JP2019024030A - Imprint mold and manufacturing method of the same - Google Patents

Abstract

To provide an imprint mold blank and an imprint mold each having a convex structure portion and a mark structure body formed with higher precision, and a method for manufacturing the same.SOLUTION: The imprint mold blank used for manufacturing an imprint mold includes: a base having a first surface and a second surface opposite to the first surface; a convex structure portion projecting from the first surface of the base; and a mark structure which is provided on the first surface of the base and is composed of a concavo-convex structure. A peripheral wall of the convex structure portion is constituted by a substantially flat surface rising at a predetermined angle from the first surface. Tops of the convex portions of the concavo-convex structure constituting the mark structure are positioned closer to the first surface than the top surface of the convex structure portion.SELECTED DRAWING: Figure 2A

Description

  The present disclosure relates to an imprint mold and a method of manufacturing the imprint mold.

  In recent years, in the technical field of semiconductor devices (for example, semiconductor memories), there is a limit in manufacturing using a photolithography method due to further progress in miniaturization and miniaturization of semiconductor devices. In addition, an exposure apparatus and a photomask used for manufacturing a semiconductor device that is becoming smaller and finer by a photolithography method are also extremely expensive as compared with the related art. Therefore, there is a current situation that it is difficult to inexpensively manufacture semiconductor devices that are becoming smaller and finer.

  Under such circumstances, in recent years, in a manufacturing process of a semiconductor device or the like, a pattern member (imprint mold) having a concavo-convex pattern formed on the surface of a substrate is used, and the concavo-convex pattern is transferred to a workpiece such as a substrate at the same magnification Nanoimprint technology, which is a forming technology, has been used.

  As an imprint mold 100 used in the nanoimprint technology, as shown in FIG. 7, a base 101 having a first surface 101A and a second surface 101B opposite to the first surface 101A, and a first surface 101A of the base 101 protrude from the first surface 101A. There is known one having a convex structure portion 102 and a concavo-convex pattern 103 formed on the upper surface of the convex structure portion 102. In a predetermined area located around the convex structure portion 102 on the first surface 101A, a mark structure constituted by a concavo-convex structure such as a name mark indicating the product name, model number, etc. of the imprint mold 100, an ID code, an alignment mark, etc. A body 104 is formed. In the nanoimprint technology, once an imprint mold is manufactured, a concavo-convex pattern can be easily transferred and formed repeatedly, so that high throughput is obtained and it is economical. Therefore, in recent years, application to various technical fields is expected in addition to the technical field of semiconductor devices.

  The imprint mold 100 is manufactured by, for example, electron beam lithography using the imprint mold blanks 200 in which the hard mask layer 201 is formed on the upper surface of the convex structure portion 102. The imprint mold blanks 200 is It is manufactured through the steps described below.

  First, a transparent base material (quartz glass substrate or the like) 301 having a first surface 301A and a second surface 301B facing the first surface 301A is prepared, and a hard mask layer 302 made of metal chromium or the like is used as the transparent base material. It is formed on the first surface 301A of 301 (see FIG. 8A). Next, a resist pattern 303 corresponding to the convex structure portion 102 and the mark structure 104 is formed over the hard mask layer 302 (see FIG. 8B), and the hard mask layer 302 is etched using the resist pattern 303 as a mask. Thus, a hard mask pattern 304 is formed (see FIG. 8C). By using this hard mask pattern 304 as a mask, the first surface 301A of the transparent substrate 301 is wet-etched to simultaneously form the convex structure 102 and the mark structure 104 on the first surface 301A, thereby imprint mold blanks. 200 is manufactured (see FIG. 8D).

  Thus, if the convex structure part 102 and the mark structure body 104 are formed simultaneously in the manufacturing process of the imprint mold blanks 200, the upper surface of the convex structure part 102 and the upper surface of the mark structure body 104 become the same height. . As a result, when the imprint mold 100 manufactured using the imprint mold blanks 200 is used to press the concave / convex pattern 103 formed on the upper surface of the convex structure portion 102 against the imprint resin on the transfer substrate. In addition, there is a problem that the mark structure 104 also comes into contact with the substrate to be transferred together with the uneven pattern 103.

  In order to solve such a problem, conventionally, the dimension of the resist pattern 303 for the mark structure 104 is made smaller than twice the height (design value) of the convex structure portion 102, and an isotropic etching solution is used. By processing the first surface 301A of the transparent substrate 301 by the wet etching used, the convex structure portion 102 and the mark structure body 104 are simultaneously formed, and the upper surface position of the mark structure body 104 is set to the upper surface of the convex structure portion 102. An imprint mold manufacturing method that can be made lower than the position has been proposed (see Patent Document 1).

Japanese Patent No. 5445714

  According to the imprint mold manufacturing method described in Patent Document 1, the dimension of the resist pattern 303 for the mark structure 104 is appropriately set in relation to the height of the convex structure portion 102, and isotropic etching solution. By utilizing the phenomenon of undercut (side etching) caused by the above, the top surface position of the mark structure 104 can be made lower than the top surface position of the convex structure portion 102.

