold according to claim 13, wherein in the resin supply step, the active energy ray-curable imprint resin is supplied in a supply amount considering a volume of the transfer pattern and the positioning pattern. A hard mask layer is provided on at least the pattern region of the upper surface portion of the convex structure portion of the imprint mold substrate,
Forming a hard mask pattern by etching the hard mask layer using the resin pattern formed on the upper surface portion of the convex structure portion as a mask in the release step;
By etching the substrate for imprint molding using the hard mask pattern as a mask, a step of forming a concavo-convex pattern in the pattern region of the upper surface portion of the convex structure portion,
The method for manufacturing an imprint mold according to claim 12, further comprising: removing the hard mask pattern and the alignment mark remaining on the upper surface of the convex structure. A method of manufacturing a master mold,
A substrate forming step of preparing a master substrate having a pattern forming surface and a facing surface facing the pattern forming surface,
A transfer pattern forming step of forming a transfer pattern including protrusions and recesses in a transfer pattern region set on the pattern formation surface of the master base material,
In the alignment pattern region set on at least a part of the region other than the transfer pattern region on the pattern forming surface of the master substrate, an alignment pattern including an uneven structure including a convex portion and a concave portion An alignment pattern forming step of forming
A mask pattern forming step of forming a mask pattern in a region other than the alignment pattern region,
An etching step of etching the alignment pattern region using the mask pattern as a mask,
A high-contrast film forming step of forming a high-contrast film made of a material having a predetermined contrast difference with respect to the master base material on a bottom surface of the concave portion of the concavo-convex structure constituting the alignment pattern. Manufacturing method of master mold. 17. The method of manufacturing a master mold according to claim 16, wherein, in the etching step, the positioning pattern region is etched at an etching depth equal to or greater than a depth of the concave portion of the transfer pattern. An etching mask having an opening corresponding to each of the transfer pattern and the alignment pattern is formed on the pattern forming surface, and the master substrate is subjected to an etching process using the etching mask, whereby the transfer pattern is formed. The method for manufacturing a master mold according to claim 16, wherein the forming step and the positioning pattern forming step are performed simultaneously.

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