JP2021027181A - Imprint mold substrate, imprint mold, and manufacturing method thereof - Google Patents

Abstract

To provide an imprint mold substrate that can be manufactured by a simple process and has a convex structure where a light-shielding film can be easily formed on a side surface and a manufacturing method thereof.SOLUTION: The imprint mold substrate includes a base having a first surface and a second surface facing the first surface and a convex structure portion protruding from the first surface of the base. The convex structure portion includes a first convex portion having a first side surface that rises from the first surface and a first upper surface substantially parallel to the first surface and a second convex portion having a second side surface rising from the first upper surface and a second upper surface substantially parallel to the first surface. The first upper surface is provided with a first protruding portion that surrounds the periphery of the second convex portion.SELECTED DRAWING: Figure 1

Description

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

The nanoimprint technology known as a microfabrication technology is a pattern forming technology that uses an imprint mold in which an uneven pattern is formed on the surface of a base material and transfers the uneven pattern to a work piece at the same magnification. In particular, with the further miniaturization of wiring patterns and the like in semiconductor devices, nanoimprint technology is attracting attention as a means in the manufacturing process and the like.

For the imprint mold used in the nanoimprint technology, for example, a substrate for imprint molding including a base material having a first surface and a second surface facing the first surface and a convex structure portion protruding from the first surface of the base material is prepared. Then, it is produced by forming a concavo-convex pattern on the upper surface of the convex structure portion of the imprint molding substrate. As a convex structure portion in an imprint mold substrate, a two-stage convex structure portion is known in which a lower portion is formed by wet etching and an upper portion is formed by dry etching (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2010-251601

Generally, the convex structure portion of the imprint mold is required to have a predetermined protruding height. Since the convex structure portion is usually formed by etching the base material, a wet etching process is selected in consideration of the etching time and the like in order to form the convex structure portion having a predetermined protruding height. On the other hand, when the convex structure portion is formed by wet etching, there is a problem that the edge of the upper surface of the convex structure portion is wavy. In that respect, in the convex structure portion described in Patent Document 1, the lower portion is formed by wet etching and the upper portion is formed by dry etching, thereby satisfying the requirement for the protrusion height of the convex structure portion as a whole. On the other hand, it is possible to suppress the occurrence of waviness on the edge of the upper surface of the convex structure portion.

However, in the convex structure portion described in Patent Document 1, since the dry etching process is adopted to form the upper portion, it is difficult to further reduce the time and cost required for manufacturing the substrate for imprint molding. Is.

Further, the convex structure portion is formed as follows. After the lower part mask 410 formed on the base material 200 is used as an etching mask and the base material 200 is wet-etched to form the lower part 310 (see FIG. 8A), the lower part mask 410 is removed for the upper part. A mask 420 is formed (see FIG. 8B), and the base material 200 is dry-etched using the upper mask 420 as an etching mask to form the upper portion 320 (see FIG. 8C). As described above, since the lower stage mask 410 and the upper stage mask 420 are formed in separate steps, the positional accuracy of the upper stage mask 420 formed on the lower stage 310 becomes a problem. More specifically, depending on the position accuracy of the upper mask 420, the upper portion 320 may be formed so as to be displaced from the center of the lower portion 310.

Further, in an imprint mold having a convex structure portion, it has been conventionally proposed to form a functional film such as a light-shielding film on the side surface of the convex structure portion. By forming a light-shielding film on the side surface of the convex structure portion, it is expected that only the resin to which the uneven pattern of the mold is transferred (the resin directly under the convex structure portion) can be cured. However, unlike the imprint mold described in Patent Document 1, since the side surface of the upper portion of the convex structure portion is a vertical surface (perpendicular to the base material surface), a film is formed on a functional film such as a light-shielding film. There is a problem that defects are likely to occur.

In view of the above problems, the present disclosure discloses an imprint mold substrate and an imprint mold having a convex structure portion on the side surface which can be manufactured by a simple process and can easily form a light-shielding film, and a method for manufacturing the same. One purpose is to provide.

In order to solve the above problems, as one embodiment of the present disclosure, a base portion having a first surface and a second surface facing the first surface, and a convex structure portion of the base portion protruding from the first surface are provided. The convex structure portion includes a first side surface rising from the first surface, a first convex portion having a first upper surface substantially parallel to the first surface, a second side surface rising from the first upper surface, and the above. An imprint mold including a second convex portion having a second upper surface substantially parallel to the first surface, and the first upper surface is provided with a first protruding portion surrounding the circumference of the second convex portion. Substrates are provided.

