Imprint mold substrate and method for manufacturing same, and imprint mold and method for manufacturing same

Abstract

This imprint mold substrate for manufacturing an imprint mold capable of transferring an uneven pattern with extremely high positional accuracy includes a base material having a first surface and a second surface positioned on the opposite side to the first surface. On the second surface of the base material, a first point, a second point, and a third point are positioned on one straight line connecting the geometric center of the second surface and an arbitrary point on the outer peripheral edge of the second surface. The first point is closest to the geometric center of the second surface, the third point is closest to the outer peripheral edge of the second surface, and the second point is positioned between the first point and the third point. In a cross-section along the thickness direction of the base material passing through the first point, the second point, and the third point, a first height T1 at the first point, a second height T2 at the second point, and a third height T3 at the third point satisfy the relationship shown in the formula T1 ≥ T3 > T2, and the first to third heights T1 to T3 are heights based on a prescribed horizontal plane when the base material is placed on the horizontal plane with the first surface positioned downward.

Description

Substrate for imprint mold and manufacturing method thereof, and imprint mold and manufacturing method thereof

[0001] The present disclosure relates to a substrate for an imprint mold and a method for manufacturing the same, as well as an imprint mold and a method for manufacturing the same.

[0002] Nanoimprinting, a known microfabrication technology, is a pattern formation technology that uses an imprint mold with a concave-convex pattern formed on the surface of a substrate to transfer the concave-convex pattern onto a workpiece at the same magnification. In particular, with the further miniaturization of wiring patterns in semiconductor devices, nanoimprinting has attracted attention in the manufacturing process.

[0003] An imprint mold generally used in nanoimprint technology is known to include, for example, a substrate having a first surface and a second surface located on the opposite side, a convex structure protruding from the first surface of the substrate, a concave-convex pattern formed on the upper surface of the convex structure, and a recessed portion formed on the second surface of the substrate. Using such an imprint mold, the concave-convex pattern of the imprint mold is brought into contact with imprint resin, which serves as a workpiece supplied onto a transfer substrate, thereby filling the concave-convex pattern with the imprint resin. The imprint resin is then cured in this state, thereby transferring the concave-convex pattern of the imprint mold to the imprint resin.

[0004] The concave-convex pattern of an imprint mold is generally produced by electron beam (EB) lithography. Specifically, a resist pattern is formed on one surface of an imprint mold substrate using an EB lithography device, and the imprint mold substrate is then subjected to a dry etching process using the resist pattern as a mask, thereby forming the concave-convex pattern. When nanoimprinting technology is implemented on an industrial scale, an imprint mold on which a concave-convex pattern has been formed by electron beam (EB) lithography is generally used as a master mold, and a large number of replica molds having a concave-convex pattern that is the inverse of the concave-convex pattern of the master mold are produced by an imprinting process using the master mold, and the replica molds are used as imprint molds in the nanoimprinting technology.

[0005] The replica molds obtained in this manner can be mass-produced at low cost. Therefore, by using them as imprint molds in nanoimprinting technology, even if the imprint mold is damaged or defects occur in the concavo-convex pattern formed on the receiving material by the imprint mold, the nanoimprinting technology can be carried out by replacing the imprint mold with a new one one after another, thereby reducing the manufacturing costs of products such as semiconductor devices. Furthermore, by producing a large number of replica molds, the replica molds can be set in multiple imprinting apparatuses and used simultaneously, thereby improving the productivity of products such as semiconductor devices.

[0006] In general, replica molds are required to form a concave-convex pattern with a desired positional accuracy depending on the application, etc., and to be able to transfer the concave-convex pattern of the replica mold to a transfer material with the desired positional accuracy. In particular, replica molds used to manufacture products such as semiconductor devices are required to form a concave-convex pattern with extremely strict positional accuracy, and it is expected that with the further miniaturization of semiconductor devices and the like, the formation of a concave-convex pattern with even stricter positional accuracy will be required. Note that "positional accuracy" refers to the amount of positional deviation (nm) of the concave-convex pattern from the design value (coordinate value).

[0007] To satisfy these requirements, currently, an extremely high degree of flatness is required for the surface (main surface) of the imprint mold substrate used to manufacture the replica mold, on which the concave-convex pattern is formed. If the flatness of the main surface is low, the concave-convex pattern of the master mold cannot be transferred with high precision, which reduces the positional precision of the concave-convex pattern in the replica mold, and therefore the positional precision of the concave-convex pattern transferred from the replica mold to the transfer material.

[0008] However, even when an imprint mold substrate with extremely high flatness of the main surface is used, the positional accuracy of the concave-convex pattern in the manufactured replica mold may be reduced. For example, the surface shape of the opposing surface (back surface) of the imprint mold substrate, which faces the main surface, may affect the positional accuracy of the concave-convex pattern of the replica mold. That is, when a concave-convex pattern is formed on the main surface of the imprint mold substrate by an imprint process using a master mold, the imprint mold substrate is typically placed on a substrate stage of an imprinting apparatus and vacuum-adsorbed. At this time, distortion occurs on the vacuum-adsorbed main surface of the imprint mold substrate depending on the surface shape of the back surface of the imprint mold substrate. After a concave-convex pattern is formed on a transfer material (e.g., an imprint resin) on the main surface of the imprint mold substrate while the distortion is occurring, the distortion is eliminated when the imprint mold substrate is released from vacuum adsorption, causing the concave-convex pattern formed on the transfer material to expand or contract.

[0009] This causes a problem in that the positional accuracy of the concave-convex pattern of the replica mold decreases depending on the amount of distortion in one direction (X direction) and the other direction orthogonal to that direction (the Y direction) in a plan view of the main surface of the imprint mold substrate. Furthermore, although a large number of replica molds are generally produced using a large number of imprint mold substrates, variations in the amount of distortion among the imprint mold substrates can cause the problem of difficulty in consistently producing replica molds having concave-convex patterns with the desired positional accuracy.

[0010] A master mold used to fabricate a replica mold is vacuum-adsorbed to a mold holder of an imprinting apparatus and subjected to the imprinting process. Therefore, if distortion occurs on the main surface (the surface on which the concave-convex pattern is formed) of the vacuum-adsorbed master mold depending on the surface shape of the backside of the master mold, the positional accuracy of the concave-convex pattern of the vacuum-adsorbed master mold will be reduced. As a result, the reduced positional accuracy is directly transferred to the replica mold substrate, resulting in a further reduction in the positional accuracy of the replica mold's concave-convex pattern. Thus, solving the problem of the surface shape of the backside of the imprint mold substrate affecting the positional accuracy of the concave-convex pattern will help meet the demand for further miniaturization of semiconductor devices and the like.

[0011] A synthetic quartz glass substrate for imprint molds has been proposed in which, when an approximate analysis is performed using the first to eighth terms of Zernike polynomials on the back surface of a circular region from the center of the substrate to an edge of radius R, the coefficient of the fourth term is −(2R / 100,000×1) μm to 0 μm, and the sum of the absolute values ​​of the coefficients of the fifth to eighth terms is 4×(2R / 100,000×1) μm to 0 μm (see Patent Document 1).

[0012] Also proposed is a glass plate for imprint molding, which has a protruding surface in the center of its first main surface that is surrounded by steps and protrudes beyond the periphery, and a non-through hole in the center of its second main surface opposite the first main surface, and in any cross section including the center line of the non-through hole, the second main surface has a remaining portion, excluding portions within 15 mm from both outer peripheral edges, divided into a first portion and a second portion by the non-through hole, and when the least-squares line of the remaining portion is taken as a reference line, in a natural state where no external force is acting, the least-squares line of the first portion and the least-squares line of the second portion each intersect the reference line obliquely, and the glass plate protrudes toward the opposite side of the first main surface from the reference line on the inner peripheral side of the intersection point (see Patent Document 2).

[0013] Japanese Patent No. 6973280 Japanese Patent Application Laid-Open No. 2017-152650

[0014] The inventions described in Patent Documents 1 and 2 focus on the shape of a predetermined region including the center of the back surface of the substrate, and optimize the shape of the predetermined region to provide a substrate from which an imprint mold capable of transferring a concave-convex pattern with high positional accuracy can be manufactured. This predetermined region including the center of the back surface of the substrate is a region that is vacuum-sucked by a mold holder or substrate stage of an imprinting apparatus, and is considered to be a region where the back surface of the substrate deforms along the holding surface of the mold holder or the mounting surface of the substrate stage due to this vacuum suction. On the other hand, the outer region surrounding this predetermined region is not vacuum-sucked by the mold holder or substrate stage of the imprinting apparatus, and is therefore considered to be a region that does not or is difficult to deform along the holding surface of the mold holder or the mounting surface of the substrate stage. For this reason, conventional techniques have not focused on the shape of the outer region surrounding this predetermined region.

[0015] However, even if a region is not vacuum-adsorbed by the mold holder or substrate stage of the imprinting apparatus and does not or is difficult to deform along the holding surface of the mold holder or the mounting surface of the substrate stage, unless the shape of the back surface of the substrate, including that region, is optimized, it may be difficult to transfer the concave-convex pattern with high positional accuracy. In particular, in order to improve the performance of autonomous driving, AI, and the like, fine line dimensions in semiconductor devices are required to be 15 nm or less, and even 10 nm or less, and it is therefore necessary to transfer the concave-convex pattern with extremely high positional accuracy.

[0016] In view of the above problems, an object of the present disclosure is to provide an imprint mold capable of transferring a relief pattern with extremely high positional accuracy, an imprint mold substrate for producing the imprint mold, and methods for producing the imprint mold and the imprint mold substrate.

[0017] In order to achieve such an object, one embodiment of the present disclosure provides a substrate having a first surface and a second surface located opposite to the first surface, wherein a first point, a second point, and a third point are located on the second surface of the substrate on a line connecting a geometric center of the second surface and an arbitrary point on an outer periphery of the second surface, and a first height T at the first point is determined in a cross section along a thickness direction of the substrate that passes through the first point, the second point, and the third point. １ , a second height T at the second point ２ and a third height T at the third point ３ satisfies the relationship shown in the following formula (1), the first point is a point located closest to the geometric center of the second surface, the third point is a point located closest to the outer periphery of the second surface, the second point is a point located between the first point and the third point, and the first height T １ , the second height T ２ and the third height T ３ The imprint mold substrate T is a height based on a predetermined horizontal plane when the base material is placed on the horizontal plane with the first surface positioned downward. １ ≧T ３ >T ２ ...(1)

[0018] As one embodiment of the present disclosure, a method includes a step of preparing a substrate having a first surface and a second surface located opposite to the first surface, and a step of polishing the second surface of the substrate, wherein in the polishing step, a first height T at the first point is measured in a cross section along a thickness direction of the substrate, the first point being a first height T, a second point being a third point located on a line connecting a geometric center of the second surface of the substrate and an arbitrary point on an outer periphery of the second surface. １ ', a second height T at the second point ２ ' and a third height T at the third point ３ the second surface of the substrate is polished so that the first height T′ satisfies the relationship shown in the following formula (2), the first point is a point located closest to the geometric center of the second surface, the third point is a point located closest to the outer periphery of the second surface, the second point is a point located between the first point and the third point, and the first height T １ ', the second height T ２ ' and the third height T ３ The height T′ is the height based on a predetermined horizontal plane when the substrate is placed on the horizontal plane with the first surface positioned downward. １ '≧T ３ '>T ２ ' ... (2)

[0019] According to the present disclosure, it is possible to provide an imprint mold capable of transferring a concave-convex pattern with extremely high positional accuracy, an imprint mold substrate for producing the same, and methods for producing the imprint mold and the imprint mold substrate.

[0020] FIG. 1 is a cross-sectional view showing a schematic configuration of one aspect of an imprint mold substrate according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional view showing a schematic configuration of another aspect of an imprint mold substrate according to an embodiment of the present disclosure. FIG. 3 is a plan view from the second surface side showing a schematic configuration of one aspect of an imprint mold substrate according to an embodiment of the present disclosure. FIG. 4 is a cross-sectional view showing a schematic configuration of another aspect of an imprint mold substrate according to an embodiment of the present disclosure. FIG. 5 is a plan view from the second surface side showing a schematic configuration of another aspect of an imprint mold substrate according to an embodiment of the present disclosure. FIG. 6 is a partially enlarged cross-sectional view showing a schematic configuration of one aspect of an imprint mold substrate according to an embodiment of the present disclosure. FIG. 7 is a cross-sectional view showing a schematic configuration of an imprint mold according to an embodiment of the present disclosure. FIG. 8A is a cross-sectional view showing a step of a method for manufacturing an imprint mold substrate according to an embodiment of the present disclosure. FIG. 8B is a cross-sectional view showing a step subsequent to the step shown in FIG. 8A . Figure 8C is a cross-sectional view showing a step of a method for manufacturing an imprint mold substrate according to an embodiment of the present disclosure, the step following the step shown in Figure 8B. Figure 8D is a cross-sectional view showing a step of a method for manufacturing an imprint mold substrate according to an embodiment of the present disclosure, the step following the step shown in Figure 8C. Figure 9 is a plan view from the second surface side of a substrate used in the method for manufacturing an imprint mold substrate according to an embodiment of the present disclosure. Figure 10 is a partially enlarged cross-sectional view showing a schematic configuration of a substrate polished by the method for manufacturing an imprint mold substrate according to an embodiment of the present disclosure. Figure 11A is a cross-sectional view showing a step of manufacturing a master mold used in the method for manufacturing an imprint mold according to an embodiment of the present disclosure, the step following the step shown in Figure 11A. Figure 11C is a cross-sectional view showing a step of manufacturing a master mold used in the method for manufacturing an imprint mold according to an embodiment of the present disclosure, the step following the step shown in Figure 11B.Figure 11D is a cross-sectional view showing a step of manufacturing a master mold used in a method of manufacturing an imprint mold according to an embodiment of the present disclosure, the step following Figure 11C. Figure 12A is a cross-sectional view showing a step of a method of manufacturing an imprint mold according to an embodiment of the present disclosure, the step following Figure 12A. Figure 12C is a cross-sectional view showing a step of a method of manufacturing an imprint mold according to an embodiment of the present disclosure, the step following Figure 12B. Figure 12D is a cross-sectional view showing a step of a method of manufacturing an imprint mold according to an embodiment of the present disclosure, the step following Figure 12C. Figure 13A is a cross-sectional view showing a step of an imprint method using an imprint mold according to an embodiment of the present disclosure, the step following Figure 13A. Figure 13B is a cross-sectional view showing a step of an imprint method using an imprint mold according to an embodiment of the present disclosure, the step following Figure 13A. Fig. 13C is a cross-sectional end view showing a step following Fig. 13B in an imprinting method using an imprint mold according to an embodiment of the present disclosure. Fig. 14 is a graph showing the results of measurement of the substrate in Example 9 along a horizontal cross section using a flatness measurement device. Fig. 15 is a graph showing the results of measurement of the substrate in Example 9 along a diagonal cross section using a flatness measurement device.

