JP6950224B2 - Imprint mold and imprint mold manufacturing method - Google Patents

Description

The present invention relates to an imprint mold and a method for manufacturing the imprint mold.

In recent years, in the manufacturing process of semiconductor devices, optical members, etc., a pattern forming in which a fine uneven pattern is transferred to a workpiece such as a substrate at the same magnification by using a mold member (imprint mold) in which a fine uneven pattern is formed on the surface of the substrate. Nanoimprint technology, which is a technology, is used.

Most of the fine concavo-convex patterns formed on the imprint mold used in the nanoimprint technology are composed of a one-step concavo-convex structure such as a line-and-space pattern having a rectangular cross section, a pillar pattern, and a hole pattern.

On the other hand, a multi-stage structure may be formed not only in the manufacture of semiconductor devices and the like, but also in the manufacturing process of optical elements, wiring circuits, recording devices, display panels, cell culture chips, microchannels and the like. In order to form such a multi-stage structure by using nanoimprint technology, an imprint mold having a stepped concavo-convex structure portion having a plurality of step portions has been conventionally used (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2010-171109

When the stepped uneven structure is transferred to an ultraviolet curable resin or the like as a material to be transferred using the imprint mold provided with the stepped uneven structure, the stepped uneven structure is cured and shrunk to become an ultraviolet curable resin. There arises a problem that the shape of the stepped concave-convex structure to be formed changes, specifically, the shape of the corners of each step is rounded. In particular, when the number of steps of the stepped uneven structure portion of the imprint mold is increased, the above problem may occur remarkably.

By using the above-mentioned imprint mold to transfer the stepped uneven structure portion to an ultraviolet curable resin or the like on a predetermined substrate and etching the substrate using the ultraviolet curable resin as a mask, the stepped uneven structure portion is transferred to the substrate. When transferring, the shape of the corners of each step that has been rounded becomes more rounded by being exposed to the etching environment for a long time, and the stepped uneven structure that is transferred to the substrate is The problem arises that it cannot be formed as designed.

If the shape of the stepped uneven structure formed on the ultraviolet curable resin is changed as described above, a problem occurs in the product manufactured through the imprint process using the imprint mold. I will end up.

In view of the above problems, it is an object of the present invention to provide an imprint mold capable of transferring a stepped uneven structure portion to a material to be transferred with high accuracy by an imprint process and a method for manufacturing the imprint mold.

In order to solve the above problems, the present invention includes a base portion and a stepped concave-convex structure portion formed on one surface side of the base portion and having a plurality of step portions, and each step portion is provided with the base portion. has a first surface substantially parallel, and a second surface you substantially perpendicular to the one surface of the base portion on one surface of said first surface, a first end, opposite to the first end The second surface extends from the first end of the first surface toward the base side, and includes at least the said second surface in a direction perpendicular to the one surface of the base. each of the plurality of stepped portions than said vicinity of the first end portion of the first face and the second end is configured to be positioned distally from the base portion, the first end of the first surface A convex portion including the first end portion is provided on the side, and a concave portion is provided in the vicinity of the second end portion of the first surface, so that the first surface is formed from the first end portion to the said portion. It is configured in a downward step shape of three or more steps toward the second end portion, and the relationship between the heights of the convex portions provided on the first surface of each step portion is related to the one surface of the base portion. Provided is an imprint mold characterized in that the height of the convex portion located closest to the above is the highest, and the height of the convex portion decreases as the convex portion moves away from one surface of the base portion. do.

Oite above onset Ming, the width of the convex portion in the side view, the 1/2 or less and even rather preferably the first side of the width, the material constituting the convex portion constituting the base materials and and even rather preferable different materials, have the preferred of the recess near the second end portion opposite the first end portion of the first surface is provided.

Oite above onset Ming, the width of the recess in the side view, the 1/2 or less and even preferred arbitrariness of the first face width.

Oite above onset bright, the first surface, rather it may also include an inclined portion inclined toward the second end side opposed to the first end portion from said first end portion side, the inclination parts are not the preferred to the inclined curved toward the second end side opposite from the first end portion to the first end.

Oite above onset bright, the imprint mold, and even not preferable imprint mold for use in imprint lithography.

Furthermore, the present invention provides a method of manufacturing the imprint mold according to the onset bright, forming a step-like uneven structure having a plurality of stepped portions on one side of the base portion, the stepped unevenness A step of forming a first hard mask layer on the stepped uneven structure portion so as to expose a part on the structural portion, and a first etching process are performed on the base portion on which the first hard mask layer is formed. As a result, a step of forming the convex portion, a step of forming a second hard mask layer on the stepped uneven structure portion by exposing a part on the stepped concave-convex structure portion, and a step of forming the second hard mask layer on the stepped concave-convex structure portion, and the second hard In the step of forming the first hard mask layer, which includes a step of forming the recess by subjecting the base portion on which the mask layer is formed to a second etching process , among the first surfaces of the step portions. In the step of forming the first hard mask layer corresponding to the convex portion in the vicinity of the first end portion and forming the second hard mask layer, the second hard mask layer having an opening corresponding to the concave portion. forming a that provides a method for manufacturing an imprint mold according to claim.

