Manufacturing method of female die for imprinting

Abstract

Provided is a method for manufacturing a master mold for imprint, with which it is possible to form a structure having a desired regular tapered shape on a base material. Comprises: a coating step for coating a resist (3) having a predetermined film thickness on a substrate (1); an exposure step in which the resist (3) coated on the substrate (1) is exposed via a mask (4); and a developing step in which the exposed resist (3) is developed, and in the exposure step, the exposure amount is set to be two times or less of the minimum exposure amount (Df) for sensitizing the total thickness of the resist (3) coated on the substrate (1), and a predetermined portion of the resist (3) is exposed. The side surface of the structure (2) composed of the resist (3) formed by the development in the development step has a positive tapered shape.

Description

Technical Field

[0001] The invention relates to a method for making a master mold for embossing. Background Art

[0002] Regarding a wiring forming method using an imprint method, the present applicant has proposed a technique disclosed in Patent Document 1 (hereinafter referred to as “conventional technique”).

[0003] like Fig.13 As shown, the prior art fills a conductive paste 22 in the recess 21 of a replica mold 20 having a recess 21 having the same pattern as a wiring pattern or a bump pattern formed on a substrate 10, and overlaps the replica mold 20 having the conductive paste 22 in the recess 21 with the substrate 10 and pressurizes (compression-bonds) the replica mold 20, thereby transferring the conductive paste 22 in the recess 21 of the replica mold 20 to the substrate 10, thereby forming a wiring 11 or a bump of a specified pattern on the substrate 10.

[0004] However, if Fig.14 As shown, the replica mold 20 used in the prior art is made by using a master mold 30 (master plate) having a structure (convex body) representing a wiring pattern or a bump pattern on a substrate, and the structure of the master mold 30 is formed by etching the substrate 31 itself (refer to Fig.14 (a)), or by patterning the resist 32 applied on the substrate 31 (see Fig.14 (b)).

[0005] When the structure of the master mold is formed from a resist, conventionally, the resist is exposed with a sufficient exposure amount, whereby the side surface shape of the structure becomes a shape that is substantially perpendicular to the substrate.

[0006] However, if the side surface of the structure is substantially perpendicular to the substrate, the structure of the master mold may be temporarily deformed into an inverted tapered shape during stacking and pressing to form a replica mold, and appropriate transfer may not be possible.

[0007] Therefore, in order to smoothly and efficiently produce the replica mold, it is preferred that the side shape of the structure of the master mold relative to the substrate is a positive cone shape, but the shape of the structure of the master mold is directly reflected in the shape of the recessed portion of the replica mold, and further, the shape of the recessed portion of the replica mold is directly reflected in the shape of the wiring or bump formed on the substrate. For example, if the taper angle becomes too large, it will hinder miniaturization or high aspect ratio. Therefore, it is not only set to a tapered shape, but also must be formed into a positive cone shape with an appropriate taper angle that takes into account the size, spacing, aspect ratio, etc. of the target pattern.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Publication No. 2021-111668 Summary of the invention

[0011] Problems to be solved by the invention

[0012] However, a method for simply controlling the taper angle of the side shape of the structure of the master mold has not been established so far. The current situation is that in order to make the side shape of the structure of the master mold a positive taper shape with a desired taper angle, many complicated operations are required, which is a time-consuming and costly operation.

[0013] The present invention has been made in view of the above situation, and its object is to provide a method for producing an imprint master mold, which can easily form a structure with a positive tapered shape having an optimal tapered angle taking into account the size, pitch, aspect ratio, etc. of the target pattern on a substrate.

[0014] Means for solving problems

[0015] The gist of the present invention will be described with reference to the accompanying drawings.

[0016] A method for preparing a master mold for imprinting, which is a method for preparing a master mold for imprinting having a structure 2 formed into a specified pattern such as a wiring pattern, a bump pattern, etc. on a substrate 1, characterized in that it includes: a coating step, coating a resist 3 with a specified film thickness on the above-mentioned substrate 1; an exposure step, exposing the above-mentioned resist 3 coated on the above-mentioned substrate 1 through a mask 4; and a development step, developing the above-mentioned resist 3 after exposure, in the above-mentioned exposure step, setting the exposure amount to an exposure amount of less than 2 times the following Df, and exposing a specified part of the above-mentioned resist 3, so that the side shape of the structure 2 composed of the above-mentioned resist 3 formed by the development in the above-mentioned development step becomes a positive cone.