[0021] Embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the shape, scale, aspect ratio, and the like of each part may be shown exaggerated or modified from the actual product to facilitate understanding. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits, respectively. In this specification, terms such as "film," "sheet," and "plate" are not distinguished from one another based on differences in nomenclature. For example, "plate" is a concept that also includes members that may be commonly called "sheet" and "film."

[0022] A first aspect of this embodiment includes a substrate having a first surface and a second surface located opposite to the first surface, and a first point, a second point, and a third point are located on the second surface of the substrate on a line connecting a geometric center of the second surface and an arbitrary point on an outer periphery of the second surface, and a first height T at the first point is determined in a cross section along a thickness direction of the substrate that passes through the first point, the second point, and the third point. １ , a second height T at the second point ２ and a third height T at the third point ３ satisfies the relationship shown in the following formula (1), the first point is a point located closest to the geometric center of the second surface, the third point is a point located closest to the outer periphery of the second surface, the second point is a point located between the first point and the third point, and the first height T １ , the second height T ２ and the third height T ３ is the height of the substrate for an imprint mold, based on a predetermined horizontal plane when the base material is placed on the horizontal plane with the first surface positioned downward. １ ≧T ３ >T ２ ...(1)

[0023] A second aspect of this embodiment is a substrate for an imprint mold in the above-described first aspect, wherein the first point is located within a circular area centered on the geometric center of the second surface, and the second point is located within an annular area surrounding the outside of the circular area.

[0024] A third aspect of the present embodiment is the substrate for an imprint mold of the first or second aspect above, wherein the second surface has a recessed portion that is recessed in the thickness direction of the base material, the first point is located within an annular region centered on the geometric center of the second surface, the inner radius of the annular region is 30 mm to 35 mm, the distance between the first point and the second point is 20 mm to 69 mm, and the distance between the first point and the third point is 35 mm to 77 mm.

[0025] A fourth aspect of the present embodiment is the substrate for an imprint mold of the first or second aspect above, wherein the second surface does not have a recess that is recessed in the thickness direction of the base material, the first point is located within a circular area centered on the geometric center of the second surface, the radius of the circular area is 30 mm or less, the distance between the first point and the second point is 25 mm to 99 mm, and the distance between the first point and the third point is 40 mm to 107 mm.

[0026] A fifth aspect of this embodiment is a substrate for an imprint mold according to the fourth aspect, wherein the circular region in which the first point is located is a region in which a recessed portion recessed in the thickness direction of the base material is formed.

[0027] A sixth aspect of the present embodiment is any of the first to fifth aspects, wherein when the base material is placed on the horizontal surface with the first surface facing downward, an angle formed by the horizontal plane and a line segment connecting the second point on the second surface and the outer periphery of the second surface is 9.0×10 －６ ° to 1.0 × 10 －３ 3. The imprint mold substrate is 3.degree.

[0028] A seventh aspect of the present embodiment is the same as any one of the first to sixth aspects, wherein the second height T ２ and the third height T ３ The difference between the thickness and the thickness of the substrate is 1 nm to 105 nm.

[0029] An eighth aspect of the present embodiment is the same as any one of the first to seventh aspects, wherein the first height T １ and the third height T ３ The difference between the thickness and the thickness of the substrate is 0 nm to 639 nm.

[0030] A ninth aspect of the present embodiment is the substrate according to any one of the first to eighth aspects, wherein, in a plan view from the second surface side, the second surface of the substrate has a first side and a second side that are opposed to each other and are generally parallel, a third side and a fourth side that are opposed to each other and are generally parallel, a first corner where ends of the first side and the third side intersect, a second corner where ends of the first side and the fourth side intersect, a third corner where ends of the second side and the third side intersect, and a fourth corner where ends of the second side and the fourth side intersect. the substrate for an imprint mold has a substantially rectangular shape including four corner portions, and the first point, the second point, and the third point are located on at least any of a first line segment that passes through the geometric center of the second surface and is substantially perpendicular to the first side and the second side, a second line segment that passes through the geometric center of the second surface and is substantially perpendicular to the third side and the fourth side, a third line segment that passes through the geometric center, the first corner portion, and the fourth corner portion, and a fourth line segment that passes through the geometric center, the second corner portion, and the third corner portion.

[0031] A tenth aspect of the present embodiment is an imprint mold substrate according to any one of the first to third aspects, wherein the second surface is provided with a recessed portion recessed in a thickness direction of the base material, the recessed portion having a substantially circular shape centered on the geometric center of the second surface when viewed in a plane from the second surface side, and wherein, when a predetermined annular region is defined within an area surrounded by the recessed portion and the outer peripheral edge of the second surface, when the second surface is approximated by a Zernike polynomial, the root mean square roughness of each component of the fifth to eighth terms of the Zernike polynomial relative to the sum of heights of each measurement point in the annular region is 12 nm or less.

[0032] An eleventh aspect of the present embodiment is the substrate for an imprint mold according to the tenth aspect, wherein, when the second surface is approximated by a Zernike polynomial, the root-mean-square roughness of each component of terms 5 to 8 of the Zernike polynomial relative to the sum of heights of each measurement point in the annular region is 7 nm or less.

[0033] A twelfth aspect of this embodiment is the substrate for an imprint mold according to the tenth or eleventh aspect, wherein the root mean square roughness of the sum of heights of the ninth and subsequent terms of the Zernike polynomial in the annular region is 10 nm or less.

[0034] A thirteenth aspect of this embodiment is any one of the tenth to twelfth aspects, wherein the first point is an imprint mold substrate located on an edge of the recessed portion.

[0035] A fourteenth aspect of the present embodiment is the substrate for an imprint mold according to any one of the first to thirteenth aspects, wherein a convex structure protruding from the first surface is provided on the first surface.

[0036] A fifteenth aspect of this embodiment is an imprint mold having a concave-convex pattern formed on the convex structure portion of the imprint mold substrate of the fourteenth aspect.

[0037] A sixteenth aspect of the present embodiment includes a step of preparing a substrate having a first surface and a second surface located opposite to the first surface, and a step of polishing the second surface of the substrate, wherein in the polishing step, a first height T at the first point is measured in a cross section along a thickness direction of the substrate, the first point being a first point, a second point being a third point located on a line connecting a geometric center of the second surface of the substrate and an arbitrary point on an outer periphery of the second surface. １ ', a second height T at the second point ２ ' and a third height T at the third point ３ the second surface of the substrate is polished so that the first height T′ satisfies the relationship shown in the following formula (2), the first point is a point located closest to the geometric center of the second surface, the third point is a point located closest to the outer periphery of the second surface, the second point is a point located between the first point and the third point, and the first height T １ ', the second height T ２ ' and the third height T ３ T' is the height of the substrate relative to a predetermined horizontal plane when the substrate is placed on the horizontal plane with the first surface positioned downward.１ '≧T ３ '>T ２ ' ... (2)

[0038] A seventeenth aspect of this embodiment is the sixteenth aspect, wherein the second height T ２ ' and the third height T of the substrate ３ The method for manufacturing a substrate for an imprint mold includes polishing the second surface of the substrate so that the difference between the first surface and the second surface is 1 nm to 103 nm.

[0039] An eighteenth aspect of this embodiment is the sixteenth or seventeenth aspect, wherein the first height T １ ' and the third height T of the substrate ３ The method for manufacturing a substrate for an imprint mold includes polishing the second surface of the substrate so that the difference between the first surface and the second surface is 0 nm to 538 nm.

[0040] A 19th aspect of the present embodiment is a method for manufacturing a substrate for an imprint mold according to any one of the 16th to 18th aspects, further comprising the step of forming a recessed portion that is recessed in the thickness direction of the substrate on the second surface of the substrate.

[0041] A twentieth aspect of the present embodiment is a method for manufacturing a substrate for an imprint mold according to the nineteenth aspect, wherein, when a predetermined annular region is defined within an area surrounded by the recessed portion and the outer peripheral edge of the second surface, the second surface of the substrate is polished so that, when the second surface is approximated by a Zernike polynomial, the root mean square roughness for the sum of heights of each measurement point in the annular region in each of the fifth to eighth terms of the Zernike polynomial is 19 nm or less.

[0042] A twenty-first aspect of the present embodiment is the method for manufacturing a substrate for an imprint mold according to the twentieth aspect, wherein the second surface of the substrate is polished so that the root mean square roughness of the sum of heights of each measurement point in the annular region for each component of the fifth to eighth terms of the Zernike polynomial is 17 nm or less.

[0043] A twenty-second aspect of the present embodiment is the method for manufacturing a substrate for an imprint mold according to the twentieth or twenty-first aspect, wherein the second surface of the substrate is polished so that the root mean square roughness for the sum of heights of the ninth and subsequent terms of the Zernike polynomial in the annular region is 9 nm or less.

[0044] A twenty-third aspect of the present embodiment is a method for manufacturing a substrate for an imprint mold according to any one of the sixteenth to twenty-second aspects, further comprising the step of forming, on the first surface of the substrate, a convex structure portion that protrudes from the first surface.

[0045] A twenty-fourth aspect of the present embodiment is a method for manufacturing an imprint mold, comprising a step of forming a concave-convex pattern on the upper surface of the convex structure portion of the imprint mold substrate manufactured by the manufacturing method in the twenty-third aspect.

[0046] [Substrate for Imprint Mold] The substrate for imprint mold 1 according to this embodiment includes a base material 2 having a first surface 21 and a second surface 22 located on the opposite side to the first surface 21 .

[0047] The substrate 2 may be a transparent substrate typically used as an imprint mold substrate 1, such as a glass substrate (e.g., a quartz glass substrate, a soda glass substrate, a fluorite substrate, a calcium fluoride substrate, a magnesium fluoride substrate, an alkali-free glass substrate such as barium borosilicate glass, aluminoborosilicate glass, or aluminosilicate glass), a resin substrate (e.g., a polycarbonate substrate, a polypropylene substrate, a polyethylene substrate, a polymethyl methacrylate substrate, or a polyethylene terephthalate substrate), or a laminated substrate formed by laminating two or more substrates arbitrarily selected from the above. In this embodiment, the term "transparent" means that the substrate is capable of transmitting light having a wavelength capable of curing the imprint resin, and has a transmittance of 60% or more, preferably 90% or more, and particularly preferably 95% or more, of light having a wavelength of 160 nm to 400 nm.

[0048] The shape of the substrate 2 in a plan view is not particularly limited, and may be, for example, a substantially rectangular shape (see FIG. 3, etc.). When the substrate 2 is made of a quartz glass substrate or the like that is generally used for photoimprinting, the shape of the substrate 2 in a plan view is usually a substantially rectangular shape.

[0049] The size of the substrate 2 (size in a plan view) is not particularly limited, but when the substrate 2 is made of the above-mentioned quartz glass substrate or the like, the size of the substrate 2 may be, for example, approximately 152 mm to 153 mm x 152 mm to 153 mm. The thickness of the substrate 2 may be, for example, in the range of approximately 300 μm to 10 mm, taking into consideration strength, ease of handling, etc.

[0050] The first surface 21 of the substrate 2 may be provided with a convex structure 3 protruding from the first surface 21 (see FIG. 1 ), or may not be provided with a convex structure 3 (see FIG. 2 ). The convex structure 3 may be provided at approximately the center of the first surface 21 of the substrate 2 when viewed from above the first surface 21 of the substrate 2. The shape of the convex structure 3 when viewed from above is approximately rectangular (see FIG. 3 , etc.). The size of the convex structure 3 may be set appropriately depending on the product manufactured by the imprint process using the imprint mold 10 (see FIG. 7 ) made from the imprint mold substrate 1, and may be, for example, approximately 30 mm × 25 mm.

[0051] Projection height H of the convex structure portion 3 ３ (The length along the thickness direction of the substrate 2 between the first surface 21 of the substrate 2 and the upper surface 31 of the convex structure portion 3) is not particularly limited as long as the imprint mold 10 produced from the imprint mold substrate 1 of this embodiment can achieve the purpose of having the convex structure portion 3, and may be, for example, approximately 5 μm to 100 μm.

[0052] When viewed in a plane from the second surface 22 side of the substrate 2, the second surface 22 has four sides (first side S1, second side S2, third side S3, and fourth side S4) that constitute its outer peripheral edge PO, and four corners (first corner C1, second corner C2, third corner C3, and fourth corner C4) that are formed by connecting the ends of adjacent sides in the circumferential direction (see Figures 3 and 5).

[0053] The second surface 22 of the substrate 2 may have recesses 4 of a predetermined size (see FIGS. 1 and 3 ). The recesses 4 allow the substrate 2, particularly the upper surface 31 of the convex structure 3, to be curved during an imprint process using an imprint mold 10 (see FIG. 7 ) fabricated from the imprint mold substrate 1 according to this embodiment, particularly upon contact with an imprint resin or upon peeling off the imprint mold 10. As a result, when the upper surface 31 of the convex structure 3 is brought into contact with the imprint resin, it is possible to prevent gas from being trapped between the concave-convex pattern 11 formed on the upper surface 31 of the convex structure 3 and the imprint resin. Furthermore, the imprint mold 10 can be easily peeled off from the transfer pattern formed by transferring the concave-convex pattern 11 to the imprint resin.