  However, since it is difficult to control the amount of undercut (side etching) with an isotropic etchant with higher accuracy, the dimensional accuracy and position accuracy of the convex structure 102 and the mark structure 104 are further improved. It is difficult. Further, when the mark structure 104 is an alignment mark, there is a problem that it is difficult to further improve the alignment accuracy using the mark structure 104. Furthermore, since the mark structure 104 whose upper surface position is lower than that of the convex structure portion 102 is formed simultaneously with the convex structure portion 102 by using an undercut by isotropic etching, the size of the mark structure 104 can be reduced. There is also a problem that there is a limit and it is difficult to form the mark structure 104 with a finer dimension.

  In view of the above problems, an object of the present invention is to provide blanks for imprint molds and imprint molds in which convex structures and mark structures are formed with higher accuracy, and methods for producing the same.

  In order to solve the above-mentioned problem, the present invention is an imprint mold blank used for manufacturing an imprint mold, and includes a base portion having a first surface and a second surface facing the first surface; A convex structure projecting from the first surface of the base, and a mark structure formed on the first surface of the base and configured by a concavo-convex structure, and the peripheral wall of the convex structure is It is constituted by a substantially flat surface rising from the first surface at a predetermined angle, and the top of the convex portion of the concavo-convex structure constituting the mark structure is located on the first surface side with respect to the upper surface of the convex structure portion. Blanks for imprint molds are provided.

  It suffices if a concave groove surrounding the convex structure is formed on the rising portion of the peripheral wall of the convex structure from the first surface, and the depth of the concave groove can be set to 100 nm to 200 nm. A concave groove part surrounding the convex part may be formed at a rising part from the first surface of the convex part of the concave-convex structure constituting the mark structure, and the peripheral wall of the convex structural part is the first wall You may stand up at an angle of 75 ° to 95 ° from the surface.

  The angle formed with respect to the first surface of the peripheral wall of the convex portion of the concavo-convex structure constituting the mark structure can be less than 90 °, and the mark structure can be exemplified by an alignment mark, You may further provide the hard mask layer provided in the upper surface of the said convex structure part.

  This invention provides the imprint mold by which an uneven | corrugated pattern is formed in the upper surface of the said convex structure part of the said blank for imprint molds.

  The present invention is provided on the first surface of the base, a base having a first surface and a second surface facing the first surface, a convex structure protruding from the first surface of the base, and And a mark structure composed of a concavo-convex structure, and a method for producing imprint mold blanks, the substrate having a first surface and a second surface facing the first surface, Preparing a base material in which a hard mask layer is formed on the first surface of the base material, and forming a resist pattern corresponding to each of the convex structure portion and the mark structure on the hard mask layer Etching the hard mask layer using the resist pattern as a mask to form a hard mask pattern corresponding to each of the convex structure portion and the mark structure, and the hard mask Performing a dry etching process on the first surface of the base material using a pattern as a mask, and the top of the convex portion of the concave-convex structure constituting the mark structure is more than the first surface of the convex structure portion. Provided is a method for manufacturing imprint mold blanks, which performs a dry etching process on the first surface of the base material under etching conditions such as being located on the surface side.

  In the above-described imprint mold blank manufacturing method, the concave groove portion is formed under an etching condition such that a concave groove portion surrounding the convex structure portion is formed at a rising portion from the first surface of the peripheral wall of the convex structure portion. A concave groove that surrounds the convex portion at a portion where the convex portion of the concave-convex structure constituting the mark structure rises from the first surface of the base under an etching condition such that the depth of the concave portion is 100 nm to 200 nm On the first surface of the base material under the etching conditions such that the peripheral wall of the convex structure portion rises at an angle of 75 ° to 95 ° from the first surface of the base portion. A dry etching process can be performed.

  The present invention is a method for producing an imprint mold, wherein the resist pattern includes a plurality of concave grooves and convex portions on the hard mask layer provided on the convex structure portions of the imprint mold blanks. Forming a hard mask pattern by etching the hard mask on the convex structure portion using the resist pattern as a mask, and etching the convex structure portion using the hard mask pattern as a mask. The process of forming an uneven | corrugated pattern on the said convex structure part is included by this, The manufacturing method of the imprint mold characterized by the above-mentioned is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the convex structure part and the mark structure can provide the imprint mold blanks and imprint mold by which a highly accurate formation is performed, and those manufacturing methods.

FIG. 1 is a cut end view showing a schematic configuration of an imprint mold blank according to an embodiment of the present invention. FIG. 2A is a partial enlarged cut end view showing a schematic configuration of a peripheral wall portion of a convex structure portion and a mark structure in an imprint mold blank according to an embodiment of the present invention. FIG. 2B is a side view for explaining an angle formed by the peripheral wall of the convex structure portion and the first surface of the base portion in the imprint mold blank according to the embodiment of the present invention. 3A and 3B are plan views showing a schematic configuration of the mark structure in the imprint mold blank according to the embodiment of the present invention. FIG. 4 is a cut end view showing a schematic configuration of an imprint mold in one embodiment of the present invention. 5 (A) to 5 (C) are process flow diagrams illustrating each process of the method for manufacturing an imprint mold blank according to an embodiment of the present invention on a cut end surface. 6 (A) to 6 (C) are process flow diagrams showing each process of the imprint mold manufacturing method according to the embodiment of the present invention on a cut end surface. FIG. 7 is a cut end view showing a schematic configuration of a conventional imprint mold. FIGS. 8A to 8D are process flow diagrams showing each process of the conventional method for manufacturing imprint mold blanks on a cut end face.