[0017] remember

[0018] Df: The minimum exposure of the total thickness of the resist 3 coated on the substrate 1

[0019] In addition, the method for preparing a master mold for imprinting as described in Technical Solution 1 is characterized in that in the above-mentioned exposure process, a binary mask composed of a light-transmitting portion 4a and a light-shielding portion 4b is used as the above-mentioned mask 4, and the above-mentioned exposure amount is set to the following D0~the above-mentioned Df.

[0020] remember

[0021] D0: Exposure amount at which the resist 3 coated on the substrate 1 starts to be exposed

[0022] In addition, the method for producing an imprint master mold as described in Technical Solution 1 is characterized in that in the above-mentioned exposure step, a grayscale mask composed of a light-transmitting portion 4a, a light-shielding portion 4b and a grayscale portion 4c is used as the above-mentioned mask 4.

[0023] In addition, the method for producing the imprint master mold as described in Technical Solution 3 is characterized in that the above-mentioned grayscale part 4c is arranged along the opening edge of the above-mentioned light-transmitting part 4a.

[0024] In addition, the method for producing an imprint master mold as described in any one of technical solutions 1 to 4 is characterized in that the above-mentioned exposure amount is determined based on predetermined relationship data between the exposure amount at a specified thickness of the above-mentioned resist 3 and the taper angle of the above-mentioned forward taper.

[0025] In addition, the method for preparing a master mold for imprinting as described in any one of technical solutions 1 to 4 is characterized in that a light-transmitting substrate is used as the above-mentioned substrate 1, a negative resist 3 is used as the above-mentioned resist 3, and includes a mask forming process for forming the above-mentioned mask 4 on the surface of the above-mentioned substrate 1, and in the above-mentioned exposure process, light is irradiated from the back side of the above-mentioned substrate 1 to expose the above-mentioned resist 3 through the above-mentioned mask 4 formed on the surface of the above-mentioned substrate 1.

[0026] In addition, the method for preparing a master mold for imprinting as described in Technical Solution 5 is characterized in that a light-transmitting substrate is used as the above-mentioned substrate 1, a negative resist 3 is used as the above-mentioned resist 3, and includes a mask forming process for forming the above-mentioned mask 4 on the surface of the above-mentioned substrate 1, and in the above-mentioned exposure process, light is irradiated from the back side of the above-mentioned substrate 1 to expose the above-mentioned resist 3 through the above-mentioned mask 4 formed on the surface of the above-mentioned substrate 1.

[0027] Effects of the Invention

[0028] As described above, the present invention is a method for producing an imprint master mold capable of easily forming a structure composed of a resist formed into a forward tapered shape with an optimal tapered angle taking into account the size, pitch, aspect ratio, etc. of a target pattern on a substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic explanatory diagram of a formation example of the structure in the present invention.

[0030] Figure 2 This is a diagram for explaining the photosensitivity characteristics of the resist in Example 1.

[0031] Figure 3 This is a process flow diagram for explaining the process in Example 1.

[0032] Figure 4This is a graph showing the photosensitivity characteristics of the resist (SU-8) in Example 1.

[0033] Figure 5 These are SEM images of a structure exposed by changing the exposure amount at a predetermined film thickness when the negative resist of Example 1 is used.

[0034] Figure 6 These are SEM images of a structure exposed by changing the exposure amount at a predetermined film thickness when the positive resist of Example 1 is used.

[0035] Figure 7 This is a process flow diagram for explaining the second embodiment.

[0036] Figure 8 This is a schematic diagram showing a mask (grayscale mask) when a negative resist is used in Example 2.

[0037] Fig. 9 This is an explanatory diagram showing the light intensity distribution during exposure when the grayscale mask in Example 2 is used (explanation of the principle).

[0038] Fig.10 This is an explanatory diagram showing the light intensity distribution during exposure when the grayscale mask in Example 2 is used (actual distribution).

[0039] Fig.11 This is an explanatory diagram showing the light intensity distribution during exposure when the binary mask in Example 2 is used (actual distribution).

[0040] Fig.12 This is a schematic diagram showing a mask (grayscale mask) when a positive resist is used in Example 2.

[0041] Fig.13 It is a schematic cross-sectional view of a wiring forming method using a replica mold in a conventional example.

[0042] Fig.14 It is a cross-sectional schematic diagram showing a method for producing a master mold and a method for producing a replica mold using the master mold in a conventional example. DETAILED DESCRIPTION

[0043] Based on the drawings, the effects of the present invention will be shown and embodiments of the present invention which are considered to be preferred will be briefly described.

