JP7139751B2 - Imprint mold manufacturing method - Google Patents

Description

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

Nanoimprint technology, known as microfabrication technology, uses an imprint mold in which a fine uneven pattern is formed on the surface of a base material, and the fine uneven pattern is transferred to the workpiece by transferring the fine uneven pattern to the same size. It is a pattern forming technology that transfers. In particular, with the further miniaturization of wiring patterns and the like in semiconductor devices, nanoimprint technology has attracted attention in the manufacturing processes thereof.

A mold having a fine concavo-convex pattern used in such nanoimprint technology can be manufactured, for example, by electron beam (EB) lithography. Although the mold manufactured in this way has high accuracy in the shape and dimensions of the fine uneven pattern, the manufacturing cost is high. In some cases, defects may occur in the transfer pattern formed on the printed resin, etc., or the fine uneven pattern of the mold may be damaged.

If the mold is replaced with a new mold when a defect in the transferred pattern or damage to the fine uneven pattern of the mold occurs in this way, the cost of the product manufactured through the nanoimprint process will increase. 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 prepared by nanoimprint lithography using the master mold. etc. are used.

The replica mold is prepared by preparing an imprint mold substrate having a base material and convex structures protruding from the surface of the base material, and applying a fine concavo-convex pattern of a master mold on the upper surface of the convex structure parts of the imprint mold substrate. Manufactured by transferring the When transferring the fine concavo-convex pattern of the master mold onto the upper surface of the convex structure of the imprint mold substrate, it is important to align 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 concavo-convex pattern.

In general, the imprint mold substrate and the master mold are aligned using alignment marks provided on both. As an alignment mark for aligning both, conventionally, an alignment mark formed of a dielectric material having a refractive index different from that of the imprint mold (see Patent Document 1) cannot be filled with imprint resin. An alignment mark consisting of a concavo-convex structure with deep recesses (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 imaging device (see Patent Document 3), and a non-transfer area of the mold. Alignment marks (see Patent Document 4), etc., are known which are formed of a structure lower than the height of a mesa structure having a transfer region as an upper surface.

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 region around the mesa structure 3' on the substrate, and an alignment mark 5' made of a convex structure is formed in the non-transfer region. . In fabricating this imprint mold, a master mold 20' provided with alignment marks 23' and an imprint mold substrate having a mesa structure 3' and an alignment mark 5' formed in a non-transfer region are prepared. 1′ is prepared, and both alignment marks 5′ and 23′ are observed from the rear surface side of the master mold 20′ using an imaging device 70 or the like, so that the relationship between the master mold 20′ and the imprint mold substrate 1′ can be determined. Alignment can be performed with high accuracy (see FIG. 21).

In recent years, along with the miniaturization of patterns and multilayering 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' It is required to further improve 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 marks 23' of the master mold 20' and the alignment marks 5' of the imprint mold substrate 1' in closer proximity. .

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

In order to bring 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'. is formed, and an alignment mark 23' is also formed on the master mold 20' so as to correspond to the alignment mark 5'. However, if an alignment mark 5' made of a structure is formed on the upper surface of the mesa structure 3', when forming a pattern on a transfer 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. When it is necessary to form a separate pattern in a post-process in a region on the substrate to be transferred facing the alignment mark 5′ during 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.

Further, since the refractive index of the base material constituting the master mold 20' and the imprint mold substrate 1' is substantially the same as the refractive index of the imprint resin, the alignment marks 5' and 23' can be visually recognized. For this purpose, alignment of the two is performed while imprint resin is not filled in the recesses of the alignment marks 23' of the master mold 20' (see Patent Document 2). The amount of imprint resin supplied onto the mesa structure 3' of the imprint mold substrate 1' is controlled so that the concave portions of the alignment marks 23' are not filled with the imprint resin. Since it is difficult to completely control the flow of the imprint resin between the mesa structure 3' and the like, the amount of the imprint resin filled in the concave portion of the alignment mark 23' increases or decreases. Sometimes. As a result, the required amount of imprint resin for transferring the pattern positioned 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 provides an imprint mold substrate that enables high-precision alignment and has removable alignment marks, and a master that enables high-precision alignment with the imprint mold substrate. An object of the present invention is to provide a mold, a method for manufacturing an imprint mold using the same, and a method for manufacturing the master mold.

In order to solve the above problems, an embodiment of the present disclosure provides a method of manufacturing an imprint mold using an imprint mold substrate and a master mold, wherein the imprint mold substrate includes a first surface and a master mold. a substrate having a second surface facing the first surface; and a convex structure projecting from the first surface of the substrate and having an upper surface, wherein the upper surface of the convex structure has unevenness. A pattern area in which a pattern can be formed and a non-pattern area which is an area other than the pattern area are set, and an alignment mark is provided in at least a part of the non-pattern area, 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 , and the master mold is the imprint mold substrate A master substrate having a pattern-forming surface and an opposing surface facing the pattern-forming surface, and a master substrate provided on the pattern-forming surface of the master substrate. a transfer pattern having concave portions and convex portions corresponding to the uneven pattern to be formed in the pattern region of the imprint mold substrate; and an alignment pattern used for alignment with the imprint mold substrate. wherein the alignment pattern is composed of an uneven structure including convex portions and concave portions, and the bottom surface of the concave portion of the uneven structure is composed of a material having a predetermined contrast difference with respect to the master base material. and a top surface of the protrusion is located closer to the opposing surface than the pattern forming surface along the thickness direction of the master substrate, and the imprint mold a preparation step of preparing a substrate for imprint mold and the master mold; a resin supply step of supplying an active energy ray-curable imprint resin to the upper surface portion of the convex structure portion of the imprint mold substrate; a contacting step of contacting the pattern-forming surface of the master mold with a curable imprint resin to fill at least the transfer pattern with the active energy ray-curable imprint resin; and bringing the pattern-forming surface of the master mold into contact. a curing step of curing the active energy ray-curable imprint resin; and the cured active energy ray-curable imprint resin. and a release step of separating the master mold from the imprint resin, and in the contact step, the alignment pattern of the master mold and the alignment marks of the imprint mold substrate are aligned with the opposing surface of the master mold. By observing from the side or the second surface side of the imprint mold substrate, alignment of the master mold and the imprint mold substrate is performed, and in the resin supply step, the transfer pattern and the alignment A method for manufacturing an imprint mold is provided, which supplies the active energy ray-curable imprint resin to such an extent that the pattern can be filled .