  Embodiments of the present invention will be described with reference to the drawings. In the drawings attached to this specification, in order to facilitate understanding, the shape, scale, vertical / horizontal dimensional ratio, etc. of each part may be changed from the actual one or may be exaggerated.

  In the present specification and the like, a numerical range expressed using “to” means a range including each of the numerical values described before and after “to” as a lower limit value and an upper limit value.

  In this specification and the like, terms such as “film”, “sheet”, and “plate” are not distinguished from each other on the basis of the difference in names. For example, the “plate” is a concept including members that can be generally called “sheet” and “film”.

[Blanks for imprint molds]
FIG. 1 is a cut end view showing a schematic configuration of an imprint mold blank according to the present embodiment, and FIG. 2 is a peripheral wall portion of a convex structure portion and a mark structure in the imprint mold blank according to the present embodiment. FIG. 3 (A) and FIG. 3 (B) are plan views showing a schematic configuration of a mark structure in the imprint mold blanks according to the present embodiment.

  The blank 1 for imprint molds according to the present embodiment includes a base 2 having a first surface 2A and a second surface 2B facing the first surface 2A, and a substantially central portion in plan view on the first surface 2A side of the base 2. And a convex structure 21 protruding from the first surface 2A, a mark structure 22 provided on the first surface 2A of the base 2 and configured by an uneven structure, and a second surface of the base 2 It is provided with the hollow part 23 formed in the plane view substantially central part in 2B side, and is used in order to manufacture the imprint mold 10 (refer FIG. 4).

  The material which comprises the base 2 of the blank 1 for imprint molds is not specifically limited, It is a general thing as blanks for imprint molds. For example, the base 2 is a substrate generally used when manufacturing the imprint mold 10 (see FIG. 4) (for example, quartz glass, soda glass, fluorite, calcium fluoride substrate, magnesium fluoride substrate). Transparent substrates such as glass substrates such as acrylic glass, resin substrates such as polycarbonate substrates, polypropylene substrates, and polyethylene substrates, and laminated substrates formed by laminating two or more substrates arbitrarily selected from these substrates; nickel substrates, titanium Substrate, metal substrate such as aluminum substrate; silicon substrate, semiconductor substrate such as gallium nitride substrate, etc.).

The thickness T ₂ of the base 2 of the imprint mold blank 1 can be appropriately set within a range of, for example, about 300 μm to 10 mm in consideration of strength, handling suitability, and the like. The size (size in plan view) of the base 2 of the imprint mold blanks 1 is not particularly limited, but when the base 2 is made of quartz glass, for example, the size of the base 2 is It is about 152 mm × 152 mm.

  The shape of the base portion 2 of the imprint mold blank 1 in plan view is not particularly limited, and examples thereof include a substantially rectangular shape and a substantially circular shape. When the imprint mold 10 (see FIG. 4) manufactured from the imprint mold blanks 1 according to the present embodiment is made of quartz glass that is generally used for optical imprinting, the plane of the base 2 is usually used. The visual shape is substantially rectangular.

  The convex structure portion 21 protruding from the first surface 2A of the base portion 2 of the imprint mold blanks 1 is provided at substantially the center of the base portion 2 (first surface 2A) in plan view. Examples of the shape of the convex structure portion 21 include a substantially rectangular shape and a substantially circular shape.

  The size (dimension) of the upper surface of the convex structure portion 21 is appropriately set according to a product manufactured through an imprint process using the imprint mold 10 (see FIG. 4). For example, when the convex structure portion 21 has a rectangular shape in plan view, the size of the upper surface of the convex structure portion 21 can be set to about 26 mm × 33 mm.

The height T ₂₁ of the convex structure 21 is not particularly limited as long as the imprint mold 10 (see FIG. 4) can achieve the purpose of including the convex structure 21, and is set to, for example, about 10 μm to 100 μm. obtain. In the present embodiment, the "height T ₂₁ of the convex portions 21 ', the length of the height from the first surface 2A of the base 2, i.e. from the first surface 2A to the upper surface of the convex portions 21 (Length in the direction perpendicular to the first surface 2A).

The peripheral wall 211 of the convex structure portion 21 is configured by a substantially flat surface that rises from the first surface 2A of the base portion 2 at a predetermined angle. Since the convex structure portion 21 of the imprint mold blank 1 according to the present embodiment is formed by dry etching as described later (see FIG. 5), the peripheral wall 211 of the convex structure portion 21 is formed by a substantially flat surface. Will be composed. As a result, the convex structure portion 21 having a transfer region with high shape and dimensional accuracy can be formed. More specifically, the angle θ ₁ formed between the peripheral wall 211 of the convex structure portion 21 and the first surface 2A of the base portion 2 is preferably 75 ° to 95 °, and more preferably 85 ° to 90 °. preferable. When the angle θ ₁ exceeds 95 °, a convex structure in which the concave / convex pattern 11 is formed when the concave / convex pattern 11 of the imprint mold 10 (see FIG. 4) produced from the imprint mold blanks 1 is transferred. It becomes difficult to press the upper surface of the portion 21 uniformly, and there is a possibility that a transfer defect such as a change in the size of the transfer pattern formed by transferring the uneven pattern 11 or a distortion of the shape may occur. In the present embodiment, the angle θ ₁ formed by the peripheral wall 211 of the convex structure portion 21 and the first surface 2A of the base portion 2 is defined by the following equation.
tan θ ₁ = T ₂₁ / D ₂₁
In the above formula, T ₂₁ represents “the height of the convex structure portion 21”, and D ₂₁ is “the peripheral portion 21 E on the upper surface of the convex structure portion 21 and the second portion of the base portion 2 in the side view of the imprint mold blank 1. This represents the length in the horizontal direction (the parallel direction of the first surface 2A) between the first surface 2A and the rising portion 21B of the peripheral wall 211 (see FIG. 2B).