[0044] The resist 3 is applied on the substrate 1 , the resist 3 applied on the substrate 1 is exposed through the mask 4 , and the exposed resist 3 is developed to form a structure 2 composed of the resist 3 .

[0045] In the above operation, the present invention sets the exposure amount when exposing the resist 3 to be less than 2 times of Df (the minimum exposure amount for the total thickness of the resist 3 coated on the substrate 1 to be photosensitized). Figure 1 As shown in (a), the resist 3 near the edge (end) of the light-transmitting portion 4a (opening) of the mask 4 is exposed under the condition that the light intensity is attenuated in the film thickness direction of the resist 3 (less than the exposure intensity Df), thereby making it easy to form Figure 1 The side surface shape shown in (b) is a structure 2 that is a forward tapered shape relative to the substrate 1.

[0046] That is, for example, when the resist 3 is exposed through the mask 4, the light intensity near the edge of the light-transmitting portion 4a of the mask 4 is weaker than the light intensity in the central portion due to the diffraction phenomenon of light, so that the photosensitive effect is reduced in the film thickness direction of the resist 3 near the edge of the light-transmitting portion 4a of the mask 4. Therefore, by setting the exposure amount to be less than 2 times the minimum exposure amount (Df) for photosensitizing the total thickness of the resist 3 applied on the substrate 1, as shown in FIG. Figure 2 As shown, near the edge of the light-transmitting portion 4a of the mask 4, the exposure amount decreases as it moves toward the edge side. Along with this, the photosensitivity of the resist 3 in the film thickness direction also decreases as it moves toward the edge side, thereby obtaining a structure 2 with a forward tapered shape.

[0047] In addition, for example, by using a grayscale mask having a grayscale portion 4c at the edge of the light-transmitting portion 4a of the mask 4, in addition to the above-mentioned diffraction phenomenon of light, the exposure amount can be spatially varied through the action of the grayscale portion 4c, thereby obtaining a structure 2 with a positive cone shape having a larger cone angle.

[0048] Example 1

[0049] based on Figure 1 to Figure 6 A specific embodiment 1 of the present invention will be described.

[0050] This embodiment is a method for producing an imprint master mold having a structure 2 formed in a predetermined pattern such as a wiring pattern or a bump pattern on a substrate 1.

[0051] Specifically, it includes: a mask forming process, forming a mask 4 on a substrate 1; a coating process, coating the resist 3 on the mask 4; an exposure process, exposing the resist 3 coated on the mask 4 through the mask 4; and a development process, developing the resist 3 after exposure.

[0052] That is, in this embodiment, a photomask is not used in the exposure process, and the resist 3 is formed into a predetermined pattern via the mask 4 formed on the substrate 1 to form the structure 2 composed of the resist 3.

[0053] It should be noted that this embodiment is a case where a negative resist 3 for thick film is used as the resist 3. When the negative resist 3 is used, when light is irradiated from the surface side of the resist 3 during exposure, the structure 2 becomes an inverted tapered shape relative to the substrate 1, so that light is irradiated from the substrate 1 side. Therefore, a substrate 1 having light transparency is used.

[0054] Specifically, in this example, SU-8 manufactured by Nippon Kayaku Co., Ltd. was used as the resist 3 , and a glass substrate was used as the substrate 1 .

[0055] Hereinafter, each step in the method for producing an imprint master mold of this embodiment using the above-mentioned substrate 1 and resist 3 will be described in detail.

[0056] First, in the mask forming step, the mask 4 having a predetermined pattern is formed on the glass substrate 1 .

[0057] Specifically, a mask film 5 for forming the mask 4 is formed on the substrate 1, and the mask film 5 is formed into a predetermined pattern by etching. In this embodiment, Cr is formed as the mask film 5 on the substrate 1 by sputtering (see Figure 3 (b)), a resist (in this embodiment, a positive resist OFPR manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied on the Cr film 5, and after exposure and development through a predetermined photomask, the Cr film 5 is etched through the resist (refer to Figure 3 (c)), after the etching process, the above-mentioned resist is removed to form a binary mask consisting of a light-transmitting portion 4a (opening portion) and a light-shielding portion 4b (refer to Figure 3 (d)).

[0058] The film thickness of the mask film 5 may be any thickness that can provide light shielding properties during exposure in the exposure step (in this embodiment, it is set to 60 nm to 120 nm (changed appropriately depending on the exposure conditions)).

[0059] The mask film 5 is not limited to Cr, and any material can be appropriately used as long as the same function and effect as that of the present embodiment can be achieved.