The base material is made of a transparent material, and a material containing a metal can be used as a material forming the concave- convex pattern structure as the alignment mark. The material forming the alignment mark may be the same material. A material containing chromium (Cr) can be used as a material for forming the alignment mark and the hard mask.

The distance along the thickness direction of the master base material between the plane including the pattern-formed surface and the top surface of the projections may be greater than or equal to the depth of the recesses of the transfer pattern. and the depth of the concave portion of the concave-convex structure as the alignment pattern should 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. The pitch may be the same as the pitch of the uneven pattern structure as a mark.

The high-contrast film may have a film thickness that allows transmission of 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.

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 volumes of the transfer pattern and the alignment pattern are considered. The active energy ray-curable imprint resin may be supplied at the supply amount.

A hard mask layer is provided on at least the pattern region of the upper surface portion of the protruded structure portion of the imprint mold substrate, and a resin pattern formed on the upper surface portion of the protruded structure portion by the releasing step. forming a hard mask pattern by etching the hard mask layer using as a mask; and removing the hard mask pattern and the alignment mark remaining on the upper surface of the convex structure.

According to the present disclosure, an imprint mold substrate that enables highly accurate alignment and has removable alignment marks, a master mold that can be aligned with the imprint mold substrate with high accuracy, and an imprint mold substrate that can be aligned with high accuracy. 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 showing 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 a convex structure in the imprint mold substrate according to one embodiment of the present disclosure. FIG. 3 is a side view showing a schematic configuration of a protruding structure in the imprint mold substrate according to the embodiment of the present disclosure. FIG. 4 is a plan view showing a schematic configuration of one aspect (Part 1) of the alignment mark in the imprint mold substrate according to the embodiment of the present disclosure. FIG. 5 is a plan view showing a schematic configuration of one mode (Part 2) of the alignment mark in the imprint mold substrate according to the embodiment of the present disclosure. FIG. 6 is a plan view showing a schematic configuration of one mode (part 3) of the alignment mark in the imprint mold substrate according to the embodiment of the present disclosure. FIG. 7A is a plan view showing a schematic configuration of one aspect (Part 1) of each of the alignment marks in the imprint mold substrate and the alignment marks of the master mold according to one embodiment of the present disclosure; 7(B) is a plan view showing a schematic configuration of a mode (No. 1) in which both alignment marks overlap. FIG. 8A is a plan view showing a schematic configuration of one aspect (part 2) of each of the alignment marks in the imprint mold substrate and the alignment marks of the master mold according to one embodiment of the present disclosure; 8(B) is a plan view showing a schematic configuration of a mode (No. 2) in which both alignment marks overlap. FIG. 9 is a process flow diagram showing each process of a method for manufacturing an imprint mold substrate according to an embodiment of the present disclosure with a partially enlarged cut end surface. FIG. 10 is a cut end view showing a schematic configuration of a master mold in one 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 in one embodiment of the present disclosure. FIG. 12 is a plan view showing a schematic configuration of a mode (part 3) in which the alignment marks of the imprint mold substrate and the alignment marks of the master mold are overlapped according to an embodiment of the present disclosure. FIGS. 13A and 13B are schematic configurations of aspects (parts 4 and 5) in which the alignment marks of the imprint mold substrate and the alignment marks of the master mold overlap according to an embodiment of the present disclosure. It is a plan view showing the. FIGS. 14A to 14C are process flow diagrams showing respective steps of a method of manufacturing a master mold according to an embodiment of the present disclosure with partially enlarged cut end surfaces. FIGS. 15(A) to 15(C) are process flow diagrams showing each process of a method of manufacturing a master mold according to an embodiment of the present disclosure, which are subsequent to FIG. FIGS. 16A to 16D are process flow diagrams showing respective steps of a method for forming a high-contrast film according to one embodiment of the present disclosure, using cut end surfaces. FIGS. 17A to 17C are process flow diagrams showing respective steps of a replica mold manufacturing method according to an embodiment of the present disclosure in terms of cut end surfaces. FIGS. 18(A) to 18(C) are process flow diagrams showing the steps following FIG. 17 in a cut end face, which are steps of the replica mold manufacturing method according to an embodiment of the present disclosure. FIGS. 19A to 19E are process flow diagrams for explaining the effects of the relationship between the depth of the alignment region of the master mold and the depth of the recesses of the transfer pattern in one embodiment of the present disclosure. FIGS. 20A to 20E are process flow diagrams for explaining the effects of the relationship between the depth of the alignment region of the master mold and the depth of the recesses of the transfer pattern in one embodiment of the present disclosure. FIG. 21 is a cut end view schematically showing an alignment method using a conventional master mold and imprint mold substrate.

Embodiments of the present disclosure will be described with reference to the drawings.
In the drawings, in order to facilitate understanding, the shape, scale, ratio of vertical and horizontal dimensions, etc. of each part may be changed from the real thing or exaggerated. In this specification and the like, a numerical range represented by "to" means a range including the numerical values described before and after "to" as lower and upper limits, respectively. In this specification and the like, terms such as "film", "sheet", and "plate" are not distinguished from each other based on the difference in designation. For example, "plate" is a concept that includes members that can be generally called "sheets" and "films."