[0054] The shape of the recess 4 in plan view from the second surface 22 side of the substrate 2 is preferably approximately circular (see FIG. 3 ). The approximately circular shape of the recess 4 allows the upper surface 31 of the convex structure 3 of the imprint mold 10 to be curved substantially uniformly within the plane during imprint processing using the imprint mold 10 produced from the imprint mold substrate 1 according to this embodiment, particularly when the upper surface 31 of the convex structure 3 is brought into contact with the imprint resin or when the imprint mold 10 is peeled off from the imprint resin. Note that the term "approximately circular" is intended to include not only a perfect circle but also an ellipse with a ratio of major axis to minor axis of approximately 1:0.5 to 0.999.

[0055] The size of the recess 4 in plan view from the second surface 22 side of the substrate 2 is not particularly limited, as long as the projected area of ​​the recess 4 projected onto the first surface 21 side of the substrate 2 is large enough to encompass the convex structure 3. If the projected area is too large to encompass the convex structure 3, it may not be possible to effectively curve the entire upper surface 31 of the convex structure 3 of the imprint mold 10 produced from the imprint mold substrate 1 according to this embodiment.

[0056] In this embodiment, when viewing a cross section of the substrate 2 along the thickness direction, a first point P1 located closest to the geometric center of the second surface 22, a second point P2 located between the first point P1 and the outer peripheral edge PO of the second surface 22, and a third point P3 located closest to the outer peripheral edge PO are defined. The first point P1, the second point P2, and the third point P3 are defined to be located on a straight line connecting the geometric center of the second surface 22 and an arbitrary point on the outer peripheral edge of the second surface 22. In this case, a first height T of the substrate 2 at the first point P1 is defined as １ and a second height T of the substrate 2 at the second point P2. ２ and a third height T of the substrate 2 at the third point P3. ３ and satisfy the relationship shown in the following formula (1). １ ≧T ３ >T ２ ...(1)

[0057] In this embodiment, the third point P3 is a third height T ３ The third point P3 may be located as close to the outer peripheral edge PO of the second surface 22 as possible so long as it can be measured, and may be located approximately 6 mm inside from the outer peripheral edge PO of the second surface 22, taking into consideration the influence of the chamfering of the end of the substrate 2, etc. Therefore, even when the third point P3 is described in this specification and drawings as being located on the outer peripheral edge PO of the second surface 22, this description should not be interpreted as limiting the third point P3 to being located on the outer peripheral edge PO of the second surface 22, but is intended to be interpreted as including the third point P3 being located approximately 6 mm inside from the outer peripheral edge PO of the second surface 22.

[0058] In this embodiment, the first height T １ , second height T ２ and the third height T ３ means the height based on a predetermined horizontal plane when the first surface 21 is positioned downward and aligned with the horizontal plane (see Figures 1 and 2).

[0059] In the imprint mold substrate 1 according to this embodiment, in at least one of the cross-sectional view taken along line A-A, the cross-sectional view taken along line B-B, the cross-sectional view taken along line C-C, and the cross-sectional view taken along line D-D in FIG. 3 (plan view of the second surface 22 side), １ and a second height T of the substrate 2 at the second point P2. ２ and a third height T of the substrate 2 at the third point P3. ３ and satisfy the relationship shown in the above formula (1). Note that the above-mentioned A-A line sectional end view, B-B line sectional end view, C-C line sectional end view, and D-D line sectional end view are all cross-sectional end views passing through the geometric center C22 of the imprint mold substrate 1, the A-A line sectional end view and the B-B line sectional end view are respectively cross-sectional end views substantially perpendicular to two opposing sides of the second surface 22, and the C-C line sectional end view and the D-D line sectional end view are respectively cross-sectional end views passing through diagonals of the second surface 22.

[0060] In this embodiment, for example, in each of the cross-sectional end views, the first height T of the substrate 2 at a first point P1 on one side from the geometric center C22 of the second surface 22 toward the outer edge portion PO is １ and a second height T of the substrate 2 at the second point P2. ２ and a third height T of the substrate 2 at the third point P3. ３ and satisfy the relationship shown in the above formula (1), but the first height T of the substrate 2 at the first point P1 on the other side １ and a second height T of the substrate 2 at the second point P2. ２ and a third height T of the substrate 2 at the third point P3. ３ For example, in the embodiment shown in FIG. 4, the first to third heights T １ ~T ３ satisfies the relationship shown in the above formula (1), but on the right side of the geometric center C22, the first to third heights T １ ~T ３ does not satisfy the relationship shown in the above formula (1), and the third height T ３ is the second height T ２ is lower than

[0061] In the case where the second surface 22 of the imprint mold substrate 1 according to this embodiment does not have a recess 4, the first point P1 may be the geometric center C22 of the second surface 22 (see FIG. 2 ), or may be any position selected within a circular first circular region 221 (see FIGS. 3 , 5 , etc.) having a diameter of 30 mm to 60 mm and centered at the geometric center C22. The second point P2 may be any position selected within an annular region 223 located outside (toward the outer peripheral edge PO) of a second annular region 222 (a region with a larger diameter than the first circular region 221) having a diameter of 60 mm to 110 mm and centered at the geometric center C22 of the second surface 22, and may be the position where the height of the substrate 2 is lowest (see FIG. 5 ). The linear distance between the first point P1 and the second point P2 may be 25 mm to 99 mm. The linear distance between the first point P1 and the third point P2 may be 40 mm to 107 mm. In an imprint mold substrate 1 that does not have a recessed portion 4 on the second surface 22, the first circular region 221 is a region where the recessed portion 4 is formed. The second annular region 222 is a region where the imprint mold 10 fabricated from the imprint mold substrate 1 is attracted by a mold holder of an imprinting apparatus. By defining a first point P1 within the first circular region 221 and a second point P2 within the annular region 223, and using an imprint mold 10 fabricated from the imprint mold substrate 1 that satisfies the relationship shown in formula (1), it is possible to form a concave-convex pattern with high precision.

[0062] When a recess 4 is provided on the second surface 22 of the imprint mold substrate 1 according to this embodiment, the first point P1 may be located on the edge 41 of the recess 4 (see FIG. 1). Specifically, the first point P1 may be located within an annular region having an inner radius of 30 mm to 35 mm and centered at the geometric center C22 of the second surface 22. The second point P2 may be located at any position within an annular region 223 located outside (toward the outer peripheral edge PO) of the second annular region 222, which has a diameter of 60 mm to 110 mm and is centered at the geometric center C22 of the second surface 22, and may be located at a position where the thickness of the substrate 2 is at its minimum (see FIG. 3). The linear distance between the first point P1 and the second point P2 may be 20 mm to 69 mm. The linear distance between the first point P1 and the third point P3 may be 35 mm to 77 mm. By defining a first point P1 at the edge 41 of the recess 4, a second point P2 within the annular region 223, and a third point P3 at the outer edge PO of the second surface 22, it becomes possible to form a concave-convex pattern with extremely high positional accuracy using an imprint mold 10 made from an imprint mold substrate 1 that satisfies the relationship shown in equation (1) above.

[0063] In a plan view from the second surface 22 side, the annular region 223 may be a substantially quadrangular annular region, or may be a substantially quadrangular annular region with rounded corners (see FIGS. 3 and 5). The annular region 223 may be a region having a width of 6 mm to 21 mm from each side (e.g., first side S1) of the second surface 22 in a direction parallel to the side (e.g., second side S2 and fourth side S4) adjacent to the side (e.g., first side S1) and a region having a width of 8 mm to 30 mm from each corner C1 to C4 of the second surface 22 toward the geometric center C22.

[0064] In a substrate 1 for an imprint mold in which a recessed portion 4 is not formed on the second surface 22, the thickness of the substrate 2 is greatest at the geometric center C22 of the second surface 22, and the thickness of the substrate 2 gradually decreases toward the outer peripheral edge PO, and the thickness of the substrate 2 gradually increases from the point where the thickness of the substrate 2 is minimum toward the outer peripheral edge PO.

[0065] When the base material 2 is placed on a horizontal surface with the first surface 21 facing downward, the angle θ (see FIG. 6) formed by the line segment L1 connecting the second point P2 of the second surface 22 and the outer peripheral edge PO (third point P3) and the horizontal plane HS is 9.0×10 －６ ° to 1.0 × 10 －３ ° is sufficient, 1.0X10 －５ °~5.0X10 －４ It is preferable that the angle θ is 9.0×10 －６ ° or the angle θ is less than 1.0 × 10 －３ If the angle exceeds 100°, it may become difficult to form a concave-convex pattern with extremely high positional accuracy using the imprint mold 10 produced from the imprint mold substrate 1.

[0066] Height T of the substrate 2 at the third point P3 ３ and the height T of the substrate 2 at the second point P2 ２ The difference between ３ -T ２ ) may be 1 nm to 105 nm, and preferably 10 nm to 80 nm. If the difference is less than 1 nm or exceeds 105 nm, it may be difficult to form a concave-convex pattern with extremely high positional accuracy.

[0067] Height T of the substrate 2 at the third point P3 ３ and the height T of the substrate 2 at the first point P1 １ The difference between １ -T ３ ) may be 0 nm to 639 nm, and preferably 200 nm to 500 nm. If the difference is within the above range, it is possible to form a concave-convex pattern with extremely high positional accuracy.

[0068] In the imprint mold substrate 1 having the recessed portion 4 according to this embodiment formed therein, when four line segments passing through the geometric center C22 of the second surface 22 and perpendicular to each of the first to fourth sides S1 to S4, and four line segments passing through the geometric center C22 and each of the first to fourth corners C1 to C4 of the second surface 22 are defined, it is preferable that the difference (maximum value - arithmetic mean value) between the maximum value of the angle θ formed by the line segment L1 connecting the second point P2 and the outer peripheral edge PO (third point P3) on each line segment (eight line segments) and the horizontal plane HS and the arithmetic mean value of the angle θ is relatively small. Specifically, it is preferable that the difference (maximum value - arithmetic mean value) is 7.0 × 10 －４ The difference (maximum value - arithmetic mean value) is relatively small, about 7.0 × 10 －４ If the angle is about 100° or less, it can be evaluated that the variation in the surface shape (height difference) of the second surface 22 is small, and it can be said that it is possible to form a concave-convex pattern with extremely high positional accuracy.

[0069] In the imprint mold substrate 1 in which the recessed portion 4 according to this embodiment is formed, when four line segments that pass through the geometric center C22 of the second surface 22 and are perpendicular to each of the first to fourth sides S1 to S4, and four line segments that pass through the geometric center C22 of the second surface 22 and each of the first to fourth corners C1 to C4, the height T of the base material 2 at a third point P3 located on each line segment (eight line segments) is defined. ３ and the height T of the substrate 2 at the second point P2 ２ The difference between ３ -T ２ ) and the difference (T ３ -T ２ ) is relatively small. Specifically, it is sufficient if the difference (maximum value - arithmetic mean value) is about 70 nm or less. If the difference (maximum value - arithmetic mean value) is relatively small, about 70 nm or less, it can be evaluated that there is little variation in the surface shape (height difference) of the second surface 22, and it can be said that it is possible to form a concave-convex pattern with extremely high positional accuracy.

[0070] In the imprint mold substrate 1 in which the recessed portion 4 according to this embodiment is formed, when four line segments that pass through the geometric center C22 of the second surface 22 and are perpendicular to each of the first to fourth sides S1 to S4, and four line segments that pass through the geometric center C22 of the second surface 22 and each of the first to fourth corners C1 to C4, the height T of the base material 2 at the first point P1 located on each line segment (eight line segments) is defined. １ and the height T of the substrate 2 at the third point P3 ３ The difference between １ -T ３ ) and the difference (T １ -T ３ ) is relatively small. Specifically, it is sufficient if the difference (maximum value - arithmetic mean value) is about 300 nm or less. If the difference (maximum value - arithmetic mean value) is relatively small, about 300 nm or less, it can be evaluated that there is little variation in the surface shape (height difference) of the second surface 22, and it can be said that it is possible to form a concave-convex pattern with extremely high positional accuracy.

[0071] In the imprint mold substrate 1 (see FIGS. 2, 5, etc.) in which the recesses 4 according to this embodiment are not formed, when a plurality of measurement points within a predetermined annular measurement region on the second surface 22 are measured using a flatness measurement device and approximated by a Zernike polynomial, the root-mean-square roughness Rq of each term of the Zernike polynomial is expressed by the following formula (1): Here, the measurement annular region may be an area whose inner boundary is a circle of a predetermined radius (e.g., a radius of 35 mm) centered on the geometric center C22 of the second surface 22, and whose outer boundary is a circle of a predetermined radius (e.g., a radius of 50 mm) centered on the geometric center C22 of the second surface 22. The area represented by the circle indicating the inner boundary of the measurement annular region may be an area in the imprint mold substrate 1 where the recesses 4 are to be formed, and the radius of the circle may be any value that corresponds to the design of the recesses 4. In this embodiment, it is sufficient that the root mean square roughness Rq (see formula (2) below) of the annular measurement region relative to the sum of the heights of the respective measurement points in the fifth to eighth terms (Z5 to Z8) of the Zernike polynomials, as expressed by the following formula (2), is 19 nm or less, and preferably 17 nm or less. By having the surface shape of the annular measurement region of the imprint mold substrate 1 in which no recess 4 is formed be such that the root mean square roughness Rq of the sum of the heights of the respective measurement points in the annular measurement region in the fifth to eighth terms (Z5 to Z8) of the Zernike polynomials is 19 nm or less, it becomes possible to form a concave-convex pattern with extremely high positional accuracy, and the difference in positional accuracy between each imprint mold 10 produced from a large number of imprint mold substrates 1 can be reduced to approximately 1 nm (3σ) or less.

[0072] In the above formula (1), Rq represents the "root mean square roughness", N represents the "total number of measurement points in the measurement annular region", and Zki represents the "height at the i-th measurement point of the k-th term of the Zernike polynomial".