[0060] Next, in the coating step, the resist 3 for forming the structure 2 is coated on the substrate 1 , in other words, the resist 3 that becomes the structure 2 is coated.

[0061] Specifically, a resist 3 (SU-8) having a predetermined film thickness is applied onto a mask 4 formed on a substrate 1 (see Figure 3 (e)).

[0062] It should be noted that the resist 3 used to form the structure 2 is not limited to the above-mentioned resist.

[0063] Next, in an exposure step, the resist 3 is exposed.

[0064] Specifically, light is irradiated from the back side of the glass substrate 1, and the resist 3 is exposed through a mask 4 provided between the glass substrate 1 and the resist 3 (see Figure 3 (f)).

[0065] The exposure amount is set to be not more than twice the following Df, preferably set to be within the following range of D0 to Df, so that the side surface shape of the structure 2 formed by development with respect to the substrate 1 becomes a forward taper.

[0066] remember

[0067] D0: Exposure amount at which the resist 3 coated on the substrate 1 starts to be exposed

[0068] Df: The minimum exposure of the total thickness of the resist 3 coated on the substrate 1

[0069] More specifically, the exposure amount is set to the exposure amount in the above range corresponding to the target taper angle based on the relationship data between the exposure amount at a predetermined thickness of the resist 3 and the taper angle of the forward taper, which is determined in advance.

[0070] D0 and Df can be confirmed from, for example, a data sheet published by the manufacturer. Figure 4 The SU-8-related datasheet (https: / / kayakuam.com / wp-content / uploads / 2020 / 09 / KAM-SU-8-2-25-Datasheet-9.3.20-final.pdf) from Kayaku Advanced Materials, Inc. shows D0 and Df.

[0071] In this embodiment, based on the determined D0 and Df, the relationship data between the exposure amount and the taper angle of the forward taper at a predetermined film thickness of the resist 3 is obtained by experiment, and the exposure amount corresponding to the target taper angle is set based on the relationship data.

[0072] Specifically, in this embodiment, a TEG pattern having a bump pattern with different diameters and a wiring pattern with different line widths is used to produce Figure 5 The sample shown in the figure is exposed by changing the exposure amount at a predetermined film thickness. The bump pattern and wiring pattern ( Figure 5 The taper angle is obtained by taking an SEM image of a bump pattern, etc., and obtaining data on the relationship between the exposure amount at a specified film thickness and the taper angle of a forward taper.

[0073] For example, by Figure 5The relationship data between the exposure amount and the taper angle as shown in Table 1 below can be obtained, and the exposure amount can be set based on the data (taper angle), or a calculation formula for determining the exposure amount can be created and used to set the exposure amount.

[0074] [Table 1]

[0075]

[0076] Finally, in the development step, the resist 3 subjected to the exposure process is developed.

[0077] In this embodiment, a negative resist 3 is used, so the resist 3 of the exposed part remains, and the structure 2 whose side shape is formed into a desired tapered shape (taper angle) is formed by the remaining resist 3, and the master mold is completed (refer to Figure 3 (g)).

[0078] It should be noted that, although the present embodiment is a case where a negative type resist 3 is used as described above, a positive type resist 3 may also be used as the resist 3 .

[0079] When the positive resist 3 is used, a mask forming step is unnecessary, and a photomask is used in the exposure step.

[0080] In addition, the positive resist 3 is opposite to the negative resist 3, and the exposed part disappears, so Figure 1 As shown, in the exposure step, exposure is performed from the surface side of the resist 3 , and the remaining resist 3 becomes the structure 2 .

[0081] in addition, Figure 6 The shapes of the structures 2 in the samples are shown in which PMER P-LA900 manufactured by Tokyo Ohka Kogyo Co., Ltd. is used as the resist 3 , the same TEG pattern as in the case of the negative resist 3 is used, and exposure is performed at a predetermined film thickness with varying exposure doses.

[0082] If the Figure 6 As shown, in the case of the positive resist 3, as in the negative resist 3, it can be confirmed that the taper angle of the structure 2 changes by changing the exposure amount, and the taper angle is calculated from the SEM image of the bump pattern and wiring pattern in the sample, and the relationship data between the exposure amount at a specified film thickness and the taper angle of the positive taper can be obtained.

[0083] As described above, this embodiment provides a method for producing an imprint master mold that can easily form a structure 2 having a forward tapered shape with an optimal tapered angle taking into account the size, pitch, aspect ratio, etc. of a target pattern on a substrate 1 .