[Substrate for imprint mold]
FIG. 1 is a cut end view showing the schematic configuration of the imprint mold substrate according to the present embodiment, and FIG. 2 is a partially enlarged cut end view showing the schematic configuration of part A in the imprint mold substrate shown in FIG. , and 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 base material 2 having a first surface 2A and a second surface 2B facing the first surface 2A; and a recessed portion 4 formed on the second surface 2B side.

As the base material 2, those commonly used as substrates for imprint molds, such as quartz glass substrates, soda glass substrates, fluorite substrates, calcium fluoride substrates, magnesium fluoride substrates, barium borosilicate glass, and aminoborosilicate glass. , glass substrates such as alkali-free glass substrates such as aluminosilicate glass, resin substrates such as polycarbonate substrates, polypropylene substrates, polyethylene substrates, polymethyl methacrylate substrates, polyethylene terephthalate substrates, and two or more substrates arbitrarily selected from these may be used, such as a transparent substrate such as a laminated substrate obtained by laminating the above, a metal substrate such as a nickel substrate, a titanium substrate, an aluminum substrate; or a semiconductor substrate such as a silicon substrate, a gallium nitride substrate, or the like. However, in the manufacturing method of the replica mold and the imprinting method using the replica mold, which will be described later, if light irradiation is performed from the base material 2 side in order to cure the imprint resin, the base material 2 does not absorb the imprint resin. It must be light transmissive so that it can be cured. In this embodiment, the term “transparent” means that light having a wavelength capable of curing the imprint resin can be transmitted, and means 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, particularly preferably 95% or more.

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

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

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 plan view. The shape of the convex structure portion 3 in plan view is substantially rectangular. The size of the protruding structure 3 is appropriately set according to the product to be manufactured through imprint processing using the imprint mold substrate 1, and is set to approximately 30 mm×25 mm, for example.

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

The upper surface portion 3A of the convex structure portion 3 is positioned substantially in the center thereof and includes a pattern area PA in which the uneven pattern 11 is formed and a non-pattern area NA surrounding the pattern area PA. A hard mask layer 6 is formed in the pattern area PA. Materials constituting the hard mask layer 6 include, for example, metals such as chromium, titanium, tantalum, silicon and aluminum; chromium compounds such as chromium nitride, chromium oxide and chromium oxynitride; tantalum oxide, tantalum oxynitride and boric oxide. tantalum compounds such as tantalum oxide and tantalum boride oxynitride; titanium nitride, silicon nitride, silicon oxynitride; can be done. The non-pattern area NA includes at least one (four in the illustrated example) alignment mark areas AA, and alignment marks 5 are formed in the alignment mark areas 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 base material 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 portion 3A of the convex structure portion 3 of the imprint mold substrate 1. The alignment mark 5 can be easily visually recognized when aligning the master mold 20 and the imprint mold substrate 1 when transferring the transfer pattern 22 . When the base material 2 is made of a transparent substrate, examples of materials that make up the alignment marks 5 include 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 during etching of the base material 2 in relation to the material forming the base material 2, and the alignment mark can be formed without damaging the base material 2. 5 is a removable material. For example, the material that constitutes the alignment marks 5 is a material that has an etching selectivity with respect to the base material 2, and by using a predetermined etchant, only the alignment marks 5 can be etched without etching the base material 2. Any material can be used as long as it is 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 portion 3A of the convex structure portion 3 . , the alignment area AA in which the alignment mark 5 is formed is not etched. As a result, after a pattern is formed on a substrate to be transferred (for example, a silicon wafer) using the replica mold 10, a pattern is formed on the substrate to be transferred corresponding to the area (alignment area AA of the imprint mold substrate 1) in the replica mold 10. It becomes possible to form a separate pattern in the area of . Further, since the alignment mark 5 is made of a removable material, the non-pattern area NA (alignment area AA) in the replica mold 10 can be made flat.

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 marks 5 are the same, the hard mask layer 6 and the alignment marks 5 may be formed or removed at the same time when the imprint mold substrate 1 is manufactured. It becomes possible to Even if both are made of the same material, if the thickness of the hard mask layer 6 and the thickness of the alignment mark 5 are different, they may be formed separately.

The shape of the projections 51 of the concave-convex pattern structure constituting the alignment mark 5 in plan view can be appropriately set according to 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 projections 51 of the concave-convex pattern structure forming the alignment mark 5 may be such that the alignment mark 5 can be visually recognized by an imaging device or the like. For example, the length of the convex portion 51 of the concave-convex pattern structure forming the alignment mark 5 in the lateral direction may be about 100 nm to 1000 nm.

When the planar view shape of the convex portions 51 of the concave-convex pattern structure constituting the alignment mark ₅ is linear (see FIG. 4), the pitch P5 of the concave-convex pattern structure is the same as the concave-convex pattern structure of the alignment mark 23 of the master mold 20 described later. It may be the same as the structure pitch P ₂₃ (see FIG. 7(A)) or may be different (see FIG. 8(A)). Since the pitch P5 of the concave-convex pattern structure of the alignment marks ₅ is the same as the pitch P23 of the concave-convex structure of the alignment marks ₂₃ of the master mold 20, the master mold 20 and the imprint mold substrate 1 are superimposed, and the imaging element is formed. When the alignment marks 5 and 23 are observed by , linear patterns with substantially equal intervals are observed (see FIG. 7B). Based on the shape of this linear pattern, it is possible to align the master mold 20 and the imprint mold substrate 1 with high accuracy. On the other hand, since the pitch P5 of the concave-convex pattern structure of the alignment marks ₅ is different from the pitch P23 of the concave-convex structure of the alignment marks ₂₃ of the master mold 20, the master mold 20 and the substrate 1 for imprint mold are superimposed, and the imaging element When the alignment marks 5 and 23 are observed by , a bright and dark striped pattern, that is, a moire pattern is observed (see FIG. 8B). In this moire pattern, the positions of bright and dark stripes change depending on the relative positional relationship between the alignment marks 5 and 23 . Therefore, based on the positions of the bright and dark stripes, it is possible to align the master mold 20 and the imprint mold substrate 1 with high accuracy.