[0073] In the above formula (2), Rq represents the "root mean square roughness for the sum of the heights of the individual measurement points," Z5i to Z8i represent the "heights of the fifth to eighth terms of the Zernike polynomial at the i-th measurement point," and N represents the "total number of measurement points in the above measurement annular region."

[0074] In the imprint mold substrate 1 according to this embodiment in which the recessed portion 4 is not formed, it is sufficient that the root mean square roughness Rq of the sum of the heights of the ninth and subsequent terms (Z9 and subsequent terms) of the Zernike polynomial in the measurement annular region is 10 nm or less. Note that the root mean square roughness Rq of the sum of the heights of the ninth and subsequent terms (Z9 and subsequent terms) of the Zenrike polynomial means the root mean square roughness of the shape obtained by subtracting from the actual shape the sum of the heights of the measurement points in the components of the first to eighth terms of the Zernike polynomial.

[0075] The "real shape" is expressed as height information of each measurement point in the measurement annular region. The height of each measurement point in the measurement annular region can be measured using, for example, UltraFlat (manufactured by SOL Corporation).

[0076] By having the surface shape of the measurement annular region in the imprint mold substrate 1 where no recessed portion 4 is formed be such that the root mean square roughness for the sum of the heights of the ninth and subsequent terms (Z9 and subsequent terms) of the Zernike polynomial is 10 nm or less, it becomes possible to form a concave-convex pattern with extremely high positional accuracy, and the difference in positional accuracy between the numerous imprint molds 10 produced from the numerous imprint mold substrates 1 can be reduced to approximately 1 nm (3σ) or less.

[0077] In the imprint mold substrate 1 (see FIGS. 1 and 3 , etc.) on which the recess 4 according to this embodiment is formed, when a plurality of measurement points within a predetermined annular measurement region on the second surface 22 are measured using a flatness measurement device and the measurement region is approximated by a Zernike polynomial, the root-mean-square roughness Rq for the sum of the heights of the measurement points in the annular measurement region in the fifth to eighth terms (Z5 to Z8) of the Zernike polynomial needs to be 12 nm or less, and preferably 7 nm or less. The annular measurement region may be an area whose inner boundary is the edge of the recess 4 on the second surface 22 (e.g., a circular edge with a radius of about 35 mm) and whose outer boundary is a circle of a predetermined radius (e.g., a radius of 50 mm) centered on the geometric center C22 of the second surface 22. By having the surface shape of the measurement annular region in the imprint mold substrate 1 in which the recessed portion 4 is formed be such that the root mean square roughness Rq for the sum of the heights of the measurement points in the measurement annular region in the fifth to eighth terms (Z5 to Z8) of the Zernike polynomial is 12 nm or less, preferably 7 nm or less, it becomes possible to form a concave-convex pattern with extremely high positional accuracy, and the difference in positional accuracy between each imprint mold 10 produced from a large number of imprint mold substrates 1 can be reduced to approximately 1 nm (3σ) or less.

[0078] In the imprint mold substrate 1 having the recessed portions 4 according to this embodiment, it is sufficient that the root-mean-square roughness Rq of the sum of the heights of the ninth and subsequent terms (Z9 and subsequent terms) of the Zernike polynomial in the measurement annular region is 10 nm or less. By having the surface shape of the measurement annular region in the imprint mold substrate 1 having the recessed portions 4 formed therein be such that the root-mean-square roughness of the sum of the heights of the ninth and subsequent terms (Z9 and subsequent terms) of the Zernike polynomial is 10 nm or less, it becomes possible to form a concave-convex pattern with extremely high positional accuracy, and the difference in positional accuracy between a large number of imprint molds 10 produced from a large number of imprint mold substrates 1 can be reduced to approximately 1 nm (3σ) or less.

[0079] Zernike polynomials are orthogonal polynomials defined on a unit circle. For example, the first term of a Zernike polynomial is a "constant term," the second term is an "X component gradient," the third term is a "Y component gradient," the fourth term is a "focus shift," the fifth term is an "astigmatism in the 0-degree and 90-degree directions," the sixth term is an "astigmatism in the ±45-degree directions," the seventh term is a "third-order coma aberration of the X component," the eighth term is a "third-order coma aberration of the Y component," and the ninth term is a "third-order spherical aberration."

[0080] In analysis of variance (ANOVA), data variation is analyzed by decomposing it into error variation and variation due to each factor. When the surface shape of the second surface 22 of the imprint mold substrate 1, i.e., the distribution of the elevation difference of the second surface 22, is expressed in the form of a sum of squares, and the elevation difference of the second surface 22 of the imprint mold substrate 1 is taken as the total sum of squares S, the total sum of squares S is expressed as the sum of the sum of the surface shape represented by each term separated by the least squares method using Zernike polynomials and the sum of the squares of the shape not included in the Zernike polynomials (the sum of squares of error components). Therefore, the root-mean-square roughness Rq in this embodiment can be expressed as the square root of the sum of each term of the Zernike polynomial, the fifth to eighth terms (Z5 to Z8), or the ninth and subsequent terms (Z9 and subsequent). Since there is no correlation between the terms in the Zernike polynomials, each term is determined regardless of the number of terms separated by the least squares method using the Zernike polynomials, etc. Therefore, the square root of the sum of each term of the Zernike polynomials, the fifth to eighth terms (Z5 to Z8) or the ninth and subsequent terms (Z9 and subsequent) is also determined uniformly in accordance with the surface shape of second surface 22.

[0081] In the imprint mold substrate 1 where the recessed portion 4 is not formed, the heights on the first to fourth sides S1 to S4 (third height T ３ ) and the height of the substrate 2 on the first to fourth corners C1 to C4 (third height T ３) are preferably substantially identical. The heights on the first to fourth sides S1 to S4 may be on a line segment that passes through the geometric center C22 of the second surface 22 and is substantially perpendicular to two opposing sides (e.g., the first side S1 and the third side S3, or the second side S2 and the fourth side S4), and may be on the two sides on which the line segment is perpendicular. When the difference between the two arithmetic mean values ​​is relatively small and is substantially identical, the amount of change in the root-mean-square roughness Rq of the fifth to eighth terms (Z5 to Z8) and the ninth and subsequent terms (Z9 and subsequent) of the Zernike polynomial before and after the formation of the recess 4 becomes relatively small. Therefore, in the imprint mold 10 manufactured from such an imprint mold substrate 1, the effect of being able to transfer the concave-convex pattern 11 with extremely high positional accuracy is achieved.

[0082] According to the imprint mold substrate 1 of this embodiment, it is possible to manufacture an imprint mold 10 that can transfer a concave-convex pattern 11 with extremely high positional accuracy.

[0083] [Imprint Mold] The imprint mold 10 in this embodiment has a concave-convex pattern 11 formed on the upper surface 31 of the convex structure portion 3 of the imprint mold substrate 1 (see FIG. 7).

[0084] The shape, dimensions, etc. of the concave-convex pattern 11 can be appropriately set according to the shape, dimensions, etc. required for products manufactured using the imprint mold 1 according to this embodiment. Examples of the shape of the concave-convex pattern 11 include a line-and-space shape, a pillar shape, a hole shape, a grid shape, and a staircase shape. The dimensions of the concave-convex pattern 11 can be set to, for example, about 10 nm to 10,000 nm. The dimensions of the concave-convex pattern 11 are defined by the shape of the concave-convex pattern 11. For example, the dimensions of the concave-convex pattern 11 are the short-side (width) length of the space-shaped recesses 111 or the line-shaped protrusions 112 in the case of a line-and-space shape; the diameter or diagonal length of the pillar-shaped protrusions 112 in the case of a pillar shape; the diameter or diagonal length of the hole-shaped recesses 111 in the case of a hole shape; the short-side (width) length of the grid-shaped protrusions 112 in the case of a grid shape; and the short-side length of the step surfaces of each step of the stair-shaped recesses 111 or protrusions 112 in the case of a staircase shape.

[0085] The imprint mold 10 in this embodiment is produced using the above-mentioned imprint mold substrate 1, and therefore the concave-convex pattern 11 can be transferred with extremely high positional accuracy by the imprint process using the imprint mold 10.

[0086] [Method for manufacturing an imprint mold substrate] A method for manufacturing an imprint mold substrate according to this embodiment will be described. The method for manufacturing an imprint mold substrate according to this embodiment includes the steps of preparing a substrate 2' having a first surface 21' and a second surface 22' located on the opposite side thereof (see FIG. 8A), polishing the second surface 22' of the substrate 2', forming a recessed portion 4 on the second surface 22' of the substrate 2' that is recessed in the thickness direction of the substrate 2', and forming a convex structure 3 on the first surface 21' of the substrate 2' that protrudes from the first surface 21'.

[0087] The substrate 2' may be a transparent substrate typically used as the imprint mold substrate 1, such as a glass substrate (e.g., a quartz glass substrate, a soda glass substrate, a fluorite substrate, a calcium fluoride substrate, a magnesium fluoride substrate, an alkali-free glass substrate such as barium borosilicate glass, aluminoborosilicate glass, or aluminosilicate glass), a resin substrate (e.g., a polycarbonate substrate, a polypropylene substrate, a polyethylene substrate, a polymethyl methacrylate substrate, or a polyethylene terephthalate substrate), or a laminated substrate formed by laminating two or more substrates arbitrarily selected from the above. In this embodiment, the term "transparent" means that the substrate is capable of transmitting light having a wavelength capable of curing the imprint resin, and has a transmittance of 60% or more, preferably 90% or more, and particularly preferably 95% or more, of light having a wavelength of 160 nm to 400 nm.

[0088] The shape of the substrate 2′ in a plan view is not particularly limited, and may be, for example, a substantially rectangular shape, etc. When the substrate 2′ is made of a quartz glass substrate or the like that is generally used for photoimprinting, the shape of the substrate 2′ in a plan view is usually a substantially rectangular shape.

[0089] The size of the substrate 2' (size in a plan view) is not particularly limited, but when the substrate 2' is made of the above-mentioned quartz glass substrate or the like, the size of the substrate 2' may be, for example, approximately 152 mm to 153 mm x 152 mm to 153 mm. The thickness of the substrate 2' may be, for example, in the range of approximately 300 μm to 10 mm, taking into consideration strength, ease of handling, etc.

[0090] The first surface 21′ and the second surface 22′ of the substrate 2′ may both be substantially flat surfaces. In this embodiment, the first surface 21′ of the substrate 2′ has a convex structure 3 formed thereon, and the second surface 22′ of the substrate 2′ is polished as described below to form a concave portion 4 on the polished second surface 22′.

[0091] Next, the second surface 22' of the substrate 2' is polished. At this time, when viewing a cross section of the substrate 2' along the thickness direction, a first point P1' located closest to the geometric center C22' of the second surface 22', a second point P2' located between the first point P1' and the outer peripheral edge PO' of the second surface 22', and a third point P3' located closest to the outer peripheral edge PO' are defined. The first point P1', the second point P2', and the third point P3' are defined to be located on a straight line connecting the geometric center of the second surface 22' and an arbitrary point on the outer peripheral edge of the second surface 22'. The height T of the substrate 2' at the first point P1' is １ ' and the height T of the substrate 2' at the second point P2'. ２ ' and the height T of the substrate 2' at the third point P3'. ３ The second surface 22' of the substrate 2' is polished so that T' and T' satisfy the relationship shown in the following formula (2). １ '≧T ３ '>T ２ ' ... (2)

[0092] In this embodiment, the first point P1' may be the geometric center C22' of the second surface 22' (see Figures 8B and 9), or may be any position selected within a first circular region 221' having a diameter of 30 mm to 60 mm and centered at the geometric center C22'. The second point P2' may be any position selected within an annular region 223' located outside (toward the outer peripheral edge PO') a second circular region 222' (a region with a larger diameter than the first circular region 221') having a diameter of 60 mm to 110 mm and centered at the geometric center C22' of the second surface 22', and may be a position where the thickness of the substrate 2' is minimized after polishing. The linear distance between the first point P1' and the second point P2' may be 25 mm to 99 mm. The linear distance between the first point P1' and the third point P3' may be 40 mm to 107 mm.

[0093] The first circular region 221' is a region where the recessed portion 4 will be formed in a step described below. The second annular region 222' is a region that is vacuum-adsorbed on a substrate stage of an imprinting apparatus when the imprint mold 10 is produced using the imprint mold substrate 1, and is a region where the imprint mold 10 produced from the imprint mold substrate 1 is vacuum-adsorbed on a mold holder of the imprinting apparatus. In a plan view from the second surface 22' side, the annular region 223' may be a substantially quadrangular annular region, or may be a substantially quadrangular annular region with rounded corners (see FIG. 9 ). The annular region 223' may be an area having a width of 6 mm to 21 mm from each side (e.g., first side S1') of the second surface 22' of the substrate 2' in a direction parallel to the side (e.g., second side S2' and fourth side S4') adjacent to the side (e.g., first side S1'), and an area having a width of 8 mm to 30 mm from each corner C1' to C4' of the second surface 22' toward the geometric center C22' (see Figure 9, etc.).

[0094] By defining a first point P1' within the first circular region 221', a second point P2' within the annular region 223', and a third point P3' on the outer peripheral edge PO', the second surface 22' can be polished so as to satisfy the relationship shown in the above formula (2), thereby making it possible to manufacture an imprint mold substrate 1 that can produce an imprint mold 10 onto which a concave-convex pattern can be transferred with high positional accuracy.

[0095] The thickness of the substrate 2' is greatest at the geometric center C22' of the second surface 22', and gradually decreases toward the outer peripheral edge PO', and the thickness of the substrate 2' gradually increases from the point where the thickness of the substrate 2' is minimum toward the outer peripheral edge PO'.

[0096] When the substrate 2' is placed on a horizontal surface with the first surface 21' facing downward, the angle θ' between the horizontal plane HS' and the line segment L1' connecting the second point P2' of the second surface 22' and the outer peripheral edge PO' is 9.0×10 －６ °~1.0X10 －３ It is preferable to polish the second surface 22' so that the angle is 1.0×10 －５ ° ~ 5.0 × 10 －４It is particularly preferable to polish the second surface 22' so that the angle θ' is 9.0×10° (see FIG. 10). －６ ° or the angle θ' is less than 1.0 × 10 －３ If the angle exceeds 100°, it may become difficult to form a concave-convex pattern with extremely high positional accuracy using the imprint mold 10 made from the imprint mold substrate 1.