A concave groove 212 surrounding the convex structure 21 is formed at the rising portion of the peripheral wall 211 of the convex structure 21 from the first surface 2A. The formation of the concave groove 212 surrounding the convex structure portion 21 causes the base 2 to be bent in the transfer process using the imprint mold 10 (see FIG. 4) manufactured from the imprint mold blanks 1. Since stress can be concentrated on the concave groove 212, deformation of the upper surface of the convex structure 21 can be suppressed, and as a result, the concave and convex pattern 11 formed on the upper surface of the convex structure 21 is transferred and formed. Therefore, the transfer pattern can be formed with high accuracy by suppressing changes in dimensions and shape of the transferred pattern. Moreover, since the boundary between the peripheral wall 211 of the convex structure portion 21 and the first surface 2A of the base portion 2 becomes clear because the concave groove portion 212 is formed, the convex structure portion 21 of the imprint mold blank 1 is formed. After that, it can be easily inspected. The depth D 212 of the concave groove portion 212 can be appropriately set according to the etching conditions when forming the convex structure portion 21 in the manufacturing process of the imprint mold blanks 1 according to the present embodiment. For example, the depth D ₂₁₂ is 100 nm to 200 nm. Can be set to a degree.

In general, in the inspection process of the imprint mold blanks 1, after detecting and inspecting the concave groove 212, the periphery of the convex structure 21 is inspected, but the angle formed by the convex structure 21 and the peripheral wall 211 (180 ° − When θ ₁ ) is close to 90 °, the distance between the peripheral edge of the convex structure portion 21 and the concave groove 212 is reduced, and the peripheral edge can be seen more clearly.・ Inspection can be performed easily. If the angle θ ₁ is less than 75 °, the distance between the peripheral edge of the convex structure portion 21 and the concave groove 212 is increased, the peripheral edge becomes unclear, and detection / inspection of the peripheral edge may be difficult. There is.

  In the imprint mold blank 1 according to the present embodiment, a mark structure 22 constituted by a concavo-convex structure is formed in a predetermined region around the convex structure portion 21 on the first surface 2A of the base portion 2. Examples of the mark structure 22 include name marks indicating product names, model numbers, ID codes, alignment marks, and the like.

  The height position of the top portion 222 of the convex portion 221 of the mark structure 22 is lower than the height position of the upper surface of the convex structure portion 21. The imprint mold manufactured from the imprint mold blanks 1 according to the present embodiment because the height position of the top portion 222 of the convex portion 221 of the mark structure 22 is lower than the height position of the upper surface of the convex structure portion 21. It is possible to prevent the mark structure 22 from coming into contact with the transfer substrate or the imprint resin during the imprint process using 10 (see FIG. 4).

The height T ₂₂ from the first surface 2A of the mark structure ₂₂ (the height position of the top portion 222) is the height T ₂₁ from the first surface 2A of the convex structure portion 21 (the height of the upper surface of the convex structure portion 21). In the imprint process using the imprint mold 10 (see FIG. 4) manufactured from the imprint mold blanks 1 according to this embodiment, the mark structure 22 is transferred to the transfer substrate or the imprint. What is necessary is just to set suitably to such an extent that it does not contact print resin.

  When the mark structure 22 is an alignment mark, the planar view shape of the mark structure 22 is not particularly limited, and may be, for example, a cross shape as shown in FIG. A line and space shape as shown in FIG. When the mark structure 22 used as the alignment mark has a line-and-space shape shown in FIG. 3B, the imprint mold 10 (see FIG. 4) provided with the mark structure 22 is used to form irregularities on the transfer substrate. When the pattern 11 is transferred, if a line-and-space alignment mark having a pitch different from that of the mark structure 22 is formed on the transfer substrate, a moire pattern (interference fringes) that can be observed by overlapping the alignment marks. ) Makes it possible to align the imprint mold 10 and the substrate to be transferred.

The angle θ ₂ formed with respect to the first surface 2A of the peripheral wall 224 of the convex portion 221 of the concavo-convex structure constituting the mark structure 22 is preferably less than 90 °, and more preferably 80 ° to 89 °. When the angle θ ₂ exceeds 90 °, the height of the mark structure 22 and the height T ₂₁ of the convex structure 21 become the same, and the imprint mold 10 (from the imprint mold blanks 1 ( When the concave / convex pattern 11 is transferred to the transfer substrate using FIG. 4), the mark structure 22 may come into contact with the transfer substrate. On the other hand, when the angle θ ₂ is less than 80 °, when the mark structure 22 is used as an alignment mark, the width (dimension) must be increased in order to have an appropriate height in alignment, but in plan view. If the dimension of the mark structure 22 is increased, the alignment accuracy may be reduced. In addition, since the mark structure 22 having an angle θ ₂ of less than 80 ° has a low reproducibility in etching as a formation process thereof, the accuracy required for the size and shape of the mark structure 22 may be satisfied. It may not be possible.