The pitch P5 of the concavo-convex pattern structure of the alignment marks ₅ on the imprint mold substrate 1 is in relation to the pitch P23 of the concavo-convex structure of the alignment marks ₂₃ of the master mold 20. may be appropriately set so that the alignment marks 5 and 23 can be observed as a moire pattern by the imaging device when they are aligned.

The height T ₅₁ of the projection 51 of the alignment mark 5 may be set as a height difference with which contrast with the recess of the alignment mark 5 can be obtained. can be set accordingly. On the other hand, in relation to the depth D213 of the alignment mark region ₂₁₃ in which the alignment mark 23 is formed in the master mold 20, which will be described later, the height _{T51 should be equal to or less than the depth D213 .} If the height T ₅₁ of the protrusions 51 of the alignment mark 23 exceeds the depth D ₂₁₃ , the alignment mark 5 may not reach the master mold 20 when imprinting the imprint mold substrate 1 using the master mold 20 . contact with the alignment mark region 213, the master mold 20 may be damaged or foreign matter may be generated.

A recess 4 having a predetermined size is formed on the second surface 2B of the base material 2 . By forming the recess 4, during imprint processing using the replica mold 10 (see FIG. 18C) manufactured from the imprint mold substrate 1 according to the present embodiment, particularly with the imprint resin, or when the replica mold 10 is peeled off, the substrate 2, particularly the upper surface portion 3A of the convex structure portion 3, can be curved. As a result, when the upper surface portion 3A of the convex structure portion 3 and the imprint resin are brought into contact with each other, gas is sandwiched between the uneven pattern 11 formed on the upper surface portion 3A of the convex structure portion 3 and the imprint resin. In addition, the replica mold 10 can be easily peeled off from the pattern obtained by transferring the concave-convex pattern 11 to the imprint resin.

It is preferable that the planar view shape of the recessed portion 4 is substantially circular. Due to the substantially circular shape, the projections of the replica mold 10 can be adjusted during the imprinting process, particularly when the imprinting resin is brought into contact with the upper surface portion 3A of the projecting structure portion 3 or when the replica mold 10 is peeled off from the imprinting resin. The upper surface portion 3A of the structural portion 3 can be curved substantially uniformly within its plane.

The size of the recessed portion 4 in a plan view is particularly limited as long as it is a size that allows the convex structure portion 3 to be included in the projection area obtained by projecting the recessed portion 4 onto the first surface 2A side of the base material 2. not to be If the projected area is too large to include the convex structure 3, the entire surface of the upper surface 3A of the convex structure 3 of the replica mold 10 may not be curved effectively.

According to the imprint mold substrate 1 having the above-described configuration, the alignment marks 5 are made of a material having a contrast difference with respect to the base material 2 , so that the alignment marks 23 of the master mold 20 are in contact with each other. Even if the printed 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 alignment with the master mold 20 can be performed with high accuracy. As a result, the uneven pattern 11 can be formed on the upper surface portion 3A of the convex structure portion 3 of the imprint mold substrate 1 with high positional accuracy. Further, in the imprint mold substrate 1 according to the present embodiment, the alignment marks 5 are made of a material having an etching selectivity with respect to the base material 2, so that the replica mold 10 can be manufactured from the imprint mold substrate 1. In the process of forming the uneven 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 removable material, the non-pattern area NA (alignment area AA) in the replica mold 10 can be made flat. As a result, after a pattern is formed on a substrate to be transferred (for example, a silicon wafer) using the replica mold 10, a pattern is formed on the substrate to be transferred corresponding to the area (alignment area AA of the imprint mold substrate 1) in the replica mold 10. It becomes possible to form a separate pattern in the area of .

[Manufacturing method of substrate for imprint mold]
A method for manufacturing the imprint mold substrate described above will be described. FIG. 9 is a process flow diagram showing each process of the method for manufacturing an imprint mold substrate according to the present embodiment, using a partially enlarged cut end surface in the vicinity of the convex structure.

First, a base material is prepared which has a first surface and a second surface facing the first surface, and which is provided with convex structures 3 protruding from the first surface and recesses formed on the second surface side. Then, a metal-containing layer 6' is formed on the upper surface portion 3A of the convex structure portion 3 (see FIG. 9A).

As the base material, those commonly used as substrates for imprint molds, such as quartz glass substrates, soda glass substrates, fluorite substrates, calcium fluoride substrates, magnesium fluoride substrates, barium borosilicate glass, aminoborosilicate glass, Glass substrates such as alkali-free glass substrates such as aluminosilicate glass substrates, resin substrates such as polycarbonate substrates, polypropylene substrates, polyethylene substrates, polymethyl methacrylate substrates, polyethylene terephthalate substrates, and two or more substrates arbitrarily selected from these substrates. A transparent substrate or the like such as a laminated substrate formed by lamination can be used.

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

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

The material constituting the metal-containing layer 6′ may be any material that constitutes the alignment marks 5 and the hard mask layer 6 in the imprint mold substrate 1, and examples thereof include chromium, (Cr), molybdenum (Mo), and tantalum. (Ta), tungsten (W), zirconium (Zr), titanium (Ti), and the like can be used singly or in combination of two or more arbitrarily selected.

