JP2018163942A - Imprint mold and method of manufacturing imprint mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imprint mold capable of highly accurately transferring a stepped uneven structure part to a transfer target material through imprint processing, and a method of manufacturing the same.SOLUTION: An imprint mold comprises a base part and a stepped uneven structure part formed on one surface side of the base part and having a plurality of step parts, and is so constituted that the respective step parts each have a first surface substantially parallel with the one surface of the base part and a second surface, extending substantially orthogonally to the one surface of the base part, from a first end part of the first surface toward the base part, and at least the plurality of step parts each have a first end part of a first surface located to be more distal from the base part than from a neighbor of a second end part opposed thereto in a direction perpendicular to the one surface of the base part.SELECTED DRAWING: Figure 1

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., pattern formation that uses a mold member (imprint mold) with a fine uneven pattern formed on the surface of the substrate and transfers the fine uneven pattern onto a workpiece such as a substrate at the same magnification. Nanoimprint technology is used.

  Many of the fine concavo-convex patterns formed in the imprint mold used in the nanoimprint technology are configured by 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, 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-step structure using nanoimprint technology, an imprint mold including a stepped concavo-convex structure portion having a plurality of step portions has been conventionally used (see Patent Document 1).

JP 2010-171109 A

  Using the imprint mold having the stepped concavo-convex structure part, when the stepped concavo-convex structure part is transferred to an ultraviolet curable resin or the like as a material to be transferred, the ultraviolet curable resin is transformed into an ultraviolet curable resin by curing shrinkage. There arises a problem that the shape of the stepped concavo-convex structure to be formed is changed, specifically, the shape of the corner of each step is rounded. In particular, when the number of steps of the stepped concavo-convex structure portion of the imprint mold is increased, the above problem can be remarkably generated.

  Using the imprint mold, the stepped concavo-convex structure portion is transferred to an ultraviolet curable resin or the like on a predetermined substrate, and the substrate is etched using the ultraviolet curable resin as a mask, whereby the stepped concavo-convex structure portion is formed on the substrate. When transferring the shape, the corners of each stepped portion that has been rounded are further rounded by being exposed to the etching environment for a long time, and the stepped concavo-convex structure portion transferred to the substrate is removed. There arises a problem that it cannot be formed as designed.

  When the shape change of the stepped concavo-convex structure formed in the ultraviolet curable resin as described above occurs, there is a problem that a defect occurs in a product manufactured through the imprint process using the imprint mold. End up.

  In view of the above problems, an object of the present invention is to provide an imprint mold that can transfer a stepped concavo-convex 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-mentioned problem, the present invention includes a base and a stepped concavo-convex structure portion having a plurality of step portions formed on one surface side of the base portion, and each step portion includes the base portion. A first surface substantially parallel to one surface of the base portion and a second surface substantially orthogonal to the one surface of the base portion and extending from the first end portion of the first surface toward the base portion, In the direction perpendicular to the one surface, at least each of the plurality of step portions is more distant from the base portion than the vicinity of the second end portion where the first end portion of the first surface opposes the first end portion. An imprint mold is provided that is configured to be positioned (Invention 1).

  The present invention also includes a base and a stepped concavo-convex structure having a plurality of steps formed on one side of the base, and each step is substantially parallel to one surface of the base. A first surface of the first surface, and a first surface of the first surface extending from the first end of the first surface toward the base. Provided on the side is an imprint mold characterized in that a convex portion including the first end portion is provided (invention 2).

  In the said invention (invention 2), it is preferable that the width | variety of the said convex part in side view is 1/2 or less of the width | variety of the said 1st surface (invention 3), and the material which comprises the said convex part is the said base. It is preferable that the material is different from the material constituting the material (invention 4), and it is preferable that a recess is provided in the vicinity of the second end facing the first end of the first surface (invention 5).

  The present invention further includes a base and a stepped concavo-convex structure portion having a plurality of step portions formed on one surface side of the base portion, and each step portion is substantially parallel to one surface of the base portion. A first surface of the first surface, and a first surface of the first surface extending from the first end of the first surface toward the base. An imprint mold is provided in which a concave portion is provided in the vicinity of the second end portion facing to (Invention 6).

  In the said invention (invention 6), it is preferable that the width | variety of the said recessed part in a side view is 1/2 or less of the width | variety of the said 1st surface (invention 7), on the 1st edge part side of the said 1st surface. It is preferable that a convex portion including the first end portion is provided (invention 8).