According to the present invention, it is possible to provide an imprint mold capable of transferring a stepped uneven structure portion to a material to be transferred with high accuracy by an imprint process, and a method for manufacturing the imprint mold.

FIG. 1 is a cut sectional view showing a schematic configuration of an imprint mold according to an embodiment of the present invention. FIG. 2 is a partially enlarged cut end view showing a schematic configuration of a stepped concave-convex structure portion of an imprint mold according to an embodiment of the present invention. FIG. 3 is a partially enlarged cut end view showing a schematic configuration of an example of a stepped portion of an imprint mold according to an embodiment of the present invention. FIG. 4 is a partially enlarged cut end view showing a schematic configuration of another example of the step portion of the imprint mold according to the embodiment of the present invention. FIG. 5 is a partially enlarged cut end view showing a schematic configuration of a first surface of a step portion of an imprint mold according to an embodiment of the present invention. FIG. 6 is a partially enlarged cut end view showing a modified example of the stepped concave-convex structure portion of the imprint mold according to the embodiment of the present invention. FIG. 7 is a process flow chart showing a manufacturing process (No. 1) of the imprint mold according to the embodiment of the present invention on the cut end face. FIG. 8 is a process flow chart showing a manufacturing process (No. 2) of the imprint mold according to the embodiment of the present invention on the cut end face. FIG. 9 is a process flow chart showing a manufacturing process (No. 3) of the imprint mold according to the embodiment of the present invention on the cut end face. FIG. 10 is a process flow chart showing a manufacturing process (No. 4) of the imprint mold according to the embodiment of the present invention on the cut end face. FIG. 11 is a process flow chart showing a manufacturing process (No. 5) of the imprint mold according to the embodiment of the present invention on the cut end face. FIG. 12 is a process flow chart showing a manufacturing process (No. 6) of the imprint mold according to the embodiment of the present invention on the cut end face. FIG. 13 is a process flow chart showing a manufacturing process (No. 7) of the imprint mold according to the embodiment of the present invention on the cut end face. FIG. 14 is a process flow chart showing another example (No. 1) of the imprint mold manufacturing process according to the embodiment of the present invention on the cut end face. FIG. 15 is a process flow chart showing another example (No. 2) of the imprint mold manufacturing process according to the embodiment of the present invention on the cut end face. FIG. 16 is a process flow chart following FIG. 15 showing another example (No. 2) of the imprint mold manufacturing process according to the embodiment of the present invention on the cut end face. FIG. 17 is a process flow chart showing each step of the imprint method using the imprint mold according to the embodiment of the present invention on the cut end face. FIG. 18 is a cut end view (No. 1) for explaining the operation in the imprint method using the imprint mold according to the embodiment of the present invention. FIG. 19 is a cut end view (No. 2) for explaining the operation in the imprint method using the imprint mold according to the embodiment of the present invention. FIG. 20 is a cut end view showing a schematic configuration of a stepped uneven pattern manufactured by an imprint method using an imprint mold according to an embodiment of the present invention. FIG. 21 is a cut end view showing a schematic configuration of a stepped concavo-convex structure transferred to a substrate to be transferred by an etching process using the stepped concavo-convex pattern shown in FIG. FIG. 22 is a cut end view (No. 1) showing a schematic configuration of a stepped concave-convex structure portion of an imprint mold according to another embodiment of the present invention. FIG. 23 is a cut end view (No. 2) showing a schematic configuration of a stepped concave-convex structure portion of an imprint mold according to another embodiment of the present invention. FIG. 24 is a process flow chart showing the manufacturing process of the imprint mold shown in FIG. 22 on the cut end face.

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cut end face view showing a schematic configuration of an imprint mold according to the present embodiment, and FIG. 2 is a partially enlarged cut end face showing a schematic configuration of a stepped concave-convex structure portion of the imprint mold according to the present embodiment. It is a figure.

[Imprint mold]
As shown in FIG. 1, the imprint mold 1 according to the present embodiment is formed on the one side 2A side of the base 2 and the base 2 having the one side 2A and the other side 2B facing the one side 2A. It is provided with a stepped concave-convex structure portion 3.