The thickness of the metal-containing layer 6 ′ is appropriately set according to the height T ₅₁ of the projections 51 of the alignment marks 5 on the imprint mold substrate 1 . The height T ₅₁ of the projection 51 of the alignment mark 5 may be set as a height difference with which contrast with the recess of the alignment mark 5 can be obtained. It can be set as appropriate. For example, the thickness of the metal-containing layer 6' can be appropriately set within a range of approximately 5 nm to 30 nm.

The method for forming the metal-containing layer 6' on the first surface of the substrate is not particularly limited, and examples include known film formation methods such as sputtering, PVD (Physical Vapor Deposition), and CVD (Chemical Vapor Deposition). 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 portion 3A of the convex structure portion 3 of the substrate. Then, the resist layer corresponding to the alignment marks 5 is subjected to electron beam drawing processing and development processing, or exposure processing and development processing through a photomask (not shown) having a predetermined opening in the resist layer. A 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 or a photosensitive resist. For example, a negative or positive photosensitive material can be used. It is preferred to use a photosensitive material of the type. The film thickness of the resist layer is not particularly limited, and can be appropriately set according to the selectivity or the like according to the 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, leaving a remaining portion of the metal-containing layer 6′. 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 portion 3A of the convex structure portion 3 of the substrate (see FIG. 9(C)). Thus, the imprint mold substrate 1 according to the present embodiment is manufactured. After forming the alignment mark 5 by etching the metal-containing layer 6', the metal-containing layer 6' remaining in the area (for example, the pattern area PA) other than the alignment area AA is completely removed by etching, and the area ( For example, a hard mask layer 6 may be formed in the pattern area PA).

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

The master mold 20 in this embodiment includes a base portion 21 having a first surface 21A and a second surface 21B facing the first surface 21A, and a transfer pattern provided in a pattern area 211 on the first surface 21A of the base portion 21. 22 and alignment marks 23 provided in a non-patterned area 212 surrounding the patterned 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 uneven pattern 11 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. is.

As the base 21, substrates commonly used for imprint molds, such as quartz glass substrates, soda glass substrates, fluorite substrates, calcium fluoride substrates, magnesium fluoride substrates, barium borosilicate glass, aminoborosilicate glass, Glass substrates such as alkali-free glass substrates such as aluminosilicate glass substrates, resin substrates such as polycarbonate substrates, polypropylene substrates, polyethylene substrates, polymethyl methacrylate substrates, polyethylene terephthalate substrates, and two or more substrates arbitrarily selected from these substrates. A transparent substrate or the like such as a laminated substrate formed by lamination may be used.

The planar view shape of the base portion 21 is not particularly limited, and includes, 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 plan view is generally rectangular.

The size of the base 21 (the size in plan view) is also not particularly limited, but when the base 21 is made of the quartz glass substrate, the size of the base 21 is, for example, about 152 mm×152 mm. Also, the thickness of the base portion 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, etc. of the transfer pattern 22 are the shapes, dimensions, etc. 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. can be set appropriately according to For example, the shape of the transfer pattern 22 may be a line-and-space shape, a pillar shape, a hole shape, a lattice shape, or the like. Also, the dimension of the transfer pattern 22 can be set to, for example, about 10 nm to 200 nm.

The alignment mark 23 is configured by an uneven structure formed in an alignment mark area 213 within the non-pattern area 212 on the first surface 21A. The alignment mark region 213 is a region recessed from the first surface 21A of the base portion 21 toward the second surface 21B side. A structure is formed.

A high-contrast film 24 made of a material having a predetermined contrast difference with respect to the base portion 21 is formed on the bottom surface of the concave portion 231 of the uneven structure forming 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 portion 21, the transfer pattern 22 of the master mold 20 can be transferred onto the upper surface portion 3A of the convex structure portion 3 of the imprint mold substrate 1. When aligning the master mold 20 and the imprint mold substrate 1 for transfer, the alignment marks 23 can be easily visually recognized. When the base 21 is made of a transparent substrate, examples of materials that make up the high-contrast film 24 include chromium, (Cr), molybdenum (Mo), tantalum (Ta), tungsten (W), zirconium (Zr), ), titanium (Ti), and the like.

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

When the concave-convex structure forming the alignment mark 23 has a linear shape in plan view, the pitch P ₂₃ of the concave-convex structure is the same as the pitch P ₅ of the concave-convex pattern structure of the alignment mark 5 of the imprint mold substrate 1 . (see FIG. 7(A)) or may be different (see FIG. 8(A)). Since the pitch P23 of the uneven structure of the alignment marks ₂₃ is the same as the pitch P5 of the uneven pattern structure of the alignment marks ₅ of the imprint mold substrate 1, the master mold 20 and the imprint mold substrate 1 are superimposed. , when the alignment marks 5 and 23 are observed by the imaging element, a line-shaped pattern with substantially equal intervals is observed (see FIG. 7B). Based on the shape of this linear pattern, it is possible to align the master mold 20 and the imprint mold substrate 1 with high accuracy. On the other hand, since the pitch P23 of the uneven structure of the alignment marks ₂₃ is different from the pitch P5 of the uneven pattern structure of the alignment marks ₅ of the imprint mold substrate 1, the master mold 20 and the imprint mold substrate 1 are superimposed. , when the alignment marks 5 and 23 are observed by the imaging device, a bright and dark striped pattern, that is, a moire pattern is observed (see FIG. 8B). In this moire pattern, the positions of bright and dark stripes change depending on the relative positional relationship between the alignment marks 5 and 23 . Therefore, based on the positions of the bright and dark stripes, it is possible to align the master mold 20 and the imprint mold substrate 1 with high accuracy.