[0084] That is, in this embodiment, the exposure amount of the resist 3 that forms the structure 2 is set to D0 (the exposure amount at which the resist 3 coated on the substrate 1 starts to be photosensitized) to Df (the minimum exposure amount at which the total thickness of the resist 3 coated on the substrate 1 is photosensitized). Therefore, near the edge of the light-transmitting portion 4a of the mask 4, the exposure amount decreases as it moves toward the edge side. Concomitantly, the photosensitivity effect of the resist 3 in the film thickness direction also decreases as it moves toward the edge side. As a result, a structure 2 whose side shape is a right cone shape can be reliably formed.

[0085] Thus, even if the structure of the master mold is deformed during stacking and pressurization when forming the replica mold, the reverse tapered shape can be prevented from being generated, and a master mold capable of pattern transfer can be produced smoothly with a high yield.

[0086] Example 2

[0087] based on Figure 7 to Figure 12 A specific embodiment 2 of the present invention will be described.

[0088] This embodiment uses a mask 4 different from that of the first embodiment.

[0089] Specifically, in this embodiment, a grayscale mask is used as the mask 4, and the grayscale mask is composed of a light-transmitting portion 4a, a light-shielding portion 4b, and a grayscale portion 4c.

[0090] Hereinafter, this embodiment will be described in detail. However, the process flow of this embodiment is the same as that of Embodiment 1 except for the mask forming process, and therefore the description of the processes other than the mask forming process will be omitted.

[0091] It should be noted that when a grayscale mask is used as the mask 4 as in this embodiment, the exposure amount is not limited, but is preferably set to the exposure condition in the exposure step of the first embodiment, that is, an exposure amount of not more than twice Df.

[0092] In the mask forming process of this embodiment, first, a light shielding film 5a for forming the light shielding portion 4b of the mask 4 is formed on the substrate 1, and the light shielding film 5a is formed into a predetermined pattern by etching. In this embodiment, as the light shielding film 5a, Cr is formed on the substrate 1 by sputtering in the same manner as in the embodiment 1 (see Figure 7 (b)), a resist 6 (in this embodiment, a positive resist OFPR manufactured by Tokyo Ohka Kogyo Co., Ltd.) is coated on the Cr film 5a, and after exposure and development through a predetermined photomask, the Cr film 5a is etched through the resist 6 (refer to Figure 7 (c)), after the etching process, the resist 6 is removed, and a light shielding portion 4b consisting of a Cr film 5a is formed on the substrate 1 (see Figure 7 (d)).

[0093] Next, a grayscale portion film 5b for forming the grayscale portion 4c of the mask 4 is formed on the substrate 1 including the light shielding portion 4b, and the grayscale portion film 5b is formed into a predetermined pattern by etching. In this embodiment, CrO is sputtered as the grayscale portion film 5b. 3 A film is formed on the substrate 1 including the light shielding portion 4b (see Figure 7 (e)), in the CrO 3 A resist 6 (in this embodiment, a positive resist OFPR manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied on the film 5b, and then exposed and developed through a predetermined photomask (see Figure 7 (f)), through the above-mentioned resist 6 to CrO 3 The film 5b is etched (see Figure 7 (g)), after etching, the resist 6 is removed, and a light-transmitting portion 4a and a grayscale portion 4c are formed on the substrate 1 (see Figure 7 (h)), a grayscale mask consisting of a light-transmitting portion 4a, a light-shielding portion 4b and a grayscale portion 4c is formed on the substrate 1.

[0094] It should be noted that, in this embodiment, in order to improve the adhesion of the resist 3, an adhesion film 5c (SiO 2 Membrane) (refer to Figure 7 (i)).

[0095] Figure 8 This is an example of the configuration of the mask 4 (grayscale mask) for the bump pattern formed as described above. Figure 8 As shown, in the mask 4 of this embodiment, the grayscale portion 4c is provided along the peripheral portion of the light-transmitting portion 4a as the boundary portion between the light-transmitting portion 4a and the light-shielding portion 4b. The exposure amount is reduced by passing through the grayscale portion 4c, and the photosensitivity of the resist 3 in the film thickness direction is also reduced. By interaction with the diffraction effect of light, a structure 2 having a positive cone shape with a larger cone angle than that of a binary mask can be easily formed (see FIG. Figure 7 (k), (j)).

[0096] The following describes the exposure mechanism when a grayscale mask is used.