  A concave groove portion 223 that surrounds the convex portion 221 is formed at a rising portion from the first surface of the convex portion 221 of the concave-convex structure constituting the mark structure 22. By forming the concave groove portion 223 surrounding the convex portion 221, the visibility of the mark structure 22 is improved, and the position detection accuracy is improved. As a result, the alignment accuracy using the mark structure 22 can be improved.

  On the second surface 2B side of the base portion 2 of the imprint mold blank 1 according to the present embodiment, a recess portion 23 that faces the convex structure portion 21 is formed. By forming the recess 23, the upper surface of the convex structure 21 can be easily curved.

  It is preferable that the shape of the recessed part 23 in the planar view from the 2nd surface 2B side of the blank 1 for imprint molds is a substantially circular shape. Since the planar view shape of the hollow part 23 is substantially circular, the upper surface of the convex structure part 21 can be curved substantially uniformly.

  The recess 23 of the imprint mold blank 1 is preferably such that the projection area obtained by projecting the outer shape of the recess 23 onto the first surface 2A side physically includes the outer shape of the convex structure 21 in plan view. Is formed on the second surface 2B side so that the center of the upper surface of the convex structure portion 21 coincides with the center of the projection region.

The depth D ₂₃ of the recess 23 of the imprint mold blanks are not particularly limited. The depth D ₂₃ of the recess ₂₃ is set so that the upper surface of the convex structure 21 can be effectively curved.

  In the present embodiment, the hard mask layer 3 is formed on the first surface 2 </ b> A of the base portion 2 of the imprint mold blanks and the upper surface of the convex structure portion 21. Examples of the material constituting the hard mask layer 3 include metals such as chromium, titanium, tantalum, silicon, and aluminum; chromium compounds such as chromium nitride, chromium oxide, and chromium oxynitride, tantalum oxide, tantalum oxynitride, and boron oxide. A tantalum compound such as tantalum tantalum or tantalum oxynitride, titanium nitride, silicon nitride, silicon oxynitride, or the like can be used alone or in combination of two or more selected arbitrarily.

  The hard mask layer 3 is patterned in one step (see FIG. 6B) in the imprint mold manufacturing method described later, and serves as a mask for etching the upper surface of the convex structure portion 21 of the imprint mold blanks 1. It is used. Therefore, it is preferable to select the constituent material of the hard mask layer 3 in consideration of the etching selection ratio and the like according to the type of the constituent material of the imprint mold blank 1. For example, when the base 2 of the imprint mold blank 1 is made of quartz glass, a metal chromium film or the like can be suitably selected as the hard mask layer 3.

  The thickness of the hard mask layer 3 is appropriately set in consideration of the etching selection ratio according to the type of the imprint mold blanks 1, the aspect ratio of the concavo-convex pattern 11 in the imprint mold 10 to be manufactured, and the like. For example, when the base 2 of the imprint mold blank 1 is made of quartz glass and the hard mask layer 3 is made of metal chromium, the thickness of the hard mask layer 3 can be set to about 1 nm to 20 nm.

  The method for forming the hard mask layer 3 on the first surface 2A of the base portion 2 of the imprint mold blank 1 and the upper surface of the convex structure portion 21 is not particularly limited. For example, sputtering, PVD (Physical Vapor Deposition) ) And CVD (Chemical Vapor Deposition).

  Next, the imprint mold 10 manufactured from the imprint mold blanks 1 according to the present embodiment will be described. FIG. 4 is a cut end view showing a schematic configuration of the imprint mold in the present embodiment.

  As shown in FIG. 4, the imprint mold 10 according to the present embodiment includes a base 2 having a first surface 2A and a second surface 2B facing the first surface 2A, and a protrusion protruding from the first surface 2A of the base 2. The structure 21, the concavo-convex pattern 11 formed on the upper surface of the convex structure 21, the mark structure 22 formed on the first surface 2 A of the base 2 and configured by the concavo-convex structure, and the base 2 And a recess 23 formed at the substantially central portion in plan view on the second surface 2B side. The imprint mold 10 in this embodiment can be manufactured from the blanks 1 for imprint molds described above. In the imprint mold 10 described below, the same reference numerals are given to the same components as the imprint mold blanks 1, and the detailed description thereof is omitted.

  The shape, dimensions, and the like of the concavo-convex pattern 11 included in the imprint mold 10 in the present embodiment can be appropriately set according to the shape, dimensions, etc. required by the imprint mold 10 (see FIG. 4), There is no particular limitation. For example, the shape of the concavo-convex pattern 11 includes a line and space shape, a pillar shape, a hole shape, a lattice shape, and the like. In the illustrated example, the concave / convex pattern 11 is a concave pattern having a plurality of concave portions formed on the upper surface of the convex structure portion 21 and convex portions located between adjacent concave portions. Moreover, the dimension of the uneven | corrugated pattern 11 should just be about 10 nm-200 nm, for example.