[0097] The height T of the substrate 2' at the third point P3' ３ ' and the height T of the substrate 2' at the second point P2'. ２ ' and the difference (T ３ '-T ２ It is preferable to polish the second surface 22' of the substrate 2' so that the difference between the surface roughness and the surface roughness (difference between the surface roughness and the surface roughness) is 1 nm to 103 nm, and it is particularly preferable to polish the second surface 22' of the substrate 2' so that the difference between the surface roughness and the surface roughness (difference between the surface roughness and the surface roughness) is 10 nm to 80 nm. If the difference is less than 1 nm or exceeds 103 nm, it may be difficult to form a concave-convex pattern with extremely high positional accuracy.

[0098] The height T of the substrate 2' at the third point P3' ３ and the difference between the height T1′ of the substrate at the first point P1′ (T １ '-T ３ It is preferable to polish the second surface 22' of the substrate 2' so that the difference (difference) is 0 nm to 538 nm. If the difference exceeds 538 nm, it may be difficult to form a concave-convex pattern with extremely high positional accuracy.

[0099] In this embodiment, when a plurality of measurement points within a predetermined annular measurement region on the polished second surface 22′ are measured using a flatness measurement device and the measurement region is approximated by a Zernike polynomial, the second surface 22′ is polished so that the root-mean-square roughness Rq (see the above formulas (1) and (2)) relative to the sum of the heights of the measurement points in the annular measurement region in the fifth to eighth terms (Z5 to Z8) of the Zernike polynomial is 19 nm or less, preferably 17 nm or less. The measurement annular region may be an area whose inner boundary is a circle of a predetermined radius (e.g., a 35 mm radius) centered on the geometric center C22′ of the second surface 22′, and whose outer boundary is a circle of a predetermined radius (e.g., a 50 mm radius) centered on the geometric center C22′ of the second surface 22′. The region represented by the circle indicating the inner boundary of the annular measurement region may be the region where recess 4 (see FIG. 8D ) is to be formed in a step described later, and the radius of the circle may be any value that corresponds to the design of recess 4. By polishing second surface 22′ so that the surface shape of the annular measurement region has a root-mean-square roughness Rq of 19 nm or less for the fifth to eighth terms (Z5 to Z8) of the Zernike polynomials relative to the sum of the heights of the measurement points on the annular measurement region, it becomes possible to form a concave-convex pattern with extremely high positional accuracy, and the difference in positional accuracy between imprint molds 10 fabricated from a large number of imprint mold substrates 1 can be reduced to approximately 1 nm (3σ) or less.

[0100] In this embodiment, second surface 22′ may be polished so that the root-mean-square roughness Rq of the surface shape of the circular region relative to the sum of heights of the ninth and subsequent terms (Z9 and subsequent terms) of the Zernike polynomial in the measurement annular region is 9 nm or less. By polishing second surface 22′ so that the surface shape of the circular region relative to the root-mean-square roughness Rq of the surface shape of the circular region relative to the sum of heights of the ninth and subsequent terms (Z9 and subsequent terms) of the Zernike polynomial in the measurement annular region is 9 nm or less, it becomes possible to form a concave-convex pattern with extremely high positional accuracy, and the difference in positional accuracy between a large number of imprint molds 10 fabricated from a large number of imprint mold substrates 1 can be reduced to approximately 1 nm (3σ) or less.

[0101] As mentioned above, the height T １', height T ２ ' and height T ３ By polishing the second surface 22' of the substrate 2' so that Z5' satisfies the relationship shown in equation (2), when the measurement annular region after polishing is approximated by a Zernike polynomial, the root-mean-square roughness Rq of the sum of the heights of the measurement points in the measurement annular region in the fifth to eighth terms (Z5 to Z8) of the Zernike polynomial is 19 nm or less, preferably 17 nm or less, and the root-mean-square roughness Rq of the sum of the heights of the ninth and subsequent terms (Z9 and subsequent) is 9 nm or less. Having such a surface shape enables formation of a concave-convex pattern with extremely high positional accuracy by an imprint process using an imprint mold 10 made from the imprint mold substrate 1. Furthermore, when a large number of imprint mold substrates 1 are produced and a large number of imprint molds 10 are made from them, the difference in positional accuracy between the multiple imprint molds 10 can be reduced to approximately 1 nm (3σ) or less.

[0102] The convex structure 3 is formed on the first surface 21′ (see FIG. 8C ). The convex structure 3 may be formed, for example, by forming a resist pattern corresponding to the convex structure 3 on the first surface 21′ of the substrate 2′ and performing etching using the resist pattern as a mask.

[0103] After polishing the second surface 22' and forming the convex structure 3 as described above, a depression 4 recessed in the thickness direction of the substrate 2' is formed on the second surface 22' (see FIG. 8D). The depression 4 may be formed, for example, by cutting and polishing the second surface 22' of the substrate 2'. In this manner, the imprint mold substrate 1 according to this embodiment is manufactured. Note that with regard to the "step of forming the convex structure 3" and the "step of forming the depression 4 on the second surface 22'," which are steps performed after polishing the second surface 22', there is no restriction on the order of these steps. The convex structure 3 may be formed after the depression 4 on the second surface 22' (not shown). The order of these steps may be determined appropriately depending on the specifications regarding the shapes of the depression 4 and the convex structure 3, etc.

[0104] According to the method for manufacturing a substrate for an imprint mold in this embodiment, after polishing of second surface 22' of substrate 2', the root-mean-square roughness Rq of the sum of the heights of the measurement points in the annular measurement region in the fifth to eighth terms (Z5 to Z8) of the Zernike polynomial is 19 nm or less, preferably 17 nm or less, and the root-mean-square roughness Rq of the sum of the heights of the ninth and subsequent terms (Z9 and subsequent) is 9 nm or less, thereby minimizing the change in shape of second surface 22' before and after forming recess 4. Therefore, using imprint mold 10 manufactured from imprint mold substrate 1 manufactured in this manner, it is possible to achieve the effect of transferring concave-convex pattern 11 with extremely high positional accuracy.

[0105] [Manufacturing Method of Imprint Mold] A method for manufacturing the imprint mold 10 in this embodiment will be described. First, a master mold 100 used to manufacture the imprint mold 10 is prepared.

[0106] When manufacturing the master mold 100, first, a master mold substrate 102 is prepared, which has a first surface 102a and a second surface 102b opposite to the first surface 102a, and a resist layer 103 formed on the first surface 102a (see FIG. 11A ). Alternatively, a hard mask layer 105 may be formed on the first surface 102a, and the master mold substrate 102 may have a resist layer 103 formed on the hard mask layer 105.

[0107] Next, the resist layer 103 is subjected to electron beam lithography or exposure via a photomask having predetermined openings, and development, thereby forming a resist pattern 104 corresponding to the concave-convex pattern 120 of the master mold 100 (see FIG. 11B ). When the resist layer 103 is formed on the hard mask layer 105, the hard mask layer 105 can be etched using the resist pattern 104 as an etching mask to form the hard mask pattern 106.

[0108] Using the resist pattern 104 (hard mask pattern 106) formed as described above as an etching mask, the first surface 102a of the master mold substrate 102 is etched (see Figure 11C), and the last remaining resist pattern 104 (hard mask pattern 106) is removed, thereby producing a master mold 100 having a concave-convex pattern 120 including protruding patterns 122 corresponding to the concave portions 111 of the imprint mold 10 and concave patterns 121 corresponding to the convex portions 112 (see Figure 11D).

[0109] Next, the imprint mold substrate 1 according to this embodiment is prepared, and the imprint resin 200 is supplied discretely onto the upper surface 31 of the convex structure portion 3 of the imprint mold substrate 1 (see FIG. 12A).

[0110] Next, the master mold 100 manufactured as described above is prepared, and the master mold 100 is brought into contact with the imprint resin 200 supplied to the upper surface 31 of the convex structure portion 3 of the imprint mold substrate 1, thereby filling the concave-convex pattern 120 of the master mold 100 with the imprint resin 200, and then the imprint resin 200 is hardened in this state (see Figure 12B).

[0111] The method for curing the imprint resin 200 may be selected appropriately depending on the curing type of the curable resin constituting the imprint resin 200. For example, if the curable resin is a photocurable type, light (e.g., ultraviolet light) may be irradiated onto the imprint resin 200 (curable resin) via the master mold 100 or the imprint mold substrate 1. If the curable resin is a thermosetting type, heat may be applied to the imprint resin 200 (curable resin). Note that if the curable resin is a thermoplastic type, a pattern-forming resin layer made of the imprint resin 200 may be formed on the upper surface 31 of the convex structure portion 3 of the imprint mold substrate 1, the master mold 100 may be brought into contact with the heated and softened pattern-forming resin layer, and the pattern-forming resin layer may be cured by cooling.

[0112] The master mold 100 is then separated from the cured imprint resin 200 (see FIG. 12C). As a result, a pattern layer 201 having a concave-convex pattern is formed on the upper surface 31 of the convex structure portion 3 of the imprint mold substrate 1. The pattern layer 201 thus formed is used as an etching mask to etch the upper surface 31 of the convex structure portion 3, thereby forming a concave-convex pattern 11 on the upper surface 31 of the convex structure portion 3 (see FIG. 12D). In this way, the imprint mold 10 is manufactured.

[0113] [Imprinting Method] An imprinting method using the imprint mold 10 of this embodiment will be described. An imprinting mold 10 and a transferee substrate 90 having a first surface 90A and a second surface 90B opposite the first surface 90A are prepared, and an imprinting resin 91 is supplied to the first surface 90A of the transferee substrate 90 (see FIG. 13A ). The method for supplying the imprinting resin 91 to the first surface 90A of the transferee substrate 90 is not particularly limited. For example, the imprinting resin 91 may be supplied discretely to the first surface 90A of the transferee substrate 90 by an inkjet method, or the imprinting resin may be applied to the first surface 90A of the transferee substrate 90 using a coating machine such as a spin coater or a spray coater.

[0114] The imprint mold 10 is brought close to the imprint resin 91 supplied to the first surface 90A of the transfer substrate 90, and the imprint resin 91 is spread between the first surface 90A of the transfer substrate 90 and the imprint mold 10 to form a molded resin layer 92 (see Figure 13B).

[0115] While the imprint mold 10 is in contact with the molded resin layer 92 (imprinted resin 91), the molded resin layer 92 (imprinted resin 91) is irradiated with light (e.g., ultraviolet light) through the imprint mold 10 to harden the molded resin layer 92. Thereafter, the imprint mold 10 is separated from the hardened molded resin layer 92 (see FIG. 13C ).

[0116] In this way, a transfer pattern 93 can be formed on the first surface 90A of the transfer substrate 90, in which the concave-convex pattern 11 of the imprint mold 10 is transferred. As described above, the transfer substrate 90 on which the transfer pattern 93 has been formed, or a concave-convex structure obtained by performing an etching process on the first surface 90A of the transfer substrate 90 using the transfer pattern 93 as an etching mask, can be manufactured as an article such as an optical product or an aerospace product.

[0117] The above-described embodiments have been described to facilitate understanding of the present disclosure, and are not intended to limit the present disclosure. Therefore, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present disclosure.

[0118] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to the following examples.

[0119] Example 1 A quartz substrate 2' (152.5 mm x 152.5 mm, thickness 6.40 mm) having a first surface 21' and a second surface 22' located on the opposite side was prepared, and the second surface 22' of the quartz substrate 2' was polished. At this time, when viewing a cross section of the quartz substrate 2' along the thickness direction, the height T of the quartz substrate 2' at a first point P1' located at the geometric center C22' of the second surface 22' was １ ' and the height T of the quartz substrate 2' at the second point P2'. ２ ' and the height T of the quartz substrate 2' at a third point P3' located on the outer peripheral edge PO' of the second surface 22'. ３ The second surface 22' of the quartz substrate 2' was polished so that the relationship between T and T was expressed by the following formula (2). １ '≧T ３ '>T ２ ' ... (2)

[0120] The height of each grating at 1 mm intervals within a square area with a side length of 144 mm and centered on the geometric center C22' of the second surface 22' of the quartz substrate 2' after polishing was measured using a flatness measuring device (UltraFlat, manufactured by SOL Corporation). １ ', T ２ ', T ３' was calculated. Height T １ ', T ２ ', T ３ As for "T", the heights of the first point P1', the second point P2', and the third point P3' located on four line segments extending from the geometric center C22' of the second surface 22' and perpendicular to each of the sides S1' to S4' constituting the second surface 22', and on line segments extending from the geometric center C22' of the second surface 22' and passing through each of the corners C1' to C4' (total of eight heights) were obtained. From the obtained results, the difference in height (T) between the first point P1' of the second surface 22' and the third point P3' located on the outer peripheral edge PO' was calculated. １ '-T ３ ') and the average value thereof and the difference in height between the second point P2' and the third point P3' (T ３ '-T ２ The second point P2' is a point located within an annular region 223' that is 6 mm to 21 mm wide from each of the sides S1' to S4' of the second surface 22' in a direction parallel to the two sides adjacent to the side, and that is 8 mm to 30 mm wide from each of the corners C1' to C4' of the second surface 22' in a direction parallel to the geometric center C22'.

[0121] The height within an annular measurement region, whose inner boundary was a circle of radius 35 mm centered on the geometric center C22' of the polished second surface 22' and whose outer boundary was a circle of radius 50 mm centered on the geometric center C22' of the second surface 22', was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and the height was approximated by a Zernike polynomial.The root mean square roughness Rq of the sum of the heights of each measurement point in the annular measurement region for terms 5 to 8 (Z5 to Z8) of the Zernike polynomial was calculated, as well as the root mean square roughness Rq of the sum of the heights of terms 9 and beyond of the Zernike polynomial.The results are shown in Table 2.