The protruding height of the first protruding portion may be lower than the height of the second convex portion, and the protruding height of the first convex portion may be higher than the protruding height of the second convex portion. The first side surface may have a concave round shape, the second side surface may have a concave round shape, and the first surface of the base may have an alignment mark. A functional second protrusion may be provided.

As one embodiment of the present disclosure, there is provided an imprint mold in which a concavo-convex pattern is formed on the second upper surface of the imprint mold substrate.

One embodiment of the present disclosure is a method of manufacturing the imprint mold substrate, which has a main surface and a facing surface facing the main surface, and a hard mask layer is provided on the main surface. By performing the base material preparation step of preparing the base material and the etching treatment on the hard mask layer, an annular opening is formed between the first hard mask pattern corresponding to the second convex portion and the first hard mask pattern. A hard mask pattern forming step of forming a hard mask pattern including a second hard mask pattern surrounding the first hard mask pattern so as to sandwich the first hard mask pattern, at least the annular opening, a part of the first hard mask pattern, and the first. 2 A resist pattern forming step of forming a resist pattern that integrally covers a part of the hard mask pattern, and a first etching step of performing a wet etching treatment on the base material using the hard mask pattern and the resist pattern as an etching mask. Provided is a method for manufacturing an imprint mold substrate, which comprises a second etching step of performing a wet etching process on the base material using the hard mask pattern as an etching mask after removing the resist pattern.

As one embodiment of the present disclosure, which is a method of manufacturing an imprint mold, on the second upper surface of the second convex portion of the imprint mold substrate manufactured by the method of manufacturing the imprint mold substrate. A method for manufacturing an imprint mold including a step of forming an uneven pattern is provided.

According to the present disclosure, there are provided an imprint mold substrate and an imprint mold having a convex structure portion which can be manufactured by a simple process and can easily form a light-shielding film on a side surface, and a method for manufacturing the same. Can be done.

FIG. 1 is a cut end view showing a schematic configuration of an aspect 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 in the vicinity of the convex structure portion of one aspect of the imprint mold substrate according to the embodiment of the present disclosure. FIG. 3 is a partially enlarged cut end view showing a schematic configuration in the vicinity of the convex structure portion of another aspect of the imprint mold substrate according to the embodiment of the present disclosure. FIG. 4 is a cut end view showing a schematic configuration of an imprint mold according to an embodiment of the present disclosure. FIG. 5A is a partially enlarged cut end view showing one step of a method for manufacturing an imprint mold substrate according to an embodiment of the present disclosure. FIG. 5B is a partially enlarged cut end view showing a step of a method for manufacturing an imprint mold substrate according to an embodiment of the present disclosure, and a step following FIG. 5A. FIG. 5C is a partially enlarged cut end view showing a step of a method for manufacturing an imprint mold substrate according to an embodiment of the present disclosure, and a step following FIG. 5B. FIG. 5D is a partially enlarged cut end view showing a step of a method for manufacturing an imprint mold substrate according to an embodiment of the present disclosure, and a step following FIG. 5C. FIG. 5E is a partially enlarged cut end view showing a step of a method for manufacturing an imprint mold substrate according to an embodiment of the present disclosure, and a step following FIG. 5D. FIG. 5F is a partially enlarged cut end view showing a step of a method for manufacturing an imprint mold substrate according to an embodiment of the present disclosure, and a step following FIG. 5E. FIG. 5G is a partially enlarged cut end view showing a step of a method for manufacturing an imprint mold substrate according to an embodiment of the present disclosure, and a step following FIG. 5F. FIG. 5H is a partially enlarged cut end view showing a step of a method for manufacturing an imprint mold substrate according to an embodiment of the present disclosure, and a step following FIG. 5G. FIG. 6A is a partially enlarged cut end view showing one step of one aspect of the method for manufacturing an imprint mold according to the embodiment of the present disclosure. FIG. 6B is a partially enlarged cut end view showing a step following the step of FIG. 6A, which is one step of one aspect of the method for manufacturing an imprint mold according to the embodiment of the present disclosure. FIG. 6C is a partially enlarged cut end view showing a step of one aspect of the method for manufacturing an imprint mold according to the embodiment of the present disclosure, and shows a step following FIG. 6B. FIG. 7A is a partially enlarged cut end view showing one step of another aspect of the method for manufacturing an imprint mold according to the embodiment of the present disclosure. FIG. 7B is a partially enlarged cut end view showing a step following the step of FIG. 7A, which is one step of another aspect of the method for manufacturing an imprint mold according to the embodiment of the present disclosure. FIG. 7C is a partially enlarged cut end view showing a step of another aspect of the method for manufacturing an imprint mold according to the embodiment of the present disclosure, which is a step following FIG. 7B. FIG. 7D is a partially enlarged cut end view showing a step following the step of FIG. 7C, which is one step of another aspect of the method for manufacturing an imprint mold according to the embodiment of the present disclosure. FIG. 7E is a partially enlarged cut end view showing a step of one aspect of the method for manufacturing an imprint mold according to the embodiment of the present disclosure, and shows a step following FIG. 7D. FIG. 8A is a partially enlarged cut end view showing one step of a conventional method for manufacturing an imprint mold substrate. FIG. 8B is a partially enlarged cut end view showing a step of a conventional method for manufacturing an imprint mold substrate, which follows the step of FIG. 8A. FIG. 8C is a partially enlarged cut end view showing a step of a conventional method for manufacturing an imprint mold substrate, which follows the step of FIG. 8B.