The base 2 is generally used as a base material for imprint molding, for example, quartz glass substrate, soda glass substrate, fluorite substrate, calcium fluoride substrate, magnesium fluoride substrate, barium borosilicate glass, aminoborosilicate glass. , Glass substrates such as non-alkali glass substrates such as aluminosilicate glass, polycarbonate substrates, polypropylene substrates, polyethylene substrates, polymethylmethacrylate substrates, resin substrates such as polyethylene terephthalate substrates, and two or more substrates arbitrarily selected from these. A transparent substrate such as a laminated substrate obtained by laminating the above can be used. In the present embodiment, "transparent" means that the photocurable resin can be cured by the light irradiated through the base 2, and for example, the transmittance of light having a wavelength of 300 to 450 nm is 70%. It is preferably 90% or more, and more preferably 90% or more.

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

The size of the base 2 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.

In the present embodiment, the stepped concave-convex structure portion 3 has a plurality of stepped portions 30. In this embodiment, an embodiment in which the stepped concave-convex structure portion 3 has four stepped portions 30 of the first to fourth stepped portions 31 to 34 in order from the one side 2A side of the base portion 2 will be described as an example. However, the present invention is not limited to this aspect. The stepped concavo-convex structure portion 3 may have at least two stepped portions 30, but the larger the number of stepped portions 30 of the stepped concavo-convex structure portion 3, the more remarkable the effect in the present embodiment can be exhibited. .. The shapes of the first to fourth step portions 31 to 34 in a plan view are not particularly limited, and examples thereof include a substantially circular shape and a substantially rectangular shape.

As shown in FIGS. 2 and 3, the first to fourth step portions 31 to 34 are substantially orthogonal to the first surface 301 substantially parallel to one surface 2A of the base 2 and the one surface 2A of the base 2, respectively. , A second surface 302 extending from the first end E1 of the first surface 301 toward the base 2 side. In the direction perpendicular to one side surface 2A of the base portion 2, the first end portion E1 of the first surface 301 is located distal to the base portion 2 with respect to the vicinity of the second end portion E2 facing the first end portion E1. That is, in the side view of the imprint mold 1, the second end portion E2 is located closer to the base portion 2 than the first end portion E1.

_{The width W 301} (see FIG. 3) of the first surface 301 of the first to fourth steps 31 to 34 is as long as it complies with the dimensions required for the product manufactured by using the imprint mold 1 according to the present embodiment. It is not particularly limited, and can be set to, for example, about 100 nm to 5 μm, more preferably about 300 nm to 1 μm.

In the present embodiment, the first surface 301 of the first to third step portions 31 to 33 is located on the convex portion 35 located on the first end portion E1 side and on the second end portion E2 side, and is one of the base portions 2. It is preferable to have a concave portion 36 including a bottom surface substantially parallel to the direction 2A, and at least one stepped portion 37 located between the convex portion 35 and the concave portion 36 on the first surface 301. The convex portion 35 includes the first end portion E1, but the concave portion 36 may have a part of the second surface 302 of the adjacent step portion 30 as a side surface (see FIG. 3). It may be located on the first end E1 side of the two surfaces 302 (see FIG. 4).

The bottom surface of the recess 36 may have a rounded shape, or may have a spike shape or a wedge shape. The shape of the bottom surface of the recess 36 may change depending on the etching conditions when the recess 36 is formed. When the bottom surface of the recess 36 is substantially parallel to one surface 2A of the base portion 2, the transfer shape formed on the imprint resin or the like by the imprint process using the imprint mold 1 according to the present embodiment can be easily controlled. It is preferable in that it is.

The first surface 301 of the fourth step portion 34 has a convex portion 35 located on the first end portion E1 side, but does not have to have a concave portion 36. As a matter of course, the first surface 301 of the fourth step portion 34 may be provided with a recess 36 or a notch portion located on the second end portion E2 side. The step portion 37 may have one or more steps down the stairs. As described above, the first surfaces 301 of the first to fourth step portions 31 to 34 in the present embodiment are configured in a downward step shape from the first end portion E1 side to the second end portion E2 side, respectively. ..

In the present embodiment, the convex portion 35 located on the first end portion E1 side of the first surface 301 is a portion that protrudes from the reference surface BS in a direction away from the base portion 2, as shown in FIG. means having less than half of the width W ₃₅ of the width W ₃₀₁ of the first surface 301, preferably having a 1 / 5-1 / 2 of the width W ₃₅ of the width W ₃₀₁ of the first surface 301, More preferably, it means one having _{a width W 35} of 1/5 to 1/3 of _{the width W 301} of the first surface 301. Similarly, the recess 36 located on the second end E2 side of the first surface 301 is also a portion recessed in the direction toward the base 2 with respect to the reference surface BS, and is 1 / _{of the width W 301 of the first surface 301.} It means those having 2 or less of the width W _36, preferably having 1 / 5-1 / 2 of the width W ₃₆ of the width W ₃₀₁ of the first surface 301, and more preferably the width W ₃₀₁ of the first surface 301 It means that it has _{a width W 36} of 1/5 to 1/3 of the above. The reference plane BS is intermediate between the uppermost portion of the first surface 301 (the portion farthest from the one surface 2A of the base portion 2) and the lowermost portion of the first surface 301 (the portion closest to the one surface 2A of the base portion 2). It is defined as a plane that passes through a point (an intermediate point in the direction perpendicular to the one surface 2A of the base 2) and is parallel to the one surface 2A of the base 2.