  In the said invention (invention 1-8), the said 1st surface may be comprised from the said 1st edge part toward the 2nd edge part which opposes the said 1st edge part in the descent | falling step shape (invention 9). ), And may be configured in three or more descending steps from the first end toward the second end facing the first end (Invention 10).

  In the above inventions (Inventions 1 to 8), the first surface may include an inclined portion inclined from the first end portion side toward the second end portion side facing the first end portion ( Invention 11) Preferably, the inclined portion is curved and inclined from the first end side toward the second end side facing the first end portion (Invention 12).

  In the said invention (invention 1-12), it is preferable that the said imprint mold is an imprint mold used for imprint lithography (invention 13).

  Furthermore, the present invention is a method for producing an imprint mold according to the above inventions (Inventions 1 to 13), wherein a stepped concavo-convex structure portion having a plurality of step portions on one side of the base portion is formed. , A step of forming a hard mask layer on the stepped concavo-convex structure portion so as to expose a part on the stepped concavo-convex structure portion, and a step of etching the base portion on which the hard mask layer is formed Each of the step portions is substantially parallel to one surface of the base portion, and substantially perpendicular to one surface of the base portion, from the first end portion of the first surface toward the base side. In the step of forming the hard mask layer, the hard mask layer is formed in the vicinity of the first end of the first surface of each step, and the first end The hard mask layer is formed in the vicinity of the second end facing the portion To provide a method of manufacturing an imprint mold, characterized in that no (invention 14).

  ADVANTAGE OF THE INVENTION According to this invention, the imprint mold which can transcribe | transfer a stair-like uneven structure part to a material to be transferred with high precision by imprint processing, and its manufacturing method can be provided.

FIG. 1 is a cross-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 the stepped concavo-convex structure portion of the imprint mold according to the embodiment of the present invention. FIG. 3 is a partially enlarged cut end view showing a schematic configuration of an example of a step portion of the imprint mold according to the embodiment of the present invention. FIG. 4 is a partially enlarged cut end view showing a schematic configuration of another example of a step portion of the imprint mold according to the embodiment of the present invention. FIG. 5 is a partial enlarged cut end view showing a schematic configuration of the first surface of the step portion of the imprint mold according to the embodiment of the present invention. FIG. 6 is a partially enlarged cut end view showing a modification of the stepped concavo-convex structure portion of the imprint mold according to the embodiment of the present invention. FIG. 7 is a process flow diagram showing a manufacturing process (part 1) of an imprint mold according to an embodiment of the present invention at a cut end surface. FIG. 8 is a process flow diagram showing a manufacturing process (No. 2) of the imprint mold according to the embodiment of the present invention at a cut end face. FIG. 9 is a process flow diagram showing a manufacturing process (No. 3) of the imprint mold according to the embodiment of the present invention on a cut end surface. FIG. 10 is a process flow diagram showing a manufacturing process (No. 4) of the imprint mold according to the embodiment of the present invention at a cut end face. FIG. 11 is a process flow diagram showing a manufacturing process (No. 5) of the imprint mold according to the embodiment of the present invention at a cut end face. FIG. 12 is a process flow diagram showing a manufacturing process (No. 6) of the imprint mold according to the embodiment of the present invention on a cut end surface. FIG. 13: is a process flowchart which shows the manufacturing process (the 7) of the imprint mold which concerns on one Embodiment of this invention in a cut end surface. FIG. 14 is a process flow diagram showing another example (No. 1) of the imprint mold manufacturing process according to the embodiment of the present invention on a cut end surface. FIG. 15 is a process flow diagram showing another example (part 2) of the imprint mold manufacturing process according to the embodiment of the present invention on a cut end surface. FIG. 16 is a process flowchart subsequent to FIG. 15, showing another example (part 2) of the imprint mold manufacturing process according to the embodiment of the present invention by a cut end surface. FIG. 17 is a process flow diagram showing each process of the imprint method using the imprint mold according to the embodiment of the present invention on a cut end surface. FIG. 18 is a cut end view (part 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 (part 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 transfer substrate 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 uneven 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 uneven structure portion of an imprint mold according to another embodiment of the present invention. FIG. 24 is a process flow diagram showing a manufacturing process of the imprint mold shown in FIG. 22 at a cut end face.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cut end view showing a schematic configuration of an imprint mold according to the present embodiment, and FIG. 2 is a partially enlarged cut end view showing a schematic configuration of a stepped uneven structure portion of the imprint mold according to the present embodiment. FIG.