The pitch P ₂₃ of the concave-convex structure of the alignment marks 23 in the master mold 20 is in relation to the pitch P ₅ of the concave-convex pattern structure of the alignment marks 5 of the imprint mold substrate 1 . may be appropriately set so that the alignment marks 5 and 23 can be observed as a moire pattern by the imaging device when they are aligned.

As will be described later, in the process of manufacturing the master mold 20 in this embodiment, the transfer pattern 22 and the alignment marks 23 are formed by simultaneous etching. Therefore, the depth D ₂₃₁ of the concave portion 231 of the concave-convex structure forming 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 region 213 is equal to or greater than the height T ₅₁ of the projections 51 of the uneven pattern structure forming the alignment marks 5 of the imprint mold substrate 1 and the depth of the recesses 221 of the transfer pattern 22 . D ₂₂₁ or higher. When the depth D ₂₁₃ of the alignment mark region 213 is less than the height T ₅₁ of the protrusion 51 of the alignment mark 5 of the imprint mold substrate 1 , the imprint mold substrate 1 is imprinted using the master mold 20 . , the alignment mark region 213 and the alignment mark 5 of the imprint mold substrate 1 may come into contact with each other, and the master mold 20 may be damaged. Further, when the depth D ₂₁₃ of the alignment mark region 213 is less than the depth D ₂₂₁ of the concave portion 221 of the transfer pattern 22, the relative positions of the concave-convex structure forming the alignment mark 23 and the concave-convex pattern structure forming the alignment mark 5 When (the positions of the convex portions and the concave portions (positions of the substrate 2 and the base portion 21 when viewed in the thickness direction during imprint processing)) do not match, the alignment marks of the imprint mold substrate 1 are not aligned. There is a risk that the base material 2 located below the 5 will be processed (etched).

According to the master mold 20 having the configuration described above, the depth D ₂₁₃ of the alignment mark region 213 is equal to or greater than the height T ₅₁ of the projections 51 of the uneven pattern structure forming the alignment marks 5 of the imprint mold substrate 1, Further, since the depth D ₂₂₁ of the concave portion 221 of the transfer pattern 22 is more than D 221 , even if the relative positions of the concave-convex structure forming the alignment mark 23 and the concave-convex pattern structure forming the alignment mark 5 do not match. , the replica mold 10 in which the non-pattern area NA is composed of a flat surface can be manufactured without processing (etching) the base material 2 positioned below the alignment marks 5 of the imprint mold substrate 1 .

[Manufacturing method of master mold]
An example of the method of manufacturing the master mold 20 described above will be described. 14 and 15 are process flow diagrams showing each process of the method of manufacturing the master mold according to this embodiment in a partially enlarged cut end view.

A base 21 having a first surface 21A and a second surface 21B facing the first surface 21A and having a hard mask layer 25 provided on the first surface 21A is prepared (see FIG. 14A), and the hard mask layer 25 is provided on the first surface 21A. A resist pattern corresponding to the uneven structure of the transfer pattern 22 and the alignment marks 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, thereby forming a hard mask pattern 26 on the first surface 21A ( See FIG. 14(B)).

As the base 21, substrates commonly used for imprint molds, such as quartz glass substrates, soda glass substrates, fluorite substrates, calcium fluoride substrates, magnesium fluoride substrates, barium borosilicate glass, aminoborosilicate glass, Glass substrates such as alkali-free glass substrates such as aluminosilicate glass substrates, resin substrates such as polycarbonate substrates, polypropylene substrates, polyethylene substrates, polymethyl methacrylate substrates, polyethylene terephthalate substrates, and two or more substrates arbitrarily selected from these substrates. A transparent substrate or the like such as a laminated substrate formed by lamination may be used.

The planar view shape of the base portion 21 is not particularly limited, and includes, 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 plan view is generally rectangular.

The size of the base 21 (the size in plan view) is also not particularly limited, but when the base 21 is made of the quartz glass substrate, the size of the base 21 is, for example, about 152 mm×152 mm. Also, the thickness of the base portion 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.

Materials constituting the hard mask layer 25 include, for example, metals such as chromium, titanium, tantalum, silicon, and aluminum; chromium-based compounds such as chromium nitride, chromium oxide, and chromium oxynitride; tantalum compounds such as tantalum oxide and tantalum boride oxynitride; titanium nitride, silicon nitride, silicon oxynitride; can be done.

The hard mask layer 25 is formed by patterning in a process to be described later, and constitutes a hard mask pattern 26 used as a mask for etching the transfer pattern 22 and the concave-convex structure that constitutes the alignment mark 23 . Therefore, it is preferable to select the constituent material of the hard mask layer 25 according to the constituent material of the base portion 21 and in consideration of the etching selectivity and the like. 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 film thickness of the hard mask layer 25 is appropriately set in consideration of the etching selectivity and the like according to the constituent material of the base portion 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 approximately 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. method.

The material forming the resist pattern formed on the hard mask layer 25 is not particularly limited, and for example, a negative-type or positive-type 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 the selection ratio or the like according to the constituent material of the hard mask layer 25 . The resist pattern can be formed by subjecting a resist layer provided on the hard mask layer 25 to electron beam drawing processing and development processing.

Next, the hard mask pattern 26 is used as a mask to dry-etch the first surface 21A of the base 21, thereby forming the uneven structure of the transfer pattern 22 and the alignment marks 23 (see FIG. 14C). The dry etching process of the base portion 21 can be performed by appropriately selecting an etching gas according to the type of constituent material of the base portion 21 . As an 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 portion 21 on which the uneven structure of the transfer pattern 22 and the alignment marks 23 is formed. A resist pattern 28 having openings corresponding to the alignment mark regions 213 is formed by exposure and development (see FIG. 15A).