_{The height T 35} (see FIG. 2) of the convex portion 35 located on the first end portion E1 side of the first surface 301 in the first to fourth step portions 31 to 34 is the imprint mold 1 according to the present embodiment. It can be appropriately set according to the curing shrinkage rate of the imprint resin used in the imprint treatment used, and can be set to, for example, 10 nm to 1 μm, more preferably about 20 nm to 100 nm. The height T ₃₅ of the convex portion 35 means the length between the reference surface BS and the top of the convex portion 35 (the length in the direction perpendicular to one surface 2A of the base portion 2).

The imprint mold 1 according to the present embodiment was used at a _{depth D 36} (see FIG. 3) of a recess 36 located on the second end E2 side of the first surface 301 in the first to fourth step portions 31 to 34. It can be appropriately set according to the curing shrinkage rate of the imprint resin used in the imprint treatment, and can be set to, for example, 10 nm to 1 μm, more preferably about 20 nm to 100 nm. The depth D ₃₆ of the recess 36 means the length between the reference surface BS and the bottom surface of the recess 36 (the length in the direction perpendicular to one surface 2A of the base portion 2).

In the stepped concave-convex structure portion 3 of the present embodiment, the convex portions 35 located on the first end portion E2 side of the first surface 301 of the first to fourth step portions 31 to 34 have the same height T _{35. However, the height T 35} of the convex portion 35 (the convex portion 35 of the first surface 301 of the first step portion 31) closest to the one surface 2A of the base portion 2 is the highest, and one of the base portions 2. It is preferable that _{the height T 35} of the convex portion 35 gradually decreases as the distance from the direction 2A increases. Further, the recesses 36 located on the second end E2 side of the first surface 301 of the first to third step portions 31 to 33 may all have the same depth D ₃₆ , but the base portion 2 deepest depth D ₃₆ of the nearest recess 36 in one surface 2A of, as the distance from one surface 2A of the base 2, preferably the depth D ₃₆ of the recess 36 is gradually reduced.

Generally, after imprinting a photocurable resin with an imprint process using an imprint mold, an uneven pattern is formed on the photocurable resin, and then the base layer (base layer of the photocurable resin) is processed by an etching process using the photocurable resin as a mask. At that time, the shape of the corner portion closer to the top of the uneven pattern of the photocurable resin, which is exposed to the etching process for a longer period of time, tends to be rounded. Therefore, in the imprint mold 1 according to the present embodiment, the height T ₃₅ of the convex portion 35 and the depth D ₃₆ of the concave portion 36 located on the side closer to one surface 2A of the base portion 2 are relatively increased. The stepped uneven structure portion 3 can be transferred with high accuracy.

As shown in FIG. 6, the convex portion 35 in the present embodiment may be made of a material different from the material constituting the base portion 2. For example, the base 2 may be made of quartz glass, and the convex portion 35 may be made of a chromium-based compound such as metallic chromium, chromium oxide, chromium nitride, or chromium oxynitride.

According to the imprint mold 1 having the above configuration, a convex portion on the first end portion E1 side of the first surface 301 of each step portion 30 (first to fourth step portions 31 to 34) of the stepped concave-convex structure portion 3. By having 35 and having the recess 36 on the second end E2 side, as will be described later, a stepped uneven pattern can be formed on the imprint resin with high accuracy through the imprint process.

[Manufacturing method of imprint mold]
Next, an example of a method for manufacturing the imprint mold 1 having the above configuration will be described. 7 to 13 are process flow charts showing each process of the imprint mold manufacturing method according to the present embodiment on the cut end face.

First, a transparent base material 20 having one side surface 21 and the other side surface 22 facing the same side surface 21 is prepared, a hard mask layer 40 is formed on one side surface 21 of the transparent base material 20, and a resist film 60 is formed on the hard mask layer 40. (See FIG. 7 (A)).

The hard mask layer 40 is, for example, a chromium-based material such as chromium, chromium nitride, chromium oxide, chromium oxynitride; tantalum, tantalum nitride, tantalum oxide, tantalum oxynitride, tantalum oxide, tantalum nitride, and the like. It can be formed by a known film forming method such as sputtering, PVD, or CVD by using a system material or the like alone or by using two or more kinds arbitrarily selected. The thickness of the hard mask layer 40 can be appropriately set according to the etching selectivity with the material constituting the transparent base material 20, the height of the stepped uneven structure portion 3 in the imprint mold 1, and the like.