In the imprint mold 10 in the present embodiment, the peripheral wall 211 of the convex structure portion 21 is configured by a substantially flat surface. Thereby, the prediction of the bending and distortion of the imprint mold 10 that occurs when the imprint mold 10 is pressed in the imprint process is facilitated, and the prediction accuracy can be increased. As a result, the accuracy of the transfer pattern formed by the imprint process can be increased, and at the same time, a finer transfer pattern can be formed. The angle θ ₁ formed between the peripheral wall 211 of the convex structure 21 and the first surface 2A of the base 2 is preferably 75 ° to 95 °, and more preferably 85 ° to 90 °. When the angle θ ₁ is less than 75 °, when the imprint mold 10 is pressed in the imprint process, when the imprint mold 10 is bent, the convex structure portion 21 is also bent and distorted. If the concavo-convex pattern 11 of the imprint mold 10 exceeds 95 °, the concavo-convex pattern 11 on the upper surface of the substrate may be deformed, resulting in a transfer failure such as a change in the size of the transfer pattern or distortion of the shape. When transferring, it becomes difficult to uniformly press the upper surface of the convex structure portion 21 on which the concavo-convex pattern 11 is formed, and the dimension of the transfer pattern formed by transferring the concavo-convex pattern 11 is changed or the shape is changed. There is a risk that transfer defects such as distortion may occur.

  Furthermore, in the imprint mold 10 according to the present embodiment, a concave groove 212 surrounding the convex structure portion 21 is formed at a rising portion from the first surface 2A of the peripheral wall 211 of the convex structure portion 21. Since the concave groove 212 surrounding the convex structure 21 is formed, stress generated when the base 2 is bent in the transfer process using the imprint mold 10 can be concentrated on the concave groove 212. The deformation of the upper surface of the portion 21 can be suppressed, and as a result, the size and shape change of the transfer pattern formed by transferring the concavo-convex pattern 11 formed on the upper surface of the convex structure portion 21 can be suppressed, and the high accuracy The transfer pattern can be formed at

  Furthermore, in the imprint mold 10 according to the present embodiment, the height position of the top portion 222 of the mark structure 22 is lower than the height position of the upper surface of the convex structure portion 21, so It is possible to prevent 22 from coming into contact with the substrate to be transferred and the imprint resin. In addition, a concave groove 223 that surrounds the convex portion 221 is formed at the rising portion from the first surface of the convex portion 221 of the concavo-convex structure constituting the mark structure 22. By forming the concave groove portion 223 surrounding the convex portion 221, the visibility of the mark structure 22 is improved, and the position detection accuracy is improved. As a result, alignment accuracy using the mark structure 22 can be improved.

  In the imprint mold 10 according to the present embodiment, since the convex structure portion 21 is formed with high dimensional accuracy, the uneven pattern 11 can be transferred with high accuracy in the imprint process using the imprint mold 10. it can. Furthermore, according to the imprint mold 10 having the above-described configuration, the rising angle from the first surface 2A of the side wall 211 of the convex structure portion 21 by forming the convex structure portion 21 by dry etching as described later. Becomes an acute angle (for example, about 75 ° to 95 °). As a result, the dimensional accuracy of the convex structure portion 21 is improved, and the imprint performance can be improved in the process of use.

  Furthermore, according to the imprint mold 10 having the above-described configuration, the convex structure portion 21 and the mark structure body 22 are formed by dry etching processing as will be described later, so that the base portion 2 of the imprint mold 10 is formed. The side surface and the second surface 2B are not etched and have no damage. Therefore, the imprint mold 10 can be stably vacuum-sucked to the mold holding part of the imprint apparatus, and the alignment accuracy can be prevented from being lowered during the imprint process.

[Method for producing imprint mold blanks]
A method for manufacturing imprint mold blanks in the present embodiment will be described. FIG. 5 is a process flow chart showing each process of the imprint mold blank manufacturing method according to the present embodiment on a cut end surface.

  First, it has the 2nd surface 40B which opposes the 1st surface 40A and 1st surface 40A used for manufacturing the blank 1 for imprint mold (refer FIG. 1), and the hard mask layer 41 is on the 1st surface 40A. The base material 40 (refer FIG. 5 (A)) in which is formed is prepared.

  The material which comprises the base material 40 is not specifically limited, It is a general thing as blanks for imprint molds. For example, the base material 40 is a substrate (for example, quartz glass, soda glass, fluorite, calcium fluoride substrate, magnesium fluoride) generally used in manufacturing the imprint mold 10 (see FIG. 4). Transparent substrates such as a substrate, a glass substrate such as acrylic glass, a resin substrate such as a polycarbonate substrate, a polypropylene substrate, and a polyethylene substrate, and a laminate substrate obtained by laminating two or more substrates selected from these; a nickel substrate, A metal substrate such as a titanium substrate or an aluminum substrate; a semiconductor substrate such as a silicon substrate or a gallium nitride substrate).

  Examples of the material constituting the hard mask layer 41 include metals such as chromium, titanium, tantalum, silicon, and aluminum; chromium-based compounds such as chromium nitride, chromium oxide, and chromium oxynitride, tantalum oxide, tantalum oxynitride, and boron oxide. A tantalum compound such as tantalum tantalum or tantalum oxynitride, titanium nitride, silicon nitride, silicon oxynitride, or the like can be used alone or in combination of two or more selected arbitrarily.