Then, by applying a dry etching process to the first surface 21A of the base 21 using the resist pattern 28 as a mask, the alignment mark 23 is formed on the bottom surface by recessing from the first surface 21A of the base 21 toward the second surface 21B. An alignment mark region 213 having an uneven structure can be formed (see FIG. 15B).

In forming the alignment mark region 213, the depth D ₂₁₃ of the alignment mark region 213 is the uneven pattern structure constituting 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 first surface 21A of the base portion 21 is dry-etched so that the height T51 of the projections ₅₁ or more and the depth D221 or more of the recesses ₂₂₁ of the transfer pattern 22 are obtained. When the depth D ₂₁₃ of the alignment mark region 213 is less than the height T ₅₁ of the protrusion 51 of the alignment mark 5 of the imprint mold substrate 1 , the imprint mold substrate 1 is imprinted using the master mold 20 . , the alignment mark region 213 and the alignment mark 5 of the imprint mold substrate 1 may come into contact with each other, and the master mold 20 may be damaged. Further, when the depth D ₂₁₃ of the alignment mark region 213 is less than the depth D ₂₂₁ of the concave portion 221 of the transfer pattern 22, the relative positions of the concave-convex structure forming the alignment mark 23 and the concave-convex pattern structure forming the alignment mark 5 When the positions of the convex portions and the concave portions (positions of the base material 2 and the base portion 21 when viewed in the thickness direction during imprint processing) do not match, the alignment marks 5 of the imprint mold substrate 1 do not match. 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 portion 21 is formed on the bottom surface of the recessed portion 231 of the concave-convex structure forming the alignment mark 23 (see FIG. 15C). When the base 21 is made of a transparent substrate, examples of materials that make up the high-contrast film 24 include chromium, (Cr), molybdenum (Mo), tantalum (Ta), tungsten (W), zirconium (Zr), ), titanium (Ti), and the like. Thus, the master mold 20 in this embodiment is manufactured.

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

Next, a resist film 27 is formed thereon, and the stepped substrate is pressed so that the film thickness of the region where the alignment mark 23 is formed is thicker than the film thickness of the region where the transfer pattern 22 is formed. to deform the resist film 27 (see FIG. 16B). The resist film 27 having such a stepped structure may be formed by imprint processing using an imprint mold having a structure corresponding to the stepped structure.

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

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

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

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

The amount of the imprint resin 40 supplied to the upper surface portion 3A of the protruding structure 3 may be an amount that allows the transfer pattern 22 and the alignment marks 23 of the master mold 20 to be completely filled 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 and The imprint resin 40 is developed between the imprint mold substrate 1 and the upper surface portion 3A of the convex structure portion 3, and the imprint resin 40 is completely filled in the transfer pattern 22 and the alignment marks 23 (FIG. 17B). reference). In this state, the master mold 20 and the imprint mold substrate 1 are aligned by observing the alignment marks 23 of the master mold 20 and the alignment marks 5 of the imprint mold substrate 1 with an imaging device or the like.

Since the alignment marks 5 are 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 surfaces of the recesses 231 of the uneven structure of the alignment marks 23, the alignment marks 5 and The alignment mark 23 can be easily visually recognized, and alignment between the two can be performed with high accuracy.

The convex portion 51 of the concave-convex pattern structure forming the alignment mark 5 has a linear shape in plan view (see FIG. 4), and the concave-convex structure forming the alignment mark 23 has a linear shape in plan view. When the pitch P5 of the pattern structure is the same as the pitch P23 of the concave _- convex structure of the alignment marks ₂₃ (see FIG. 7A), the master mold 20 and the imprint mold substrate 1 are superimposed and aligned using an imaging device. When the marks 5 and 23 are observed, line-shaped patterns with substantially equal intervals are observed (see FIG. 7B). Based on the shape of this linear pattern, it is possible to align the master mold 20 and the imprint mold substrate 1 with high accuracy. On the other hand, when the pitch P5 of the concave-convex pattern structure of the alignment marks ₅ is different from the pitch P23 of the concave-convex structure of the alignment marks ₂₃ , the master mold 20 and the imprint mold substrate 1 are overlapped, and the alignment marks 5 and 5 are detected by the imaging element. 23, a bright and dark striped pattern, that is, a moire pattern is observed (see FIG. 8(B)). In this moire pattern, the positions of bright and dark stripes change depending on the relative positional relationship between the alignment marks 5 and 23 . Therefore, based on the positions of the bright and dark stripes, it is possible to align the master mold 20 and the imprint mold substrate 1 with high accuracy.

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

Subsequently, the residual film of the resist pattern 41 is removed (see FIG. 18A), and the resist pattern 41 is used as a mask to perform the dry etching process using, for example, 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, using the hard mask pattern 61 as a mask, the imprint mold substrate 1 is subjected to a dry etching process to form the uneven pattern 11 on the upper surface portion 3A of the convex structure portion 3 . After that, by removing the hard mask pattern 61 and the alignment marks 5 remaining on the upper surface portion 3A of the convex structure portion 3, the replica mold 10 is manufactured (see FIG. 18(C)). The dry etching of the imprint mold substrate 1 can be performed by appropriately selecting an etching gas according to the type of constituent material of the imprint mold substrate 1 . As an 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 this embodiment is made of a removable material, the non-pattern area NA of the upper surface portion 3A of the convex structure portion 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 (hard mask layer 6 ), the alignment mark 5 can be removed at the same time as the hard mask pattern 61 .

Since the depth D ₂₁₃ of the alignment mark region 213 of the master mold 20 in this embodiment is equal to or greater than the depth D ₂₂₁ of the concave portion 221 of the transfer pattern 22, the effects described below are exhibited.