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

FIG. 1 is a cut end view showing a schematic configuration of one aspect of the imprint mold substrate according to the present embodiment, and FIG. 2 is a convex structure of one aspect of the imprint mold substrate according to the present embodiment. FIG. 3 is a partially enlarged cut end view showing a schematic configuration in the vicinity of the portion, and FIG. 3 is a partially enlarged cut end view showing a schematic configuration in the vicinity of the convex structure portion of another embodiment of the substrate for imprint molding according to the present embodiment. Is.

As shown in FIGS. 1 to 3, the imprint mold substrate 1 according to the present embodiment has a base portion 2 having a first surface 2A and a second surface 2B facing the first surface 2A, and a first portion of the base portion 2. A convex structure portion 3 protruding from the surface 2A and a recessed portion 4 formed on the second surface 2B side of the base portion 2 are provided.

The base 2 is 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 aminoborosilicate glass, and an aluminoke. Among these, a glass substrate such as a non-alkali glass substrate such as acid glass, a resin substrate such as a polycarbonate substrate, a polypropylene substrate, a polyethylene substrate, a polymethylmethacrylate substrate, and a polyethylene terephthalate substrate, and the above-mentioned substrate in which metal is doped at least partially. It may be composed of a transparent substrate such as a laminated substrate obtained by laminating two or more arbitrarily selected substrates. In addition, in this embodiment, "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, and particularly preferably 95% or more.

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

The convex structure portion 3 protruding from the first surface 2A of the base portion 2 is provided substantially in the center of the base portion 2 in a plan view, and is substantially formed on the first side surface 31S and the first surface 2A rising from the first surface 2A of the base portion 2. A first convex portion 31 having a first upper surface 31A substantially parallel to the first upper surface 31A, and a second convex portion 32 having a second upper surface 32A substantially parallel to the second surface 32S rising from the first upper surface 31A and the first surface 2A. including. Since the first convex portion 31 and the second convex portion 32 are formed by a wet etching process, the first side surface 31S and the second side surface 32S have a concavely curved round shape.

The outer shape of the second convex portion 32 in a plan view is substantially rectangular. The outer shape of the first convex portion 31 in a plan view is not particularly limited. The second upper surface 32A of the second convex portion 32 is a pattern region in which the uneven pattern 11 is to be formed when the imprint mold 10 (see FIG. 4) is manufactured from the imprint mold substrate 1 according to the present embodiment. Including. Therefore, the size of the second upper surface 32A is appropriately set according to the product or the like manufactured through the imprint processing using the imprint mold 10 (see FIG. 4), for example, 30 mm × 25 mm. Set to degree.

Projection height T ₃ of the convex portions 3 (the length along the thickness direction of the base 2 in between the first surface 2A and a second upper surface 32A of the second convex portion 32 of the base 2), in this embodiment As long as the imprint mold substrate 1 can fulfill the purpose of including the convex structure portion 3, it is not particularly limited and may be set to, for example, about 10 μm to 100 μm.

Projection height T ₃₁ of the first convex portion 31 (the length along the thickness direction of the base 2 in between the first surface 2A of the base 2 and the first upper surface 31A of the first convex portion 31), second convex It is longer than the protruding height T _{32 of} the portion 32 (the length along the thickness direction of the base portion 2 between the first upper surface 31A of the first convex portion 31 and the second upper surface 32A of the second convex portion 32). Projection height T ₃₂ of the second protrusion 32 may be any 0.1 m to 10 m, preferably from 0.5 m to 5 m. The second convex portion 32 of the imprint mold substrate 1 according to the present embodiment is formed by wet etching as described later (see FIG. 5H), _{but when the protrusion height T 32} exceeds 10 μm, Wet etching for forming the second convex portion 32 may cause waviness at the end edge of the second upper surface 32A of the second convex portion 32. In the present embodiment, when the protrusion height T32 of the second convex portion 32 is within the above range, the second upper surface 32A of the second convex portion 32, that is, the surface on which the uneven pattern 11 is formed in the imprint mold 10 is formed. undulation is not generated in the edge side, and by the relatively high first convex portion 31 of the projection height T _31, can be secured projection height T ₃ of the entire convex portions 3.