  The hard mask layer 41 is patterned in a process described later (see FIG. 5B), and is used as a mask when etching the upper surface of the convex structure portion 21 and the mark structure body 22 of the imprint mold blank 1. It is. Therefore, it is preferable to select the constituent material of the hard mask layer 41 in consideration of the etching selection ratio and the like according to the type of the constituent material of the imprint mold blank 1. For example, when the base material 40 is made of quartz glass, a metal chromium film or the like can be suitably selected as the hard mask layer 41.

The thickness of the hard mask layer 41, etching selectivity depending on the type of substrate 40 is appropriately set in consideration of the height T ₂₁ etc. of convex portions 21. For example, when the base material 40 is made of quartz glass and the hard mask layer 41 is made of metal chromium, the thickness of the hard mask layer 41 can be set to about 100 nm to 1 μm.

  The method for forming the hard mask layer 41 on the first surface 40A of the base material 40 is not particularly limited, and known methods such as sputtering, PVD (Physical Vapor Deposition), CVD (Chemical Vapor Deposition), and the like can be used. A membrane method is mentioned.

  Constructed on the hard mask layer 41 by a negative or positive electron beam reactive resist material, an ultraviolet reactive resist material, etc. corresponding to each of the convex structure portion 21 and the mark structure 22 of the imprint mold blank 1 A resist pattern 42 to be formed is formed (see FIG. 5A). A method for forming the resist pattern 42 on the hard mask layer 41 is not particularly limited. For example, a resist film is formed on the hard mask layer 41 and a light shielding portion or an opening corresponding to the resist pattern 42 is formed. For example, a method (photolithographic method) of performing exposure / development treatment on the resist film using a photomask having the above may be used.

Subsequently, the hard mask layer 41 is dry-etched using the resist pattern 42 as a mask to form a hard mask pattern 43 (see FIG. 5B), and the hard mask pattern 43 is used as a mask on the first surface 40A. By performing a dry etching process using a fluorine-based etching gas such as CF ₄ or CHF ₃ , the convex structure portion 21 and the mark structure body 22 are formed (see FIG. 5C).

In the dry etching process of the first surface 40A using the hard mask pattern 43 as a mask, the height position of the top portion 222 of the convex portion 221 of the concavo-convex structure constituting the mark structure 22 is the height position of the upper surface of the convex structure portion 21. The etching conditions are set so as to be lower. Examples of such etching conditions include conditions that are more isotropic than normal dry etching (for example, vacuum degree: 180 mm Torr, CF ₄ flow rate: 30 cm ³ / second, O ₂ flow rate: 20 cm ³ / second, etc.). . By subjecting the first surface 40A to a dry etching process under such etching conditions, the height position of the top portion 222 of the convex portion 221 of the concavo-convex structure constituting the mark structure 22 is set to the height of the upper surface of the convex structure portion 21. It can be lower than the position. In addition, etching is performed under highly isotropic conditions (for example, degree of vacuum: 300 mmTorr, CF ₄ flow rate: 40 cm ³ / sec, O ₂ flow rate: 20 cm ³ / sec, etc.) as the first step (etching depth: 1 to 10 μm), and etching under conditions with high anisotropy (for example, vacuum degree: 120 Torr, CF ₄ flow rate: 20 cm ³ / second, O ₂ flow rate: 10 cm ³ / second, etc.) as the second step (total etching depth: (30 μm) By performing the two-step etching, the height position of the top portion 222 of the convex portion 221 of the concavo-convex structure constituting the mark structure 22 can be made lower than the height position of the upper surface of the convex structure portion 21. .

In the dry etching process, a concave shape surrounding each of the convex structure portion 21 and the convex portion 221 is formed on each of the rising portion of the peripheral wall 211 of the convex structure portion 21 and the rising portion of the convex portion 221 of the concavo-convex structure constituting the mark structure 22. Etching conditions such that the grooves 212 and 223 are formed, etching conditions such that the angle θ ₁ formed with respect to the first surface 2A of the peripheral wall 211 of the convex structure portion 21 is 75 ° to 95 °, and the first surface of the convex portion 221 It is preferable to set the etching conditions such that the angle θ ₂ formed with respect to 2A is less than 90 °.

  According to the imprint mold blanks manufacturing method described above, the convex structure portion 21 and the mark structure body 22 can be formed by the same dry etching process. It can be formed with accuracy and positional accuracy.

[Imprint Mold Manufacturing Method]
A method for producing an imprint mold using the imprint mold blanks produced as described above will be described. FIG. 6 is a process flow chart showing each process of the imprint mold manufacturing method according to the present embodiment on a cut end surface.

  In the imprint mold manufacturing method in the present embodiment, first, the imprint mold blanks 1 (see FIGS. 1 and 5C) are prepared, and the hard mask layer 3 on the upper surface of the convex structure portion 21 is prepared. Then, a resist pattern 51 corresponding to the concavo-convex pattern 11 of the imprint mold 10 is formed (see FIG. 6A). In addition, if the imprint mold blanks 1 have a form in which the hard mask layer 3 is not provided on the upper surface of the convex structure portion 21, the hard mask layer 3 is provided in advance.