[0122] After the polishing, a recess 4 was formed on the second surface 22' of the quartz substrate 2' by cutting and polishing. The height T １ ', T ２ ', T ３ ' is calculated in the same manner as above, and the height difference (T １ '-T ３ ') and the average value and the height difference (T ３ '-T ２ The angle θ′) and its average value were calculated. １ '-T ３ '), difference (T ３ '-T ２ The maximum values ​​of the angle θ′ and the angle θ′ are shown in Table 1.

[0123] The height of the annular measurement region on the second surface 22' of the quartz substrate 2' on which the recess 4 was formed was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and approximated by a Zernike polynomial. The root mean square roughness Rq of the sum of the heights of the measurement points in the annular measurement region for the fifth to eighth terms (Z5 to Z8) of the Zernike polynomial, and the root mean square roughness Rq of the sum of the heights of the ninth and subsequent terms of the Zernike polynomial were calculated. The results are shown in Table 2.

[0124] A master mold 100 was prepared, and a convex structure portion 3 formed by etching via a resist pattern on the first surface 21' of a quartz substrate 2' on which a recessed portion 4 was formed was subjected to an imprinting process using the master mold 100, and the concave-convex pattern 120 of the master mold 100 was transferred to the upper surface 31 of the convex structure portion 3 to form the concave-convex pattern 11, thereby producing an imprint mold 10.

[0125] The positional accuracy (3σ) of the concave-convex pattern 11 of the imprint mold 10 was measured using a coordinate measuring device (IPRO Series, manufactured by KLA Tencor Corporation) and the results are shown in Table 2.

[0126] [Example 2] As in Example 1, when viewing a cross section of the quartz substrate 2' along the thickness direction, the height T of the quartz substrate 2' at the first point P1' located at the geometric center C22' of the second surface 22' is １ ' and the height T of the quartz substrate 2' at the second point P2'. ２ ' and the height T of the quartz substrate 2' at a third point P3' located on the outer peripheral edge PO' of the second surface 22'. ３ The second surface 22' of the quartz substrate 2' was polished so that the relationship between T and T was expressed by the following formula (2). １ '≧T ３ '>T ２ ' ... (2)

[0127] Then, similarly to Example 1, the flatness was measured using a flatness measuring device (UltraFlat, manufactured by SOL Corporation) to determine the height T １ ', T ２ ', T ３ ' is calculated, and the difference in height between the first point P1' on the second surface 22' and the third point P3' located on the outer peripheral edge PO' (T １ '-T ３ ') and the average value thereof and the difference in height between the second point P2' and the third point P3' (T ３ '-T ２ ') and its average value, and the angle θ' formed by the line segment L1' connecting the second point P2' of the second surface 22' and the outer peripheral edge PO' (third point P3') and the horizontal plane HS' and its average value were calculated. １ '-T ３ '), difference (T ３ '-T ２ The maximum values ​​of the angle θ′ and the angle θ′ are shown in Table 1.

[0128] The height within an annular measurement region, whose inner boundary was a circle of radius 35 mm centered on the geometric center C22' of the polished second surface 22' and whose outer boundary was a circle of radius 50 mm centered on the geometric center C22' of the second surface 22', was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and the height was approximated by a Zernike polynomial.The root mean square roughness Rq of the sum of the heights of each measurement point in the annular measurement region for terms 5 to 8 (Z5 to Z8) of the Zernike polynomial was calculated, as well as the root mean square roughness Rq of the sum of the heights of terms 9 and beyond of the Zernike polynomial.The results are shown in Table 2.

[0129] After the polishing, a recess 4 was formed on the second surface 22' of the quartz substrate 2' by cutting and polishing. The height T １ ', T ２ ', T ３ ' is calculated in the same manner as above, and the height difference (T １ '-T ３ ') and the average value and the height difference (T ３ '-T ２ The angle θ′) and its average value were calculated. １ '-T ３ '), difference (T ３ '-T ２ The maximum values ​​of the angle θ′ and the angle θ′ are shown in Table 1.

[0130] The height of the annular measurement region on the second surface 22' of the quartz substrate 2' on which the recess 4 was formed was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and approximated by a Zernike polynomial. The root mean square roughness Rq of the sum of the heights of the measurement points in the annular measurement region for the fifth to eighth terms (Z5 to Z8) of the Zernike polynomial, and the root mean square roughness Rq of the sum of the heights of the ninth and subsequent terms of the Zernike polynomial were calculated. The results are shown in Table 2.

[0131] A master mold 100 was prepared, and a convex structure portion 3 formed by etching via a resist pattern on the first surface 21' of a quartz substrate 2' on which a recessed portion 4 was formed was subjected to an imprinting process using the master mold 100, and the concave-convex pattern 120 of the master mold 100 was transferred to the upper surface 31 of the convex structure portion 3 to form the concave-convex pattern 11, thereby producing an imprint mold 10.

[0132] The positional accuracy (3σ) of the concave-convex pattern 11 of the imprint mold 10 was measured using a coordinate measuring device (IPRO Series, manufactured by KLA Tencor Corporation) and the results are shown in Table 2.

[0133] [Example 3] As in Example 1, when viewing a cross section of the quartz substrate 2' along the thickness direction, the height T of the quartz substrate 2' at the first point P1' located at the geometric center C22' of the second surface 22' is １ ' and the height T of the quartz substrate 2' at the second point P2'. ２ ' and the height T of the quartz substrate 2' at a third point P3' located on the outer peripheral edge PO' of the second surface 22'. ３ The second surface 22' of the quartz substrate 2' was polished so that the relationship between T and T was expressed by the following formula (2). １ '≧T ３ '>T ２ ' ... (2)

[0134] Then, similarly to Example 1, the flatness was measured using a flatness measuring device (UltraFlat, manufactured by SOL Corporation) to determine the height T １ ', T ２ ', T ３ ' is calculated, and the difference in height between the first point P1' on the second surface 22' and the third point P3' located on the outer peripheral edge PO' (T １ '-T ３ ') and the average value thereof and the difference in height between the second point P2' and the third point P3' (T ３ '-T ２ ') and its average value, and the angle θ' formed by the line segment L1' connecting the second point P2' of the second surface 22' and the outer peripheral edge PO' (third point P3') and the horizontal plane HS' and its average value were calculated. １ '-T ３ '), difference (T３ '-T ２ The maximum values ​​of the angle θ′ and the angle θ′ are shown in Table 1.

[0135] The height within an annular measurement region, whose inner boundary was a circle of radius 35 mm centered on the geometric center C22' of the polished second surface 22' and whose outer boundary was a circle of radius 50 mm centered on the geometric center C22' of the second surface 22', was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and the height was approximated by a Zernike polynomial.The root mean square roughness Rq of the sum of the heights of each measurement point in the annular measurement region for terms 5 to 8 (Z5 to Z8) of the Zernike polynomial was calculated, as well as the root mean square roughness Rq of the sum of the heights of terms 9 and beyond of the Zernike polynomial.The results are shown in Table 2.

[0136] After the polishing, a recess 4 was formed on the second surface 22' of the quartz substrate 2' by cutting and polishing. The height T １ ', T ２ ', T ３ ' is calculated in the same manner as above, and the height difference (T １ '-T ３ ') and the average value and the height difference (T ３ '-T ２ The angle θ′) and its average value were calculated. １ '-T ３ '), difference (T ３ '-T ２ The maximum values ​​of the angle θ′ and the angle θ′ are shown in Table 1.

[0137] The height of the annular measurement region on the second surface 22' of the quartz substrate 2' on which the recess 4 was formed was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and approximated by a Zernike polynomial. The root mean square roughness Rq of the sum of the heights of the measurement points in the annular measurement region for the fifth to eighth terms (Z5 to Z8) of the Zernike polynomial, and the root mean square roughness Rq of the sum of the heights of the ninth and subsequent terms of the Zernike polynomial were calculated. The results are shown in Table 2.

[0138] A master mold 100 was prepared, and a convex structure portion 3 formed by etching via a resist pattern on the first surface 21' of a quartz substrate 2' on which a recessed portion 4 was formed was subjected to an imprinting process using the master mold 100, and the concave-convex pattern 120 of the master mold 100 was transferred to the upper surface 31 of the convex structure portion 3 to form the concave-convex pattern 11, thereby producing an imprint mold 10.

[0139] The positional accuracy (3σ) of the concave-convex pattern 11 of the imprint mold 10 was measured using a coordinate measuring device (IPRO Series, manufactured by KLA Tencor Corporation) and the results are shown in Table 2.

[0140] [Example 4] As in Example 1, when viewing a cross section of the quartz substrate 2' along the thickness direction, the height T of the quartz substrate 2' at the first point P1' located at the geometric center C22' of the second surface 22' is １ ' and the height T of the quartz substrate 2' at the second point P2'. ２ ' and the height T of the quartz substrate 2' at a third point P3' located on the outer peripheral edge PO' of the second surface 22'. ３ The second surface 22' of the quartz substrate 2' was polished so that the relationship between T and T was expressed by the following formula (2). １ '≧T ３ '>T ２ ' ... (2)

[0141] Then, similarly to Example 1, the flatness was measured using a flatness measuring device (UltraFlat, manufactured by SOL Corporation) to determine the height T １ ', T ２ ', T ３ ' is calculated, and the difference in height between the first point P1' on the second surface 22' and the third point P3' located on the outer peripheral edge PO' (T １ '-T ３ ') and the average value thereof and the difference in height between the second point P2' and the third point P3' (T ３ '-T ２ ') and its average value, and the angle θ' formed by the line segment L1' connecting the second point P2' of the second surface 22' and the outer peripheral edge PO' (third point P3') and the horizontal plane HS' and its average value were calculated. １ '-T ３ '), difference (T３ '-T ２ The maximum values ​​of the angle θ′ and the angle θ′ are shown in Table 1.

[0142] The height within an annular measurement region, whose inner boundary was a circle of radius 35 mm centered on the geometric center C22' of the polished second surface 22' and whose outer boundary was a circle of radius 50 mm centered on the geometric center C22' of the second surface 22', was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and the height was approximated by a Zernike polynomial.The root mean square roughness Rq of the sum of the heights of each measurement point in the annular measurement region for terms 5 to 8 (Z5 to Z8) of the Zernike polynomial was calculated, as well as the root mean square roughness Rq of the sum of the heights of terms 9 and beyond of the Zernike polynomial.The results are shown in Table 2.

[0143] After the polishing, a recess 4 was formed on the second surface 22' of the quartz substrate 2' by cutting and polishing. The height T １ ', T ２ ', T ３ ' is calculated in the same manner as above, and the height difference (T １ '-T ３ ') and the average value and the height difference (T ３ '-T ２ The angle θ′) and its average value were calculated. １ '-T ３ '), difference (T ３ '-T ２ The maximum values ​​of the angle θ′ and the angle θ′ are shown in Table 1.

[0144] The height of the annular measurement region on the second surface 22' of the quartz substrate 2' on which the recess 4 was formed was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and approximated by a Zernike polynomial. The root mean square roughness Rq of the sum of the heights of the measurement points in the annular measurement region for the fifth to eighth terms (Z5 to Z8) of the Zernike polynomial, and the root mean square roughness Rq of the sum of the heights of the ninth and subsequent terms of the Zernike polynomial were calculated. The results are shown in Table 2.

[0145] A master mold 100 was prepared, and a convex structure portion 3 formed by etching via a resist pattern on the first surface 21' of a quartz substrate 2' on which a recessed portion 4 was formed was subjected to an imprinting process using the master mold 100, and the concave-convex pattern 120 of the master mold 100 was transferred to the upper surface 31 of the convex structure portion 3 to form the concave-convex pattern 11, thereby producing an imprint mold 10.

[0146] The positional accuracy (3σ) of the concave-convex pattern 11 of the imprint mold 10 was measured using a coordinate measuring device (IPRO Series, manufactured by KLA Tencor Corporation) and the results are shown in Table 2.

[0147] [Example 5] As in Example 1, when viewing a cross section of the quartz substrate 2' along the thickness direction, the height T of the quartz substrate 2' at the first point P1' located at the geometric center C22' of the second surface 22' is １ ' and the height T of the quartz substrate 2' at the second point P2'. ２ ' and the height T of the quartz substrate 2' at a third point P3' located on the outer peripheral edge PO' of the second surface 22'. ３ The second surface 22' of the quartz substrate 2' was polished so that the relationship between T and T was expressed by the following formula (2). １ '≧T ３ '>T ２ ' ... (2)

[0148] Then, similarly to Example 1, the flatness was measured using a flatness measuring device (UltraFlat, manufactured by SOL Corporation) to determine the height T １ ', T ２ ', T ３ ' is calculated, and the difference in height between the first point P1' on the second surface 22' and the third point P3' located on the outer peripheral edge PO' (T １ '-T ３ ') and the average value thereof and the difference in height between the second point P2' and the third point P3' (T ３ '-T ２ ') and its average value, and the angle θ' formed by the line segment L1' connecting the second point P2' of the second surface 22' and the outer peripheral edge PO' (third point P3') and the horizontal plane HS' and its average value were calculated. １ '-T ３ '), difference (T３ '-T ２ The maximum values ​​of the angle θ′ and the angle θ′ are shown in Table 1.

[0149] The height within an annular measurement region, whose inner boundary was a circle of radius 35 mm centered on the geometric center C22' of the polished second surface 22' and whose outer boundary was a circle of radius 50 mm centered on the geometric center C22' of the second surface 22', was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and the height was approximated by a Zernike polynomial.The root mean square roughness Rq of the sum of the heights of each measurement point in the annular measurement region for terms 5 to 8 (Z5 to Z8) of the Zernike polynomial was calculated, as well as the root mean square roughness Rq of the sum of the heights of terms 9 and beyond of the Zernike polynomial.The results are shown in Table 2.

[0150] After the polishing, a recess 4 was formed on the second surface 22' of the quartz substrate 2' by cutting and polishing. The height T １ ', T ２ ', T ３ ' is calculated in the same manner as above, and the height difference (T １ '-T ３ ') and the average value and the height difference (T ３ '-T ２ The angle θ′) and its average value were calculated. １ '-T ３ '), difference (T ３ '-T ２ The maximum values ​​of the angle θ′ and the angle θ′ are shown in Table 1.