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

  As the base 2, a general substrate for imprint molding, for example, a quartz glass substrate, a soda glass substrate, a fluorite substrate, a calcium fluoride substrate, a magnesium fluoride substrate, a barium borosilicate glass, an aminoborosilicate glass 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, two or more substrates arbitrarily selected from these A transparent substrate such as a laminated substrate formed by laminating layers can be used. In the present embodiment, “transparent” may be of a level that can cure the photo-curable resin with the light irradiated through the base 2. For example, the transmittance of light having a wavelength of 300 to 450 nm is 70%. It is preferable that the ratio be 90% or more.

  The shape of the base 2 in plan view 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 that is generally used for optical imprinting, the shape of the base 2 in a plan view is usually a substantially rectangular shape.

  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. In addition, the thickness of the base portion 2 can be set as appropriate within a 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 uneven structure portion 3 has a plurality of step portions 30. In the present embodiment, the stepped concavo-convex structure portion 3 is described by taking an example in which the four step portions 30 of the first to fourth step portions 31 to 34 are sequentially provided from the one surface 2A side of the base portion 2. However, the present invention is not limited to this mode. The stepped concavo-convex structure portion 3 only needs to have at least two stepped portions 30, but as the number of stepped portions 30 of the stepped concavo-convex structure portion 3 is larger, the effect in the present embodiment can be remarkably exhibited. . Although the shape in planar view of the 1st-4th step parts 31-34 is not specifically limited, For example, a substantially circular shape, a substantially rectangular shape, etc. are mentioned.

  As shown in FIGS. 2 and 3, the first to fourth step portions 31 to 34 are respectively substantially orthogonal to the first surface 301 substantially parallel to the one surface 2 </ b> A of the base 2 and the one surface 2 </ b> A of the base 2. The second surface 302 extends from the first end E1 of the first surface 301 toward the base 2 side. In a direction perpendicular to the one surface 2A of the base portion 2, the first end E1 of the first surface 301 is located farther from the base portion 2 than 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.

As long as the width W ₃₀₁ (see FIG. 3) of the first surface 301 of the first to fourth step portions 31 to 34 conforms to the dimensions required for a product manufactured using the imprint mold 1 according to this 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 surfaces 301 of the first to third step portions 31 to 33 are located on the first end E1 side and the second end E2 side, and are located on one side of the base 2. It is preferable to have a recess 36 including a bottom surface substantially parallel to the direction 2 </ b> A and at least one stepped portion 37 positioned between the protrusion 35 and the recess 36 on the first surface 301. The convex portion 35 includes the first end 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). You may be located in the 1st edge part E1 side rather than the 2nd surface 302 (refer FIG. 4).

  Note that 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 vary depending on the etching conditions when forming the recess 36. When the bottom surface of the recess 36 is substantially parallel to the one surface 2A of the base 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 at this point.

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

In the present embodiment, the convex portion 35 located on the first end E1 side of the first surface 301 is a portion protruding in a direction away from the base portion 2 with respect to the reference surface BS, as shown in FIG. It 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, the first surface 301 has a width W ₃₅ that is 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 a portion that is 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 And having a width W ₃₆ of 1/5 to 1/3. The reference surface BS is an intermediate point between the uppermost portion of the first surface 301 (the portion farthest from the one surface 2A of the base 2) and the lowermost portion of the first surface 301 (the portion closest to the one surface 2A of the base 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 E1 side of the first surface 301 in the first to fourth step portions 31 to 34 is the same as that of the imprint mold 1 according to this embodiment. Although it can set suitably according to the cure shrinkage rate etc. of the imprint resin used by the used imprint process, for example, it can set to about 10 nm-1 micrometer, More preferably, about 20 nm-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 the one surface 2A of the base portion 2).

The depth D ₃₆ (see FIG. 3) of the concave portion 36 located on the second end E2 side of the first surface 301 in the first to fourth step portions 31 to 34, and the imprint mold 1 according to the present embodiment was used. Although it can set suitably according to the cure shrinkage rate etc. of the imprint resin used in the imprint process, for example, it can be set to about 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 the one surface 2A of the base 2).