The first upper surface 31A is provided with a first protruding portion 5 that surrounds the periphery of the second convex portion 32 of the convex structure portion 3. Further, a second protruding portion 6 that functions as an alignment mark is provided on the first surface 2A of the base portion 2. The protrusion height T 6 of the second protrusion ₆ is the second protrusion during the imprint process using the imprint mold 10 (see FIG. 4) created from the imprint mold substrate 1 according to the present embodiment. There is no particular limitation as long as 6 can function as an alignment mark, that is, the second protrusion 6 can be recognized by the alignment device in the imprint device.

In the present embodiment, the second protruding portion 6 is formed by wet etching (see FIG. 5E), but the etching mask (third mask pattern 213) corresponding to the second protruding portion 6 is a convex structure portion 3 (third). It is formed by photolithography at the same time as the etching masks (first mask pattern 211 and second mask pattern 212) corresponding to the one convex portion 31 and the second convex portion 32). Therefore, the second protruding portion 6 is formed with high positional accuracy with respect to the convex structure portion 3 (the first convex portion 31 and the second convex portion 32). Therefore, it is possible to improve the alignment accuracy at the time of the imprint processing using the imprint mold 10 produced from the imprint mold substrate 1 according to the present embodiment.

As shown in FIG. 3, a light-shielding film 7 may be provided on the second side surface 32S of the second convex portion 32. In the imprint mold substrate 1 according to the present embodiment, the second side surface 32S of the second convex portion 32 is formed by wet etching and has a concave round shape. Therefore, the light-shielding film 7 provided on the second side surface 32S does not substantially have a film forming defect (pinhole or the like). Therefore, in the imprint processing using the imprint mold 10 (see FIG. 4) produced from the imprint mold substrate 1 according to the present embodiment, the uneven pattern formed on the second upper surface 32A of the second convex portion 32. 11 can be transferred with high accuracy.

The light-shielding film 7 provided on the second side surface 32S can block the light (for example, UV light) irradiated to the imprint mold 10 in the imprint process using the imprint mold 10 (see FIG. 4). Materials such as 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 oxide and tantalum nitride. It may be composed of a tantalum compound such as, titanium nitride, silicon nitride, silicon oxynitride, or the like. Further, the film thickness of the light-shielding film 7 is not particularly limited as long as it is thick enough to block the light.

A recessed portion 4 having a predetermined size is formed on the second surface 2B of the base portion 2. Since the recessed portion 4 is formed, during the imprint processing using the imprint mold 10 (see FIG. 4) produced from the imprint mold substrate 1 according to the present embodiment, particularly contact with the imprint resin. At the time of peeling of the imprint mold 10, the thickness of the base 2 formed by the recess 4 is increased by applying pressure to the recess 4 while the second surface 2B of the base 2 is held by the suction chuck or the like. Only the thin part (thin plate part) can be curved. As a result, when the second upper surface 32A of the second convex portion 32 of the convex structure portion 3 and the imprint resin are brought into contact with each other, the unevenness formed on the second upper surface 32A of the second convex portion 32 of the convex structure portion 3 It is possible to prevent gas from being caught between the pattern 11 and the imprint resin, and the imprint mold 10 can be easily peeled off from the transfer pattern in which the uneven pattern 11 is transferred to the imprint resin. can do.

The plan view shape of the recessed portion 4 is preferably a substantially circular shape. Due to the substantially circular shape, the imprint mold 10 is peeled off from the imprint resin during the imprint process, especially when the second upper surface 32A of the second convex portion 32 of the convex structure portion 3 is brought into contact with the imprint resin. At this time, the thin plate portion of the imprint mold 10 and the second upper surface 32A of the second convex portion 32 of the convex structure portion 3 can be curved substantially uniformly in the plane.

The size of the recessed portion 4 in a plan view is particularly limited as long as the convex structure portion 3 is included in the projection region in which the recessed portion 4 is projected onto the first surface 2A side of the base portion 2. It's not something. If the projected region has a size that cannot include the convex structure portion 3, the entire surface of the second upper surface 32A of the second convex portion 32 of the convex structure portion 3 of the imprint mold 10 cannot be effectively curved. There is a risk.