The resin material (resist material) constituting the resist film 60 is not particularly limited, and is a negative type or positive type electron beam reactive resist material generally used in electron beam lithography processing, photolithography processing and the like. , Ultraviolet reactive resist material and the like.

The thickness of the resist film 60 is not particularly limited. In the step described later (see FIG. 7B), the resist pattern formed by patterning the resist film 60 is used as a mask when etching the hard mask layer 40. Therefore, the thickness of the resist film 60 is appropriately set so that the resist pattern remains after the etching treatment of the hard mask layer 40 in consideration of the material and thickness constituting the hard mask layer 40.

The method of forming the resist film 60 on the hard mask layer 40 is not particularly limited, and a conventionally known method, for example, coating a resist material on the hard mask layer 40 with a spin coater, a spray coater, or the like. Examples thereof include a method of applying using a machine or laminating a dry film resist containing the above resin component on the hard mask layer 40 and heating (prebaking) at a predetermined temperature as desired.

Next, as shown in FIG. 7B, a first resist pattern 61 having a predetermined first opening 51 at a desired position on the hard mask layer 40 is formed. The first resist pattern 61 can be formed by, for example, electron beam lithography using an electron beam drawing apparatus, photolithography using a photomask having a predetermined opening and a light-shielding portion, and the like.

The shape of the first opening 51 in the first resist pattern 61 is appropriately set according to the design of the imprint mold 1 according to the present embodiment, and is not particularly limited. For example, in a plan view. It has a substantially annular shape, a substantially square shape in a plan view, a substantially square frame shape in a plan view, and the like.

Similar to the above shape, the dimensions of the first opening 51 are appropriately set according to the design dimensions of the imprint mold 1 manufactured in the present embodiment, and are not particularly limited. For example, it is about 300 nm to 100 μm. The dimension of the first opening 51 means the width of the first opening 51 in the lateral direction.

The hard mask layer 40 is etched using the first resist pattern 61 formed as described above as a mask to form the first hard mask pattern 41 (see FIG. 7B), and the first hard mask pattern is formed. Using 41 as a mask, one side 21 side of the transparent base material 20 is etched (see FIG. 7C).

Next, after forming a second resist pattern 62 having a predetermined second opening 52 at a desired position on the remaining first hard mask pattern 41, the first hard mask pattern 41 is etched to perform a second hard. The mask pattern 42 is formed. Then, the second hard mask pattern 42 is used as a mask to etch one side 21 side of the transparent base material 20 (see FIG. 7D).

Subsequently, after forming a third resist pattern 63 having a predetermined third opening 53 at a desired position on the second hard mask pattern 42, the second hard mask pattern 42 is etched to form a third hard mask pattern. Form 43 (see FIG. 8B). Then, the third hard mask pattern 43 is used as a mask to etch one side 21 side of the transparent base material 20 (see FIG. 8C).

Then, after forming a fourth resist pattern 64 having a predetermined fourth opening 54 at a desired position on the third hard mask pattern 43, the third hard mask pattern 43 is etched to form the fourth hard mask pattern 44. (See FIG. 9 (A)). Then, the fourth hard mask pattern 44 is used as a mask to etch one side 21 side of the transparent base material 20 (see FIG. 9B). Finally, by removing the fourth hard mask pattern 44, a stepped uneven structure 3'having no convex portion 35 and concave portion 36 is formed on one surface 21 side of the transparent base material 20 (FIG. 9 (C). )reference)

In this way, after the stepped concave-convex structure 3'is formed on the one side 21 side of the transparent base material 20, the convex portion 35 and the concave portion 36 are formed on the first surface 301'of the stepped concave-convex structure 3'. do. First, the hard mask layer 70 is formed on one side 21 side of the transparent base material 20 by sputtering or the like (see FIG. 10A).

Next, an electron beam-reactive resist or the like is applied by a spin coating method or the like so as to cover the hard mask layer 70 to form a resist layer 80 (see FIG. 10B), and an electron beam or the like is irradiated. The resist pattern 81 is formed by subjecting the cells to exposure and then developing the resist pattern 81 (see FIGS. 11A and 11B).

The hard mask layer 70 is etched using the resist pattern 81 as a mask to form the hard mask pattern 71 (see FIG. 12A). Then, by etching one surface 21 side of the transparent base material 20 using the hard mask pattern 71 as a mask, a convex portion 35 is formed on the first surface 301'of the stepped concave-convex structure 3'(FIG. 12B). reference). Similarly, a hard mask pattern 72 having an opening corresponding to the recess 36 is formed (see FIG. 13A), and one side 21 side of the transparent base material 20 is etched using the hard mask pattern 72 as a mask. , A recess 36 is formed on the first surface 301'of the stepped concave-convex structure 3'(see FIG. 13B). In this way, the imprint mold 1 (see FIG. 1) according to the present embodiment can be manufactured. After forming the hard mask pattern 71 (see FIG. 12A), the imprint mold 1 shown in FIG. 6 can be manufactured by removing the resist pattern 81 while leaving the hard mask pattern 71. Is.