In the stepped concavo-convex structure portion 3 in 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 all have the same height _T35. 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 It is preferable that the height T ₃₅ of the convex portion 35 gradually decreases as the distance from the direction 2A increases. The recess 36 located in the second end E2 side of the first surface 301 of the first to third step portions 31 to 33 are all may have the same depth D _36, but the base 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.

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

  In addition, as shown in FIG. 6, the convex part 35 in this embodiment may be comprised with the material different from the material which comprises the base part 2. As shown in FIG. 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 metal 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 uneven structure portion 3. 35, and having the recess 36 on the second end E2 side, a stepped concavo-convex pattern can be formed on the imprint resin with high accuracy through imprint processing, as will be described later.

[Imprint Mold Manufacturing Method]
Next, an example of the manufacturing method of the imprint mold 1 having the above configuration will be described. 7 to 13 are process flow diagrams showing the respective steps of the imprint mold manufacturing method according to the present embodiment on a cut end surface.

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

  The hard mask layer 40 is made of, for example, a chromium-based material such as chromium, chromium nitride, chromium oxide, or chromium oxynitride; It can be formed by a known film formation method such as sputtering, PVD, or CVD, using a single system material or the like, or two or more kinds selected arbitrarily. The thickness of the hard mask layer 40 can be set as appropriate according to the etching selection ratio with the material constituting the transparent substrate 20, the height of the stepped concavo-convex 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 or positive electron beam reactive resist material generally used in electron beam lithography processing, photolithography processing and the like. And ultraviolet reactive resist materials.

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

  The method for forming the resist film 60 on the hard mask layer 40 is not particularly limited, and a conventionally known method, for example, a resist material is applied on the hard mask layer 40 by spin coater, spray coater or the like. Examples include a method of applying using a machine or laminating a dry film resist containing the resin component on the hard mask layer 40 and heating (pre-baking) at a predetermined temperature if 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. They are a substantially annular shape, a substantially square shape in plan view, a substantially rectangular frame shape in plan view, and the like.

  The dimension of the first opening 51 is appropriately set according to the design dimension of the imprint mold 1 manufactured in the present embodiment, as in the above shape, and is not particularly limited. For example, it is about 300 nm to 100 μm. In addition, the dimension of the 1st opening part 51 means the width | variety in the transversal direction of the 1st opening part 51. FIG.

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

  Next, a second resist pattern 62 having a predetermined second opening 52 is formed at a desired position on the remaining first hard mask pattern 41, and then the first hard mask pattern 41 is etched to form a second hard mask. A mask pattern 42 is formed. And the one surface 21 side of the transparent base material 20 is etched using the said 2nd hard mask pattern 42 as a mask (refer FIG.7 (D)).

  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. 43 is formed (see FIG. 8B). And the one surface 21 side of the transparent base material 20 is etched using the said 3rd hard mask pattern 43 as a mask (refer FIG.8 (C)).

  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 a fourth hard mask pattern 44. (See FIG. 9A). And the one surface 21 side of the transparent base material 20 is etched using the said 4th hard mask pattern 44 as a mask (refer FIG.9 (B)). Finally, by removing the fourth hard mask pattern 44, the stepped concavo-convex structure 3 ′ having no convex portions 35 and concave portions 36 is formed on the one surface 21 side of the transparent substrate 20 (FIG. 9C )reference)

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

  Next, an electron beam reactive resist or the like is applied by spin coating or the like so as to cover the hard mask layer 70 to form a resist layer 80 (see FIG. 10B), and then irradiated with an electron beam or the like. Then, a resist pattern 81 is formed by performing a development process thereafter (see FIGS. 11A and 11B).

  The hard mask layer 70 is etched using the resist pattern 81 as a mask to form a hard mask pattern 71 (see FIG. 12A). And the convex part 35 is formed in 1st surface 301 'of stair-like uneven structure 3' by etching the one surface 21 side of the transparent base material 20 by using the said hard mask pattern 71 as a mask (FIG.12 (B)). reference). Similarly, a hard mask pattern 72 having an opening corresponding to the recess 36 is formed (see FIG. 13A), and the one surface 21 side of the transparent substrate 20 is etched using the hard mask pattern 72 as a mask. Then, the recess 36 is formed on the first surface 301 ′ of the stepped concavo-convex structure 3 ′ (see FIG. 13B). Thus, the imprint mold 1 (refer FIG. 1) which concerns on this 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. It is.