[0151] The height of the annular measurement region on the second surface 22' of the quartz substrate 2' on which the recess 4 was formed was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and approximated by a Zernike polynomial. The root mean square roughness Rq of the sum of the heights of the measurement points in the annular measurement region for the fifth to eighth terms (Z5 to Z8) of the Zernike polynomial, and the root mean square roughness Rq of the sum of the heights of the ninth and subsequent terms of the Zernike polynomial were calculated. The results are shown in Table 2.

[0152] Example 6 As in Example 1, when viewing a cross section of the quartz substrate 2′ along the thickness direction, the height T of the quartz substrate 2′ at the first point P1′ located at the geometric center C22′ of the second surface 22′ is １ ' and the height T of the quartz substrate 2' at the second point P2'. ２ ' and the height T of the quartz substrate 2' at a third point P3' located on the outer peripheral edge PO' of the second surface 22'. ３ The second surface 22' of the quartz substrate 2' was polished so that the relationship between T and T was expressed by the following formula (2). １ '≧T ３ '>T ２ ' ... (2)

[0153] Then, similarly to Example 1, the flatness was measured using a flatness measuring device (UltraFlat, manufactured by SOL Corporation) to determine the height T １ ', T ２ ', T ３ ' is calculated, and the difference in height between the first point P1' on the second surface 22' and the third point P3' located on the outer peripheral edge PO' (T １ '-T ３ ') and the average value thereof and the difference in height between the second point P2' and the third point P3' (T ３ '-T ２ ') and its average value, and the angle θ' formed by the line segment L1' connecting the second point P2' of the second surface 22' and the outer peripheral edge PO' (third point P3') and the horizontal plane HS' and its average value were calculated. １ '-T ３ '), difference (T ３ '-T ２ The maximum values ​​of the angle θ′ and the angle θ′ are shown in Table 1.

[0154] The height within an annular measurement region, whose inner boundary was a circle of radius 35 mm centered on the geometric center C22' of the polished second surface 22' and whose outer boundary was a circle of radius 50 mm centered on the geometric center C22' of the second surface 22', was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and the height was approximated by a Zernike polynomial.The root mean square roughness Rq of the sum of the heights of each measurement point in the annular measurement region for terms 5 to 8 (Z5 to Z8) of the Zernike polynomial was calculated, as well as the root mean square roughness Rq of the sum of the heights of terms 9 and beyond of the Zernike polynomial.The results are shown in Table 2.

[0155] After the polishing, a recess 4 was formed on the second surface 22' of the quartz substrate 2' by cutting and polishing. The height T １ ', T ２ ', T ３ ' is calculated in the same manner as above, and the height difference (T １ '-T ３ ') and the average value and the height difference (T ３ '-T ２ The angle θ′) and its average value were calculated. １ '-T ３ '), difference (T ３ '-T ２ The maximum values ​​of the angle θ′ and the angle θ′ are shown in Table 1.

[0156] The height of the annular measurement region on the second surface 22' of the quartz substrate 2' on which the recess 4 was formed was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and approximated by a Zernike polynomial. The root mean square roughness Rq of the sum of the heights of the measurement points in the annular measurement region for the fifth to eighth terms (Z5 to Z8) of the Zernike polynomial, and the root mean square roughness Rq of the sum of the heights of the ninth and subsequent terms of the Zernike polynomial were calculated. The results are shown in Table 2.

[0157] [Example 7] As in Example 1, when viewing a cross section of the quartz substrate 2' along the thickness direction, the height T of the quartz substrate 2' at the first point P1' located at the geometric center C22' of the second surface 22' is １ ' and the height T of the quartz substrate 2' at the second point P2'. ２ ' and the height T of the quartz substrate 2' at a third point P3' located on the outer peripheral edge PO' of the second surface 22'. ３ The second surface 22' of the quartz substrate 2' was polished so that the relationship between T and T was expressed by the following formula (2). １ '≧T ３ '>T ２ ' ... (2)

[0158] Then, similarly to Example 1, the flatness was measured using a flatness measuring device (UltraFlat, manufactured by SOL Corporation) to determine the height T １ ', T ２ ', T ３ ' is calculated, and the difference in height between the first point P1' on the second surface 22' and the third point P3' located on the outer peripheral edge PO' (T １ '-T ３ ') and the average value thereof and the difference in height between the second point P2' and the third point P3' (T ３ '-T ２ ') and its average value, and the angle θ' formed by the line segment L1' connecting the second point P2' of the second surface 22' and the outer peripheral edge PO' (third point P3') and the horizontal plane HS' and its average value were calculated. １ '-T ３ '), difference (T ３ '-T ２ The maximum values ​​of the angle θ′ and the angle θ′ are shown in Table 1.

[0159] The height within an annular measurement region, whose inner boundary was a circle of radius 35 mm centered on the geometric center C22' of the polished second surface 22' and whose outer boundary was a circle of radius 50 mm centered on the geometric center C22' of the second surface 22', was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and the height was approximated by a Zernike polynomial.The root mean square roughness Rq of the sum of the heights of each measurement point in the annular measurement region for terms 5 to 8 (Z5 to Z8) of the Zernike polynomial was calculated, as well as the root mean square roughness Rq of the sum of the heights of terms 9 and beyond of the Zernike polynomial.The results are shown in Table 2.

[0160] After the polishing, a recess 4 was formed on the second surface 22' of the quartz substrate 2' by cutting and polishing. The height T １ ', T ２ ', T ３ ' is calculated in the same manner as above, and the height difference (T １ '-T ３ ') and the average value and the height difference (T ３ '-T ２ The angle θ′) and its average value were calculated. １ '-T ３ '), difference (T ３ '-T ２ The maximum values ​​of the angle θ′ and the angle θ′ are shown in Table 1.

[0161] The height of the annular measurement region on the second surface 22' of the quartz substrate 2' on which the recess 4 was formed was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and approximated by a Zernike polynomial. The root mean square roughness Rq of the sum of the heights of the measurement points in the annular measurement region for the fifth to eighth terms (Z5 to Z8) of the Zernike polynomial, and the root mean square roughness Rq of the sum of the heights of the ninth and subsequent terms of the Zernike polynomial were calculated. The results are shown in Table 2.

[0162] Example 8 As in Example 1, when viewing a cross section of the quartz substrate 2′ along the thickness direction, the height T of the quartz substrate 2′ at the first point P1′ located at the geometric center C22′ of the second surface 22′ is １ ' and the height T of the quartz substrate 2' at the second point P2'. ２ ' and the height T of the quartz substrate 2' at a third point P3' located on the outer peripheral edge PO' of the second surface 22'. ３ The second surface 22' of the quartz substrate 2' was polished so that the relationship between T and T was expressed by the following formula (2). １ '≧T ３ '>T ２ ' ... (2)

[0163] Then, similarly to Example 1, the flatness was measured using a flatness measuring device (UltraFlat, manufactured by SOL Corporation) to determine the height T １ ', T ２ ', T ３ ' is calculated, and the difference in height between the first point P1' on the second surface 22' and the third point P3' located on the outer peripheral edge PO' (T １ '-T ３ ') and the average value thereof and the difference in height between the second point P2' and the third point P3' (T ３ '-T ２ ') and its average value, and the angle θ' formed by the line segment L1' connecting the second point P2' of the second surface 22' and the outer peripheral edge PO' (third point P3') and the horizontal plane HS' and its average value were calculated. １ '-T ３ '), difference (T ３ '-T ２ The maximum values ​​of the angle θ′ and the angle θ′ are shown in Table 1.

[0164] The height within an annular measurement region, whose inner boundary was a circle of radius 35 mm centered on the geometric center C22' of the polished second surface 22' and whose outer boundary was a circle of radius 50 mm centered on the geometric center C22' of the second surface 22', was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and the height was approximated by a Zernike polynomial.The root mean square roughness Rq of the sum of the heights of each measurement point in the annular measurement region for terms 5 to 8 (Z5 to Z8) of the Zernike polynomial was calculated, as well as the root mean square roughness Rq of the sum of the heights of terms 9 and beyond of the Zernike polynomial.The results are shown in Table 2.

[0165] After the polishing, a recess 4 was formed on the second surface 22' of the quartz substrate 2' by cutting and polishing. The height T １ ', T ２ ', T ３ ' is calculated in the same manner as above, and the height difference (T １ '-T ３ ') and the average value and the height difference (T ３ '-T ２ The angle θ′) and its average value were calculated. １ '-T ３ '), difference (T ３ '-T ２ The maximum values ​​of the angle θ′ and the angle θ′ are shown in Table 1.

[0166] The height of the annular measurement region on the second surface 22' of the quartz substrate 2' on which the recess 4 was formed was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and approximated by a Zernike polynomial. The root mean square roughness Rq of the sum of the heights of the measurement points in the annular measurement region for the fifth to eighth terms (Z5 to Z8) of the Zernike polynomial, and the root mean square roughness Rq of the sum of the heights of the ninth and subsequent terms of the Zernike polynomial were calculated. The results are shown in Table 2.

[0167] Comparative Example 1 When viewing a cross section of the quartz substrate 2′ along the thickness direction, the height T of the quartz substrate 2′ at the first point P1′ located at the geometric center C22′ of the second surface 22′ is１ ' and the height T of the quartz substrate 2' at the second point P2'. ２ ' and the height T of the quartz substrate 2' at a third point P3' located on the outer peripheral edge PO' of the second surface 22'. ３ The second surface 22' of the quartz substrate 2' was polished so that the relationship between T and T was as shown in the following formula: １ '>T ２ '>T ３ '

[0168] Then, similarly to Example 1, the flatness was measured using a flatness measuring device (UltraFlat, manufactured by SOL Corporation) to determine the height T １ ', T ２ ', T ３ ' is calculated, and the difference in height between the first point P1' on the second surface 22' and the third point P3' located on the outer peripheral edge PO' (T １ '-T ３ The results of these calculations and the difference (T １ '-T ３ The maximum values ​​of ') are shown in Table 1.

[0169] The height within an annular measurement region, whose inner boundary was a circle of radius 35 mm centered on the geometric center C22' of the polished second surface 22' and whose outer boundary was a circle of radius 50 mm centered on the geometric center C22' of the second surface 22', was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and the height was approximated by a Zernike polynomial.The root mean square roughness Rq of the sum of the heights of each measurement point in the annular measurement region for terms 5 to 8 (Z5 to Z8) of the Zernike polynomial was calculated, as well as the root mean square roughness Rq of the sum of the heights of terms 9 and beyond of the Zernike polynomial.The results are shown in Table 2.

[0170] After the polishing, a recess 4 was formed on the second surface 22' of the quartz substrate 2' by cutting and polishing. The height T １ ', T ２ ', T ３ ' is calculated in the same manner as above, and the height difference (T １ '-T ３ ') and the average value and the height difference (T ３ '-T ２The results of these calculations and the difference (T １ '-T ３ ') and the difference (T ３ '-T ２ The maximum values ​​of ') are shown in Table 1.

[0171] The height of the annular measurement region on the second surface 22' of the quartz substrate 2' on which the recess 4 was formed was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and approximated by a Zernike polynomial. The root mean square roughness Rq of the sum of the heights of the measurement points in the annular measurement region for the fifth to eighth terms (Z5 to Z8) of the Zernike polynomial, and the root mean square roughness Rq of the sum of the heights of the ninth and subsequent terms of the Zernike polynomial were calculated. The results are shown in Table 2.

[0172] A master mold 100 was prepared, and a convex structure portion 3 formed by etching via a resist pattern on the first surface 21' of a quartz substrate 2' on which a recessed portion 4 was formed was subjected to an imprinting process using the master mold 100, and the concave-convex pattern 120 of the master mold 100 was transferred to the upper surface 31 of the convex structure portion 3 to form the concave-convex pattern 11, thereby producing an imprint mold 10.

[0173] The positional accuracy (3σ) of the concave-convex pattern 11 of the imprint mold 10 was measured using a coordinate measuring device (IPRO Series, manufactured by KLA Tencor Corporation) and the results are shown in Table 2.

[0174] Comparative Example 2 When viewing a cross section of the quartz substrate 2′ along the thickness direction, the height T of the quartz substrate 2′ at the first point P1′ located at the geometric center C22′ of the second surface 22′ is １ ' and the height T of the quartz substrate 2' at the second point P2'. ２ ' and the height T of the quartz substrate 2' at a third point P3' located on the outer peripheral edge PO' of the second surface 22'. ３ The second surface 22' of the quartz substrate 2' was polished so that the relationship between T and T was as shown in the following formula: １ '>T ２ '>T ３ '

[0175] Then, similarly to Example 1, the flatness was measured using a flatness measuring device (UltraFlat, manufactured by SOL Corporation) to determine the height T １ ', T ２ ', T ３ ' is calculated, and the difference in height between the first point P1' on the second surface 22' and the third point P3' located on the outer peripheral edge PO' (T １ '-T ３ The results of these calculations and the difference (T １ '-T ３ The maximum values ​​of ') are shown in Table 1.

[0176] The height within an annular measurement region, whose inner boundary was a circle of radius 35 mm centered on the geometric center C22' of the polished second surface 22' and whose outer boundary was a circle of radius 50 mm centered on the geometric center C22' of the second surface 22', was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and the height was approximated by a Zernike polynomial.The root mean square roughness Rq of the sum of the heights of each measurement point in the annular measurement region for terms 5 to 8 (Z5 to Z8) of the Zernike polynomial was calculated, as well as the root mean square roughness Rq of the sum of the heights of terms 9 and beyond of the Zernike polynomial.The results are shown in Table 2.

[0177] After the polishing, a recess 4 was formed on the second surface 22' of the quartz substrate 2' by cutting and polishing. The height T １ ', T ２ ', T ３ ' is calculated in the same manner as above, and the height difference (T １ '-T ３ ') and the average value and the height difference (T ３ '-T ２ The results of these calculations and the difference (T １ '-T ３ ') and the difference (T ３ '-T ２ The maximum values ​​of ') are shown in Table 1.