According to the imprint mold substrate 1 according to the present embodiment, it can be manufactured by a simple process, and the light-shielding film 7 can be easily formed on the second side surface 32S of the second convex portion 32.

The second upper surface 32A of the second convex portion 32 of the imprint mold substrate 1 according to the present embodiment has a hard mask layer (not shown) that can be used as a mask when the second upper surface 32A is etched. It may be provided.

Examples of the material constituting the hard mask layer 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, and boroborooxide. Examples thereof include tantalum compounds such as tantalum and tantalum boronitride, titanium nitride, silicon nitride, silicon oxynitride and the like, and these can be used alone or in combination of two or more arbitrarily selected.

The hard mask layer is used as a mask pattern when etching the second upper surface 32A of the second convex portion 32 of the imprint mold substrate 1. Therefore, the constituent material of the hard mask layer may be selected in consideration of the etching selection ratio and the like according to the constituent material of the base 2. For example, when the base 2 is made of quartz glass, chromium oxide or the like can be preferably selected as the material for forming the hard mask layer.

The thickness of the hard mask layer is appropriately set in consideration of the etching selection ratio and the like according to the constituent material of the base 2. For example, when the base 2 is made of quartz glass and the hard mask layer is made of chromium oxide, the thickness of the hard mask layer can be appropriately set within the range of about 0.5 nm to 200 nm.

FIG. 4 is a cut end view showing a schematic configuration of the imprint mold in the present embodiment. The imprint mold 10 in the present embodiment is manufactured by using the imprint mold substrate 1 (see FIGS. 1 to 3) according to the present embodiment. Therefore, the same components as those of the imprint mold substrate 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

The imprint mold 10 in the present embodiment has irregularities formed on the second upper surface 32A of the second convex portion 32 of the convex structure portion 3 of the imprint mold substrate 1 (see FIGS. 1 to 3) according to the present embodiment. It has a pattern 11.

The shape, dimensions, and the like of the uneven pattern 11 can be appropriately set according to the shape, dimensions, and the like required for the product or the like manufactured by using the imprint mold 10 according to the present embodiment. For example, examples of the shape of the uneven pattern 11 include a line-and-space shape, a pillar shape, a hole shape, and a grid shape. Further, the dimensions of the uneven pattern 11 can be set to, for example, about 10 nm to 200 nm.

According to the imprint mold 10 in the present embodiment, there is an effect that the imprint mold 10 can be manufactured by a simple process and the light-shielding film 7 can be easily formed on the second side surface 32S of the second convex portion 32. To.

An example of a method for manufacturing the imprint mold substrate 1 having the above-described configuration will be described. 5A to 5H are partially enlarged cut end views showing each step of the method for manufacturing the substrate for imprint molding according to the present embodiment.

First, a substrate 20 having a main surface 20A and a facing surface 20B facing the main surface 20A is prepared, and a hard mask layer 21 and a resist layer 22 are laminated in this order on the main surface 20A of the substrate 20 (see FIG. 5A). By performing exposure processing and development processing on the resist layer 22 via a photomask (not shown) having a predetermined opening, a first resist pattern corresponding to the first convex portion 31 of the substrate 1 for imprint molding 1 is applied. The second resist pattern 222 corresponding to 221 and the second convex portion 32 and the third resist pattern 223 corresponding to the second protruding portion 6 are formed (see FIG. 5B).

Examples of the material constituting the hard mask layer 21 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 and tantalum oxide. Examples thereof include tantalum compounds such as tantalum nitride and tantalum boride oxynitride, titanium nitride, silicon nitride, silicon oxynitride, and the like, and these can be used alone or in combination of two or more arbitrarily selected.

The hard mask layer 21 is patterned in a step (see FIG. 5C) described later, and is used as a mask pattern when the first convex portion 31 and the second convex portion 32 of the imprint mold substrate 1 are formed by etching. Is. Therefore, it is preferable to select the constituent material of the hard mask layer 21 in consideration of the etching selection ratio and the like according to the constituent material of the base 2. For example, when the base 2 is made of quartz glass, chromium oxide or the like can be preferably selected as the material forming the hard mask layer 21.

The thickness of the hard mask layer 21 is appropriately set in consideration of the etching selection ratio and the like according to the constituent materials of the substrate 20. For example, when the constituent material of the substrate 20 is quartz glass and the constituent material of the hard mask layer 21 is chromium oxide, the thickness of the hard mask layer 21 is appropriately set within the range of about 0.5 nm to 200 nm. obtain.