  Then, the other example of the manufacturing method of the imprint mold 1 which concerns on this embodiment is demonstrated. FIG. 14 is a process flow diagram showing each process of the imprint mold manufacturing method according to the present embodiment on a cut end surface. The manufacturing method shown in FIG. 14 is different from the manufacturing method shown in FIGS. 7 to 13 in the step of forming the convex portions 35 and the concave portions 36 on the first surface 301 of the stepped concavo-convex structure portion 3. Therefore, below, the process of forming the convex part 35 and the recessed part 36 in the 1st surface 301 of the step-shaped uneven structure part 3 is demonstrated.

First, as shown in FIG. 14A, sputtering is performed in a direction inclined at a predetermined angle with respect to the one surface 21 of the transparent substrate 20. At this time, the target atoms (hard mask 90) are configured in the direction of the line segment (the direction indicated by the arrow in FIG. 14A) connecting the first end E1 of the first surface 301 ′ of the stepped concavo-convex structure 3 ′. Atoms) enter one surface 21 of the transparent substrate 20. Thereby, the hard mask 90 is formed only on the first end E1 side of the first surface 301 ′ of the stepped concavo-convex 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.

  And as shown in FIG.14 (B), the one surface 21 side of the transparent base material 20 is etched using the said hard mask 90 as a mask, and the convex part 35 is formed in 1st surface 301 'of stair-like uneven structure 3'. Is done. Then, the imprint mold 1 (refer FIG. 1) which concerns on this embodiment can be manufactured by forming the recessed part 36. FIG. If the etching after forming the hard mask 90 is not performed, the imprint mold 1 shown in FIG. 6 can be manufactured.

  Furthermore, the other example of the manufacturing method of the imprint mold 1 which concerns on this embodiment is demonstrated. FIG.15 and FIG.16 is a process flowchart which shows each process of the manufacturing method of the imprint mold which concerns on this embodiment in a cut end surface. 15 and FIG. 16 also differs from the manufacturing method shown in FIGS. Therefore, below, the process of forming the convex part 35 and the recessed part 36 in the 1st surface 301 of the step-shaped uneven structure part 3 is demonstrated.

  First, as shown in FIG. 15A, a hard mask pattern 71 is formed on the first end E1 side of the first surface 301 'of the stepped concavo-convex structure 3'. As a method of forming the hard mask pattern 71, a method similar to the method shown in FIGS. 10A to 12A can be adopted, and detailed description thereof is omitted here.

  Next, as shown in FIG. 15B, a resist pattern 82 that covers at least a part of the hard mask pattern 71 and a part of the first surface 301 ′ but has an opening corresponding to the recess 36 is formed. To do. As a method of forming the resist pattern 82, a method similar to the method shown in FIGS. 10B to 11B can be employed.

  Then, as shown in FIG. 15C, the first surface 301 ′ of the stepped concavo-convex structure 3 ′ is etched by etching the one surface 21 side of the transparent substrate 20 using the resist pattern 82 and the hard mask pattern 71 as a mask. A recess 36 is formed in the substrate. Subsequently, after removing the resist pattern 82 by etching or ashing (see FIG. 16A), the one surface 21 side of the transparent substrate 20 is etched using the hard mask pattern 71 as a mask. Thereby, the convex part 35 can be formed in 1st surface 301 'of stair-like uneven structure 3' (refer FIG.16 (B)). According to the manufacturing method shown in FIGS. 15 to 16, the number of lithography steps performed when forming the convex portions 35 and the concave portions 36 on the first surface 301 ′ of the stepped concavo-convex structure 3 ′ is shown in FIGS. 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 diagram showing each process of the imprint method using the imprint mold 1 according to the present embodiment on a cut end surface. Examples of the concavo-convex structure 100 manufactured through the imprint method in the present embodiment include an optical element, a wiring circuit, a recording device, a display panel, a medical test chip, a microchannel, and the like. A stepped uneven structure portion 3 corresponding to the stepped uneven structure 103 is provided in the imprint mold 1.

  First, a transfer substrate 110 such as a glass substrate such as a silicon wafer, a quartz glass wafer, or an alkali-free glass, and the 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. 17A). Examples of the imprint resin 120 include an epoxy resin, a phenol resin, a polyimide resin, a polysulfone resin, a polyester resin, and a polycarbonate resin, and an ultraviolet curable resin that is cured by irradiation with ultraviolet rays is used. Is preferred.