[0097] Fig. 9 In the grayscale mask shown in this embodiment, the intensity distribution derived based on Fresnel diffraction of light passing through the light-transmitting portion 4a (upper stage) and the intensity distribution derived based on Fresnel diffraction of light passing through the grayscale portion 4c (lower stage) are shown.

[0098] exist Fig. 9In the structure of the grayscale portion 4c shown in the figure, the grayscale portion 4c is within the range where Fresnel diffraction occurs. Therefore, the intensity distribution derived based on the Fresnel diffraction of the light passing through the light-transmitting portion 4a and the intensity distribution derived based on the Fresnel diffraction of the light passing through the grayscale portion 4c can be overlapped (synthesized). Therefore, in the grayscale mask of this embodiment, Fig.10 Light intensity distribution shown.

[0099] Used the Fig.10 The light intensity distribution when the grayscale mask is shown is equivalent to that when using Fig.11 The light intensity distribution in the case of the binary mask shown is shifted toward the light shielding portion 4b (left direction in the figure) by the area (width) of the grayscale portion 4c. Therefore, by using the grayscale mask, the amount of retreat of the side surface of the structure 2 increases by the amount of the grayscale portion 4c, and the taper angle of the side surface of the structure 2 also increases accordingly.

[0100] Table 2 below shows the results of measuring the side taper angle of the structure 2 with a bump diameter of 10 μm when the resist 3 with a film thickness of 40 μm was exposed using a binary mask and a grayscale mask. It should be noted that the grayscale mask used had a grayscale portion 4c with an area (width) of 1.5 μm.

[0101] [Table 2]

[0102]

[0103] The results shown in Table 2 also confirm that the taper angle of the side surface of the structure 2 can be increased by using a grayscale mask.

[0104] It should be noted that, in this embodiment, the negative resist 3 is used as described above, but a positive resist 3 (for example, PMER P-LA900 manufactured by Tokyo Ohka Kogyo Co., Ltd.) may also be used as the resist 3 .

[0105] When the positive resist 3 is used, a mask forming step is unnecessary, and a photomask is used in the exposure step.

[0106] In addition, as a photomask, it is preferable Fig.12 The mask structure shown (the symbol 4a in the figure is the light-transmitting part, 4b is the light-shielding part, and 4c is the grayscale part).

[0107] It should be noted that the present invention is not limited to this embodiment, and the specific structure of each technical feature can be appropriately designed.

Claims

1. A method for producing an imprinting master mold, which is a method for producing an imprinting master mold having a structure formed into a predetermined pattern such as a wiring pattern and a bump pattern on a substrate, characterized in that: include: A coating step of coating a resist having a predetermined film thickness on the substrate; an exposure step of exposing the resist coated on the substrate through a mask; and a developing step, developing the exposed resist, wherein in the exposure step, the exposure amount is set to an exposure amount of less than 2 times the following Df so that the side shape of the structure formed by the resist formed by the development in the developing step becomes a forward cone, and a predetermined portion of the resist is exposed, remember Df: The minimum exposure to light that is sensitive to the total thickness of the resist coated on the substrate.

2. The method for producing a master mold for imprinting according to claim 1, characterized in that: In the exposure step, a binary mask composed of a light-transmitting portion and a light-shielding portion is used as the mask, and the exposure amount is set to the following D0 to the above Df, remember D0: The exposure amount at which the resist coated on the substrate begins to be photosensitized.

3. The method for making a master mold for imprinting according to claim 1, characterized in that: In the exposure step, a grayscale mask composed of a light-transmitting portion, a light-shielding portion, and a grayscale portion is used as the mask.

4. The method for producing a master mold for imprinting according to claim 3, characterized in that: The grayscale portion is arranged along an opening edge of the light-transmitting portion.

5. The method for producing an imprint master mold according to any one of claims 1 to 4, characterized in that: The exposure amount is determined based on predetermined data on the relationship between the exposure amount at a predetermined thickness of the resist and the taper angle of the forward taper.

6. The method for producing an imprint master mold according to any one of claims 1 to 4, characterized in that: A light-transmitting substrate is used as the substrate, a negative resist is used as the resist, and a mask forming process is included for forming the mask on the surface of the substrate. In the exposure process, light is irradiated from the back side of the substrate to expose the resist through the mask formed on the surface of the substrate.

7. The method for producing a master mold for imprinting according to claim 5, characterized in that: A light-transmitting substrate is used as the substrate, a negative resist is used as the resist, and a mask forming process is included for forming the mask on the surface of the substrate. In the exposure process, light is irradiated from the back side of the substrate to expose the resist through the mask formed on the surface of the substrate.

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