The method for forming the hard mask layer 21 on the main surface 20A of the substrate 20 is not particularly limited, and for example, known film forming methods such as sputtering, PVD (Physical Vapor Deposition), and CVD (Chemical Vapor Deposition). Can be mentioned.

The material constituting the resist layer 22 formed by the spin coating method or the like so as to cover the hard mask layer 21 on the main surface 20A of the substrate 20 is not particularly limited, and is, for example, a negative type or a positive type. Although a photosensitive material or the like can be used, it is preferable to use a negative type photosensitive material. The film thickness of the resist layer 22 is not particularly limited, and may be appropriately set according to the selection ratio or the like according to the constituent material of the hard mask layer 21.

In the present embodiment, the hard mask layer 21 is subjected to a dry etching process using the first resist pattern 221 and the second resist pattern 222 and the third resist pattern 223 as masks, whereby the first mask pattern corresponding to the first convex portion 31 is applied. 211, the second mask pattern 212 corresponding to the second convex portion 32, and the third mask pattern 213 corresponding to the second protruding portion 6 are formed. That is, the size (size) of each resist pattern 221 to 223 and the size (size) of each mask pattern 211 to 213 are substantially the same. The size (size) of the outer shape of the first mask pattern 211 is larger than the size (size) of the outer shape of the first convex portion 31, and is configured to be large enough to include the first upper surface 31A. .. Therefore, the size (size) of the outer shape of the first resist pattern 221 is also larger than the size (size) of the outer shape of the first convex portion 31, and is configured to be large enough to include the first upper surface 31A. ..

The first resist pattern 221 is formed so as to surround the second resist pattern 222 and to have a predetermined distance from the second resist pattern 222. Since there is a predetermined interval between the first resist pattern 221 and the second resist pattern 222, the annular opening 23 can be formed between the first mask pattern 211 and the second mask pattern 212. .. The first mask pattern 211 is used as a mask for forming the first convex portion 31 in the first wet etching step (see FIG. 5E) described later, and the second mask pattern 212 is the second wet etching step (see FIG. 5E) described later. Although it is used as a mask for forming the second convex portion 32 in FIG. 5H), the positional accuracy of the second mask pattern 212 with respect to the outer shape of the first mask pattern 211 is the photo forming each resist pattern 221 to 223. It will depend on the accuracy in lithography. Therefore, the second mask pattern 212 can be formed with high accuracy so as to be substantially centered on the outer shape of the first mask pattern 211.

Each resist pattern 221 to 223 formed as described above is used as an etching mask, and the hard mask layer 21 exposed from the opening is dry-etched _{with, for example, a chlorine-based (Cl 2} + O _{2) etching gas.} Each mask pattern 211 to 213 is formed on the main surface 20A of the substrate 20 (see FIG. 5C).

The first mask pattern 211 is used as a mask for forming the first convex portion 31 in the first wet etching step (see FIG. 5E) described later. Then, in the wet etching step for forming the first convex portion 31, so-called side etching occurs, and the main surface 20A of the substrate 20 is etched in the lateral direction (in-plane direction). Therefore, the size (size) of the first upper surface 31A of the first convex portion 31 is smaller than the size (size) of the first mask pattern 211. That is, the size (size) of the first mask pattern 211 is configured to be larger than the size (size) of the first upper surface 31A of the first convex portion 31. The size of the first mask pattern 211 is set according to the etching time required to form the first convex portion 31 of the _{predetermined protrusion height T 31 and the side etching amount of the substrate 20 in the etching time.} For example, it may be as large as 1 μm to 200 μm.

Similarly, the second mask pattern 212 is used as a mask for forming the second convex portion 32 in the second wet etching step (see FIG. 5H) described later, and is used as a mask for forming the second convex portion 32. 2 In the wet etching step, so-called side etching occurs. Therefore, the size (size) of the second upper surface 32A of the second convex portion 32 is smaller than the size (size) of the second mask pattern 212. That is, the size (size) of the second mask pattern 212 is configured to be larger than the size (size) of the second upper surface 32A of the second convex portion 32. The size of the second mask pattern 212 is set according to the etching time required to form the second convex portion 32 having _{a predetermined protrusion height T 32 and the side etching amount of the substrate 20 during the etching time.} For example, it may be as large as 0.1 μm to 10 μm.

The third mask pattern 213 is used as a mask for forming the second protruding portion 6 in the first wet etching step (see FIG. 5E) described later. In the present embodiment, the third mask pattern 213 is configured to have a size (size) such that it peels off in the middle of the first wet etching step. Accordingly, the second protrusions 6 having a projection height T ₆ lower than the projection height T ₃₁ of the first convex portion 31 is formed (see FIG. 5E).