  The imprint resin 120 is cured in a state where the imprint mold 1 is pressed against the imprint resin 120 on the transfer substrate 110 (see FIG. 17B). The method for curing the imprint resin 120 may be selected as appropriate 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 can be cured by irradiating ultraviolet light with the imprint mold 1 pressed against the print resin 120.

  The imprint mold 1 is peeled from the cured imprint resin 120. Thereby, the step-like uneven | corrugated pattern 123 corresponding to the step-like uneven | corrugated structure part 3 of the imprint mold 1 is formed (refer FIG.17 (C)). 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 concavo-convex structure portion 3. Therefore, in a state where the imprint mold 1 is pressed against the imprint resin 120, the imprint resin 120 is shaped along the shape of the stepped concavo-convex structure portion 3 of the imprint mold 1 as shown in FIG. The When the imprint resin 120 is cured in this state, the imprint resin 120 is deformed by curing shrinkage. At this time, a portion of the stepped concavo-convex pattern 123 that protrudes 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, a portion of the stepped concavo-convex pattern 123 that is recessed corresponding to the protrusion 35 of the imprint mold 1 is deformed so as to fill the recessed portion with rounded corners. Thereby, as shown in FIG. 19, the stepped concavo-convex structure portion 3 of the imprint mold 1 is transferred to the imprint resin 120 with high accuracy.

When transferring the stepped concavo-convex structure portion 3 to the transfer substrate 110 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. Thereby, the concavo-convex structure 100 including the stepped concavo-convex structure 103 is manufactured. When the imprint mold 1 according to this 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 etching of the transfer substrate 110. In consideration of 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 set as appropriate.

More specifically, of the stepped uneven pattern 123 formed on the imprint resin 120 by the imprint process using the imprint mold 1, a portion and a protrusion that protrude corresponding to the recessed portion 36 of the imprint mold 1. The height of the convex portion 35 of the imprint mold 1 so that the concave portion corresponding to 35 can exist as a protrusion and a groove even after the imprint mold 1 is peeled off (see FIG. 20). It is preferable to set T ₃₅ and the depth D ₃₆ of the recess 36. By etching the transferred substrate 110 using the 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 transferred substrate 110 is etched using the stepped uneven pattern 123 as a mask, the corner of the end portion E120 of the first surface 121 of each stepped portion of the stepped uneven pattern 123 tends to be rounded because the etching easily proceeds. . Corresponding to this, the corners of the end E110 of the first surface 101 of the stepped concavo-convex structure 103 formed on the transfer substrate 110 are also easily rounded. On the other hand, etching hardly proceeds at the corners of the end E121 of the first surface 121 of each stepped portion of the stepped uneven pattern 123. Therefore, as in the present embodiment, the end portion E120 of the first surface 121 of each stepped portion of the stepped uneven pattern 123 has a portion protruding corresponding to the recess 36 of the imprint mold 1, and the end portion E121. Therefore, the stepped concavo-convex structure 103 can be formed with high accuracy. Further, the upper stepped portion of the stepped uneven pattern 123 is exposed to etching for a longer time than the lower stepped portion, so that the upper stepped portion has a height or convexity that protrudes corresponding to the recess 36. The height T ₃₅ of the convex portion 35 of the imprint mold 1 is such that the depth of the concave portion corresponding to the portion is large, and the height of the protruding portion and the depth of the concave portion are smaller in the lower step portion. and preferably the depth D ₃₆ of the recess 36 is set.

  The embodiment described above is described for facilitating understanding of the present invention, and is 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 the convex portion 35 and the 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 aspect which has a plane substantially parallel to 2A was mentioned as an example and demonstrated, it is not limited to this aspect. For example, as shown in FIG. 22, the stepped portion 37 between the convex portion 35 and the concave portion 36 may be configured by an inclined portion that inclines so as to descend from the convex portion 35 toward the concave portion 36. As shown in FIG. 23, the step part 37 constituted by the inclined part may be curved.