[0178] The height of the annular measurement region on the second surface 22' of the quartz substrate 2' on which the recess 4 was formed was measured using a flatness measurement device (UltraFlat, manufactured by SOL Corporation) in the same manner as above, and approximated by a Zernike polynomial. The root mean square roughness Rq of the sum of the heights of the measurement points in the annular measurement region for the fifth to eighth terms (Z5 to Z8) of the Zernike polynomial, and the root mean square roughness Rq of the sum of the heights of the ninth and subsequent terms of the Zernike polynomial were calculated. The results are shown in Table 2.

[0179]

[0180]

[0181] In Table 2, "difference in positional accuracy" refers to the difference between the positional accuracy value and the reference value, which is the arithmetic mean value of the positional accuracy in the X and Y directions for Examples 1 to 4. Furthermore, "change in Rq before and after recess formation" in Table 2 is the root mean square roughness Rq for the sum of the heights of the measurement points in the measurement annular region in terms 5 to 8 (Z5 to Z8) of the Zernike polynomial after recess formation minus the root mean square roughness Rq for the sum of the heights of the measurement points in the measurement annular region in terms 5 to 8 (Z5 to Z8) of the Zernike polynomial before recess formation.

[0182] As shown in Table 1, in the imprint mold substrates of Examples 1 to 8, the formula "T １ '≧T ３ '>T ２ By polishing the second surface 22′ so as to satisfy the relationship of “′”, the height T １ ', T ３ ' difference (T １ '-T ３ ') the difference between the maximum and average values ​​of height T ３ ', T ２ ' difference (T ３ '-T ２ It was confirmed that the difference between the maximum and average values ​​of the angle θ and the angle θ′ was relatively small, and the variation in the surface shape of the second surface 22′ was relatively small.

[0183] Furthermore, as shown in Table 2, for Examples 1 to 8, the change in Rq before and after the formation of the recessed portion was 1 or less (-13 to 0.9), confirming that the surface shape of the second surface 22' was extremely good. Furthermore, it was confirmed that the manufacturing methods of Examples 1 to 8 could achieve an extremely good surface shape of the second surface 22'.

[0184] From the results shown in Tables 1 and 2, it was confirmed that the root mean square roughness Rq of the sum of the heights of each measurement point in the annular measurement region in the fifth to eighth terms (Z5 to Z8) of the Zernike polynomial before the formation of the recess was 19 nm or less, and the root mean square roughness Rq of the sum of the heights of the ninth and subsequent terms (Z9 and subsequent) was 9 nm or less, and that the root mean square roughness Rq of the sum of the heights of each measurement point in the annular measurement region in the fifth to eighth terms (Z5 to Z8) of the Zernike polynomial after the formation of the recess was 12 nm or less, and the root mean square roughness Rq of the sum of the heights of the ninth and subsequent terms (Z9 and subsequent) was 10 nm or less, thereby enabling imprinting with extremely high positional accuracy.

[0185] Example 9 A quartz substrate 2' (152.5 mm x 152.5 mm, thickness 6.40 mm) having a first surface 21' and a second surface 22' located on the opposite side thereof was prepared, and the second surface 22' of the quartz substrate 2' was polished. At this time, when a cross section passing through the geometric center C22' of the second surface 22' along the thickness direction of the quartz substrate 2' (a cross section (horizontal cross section) in a direction parallel to two opposing sides of the second surface 22' (e.g., the first side S1' and the third side S3') and a cross section (diagonal cross section) passing through two opposing corners of the second surface 22' (e.g., the corners C1' and C3')) of the second surface 22' was viewed, the height T of the quartz substrate 2' at a first point P1' located at the geometric center C22' of the second surface 22' was measured. １ ' and the height T of the quartz substrate 2' at the second point P2'. ２ ' and the height T of the quartz substrate 2' at a third point P3' located on the outer peripheral edge PO' of the second surface 22'. ３ The second surface 22' of the quartz substrate 2' was polished so that the relationship between T and T was expressed by the following formula (2). １ '≧T ３ '>T ２ ' ... (2)

[0186] Then, similarly to Example 1, a flatness measuring device (UltraFlat, manufactured by SOL Corporation) was used to measure the heights T １ ', T ２ ', T ３ ' is calculated, and the height difference (T １ '-T ２ The maximum values ​​on one side and the other side of the height difference (T １ '-T ３ The results of measurements along the horizontal cross section using a flatness measuring device are shown in FIG. 14, the results of measurements along the diagonal cross section using a flatness measuring device are shown in FIG. 15, and the calculation results of the differences are shown in Table 3.

[0187] After the polishing, a recess 4 was formed on the second surface 22' of the quartz substrate 2' by cutting and polishing. The height T １ ', T ２ ', T ３ The heights T′ on one side and the other side of the second surface 22′ are measured in the same manner as above, and the heights T′ on one side and the other side are determined based on the geometric center C22′ of the second surface 22′. １ ', T ２ ', T ３ ' is calculated, and the height difference (T １ '-T ２ The maximum values ​​on one side and the other side of the height difference (T １ '-T ３ The results of measurements along the horizontal cross section using a flatness measuring device are shown in FIG. 14, the results of measurements along the diagonal cross section using a flatness measuring device are shown in FIG. 15, and the calculation results of the differences are shown in Table 3.

[0188]

[0189] 14 and 15, the vertical axis represents the height (μm) of the substrate 2′, and the horizontal axis represents the distance (mm) from the geometric center C22′ of the second surface 22′. As shown in FIGS. 14, 15 and Table 3, the height T of the first point P1′ before and after the formation of the recessed portion １ It was confirmed that the height was the highest at the first point P1', and gradually decreased from the first point P1' to the second point P2', and gradually increased toward the third point P3'.

[0190] In addition, in the imprint mold substrates of Examples 1 to 9 and Comparative Examples 1 and 2, 144 measurement points were set at equal intervals on each of the four sides, and the relationship between the heights T1', T2', and T3' of the first point P1', the second point P2', and the third point P3' on 576 (=144×4) straight lines connecting the second surface 22' and each measurement point was calculated (the relationship (T １ '≧T ３ '>T ２ When it was confirmed whether the relationship shown in formula (2) above was satisfied, it was found that in Examples 1 to 9, the proportion (proportion among 576 straight lines) satisfying the relationship shown in formula (2) above was higher than in Comparative Examples 1 and 2.

[0191] REFERENCE SIGNS LIST 1... Substrate for imprint mold 2... Base material 21... First surface 22... Second surface 3... Convex structure portion 4... Depression portion

Claims

1. A substrate having a first surface and a second surface located on the opposite side of the first surface, wherein a first point, a second point, and a third point are located on the second surface of the substrate on a line connecting the geometric center of the second surface and an arbitrary point on the outer periphery of the second surface, and a first height T at the first point is measured in a cross section along the thickness direction of the substrate that passes through the first point, the second point, and the third point. １ , a second height T at the second point ２ and a third height T at the third point ３ satisfies the relationship shown in the following formula (1), the first point is a point located closest to the geometric center of the second surface, the third point is a point located closest to the outer periphery of the second surface, the second point is a point located between the first point and the third point, and the first height T １ , the second height T ２ and the third height T ３ is the height of the imprint mold substrate based on a predetermined horizontal plane when the base material is placed on the horizontal plane with the first surface positioned downward. １ ≧T ３ >T ２ ...(1) 2. A substrate for an imprint mold according to claim 1, wherein the first point is located within a circular area centered on the geometric center of the second surface, and the second point is located within an annular area surrounding the outside of the circular area.

3. A substrate for an imprint mold according to claim 1 or 2, wherein a recessed portion recessed in the thickness direction of the base material is formed on the second surface, the first point is located within an annular region centered on the geometric center of the second surface, the inner radius of the annular region is 30 mm to 35 mm, the distance between the first point and the second point is 20 mm to 69 mm, and the distance between the first point and the third point is 35 mm to 77 mm.

4. A substrate for an imprint mold according to claim 1 or 2, wherein the second surface does not have a recess that is recessed in the thickness direction of the base material, the first point is located within a circular area centered on the geometric center of the second surface, the radius of the circular area is 30 mm or less, the distance between the first point and the second point is 25 mm to 99 mm, and the distance between the first point and the third point is 40 mm to 107 mm.

5. A substrate for an imprint mold according to claim 4, wherein the circular region in which the first point is located is a region in which a recessed portion recessed in the thickness direction of the base material is formed.

6. When the base material is placed on the horizontal surface with the first surface facing downward, the angle formed by the line segment connecting the second point on the second surface and the outer periphery of the second surface and the horizontal plane is 9.0 x 10 －６ ° to 1.0 × 10 －３ 3. The substrate for an imprint mold according to claim 1 or 2, wherein the thickness is 100 nm.

7. The second height T ２ and the third height T ３ The substrate for an imprint mold according to claim 1 or 2, wherein the difference between the above and the above is 1 nm to 105 nm.

8. The first height T １ and the third height T ３ 3. The substrate for an imprint mold according to claim 1, wherein the difference between the above and the above is 0 nm to 639 nm.

9. In a plan view from the second surface side, the second surface of the base material has a substantially rectangular shape including a first side and a second side that are opposed to each other and substantially parallel to each other, a third side and a fourth side that are opposed to each other and substantially parallel to each other, a first corner where ends of the first side and the third side intersect, a second corner where ends of the first side and the fourth side intersect, a third corner where ends of the second side and the third side intersect, and a fourth corner where ends of the second side and the fourth side intersect, 3. The substrate for an imprint mold according to claim 1, wherein the first point, the second point, and the third point are located on at least any of a first line segment that passes through the geometric center of the second surface and is approximately perpendicular to the first side and the second side, a second line segment that passes through the geometric center of the second surface and is approximately perpendicular to the third side and the fourth side, a third line segment that passes through the geometric center, the first corner, and the fourth corner, and a fourth line segment that passes through the geometric center, the second corner, and the third corner.

10. A substrate for an imprint mold according to claim 1 or 2, wherein the second surface is provided with a recessed portion recessed in the thickness direction of the base material, the recessed portion having a substantially circular shape centered on the geometric center of the second surface when viewed in a plane from the second surface side, and when a predetermined annular region is defined within the region surrounded by the recessed portion and the outer peripheral edge of the second surface, when the second surface is approximated by a Zernike polynomial, the root mean square roughness for the sum of heights of each measurement point in the annular region in each of the components of terms 5 to 8 of the Zernike polynomial is 12 nm or less.

11. The imprint mold substrate according to claim 10, wherein, when the second surface is approximated by a Zernike polynomial, the root mean square roughness of each component of terms 5 to 8 of the Zernike polynomial relative to the sum of heights of each measurement point in the annular region is 7 nm or less.

12. The substrate for an imprint mold according to claim 10, wherein the root mean square roughness for the sum of heights of the ninth and subsequent terms of the Zernike polynomial in the annular region is 10 nm or less.

13. The substrate for an imprint mold according to claim 10, wherein the first point is located on the edge of the recess.

14. The substrate for an imprint mold according to claim 1 or 2, wherein the first surface is provided with a convex structure portion that protrudes from the first surface.

15. An imprint mold having a concave-convex pattern formed on the convex structure portion of the substrate for an imprint mold according to claim 14.

16. A method for polishing a substrate, comprising: preparing a substrate having a first surface and a second surface located opposite to the first surface; and polishing the second surface of the substrate, wherein in the polishing step, a first height T at the first point is measured in a cross section along the thickness direction of the substrate, the first point being a first height T, a second point being a third point located on a line connecting the geometric center of the second surface of the substrate and an arbitrary point on the outer periphery of the second surface. １ ', a second height T at the second point ２ ' and a third height T at the third point ３ the second surface of the substrate is polished so that the first height T′ satisfies the relationship shown in the following formula (2), the first point is a point located closest to the geometric center of the second surface, the third point is a point located closest to the outer periphery of the second surface, the second point is a point located between the first point and the third point, and the first height T １ ', the second height T ２ ' and the third height T ３ ' is the height based on a predetermined horizontal plane when the substrate is placed on the horizontal plane with the first surface positioned downward. １ '≧T ３ '>T ２ ' ... (2) 17. A second height T of the substrate ２ ' and the third height T of the substrate ３ The method for manufacturing a substrate for an imprint mold according to claim 16, wherein the second surface of the substrate is polished so that the difference between the first surface and the second surface is 1 nm to 103 nm.

18. The first height T of the substrate １ ' and the third height T of the substrate ３ 18. The method for manufacturing a substrate for an imprint mold according to claim 16, wherein the second surface of the substrate is polished so that the difference between the first surface and the second surface is 0 nm to 538 nm.

19. The method for manufacturing a substrate for an imprint mold according to claim 16 or 17, further comprising the step of forming a recessed portion recessed in the thickness direction of the substrate on the second surface of the substrate.

20. A method for manufacturing a substrate for an imprint mold according to claim 19, wherein, when a predetermined annular region is defined within the region surrounded by the recessed portion and the outer peripheral edge of the second surface, the second surface of the substrate is polished so that, when the second surface is approximated by a Zernike polynomial, the root mean square roughness for the sum of heights of each measurement point in the annular region in each of the components of terms 5 to 8 of the Zernike polynomial is 19 nm or less.

21. A method for manufacturing a substrate for an imprint mold according to claim 20, wherein the second surface of the substrate is polished so that the root mean square roughness of the sum of heights of each measurement point in the annular region for each component of terms 5 to 8 of the Zernike polynomial is 17 nm or less.

22. A method for manufacturing a substrate for an imprint mold according to claim 20, wherein the second surface of the substrate is polished so that the root mean square roughness for the sum of heights of the ninth and subsequent terms of the Zernike polynomial in the annular region is 9 nm or less.

23. A method for manufacturing a substrate for an imprint mold according to claim 16 or 17, further comprising the step of forming a convex structure on the first surface of the substrate so as to protrude from the first surface.

24. A method for manufacturing an imprint mold, comprising the step of forming a concave-convex pattern on the upper surface of the convex structure portion of the imprint mold substrate manufactured by the manufacturing method described in claim 23.

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