Subsequently, another example of the method for manufacturing the imprint mold 1 according to the present embodiment will be described. FIG. 14 is a process flow chart showing each process of the imprint mold manufacturing method according to the present embodiment on the cut end face. The manufacturing method shown in FIG. 14 is different from the manufacturing methods shown in FIGS. 7 to 13 in that the steps of forming the convex portion 35 and the concave portion 36 on the first surface 301 of the stepped concave-convex structure portion 3 are different. Therefore, in the following, the step of forming the convex portion 35 and the concave portion 36 on the first surface 301 of the stepped concave-convex structure portion 3 will be described.

First, as shown in FIG. 14A, sputtering is performed in a direction in which the transparent base material 20 is inclined at a predetermined angle with respect to one surface 21 of the transparent base material 20. At this time, the target atom (hard mask 90 is formed) in the direction of the line segment connecting the first end portion E1 on the first surface 301'of the stepped concave-convex structure 3'(the direction indicated by the arrow in FIG. 14A). Atom) is incident on one side 21 of the transparent base material 20. As a result, the hard mask 90 is formed only on the first end portion E1 side of the first surface 301'of the stepped uneven structure 3'. The width of the hard mask 90 (the width W ₃₅ of the projections 35) can be controlled by adjusting the incident angle of the target atoms.

Then, as shown in FIG. 14B, the hard mask 90 is used as a mask to etch one side 21 side of the transparent base material 20, and a convex portion 35 is formed on the first surface 301'of the stepped uneven structure 3'. Will be done. After that, by forming the recess 36, the imprint mold 1 (see FIG. 1) according to the present embodiment can be manufactured. It is also possible to manufacture the imprint mold 1 shown in FIG. 6 without etching after forming the hard mask 90.

Further, another example of the method for manufacturing the imprint mold 1 according to the present embodiment will be described. 15 and 16 are process flow charts showing each process of the imprint mold manufacturing method according to the present embodiment on the cut end face. Also in the manufacturing methods shown in FIGS. 15 and 16, the steps of forming the convex portion 35 and the concave portion 36 on the first surface 301 of the stepped concave-convex structure portion 3 are different from the manufacturing methods shown in FIGS. 7 to 13. Therefore, in the following, the step of forming the convex portion 35 and the concave portion 36 on the first surface 301 of the stepped concave-convex structure portion 3 will be described.

First, as shown in FIG. 15A, the hard mask pattern 71 is formed on the first end portion E1 side of the first surface 301'of the stepped uneven structure 3'. As a method for forming the hard mask pattern 71, the same method as that shown in FIGS. 10 (A) to 12 (A) can be adopted, and therefore detailed description thereof will be omitted here.

Next, as shown in FIG. 15B, at least a part of the hard mask pattern 71 and a part of the first surface 301'are covered, but a resist pattern 82 having an opening is formed in the portion corresponding to the recess 36. do. As a method for forming the resist pattern 82, the same method as that shown in FIGS. 10 (B) to 11 (B) can be adopted.

Then, as shown in FIG. 15C, by etching one side 21 side of the transparent base material 20 using the resist pattern 82 and the hard mask pattern 71 as masks, the first surface 301'of the stepped uneven structure 3'is formed. A recess 36 is formed in the recess 36. Subsequently, after removing the resist pattern 82 by etching or ashing (see FIG. 16A), one side 21 side of the transparent base material 20 is etched using the hard mask pattern 71 as a mask. As a result, the convex portion 35 can be formed on the first surface 301'of the stepped concave-convex structure 3'(see FIG. 16B). According to the manufacturing methods shown in FIGS. 15 to 16, the number of lithography steps performed when forming the convex portion 35 and the concave portion 36 on the first surface 301'of the stepped concave-convex structure 3'is shown in FIGS. 10 to 13. Can be reduced than the method.

[Imprint method]
An imprint method using the imprint mold 1 having the above-described configuration will be described. FIG. 17 is a process flow chart showing each step of the imprint method using the imprint mold 1 according to the present embodiment on the cut end face. Examples of the concave-convex structure 100 manufactured through the imprint method in the present embodiment include optical elements, wiring circuits, recording devices, display panels, medical examination chips, microchannels, and the like. The imprint mold 1 is provided with a stepped concave-convex structure portion 3 corresponding to the stepped concave-convex structure 103.