A resist pattern 24 is formed to cover a part of the inner edge side of the first mask pattern 211, the annular opening 23, and the second mask pattern 212 (see FIG. 5D). The resist material constituting the resist pattern 24 is not particularly limited, and for example, a negative type or a positive type photosensitive material can be used. By covering a part of the inner edge side of the first mask pattern 211, the annular opening 23 and the second mask pattern 212, the resist pattern 24 passes through the annular opening 23 in the first wet etching step (see FIG. 5E) to form the substrate 20. Can be prevented from being etched, and after the first wet etching step (see FIG. 5E), the exposed portion of the first mask pattern 211 can be removed by etching using the resist pattern 24 as a mask. As a result, the second convex portion 32 protruding from the first upper surface 31A of the first convex portion 31 can be formed by the second wet etching step (see FIG. 5H) using the remaining second mask pattern 212 as a mask. .. Width W ₂₁₁ of the first mask pattern 211 is covered with the resist pattern 24 may be less than two times the projection height T ₃₂ of the second convex portion 32, preferably, 0.5 to 1.5 times It should be about. When the width W ₂₁₁ is twice or more projection height T ₃₂ of the second convex portion 32, the protruding height of the first protrusion 5 T ₅ and the projection height T ₃₂ of the second convex portion 32 is the same turn into.

The substrate 20 is subjected to a wet etching process using the first mask pattern 211 and the third mask pattern 213 formed as described above and exposed from the resist pattern 24 as masks (FIG. 5E). As the etching solution in the wet etching treatment, for example, hydrofluoric acid or the like is preferably used. Thus, the first convex portion 31 of the predetermined projection height T ₃₁ will be formed (see FIG. 5E).

After the first convex portion 31 is formed, the first mask pattern 211 exposed from the resist pattern 24 is removed by etching (see FIG. 5F). The removal of the first mask pattern 211 can be performed by, for example, a dry etching process using a _{chlorine-based (Cl 2} + O ₂ ) etching gas in the same manner as in the mask pattern forming step (see FIG. 5C). Although a part of the first mask pattern 211 (the part covered by the resist pattern 24) remains, the first is performed by the second wet etching step using a part of the remaining first mask pattern 211 as a mask. The first protruding portion 5 is formed on the first upper surface 31A of the convex portion 31 (see FIG. 5H).

The resist pattern 24 is removed, and the substrate 20 is subjected to a wet etching process using a part of the remaining first mask pattern 211 and the second mask pattern 212 as masks (see FIG. 5G). As the etching solution in the wet etching treatment, for example, hydrofluoric acid or the like is preferably used. In the middle of the wet etching process, a part of the remaining first mask pattern 211 is peeled off. After a part of the first mask pattern 211 is peeled off, the substrate 20 is further subjected to a wet etching process. Accordingly, the second convex portion 32 of the predetermined projection height T ₃₂ is formed (see FIG. 5H). Finally, the facing surface 20B of the substrate 20 is ground to form the recessed portion 4. As a result, the imprint mold substrate 1 according to the present embodiment is manufactured.

According to the method for manufacturing an imprint mold substrate according to the present embodiment, the two-stage convex structure portion 3 having the first convex portion 31 and the second convex portion 32 can be formed by wet etching having a high processing speed. Therefore, the substrate for imprint molding can be manufactured efficiently and at low cost. Further, by controlling the protrusion height T ₃₂ of the second convex portion 32, it is possible to suppress the occurrence of undulation on the end edge of the second upper surface 32A of the second convex portion 32 due to wet etching. Further, the first mask pattern 211, the second mask pattern 212, and the third mask pattern 213 for forming the first convex portion 31, the second convex portion 32, and the second protruding portion 6 are formed by the same photolithography step. Therefore, the first convex portion 31, the second convex portion 32, and the second protruding portion 6 can be formed with high positional accuracy.

A method of manufacturing the imprint mold 10 (see FIG. 4) using the imprint mold substrate 1 manufactured as described above will be described. 6A to 6C are partially enlarged cut end views showing each step of one embodiment of the imprint mold manufacturing method in the present embodiment, and FIGS. 7A to 7E are manufacturing of the imprint mold in the present embodiment. FIG. 5 is a partially enlarged cut end view showing each step of another aspect of the method.