  The resist pattern 51 may be formed by a photolithography method using a photomask having an opening and a light shielding portion corresponding to the resist pattern 51, or may be formed by an electron beam lithography method using an electron beam drawing apparatus. Alternatively, it may be formed by an imprint method using a master mold having a concavo-convex pattern corresponding to the resist pattern 51.

  Then, the hard mask layer 3 is etched using the resist pattern 51 as a mask to form a hard mask pattern 52 (see FIG. 6B), and the upper surface of the convex structure portion 21 is etched using the hard mask pattern 52 as a mask. Thus, the concavo-convex pattern 11 is formed. Thus, the imprint mold 10 (refer FIG. 4) in this embodiment can be manufactured.

  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 said embodiment, although the aspect in which the hard mask layer 3 was provided in the upper surface of the convex structure part 21 of the blank 1 for imprint molds was mentioned as an example, it is not limited to this aspect, The said hard The mask layer 3 may not be provided.

  The present invention is useful as a method of manufacturing an imprint mold used in a manufacturing process of a semiconductor device.

DESCRIPTION OF SYMBOLS 1 ... Blank for imprint mold 2 ... Base 21 ... Convex structure 22 ... Mark structure 10 ... Imprint mold 11 ... Concave / convex pattern

Claims (15)

Blanks for imprint molds used for producing imprint molds,
A base having a first surface and a second surface opposite the first surface;
A convex structure protruding from the first surface of the base;
A mark structure which is provided on the first surface of the base and is configured by an uneven structure;
The peripheral wall of the convex structure portion is configured by a substantially flat surface that rises at a predetermined angle from the first surface,
An imprint mold blank in which a top portion of a convex portion of the concavo-convex structure constituting the mark structure is positioned closer to the first surface than an upper surface of the convex structure portion.   2. The imprint mold blank according to claim 1, wherein a concave groove portion surrounding the convex structure portion is formed at a rising portion of the peripheral wall of the convex structure portion from the first surface.   The blank for imprint mold according to claim 2, wherein the depth of the concave groove is 100 nm to 200 nm.   The imprint according to any one of claims 1 to 3, wherein a concave groove portion surrounding the convex portion is formed at a rising portion of the convex portion of the concave-convex structure constituting the mark structure from the first surface. Blanks for molds.   The blank for an imprint mold according to any one of claims 1 to 4, wherein a peripheral wall of the convex structure portion rises at an angle of 75 ° to 95 ° from the first surface.   The blank for imprint mold according to any one of claims 1 to 5, wherein an angle formed with respect to the first surface of a peripheral wall of the convex portion of the concave-convex structure constituting the mark structure is less than 90 °.   The imprint mold blank according to claim 1, wherein the mark structure is an alignment mark.   The blank for imprint molds according to any one of claims 1 to 7, further comprising a hard mask layer provided on an upper surface of the convex structure portion.   The imprint mold by which an uneven | corrugated pattern is formed in the upper surface of the said convex structure part of the blanks for imprint molds in any one of Claims 1-7. A base portion having a first surface and a second surface facing the first surface, a convex structure portion projecting from the first surface of the base portion, and a concavo-convex structure provided on the first surface of the base portion A method for producing imprint mold blanks comprising a mark structure comprising:
Preparing a base material having a first surface and a second surface facing the first surface, wherein a hard mask layer is formed on the first surface of the base material;
Forming a resist pattern corresponding to each of the convex structure portion and the mark structure on the hard mask layer;
Etching the hard mask layer using the resist pattern as a mask to form a hard mask pattern corresponding to each of the convex structure portion and the mark structure;
Performing a dry etching process on the first surface of the base material using the hard mask pattern as a mask,
Dry etching treatment is performed on the first surface of the base material under etching conditions such that the top of the convex portion of the concavo-convex structure constituting the mark structure is located closer to the first surface than the upper surface of the convex structure portion A method for manufacturing imprint mold blanks.   The dry etching treatment is performed on the first surface of the base material under an etching condition such that a concave groove surrounding the convex structure portion is formed at a rising portion of the peripheral wall of the convex structure portion from the first surface. Item 11. A method for producing imprint mold blanks according to Item 10.   The manufacturing method of the blank for imprint molds of Claim 11 which performs a dry etching process on the said 1st surface of the said base material on the etching conditions that the depth of the said concave groove part will be 100 nm-200 nm.   In the etching conditions such that a concave groove surrounding the convex portion is formed in a portion where the convex portion of the concave-convex structure constituting the mark structure rises from the first surface of the base portion. The manufacturing method of the blank for imprint molds in any one of Claims 10-12 which performs dry etching process on 1 surface.   The dry etching process of the said 1st surface of the said base material is given to the said 1st surface of the said base material on the etching conditions that the surrounding wall of the said convex structure part stands at an angle of 75 degrees-95 degrees from the said 1st surface of the said base. The manufacturing method of the blank for imprint molds in any one. A method of manufacturing an imprint mold,
Forming a resist pattern including a plurality of concave grooves and convex portions on the hard mask layer provided on the convex structure portion of the blank for imprint mold according to claim 8;
Etching the hard mask on the convex structure portion using the resist pattern as a mask to form a hard mask pattern;
Etching the convex structure portion using the hard mask pattern as a mask to form a concave / convex pattern on the convex structure portion.

Images