First, a transfer substrate 110 such as a silicon wafer, a quartz glass wafer, or a glass substrate such as non-alkali glass, and an imprint mold 1 according to the present embodiment are prepared. Then, the imprint resin 120 is applied onto the transfer substrate 110, and the imprint mold 1 is pressed against the imprint resin 120 (see FIG. 17 (A)). Examples of the imprint resin 120 include epoxy-based resin, phenol-based resin, polyimide-based resin, polysulfone-based resin, polyester-based resin, polycarbonate-based resin, and the like, and an ultraviolet curable resin that is cured by irradiation with ultraviolet rays is used. Is preferable.

The imprint resin 120 is cured while the imprint mold 1 is pressed against the imprint resin 120 on the substrate 110 to be transferred (see FIG. 17B). The method for curing the imprint resin 120 may be appropriately selected according to the curing characteristics of the resin material constituting the imprint resin 120. For example, when the imprint resin 120 is composed of an ultraviolet curable resin, the imprint resin 120 may be cured. The imprint resin 120 can be cured by irradiating the print resin 120 with ultraviolet rays while the imprint mold 1 is pressed against the print resin 120.

The imprint mold 1 is peeled off from the cured imprint resin 120. As a result, the step-like unevenness pattern 123 corresponding to the step-like unevenness structure portion 3 of the imprint mold 1 is formed (see FIG. 17C). The imprint mold 1 according to the present embodiment has a convex portion 35 and a concave portion 36 on the first surface 301 of the stepped concave-convex structure portion 3. Therefore, when the imprint mold 1 is pressed against the imprint resin 120, the imprint resin 120 is shaped along the shape of the stepped uneven structure portion 3 of the imprint mold 1 as shown in FIG. NS. When the imprint resin 120 is cured in this state, the imprint resin 120 is deformed due to curing shrinkage. At this time, of the stepped uneven pattern 123, the portion protruding corresponding to the concave portion 36 of the imprint mold 1 is easily affected by curing shrinkage, so that the corners are rounded and larger than the other portions. Shrink. On the other hand, in the stepped uneven pattern 123, the portion that is recessed corresponding to the convex portion 35 of the imprint mold 1 is deformed so as to fill the concave portion while having rounded corners. As a result, as shown in FIG. 19, the stepped uneven structure portion 3 of the imprint mold 1 is transferred to the imprint resin 120 with high accuracy.

When the stepped concavo-convex structure portion 3 is transferred to the substrate 110 to be transferred using the imprint mold 1 according to the present embodiment, that is, the imprint mold 1 according to the present embodiment is used for imprint lithography. In this case, the transferred substrate 110 is etched using the stepped uneven pattern 123 as a mask. As a result, the concavo-convex structure 100 including the stepped concavo-convex structure 103 is manufactured. When the imprint mold 1 according to the present embodiment is used for imprint lithography, the imprint resin 120 used as a mask for etching the transfer substrate 110 is being etched during the transfer substrate 110. Considering the reduction of the film, the height T _{35 of the convex portion 35 and the depth D 36} of the concave portion 36 of the imprint mold 1 may be appropriately set.

More specifically, of the stepped uneven pattern 123 formed on the imprint resin 120 by the imprint process using the imprint mold 1, the protruding portion and the convex portion corresponding to the concave portion 36 of the imprint mold 1. The height of the convex portion 35 of the imprint mold 1 so that the recessed portion corresponding to 35 can exist as a protrusion and a groove even after the imprint mold 1 is peeled off (see FIG. 20). preferably set the depth D ₃₆ of the T ₃₅ and the recess 36. By etching the transfer substrate 110 using such a stepped uneven pattern 123 as a mask, the stepped uneven structure 103 can be formed on the transferred substrate 110 with high accuracy (see FIG. 21).

When the substrate 110 to be transferred is etched using the stepped uneven pattern 123 as a mask, the corners of the end E120 of the first surface 121 of each step of the stepped uneven pattern 123 are likely to be rounded due to the easy progress of etching. .. Corresponding to this, the corners of the end portion E110 of the first surface 101 of the stepped concave-convex structure 103 formed on the transfer substrate 110 are also likely to be rounded. On the other hand, it is difficult for etching to proceed at the corner of the end portion E121 of the first surface 121 of each step portion of the stepped uneven pattern 123. Therefore, as in the present embodiment, the end E120 of the first surface 121 of each step of the stepped uneven pattern 123 has a protruding portion corresponding to the recess 36 of the imprint mold 1, and the end E121. Since there is a recessed portion corresponding to the convex portion 35, the stepped concave-convex structure 103 can be formed with high accuracy. Further, since the upper step portion of the stepped uneven pattern 123 is exposed to etching for a longer time than the lower step portion, the height and convexity of the protruding portion corresponding to the concave portion 36 are higher in the upper step portion. _{The height of the convex portion 35 of the imprint mold 1 is T 35} so that the depth of the recessed portion is large corresponding to the portion and the height of the protruding portion and the depth of the recessed portion are smaller toward the lower step portion. and preferably the depth D ₃₆ of the recess 36 is set.