A hard mask layer 41 and a resist layer are formed on the second upper surface 32A (pattern region) of the second convex portion 32 of the imprint mold substrate 1, and the resist layer is patterned to form a resist pattern 42 (see FIG. 6A). .. Next, the hard mask layer 41 is dry-etched using the resist pattern 42 as a mask to form the mask pattern 43 corresponding to the uneven pattern 11 (see FIG. 6B). Then, the imprint mold substrate 1 is subjected to a dry etching process using the mask pattern 43 as a mask to form the uneven pattern 11 on the second upper surface 32A of the second convex portion 32 (see FIG. 6C). As a result, the imprint mold 10 (see FIG. 4) can be manufactured. 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.

The uneven pattern 11 of the imprint mold 10 in the present embodiment may be formed by dry etching using the side wall pattern formed by using the ALD method as a mask.

A hard mask layer 41 and a resist layer are formed on the second upper surface 32A of the second convex portion 32 of the imprint mold substrate 1, and the resist layer is patterned to form a resist pattern 42 (see FIG. 7A). Next, the side wall material film 44 is formed by depositing a side wall material of a silicon-based material (silicon oxide or the like) on the resist pattern 42 by the ALD method (Atomic layer deposition) (see FIG. 7B). Subsequently, the side wall material film 44 is subjected to an etch back treatment by anisotropic etching such as RIE (Reactive Ion Etching) to remove the remaining resist pattern 42, whereby the side wall pattern 45 is formed on the hard mask layer 41. Form (see FIG. 7C). Then, the hard mask layer 41 is dry-etched using the side wall pattern 45 as a mask to form a mask pattern 46 corresponding to the uneven pattern 11 (see FIG. 7D), and the mask pattern 46 is used as a mask on the imprint mold substrate 1. A dry etching process is performed to form a concavo-convex pattern 11 on the second upper surface 32A of the second convex portion 32 (see FIG. 7E). As a result, the imprint mold 10 (see FIG. 4) according to the present embodiment 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.

1 ... Imprint mold substrate 2 ... Base 2A ... First surface 2B ... Second surface 3 ... Convex structure 31 ... First convex part 31A ... First upper surface 31S ... First side surface 32 ... Second convex part 32A ... Second 2 Top surface 32S ... Second side surface 4 ... Recessed portion 5 ... First protruding portion 6 ... Second protruding portion 10 ... Imprint mold 11 ... Concavo-convex pattern

Claims (9)

A base having a first surface and a second surface facing the first surface,
A convex structure portion of the base portion protruding from the first surface thereof is provided.
The convex structure portion includes a first side surface rising from the first surface, a first convex portion having a first upper surface substantially parallel to the first surface, a second side surface rising from the first upper surface, and the first surface. Including a second convex portion having a second upper surface substantially parallel to the surface,
An imprint mold substrate provided with a first protruding portion that surrounds the periphery of the second convex portion on the first upper surface. The imprint molding substrate according to claim 1, wherein the protruding height of the first protruding portion is lower than the height of the second convex portion. The imprint mold substrate according to claim 1 or 2, wherein the protruding height of the first convex portion is higher than the protruding height of the second convex portion. The imprint mold substrate according to any one of claims 1 to 3, wherein the first side surface has a concave round shape. The imprint mold substrate according to any one of claims 1 to 4, wherein the second side surface has a concave round shape. The imprint molding substrate according to any one of claims 1 to 5, wherein a second protruding portion that functions as an alignment mark is provided on the first surface of the base portion. An imprint mold in which an uneven pattern is formed on the second upper surface of the imprint mold substrate according to any one of claims 1 to 6. The method for manufacturing an imprint mold substrate according to any one of claims 1 to 6.
A base material preparation step of preparing a base material having a main surface and a facing surface facing the main surface and having a hard mask layer provided on the main surface.
By performing an etching process on the hard mask layer, a first mask surrounding the second mask pattern so as to sandwich an annular opening between the second mask pattern corresponding to the second convex portion and the second mask pattern. A mask pattern forming step of forming a mask pattern including a pattern,
A resist pattern forming step of forming a resist pattern that integrally covers at least the annular opening and the second mask pattern.
The first etching step of performing a wet etching treatment on the base material using the mask pattern and the resist pattern as an etching mask,
A mask pattern removing step of removing the exposed first mask pattern, and
A method for manufacturing an imprint mold substrate, which comprises a second etching step of performing a wet etching process on the base material using the second mask pattern remaining after removing the resist pattern as an etching mask. A method of manufacturing imprint molds
A method for manufacturing an imprint mold, which comprises a step of forming a concavo-convex pattern on the second upper surface of the second convex portion of the imprint mold substrate manufactured by the method for manufacturing the imprint mold substrate according to claim 8. ..

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