  The imprint mold 1 having the configuration shown in FIG. 22 can be manufactured as follows. First, the hard mask pattern 71 is formed on the first end E1 side of the first surface 301 ′ of the stepped concavo-convex structure 3 ′, and covers at least a part of the hard mask pattern 71 and a part of the first surface 301 ′. However, a resist pattern 82 having an opening in a portion corresponding to the recess 36 is formed (see FIG. 24A). Then, the one surface 21 side of the transparent substrate 20 is dry-etched using the resist pattern 82 and the hard mask pattern 71 as a mask. 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 (the first surface 301 ′ of the stepped concavo-convex structure 3 ′) from which the resist pattern 82 has been removed is exposed to etching. As a result, it is possible to form the stepped portion 37 and the recessed portion 36 constituted by the inclined portions on the first surface 301 ′ of the stepped concavo-convex structure 3 ′ (see FIG. 24B).

DESCRIPTION OF SYMBOLS 1 ... Imprint mold 2 ... Transparent base material 2A ... One side 2B ... The other side 3 ... Stair-like uneven structure part 31 ... 1st step part 32 ... 2nd step part 33 ... 3rd step part 34 ... 4th step part 35 ... convex part 37 ... concave part

Claims (14)

A base, and a stepped concavo-convex structure having a plurality of steps formed on one side of the base,
Each of the step portions includes a first surface that is substantially parallel to one surface of the base portion, and a second surface that is substantially orthogonal to the one surface of the base portion and extends from the first end of the first surface toward the base portion. And
In the direction perpendicular to the one surface of the base, at least each of the plurality of stepped portions is more distant from the base than the vicinity of the second end where the first end of the first surface faces the first end. An imprint mold, wherein the imprint mold is configured to be located distally. A base, and a stepped concavo-convex structure having a plurality of steps formed on one side of the base,
Each of the step portions has a first surface substantially parallel to the base portion, and a second surface substantially orthogonal to the base portion and extending from the first end portion of the first surface to the base side,
An imprint mold, wherein a convex portion including the first end portion is provided on the first end portion side of the first surface.   3. The imprint mold according to claim 2, wherein, in a side view, the width of the convex portion is ½ or less of the width of the first surface.   4. The imprint mold according to claim 2, wherein a material constituting the convex portion is a material different from a material constituting the base portion. 5.   The imprint mold according to claim 2, wherein a concave portion is provided in the vicinity of the second end portion facing the first end portion of the first surface. A base, and a stepped concavo-convex structure having a plurality of steps formed on one side of the base,
Each of the step portions includes a first surface substantially parallel to one surface of the base portion, and a second surface substantially orthogonal to the one surface of the base portion and extending from the first end portion of the first surface to the base side. Have
An imprint mold, wherein a concave portion is provided in the vicinity of a second end portion facing the first end portion of the first surface.   The imprint mold according to claim 6, wherein, in a side view, the width of the concave portion is ½ or less of the width of the first surface.   The imprint mold according to claim 6, wherein a convex portion including the first end portion is provided on the first end portion side of the first surface.   The said 1st surface is comprised in the downward staircase shape toward the 2nd end part which opposes the said 1st end part from the said 1st end part, The Claim 1 characterized by the above-mentioned. Imprint mold.   The said 1st surface is comprised in the descending step shape of 3 steps or more toward the 2nd end part which opposes the said 1st end part from the said 1st end part, The any one of Claims 1-9 characterized by the above-mentioned. Imprint mold according to crab.   The said 1st surface contains the inclination part which inclines toward the 2nd edge part side which opposes the said 1st edge part from the said 1st edge part side. Imprint mold.   The imprint mold according to claim 11, wherein the inclined portion is curved and inclined from the first end portion side toward the second end portion side facing the first end portion.   The imprint mold according to any one of claims 1 to 12, wherein the imprint mold is an imprint mold used for imprint lithography. A method for producing an imprint mold according to claim 1,
Forming a stepped concavo-convex structure portion having a plurality of step portions on one side of the base portion;
Forming a hard mask layer on the stepped concavo-convex structure portion so as to expose a part of the stepped concavo-convex structure portion;
Etching the base portion on which the hard mask layer is formed,
Each of the step portions includes a first surface that is substantially parallel to one surface of the base portion, and a second surface that is substantially orthogonal to the one surface of the base portion and extends from the first end of the first surface toward the base portion. And
In the step of forming the hard mask layer, in the first surface of each step portion, the hard mask layer is formed in the vicinity of the first end portion, and in the vicinity of the second end portion facing the first end portion. The method of manufacturing an imprint mold is characterized in that the hard mask layer is not formed.

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