The relative positions of the alignment marks 23 of the master mold 20 and the concave-convex pattern structure of the alignment marks 5 of the imprint mold substrate 1 (the positions of the convex portions and the concave portions (the thickness direction of the substrate 2 and the base portion 21 during imprint processing) ) do not match (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 (see FIG. 19 (B)), 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 portions 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 portions. (See FIG. 19C), the alignment marks 5 are masked by the resist pattern 41 during the etching process of the hard mask layer 6 . As a result, the film thickness of the alignment mark 5 becomes difficult to decrease (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 marks 5 and is not etched. That is, 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 non-pattern region NA is formed of a flat surface. It can be manufactured (see FIG. 19(E)).

On the other hand, the depth D213 of the alignment mark region ₂₁₃ of the master mold 20 is less than the depth D221 of the concave portion 221 of the transfer pattern 22, and the uneven structure of the alignment mark 23 of the master mold 20 and the imprint mold substrate 1 are aligned. When the relative positions of the marks 5 and the concave-convex pattern structure (the positions of the convex portions and the concave portions (positions of the substrate 2 and the base portion 21 when viewed in the thickness direction during imprint processing)) do not match ( 20A), 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 residual film 411 of the resist pattern 41 is removed. Then (see FIG. 20C), the thin film portion 412 of the resist pattern 41 on the convex portion of the concave-convex pattern structure portion of the alignment mark 5 disappears, and the thickness of the resist pattern 41 on a portion of the concave portion is reduced. 20(C)), part of the resist pattern 41 that masks the concave portion of the alignment mark 5 disappears during the etching process of the hard mask layer 6. Then, as shown in FIG. As a result, a part of the alignment mark 5 is etched and disappears, or the film thickness of a part of the alignment mark 5 becomes extremely thin (see FIG. 20(D)). Therefore, when the imprint mold substrate 1 is subsequently etched, 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 marks 5 and is etched (FIG. 20 (E )reference).

Thus, 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 portion 3 It is possible to manufacture a replica mold 10 in which the non-patterned area NA in 3A is composed of a flat surface.

The embodiments described above are described to facilitate understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiments is meant to include all design changes and equivalents that fall within the technical scope of the present invention.

REFERENCE SIGNS LIST 1 Imprint mold substrate 2 Base material 2A First surface 2B Second surface 3 Convex structure portion 3A Upper surface portion 32 Side surface portion 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 (10)

A method for manufacturing an imprint mold using an imprint mold substrate and a master mold ,
The imprint mold substrate includes a base material having a first surface and a second surface facing the first surface, and a protruding structure part protruding from the first surface of the base material and having an upper surface part, A pattern area located substantially in the center of the upper surface and a non-pattern area surrounding the pattern area are set on the upper surface of the convex structure, and at least a part of the non-pattern area is provided. is provided with an alignment mark, 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. and
The master mold is used for forming an uneven pattern in the pattern region of the imprint mold substrate, and includes a master substrate having a pattern formation surface and an opposing surface facing the pattern formation surface; A transfer pattern provided on the pattern forming surface of the master base material and having recesses and protrusions corresponding to the uneven pattern to be formed in the pattern region of the imprint mold substrate, and the imprint mold substrate. and an alignment pattern used for alignment with the master base material, wherein the alignment pattern is configured by an uneven structure including a convex portion and a concave portion, and the bottom surface of the concave portion of the uneven structure is provided with the master base material A high-contrast film made of a material having a predetermined contrast difference is provided, and the top surface of the convex portion is located closer to the opposing surface than the pattern-formed surface along the thickness direction of the master base material. is located on the side of
a preparation step of preparing the imprint mold substrate and the master mold;
a resin supply step of supplying an active energy ray-curable imprint resin to the upper surface portion of the convex structure portion of the imprint mold substrate;
a contact step of bringing the pattern formation surface of the master mold into contact with the active energy ray-curable imprint resin to fill 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 with which the pattern formation surface of the master mold is brought into contact;
a releasing 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 marks 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. By doing so, the master mold and the imprint mold substrate are aligned ,
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.
A method for manufacturing an imprint mold. 2. The method of manufacturing an imprint mold according to claim 1 , wherein in the resin supply step, the active energy ray-curable imprint resin is supplied in a supply amount in consideration of volumes of the transfer pattern and the alignment pattern. a hard mask layer is provided in 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 in the releasing step as a mask;
a step of etching the imprint mold substrate using the hard mask pattern as a mask to form an uneven pattern in the pattern region of the upper surface portion of the convex structure portion;
3. The method of manufacturing an imprint mold according to claim 1, further comprising removing the hard mask pattern and the alignment mark remaining on the top surface of the convex structure. A material forming the hard mask layer and a material forming the alignment mark are the same material.
The method for manufacturing an imprint mold according to claim 3. The base material is made of a transparent material,
A material constituting the concave-convex pattern structure as the alignment mark is a material containing metal.
A method for manufacturing an imprint mold according to any one of claims 1 to 4. The alignment mark is made of a material containing chromium.
A method for manufacturing an imprint mold according to any one of claims 1 to 5. The distance along the thickness direction of the master substrate between the plane including the pattern-formed surface and the top surface of the projections is equal to or greater than the depth of the recesses of the transfer pattern.
A method for manufacturing an imprint mold according to any one of claims 1 to 6. The depth of the concave portion of the transfer pattern and the depth of the concave portion of the concave-convex structure as the alignment pattern are substantially the same.
A method for manufacturing an imprint mold according to any one of claims 1 to 7. The pitch of the concavo-convex structure as the alignment pattern of the master mold is different from the pitch of the concavo-convex pattern structure as the alignment mark of the imprint mold substrate.
A method for manufacturing an imprint mold according to any one of claims 1 to 8. The pitch of the concave-convex structure as the alignment pattern is the same as the pitch of the concave-convex pattern structure as the alignment mark of the imprint mold substrate.
A method for manufacturing an imprint mold according to any one of claims 1 to 9.

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