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

In the above embodiment, the first surface 301 of each step portion 31 to 34 of the imprint mold 1 has a convex portion 35 and a concave portion 36, and the step portion 37 between the convex portion 35 and the concave portion 36 is one surface of the base portion 2. Although the embodiment having a plane substantially parallel to 2A has been described as an example, the present invention is not limited to this embodiment. For example, as shown in FIG. 22, the step portion 37 between the convex portion 35 and the concave portion 36 may be composed of an inclined portion that is inclined so as to descend from the convex portion 35 toward the concave portion 36. As shown in 23, the stepped portion 37 formed by the inclined portion may be curved.

The imprint mold 1 having the configuration shown in FIG. 22 can be manufactured as follows. First, a hard mask pattern 71 is formed on the first end E1 side of the first surface 301'of the stepped uneven structure 3', and at least a part of the hard mask pattern 71 and a part of the first surface 301' are covered. Form a resist pattern 82 having an opening in a portion corresponding to the recess 36 (see FIG. 24 (A)). Then, using the resist pattern 82 and the hard mask pattern 71 as masks, the one side 21 side of the transparent base material 20 is dry-etched. During this dry etching, the amount (partial pressure) of oxygen in the etching gas is adjusted so that the resist pattern 82 is easily etched. As a result, the exposed portion (first surface 301'of the stepped uneven structure 3') from which the resist pattern 82 has been removed is exposed to etching. As a result, the stepped portion 37 and the recessed portion 36 formed by the inclined portion can be formed on the first surface 301'of the stepped uneven structure 3'(see FIG. 24 (B)).

1 ... Imprint mold 2 ... Transparent base material 2A ... One side 2B ... The other side 3 ... Step-like uneven structure 31 ... First step 32 ... Second step 33 ... Third step 34 ... Fourth step 35 … Convex 37… Concave

Claims (9)

It is provided with a base portion and a stepped concave-convex structure portion formed on one surface side of the base portion and having a plurality of step portions.
Wherein the step portions has a first surface substantially parallel to one surface of the base and a second surface you substantially perpendicular to the one surface of the base,
The first surface includes a first end portion and a second end portion located opposite to the first end portion.
The second surface extends from the first end portion of the first surface toward the base side.
In the direction perpendicular to the one surface of the base, each of the at least the plurality of stepped portions, so that the first end portion of said first surface is located distally from said base portion than in the vicinity of the second end is composed,
A convex portion including the first end portion is provided on the first end portion side of the first surface, and a concave portion is provided in the vicinity of the second end portion of the first surface, whereby the first surface is provided. The surface is formed in a downward step shape of three or more steps from the first end portion to the second end portion.
Regarding the relationship between the heights of the convex portions provided on the first surface of each step portion, the height of the convex portions located closest to the one surface of the base portion is the highest, and the convex portions have the highest height. An imprint mold characterized in that the height of the convex portion decreases as the distance from one surface of the base portion increases. In a side view, a width of the convex portion, the imprint mold according to claim 1, wherein the at half or less of the first surface width. The imprint mold according to claim 1 or 2 , wherein the material constituting the convex portion is a material different from the material constituting the base portion. The imprint mold according to any one of claims 1 to 3 , wherein a recess is provided in the vicinity of the second end portion facing the first end portion of the first surface. The imprint mold according to any one of claims 1 to 4, wherein the width of the recess is ½ or less of the width of the first surface in a side view. Said first surface, the imprint mold according to any one of claims 1 to 5, characterized in that it comprises an inclined portion inclined toward the second end side from the first end portion side. The inclined portion, the imprint mold according to claim 6, wherein the inclined curved toward the second end side from the first end portion side. The imprint mold according to any one of claims 1 to 7 , wherein the imprint mold is an imprint mold used for imprint lithography. The method for manufacturing an imprint mold according to any one of claims 1 to 8.
A step of forming a stepped concave-convex structure having a plurality of steps on one side of the base, and
A step of forming a first hard mask layer on the stepped concavo-convex structure portion by exposing a part on the stepped concavo-convex structure portion, and
A step of forming the convex portion by performing a first etching process on the base portion on which the first hard mask layer is formed, and a step of forming the convex portion.
A step of forming a second hard mask layer on the stepped concavo-convex structure portion by exposing a part on the stepped concavo-convex structure portion, and
A step of forming the recess by subjecting the base portion on which the second hard mask layer is formed to a second etching process is included.
In the step of forming the first hard mask layer, of the first surface of the respective stepped portions to form a first hard mask layer corresponding to the convex portion to the first end portion,
A method for manufacturing an imprint mold, which comprises forming the second hard mask layer having an opening corresponding to the recess in the step of forming the second hard mask layer.

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