Electroforming mold manufacturing method and photomask

Abstract

The present invention prevents the tip of a corner portion of a photoresist layer pattern from blunting. A photomask (80) has formed therein a pattern comprising a light-blocking section (82) and a light-transmitting section (81), which forms an electroforming mold based on a pattern comprising a melting section (22) and a non-melting section (21) in a photoresist layer (20) formed layered on a substrate (10). When a corner (82a) is formed in the light-blocking section (82), a light-blocking section corner correction section (84), which suppresses diminishment of the sharpness of the corner (82a) of the light-blocking section (82), is formed in a region facing the corner (82a) of the light-blocking section (82) across a vertex (82b) of the corner (82a) of the light-blocking section (82).

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing an electroforming mold and a photomask. [Background technology]

[0002] For example, minute structures such as watch parts are manufactured by electroforming (electroforming; a method for manufacturing, repairing, or replicating metal products by electroplating). When manufacturing parts (electroformed products) by electroforming, a photoresist layer is formed on a substrate, and a pattern of soluble and insoluble parts is formed in the photoresist layer to manufacture an electroforming mold (see, for example, Patent Document 1).

[0003] Electroforming molds with a pattern of soluble and insoluble parts can be formed by irradiating light using a photomask on which a pattern is formed by light-shielding and light-transmitting parts, or by irradiating the areas corresponding to the insoluble parts by scanning with laser light without using a photomask. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4550569 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, the photoresist layer can deform slightly during the exposure process or, in the case of chemically amplified resists, during the PEB (Post Exposure Bake: bake after exposure and before development) process after exposure, causing the corners of the electroforming mold to become dull. In other words, the corners become rounded at the tips, reducing resolution (sharpness). This can result in poor reproducibility of the corner tip shape in electroformed products manufactured using the electroforming mold.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing an electroforming mold and a photomask that can prevent the corners of the pattern in the photoresist layer from becoming blunt. [Means for solving the problem]

[0007] The first aspect of the present invention is a method for manufacturing an electroforming mold, which involves forming a pattern consisting of a soluble portion and an insoluble portion in a photoresist layer formed by laminating on a substrate, and removing the soluble portion to form a cavity, and when a corner is formed in the soluble portion, a soluble portion corner correction portion is formed in an area facing the corner of the soluble portion across the apex of the corner of the soluble portion, which suppresses a decrease in sharpness of the corner of the soluble portion.

[0008] The second aspect of the present invention is a method for manufacturing an electroforming mold, which involves forming a pattern consisting of a soluble portion and an insoluble portion in a photoresist layer formed by laminating on a substrate, and removing the soluble portion to form a cavity, and when a corner is formed in the insoluble portion, an insoluble portion corner correction portion is formed in an area facing the corner across the apex of the corner to suppress a decrease in the sharpness of the corner.

[0009] A third aspect of the present invention is a photomask used to form a pattern consisting of soluble portions and insoluble portions in a photoresist layer formed by laminating on a substrate, wherein a pattern consisting of light-shielding portions and light-transmitting portions is formed, and when a corner is formed in the light-shielding portion, the photomask has a light-shielding portion angle correction portion formed in an area facing the corner of the light-shielding portion across the apex of the corner of the light-shielding portion, which suppresses a decrease in sharpness of the corner of the light-shielding portion.

[0010] A fourth aspect of the present invention is a photomask used to form a pattern composed of soluble portions and insoluble portions in a photoresist layer formed by laminating on a substrate, wherein a pattern composed of light-shielding portions and light-transmitting portions is formed, and when a corner is formed in the light-transmitting portion, the photomask has a light-transmitting portion corner correction portion formed in an area facing the corner of the light-transmitting portion across the apex of the corner of the light-transmitting portion, which suppresses a decrease in sharpness of the corner of the light-transmitting portion. [Effects of the Invention]

[0011] The electroforming mold manufacturing method and photomask according to the present invention can prevent the corners of the pattern in the photoresist layer from becoming blunt. [Brief explanation of the drawings]

[0012] [Figure 1] 1A to 1C are cross-sectional views schematically illustrating a flow of a manufacturing method for an electroformed product to which an example of a manufacturing method for an electroforming mold is applied. [Figure 2] FIG. 2 is a plan view of an example of a photomask conventionally used in the method for manufacturing the electroforming mold shown in FIG. [Figure 3] 2 is a plan view of one embodiment of a photomask according to the present invention, which is used in the method for manufacturing the electroforming mold shown in FIG. 1. FIG. [Figure 4] 10A and 10B are diagrams illustrating the state of corners formed in cavities in a photoresist layer in a conventional method for manufacturing an electroforming mold using a photomask. [Figure 5] FIG. 1 is a diagram showing a schematic view of a corner formed in an insoluble portion of a photoresist layer in a conventional method for manufacturing an electroforming mold using a photomask. [Figure 6] 10 is a diagram schematically showing details of a light-shielding portion corner correction portion formed opposite a corner of a light-shielding portion of a photomask. FIG. [Figure 7] 10A and 10B are diagrams schematically illustrating details of a light-transmitting portion corner correction portion formed opposite a corner of a light-transmitting portion of a photomask. [Figure 8]10A and 10B are diagrams illustrating the state of corners formed in cavities in a photoresist layer in a method for manufacturing an electroforming mold using the photomask of the present embodiment. [Figure 9] 10A and 10B are diagrams illustrating the state of corners formed in insoluble portions of a photoresist layer in a method for manufacturing an electroforming mold using the photomask of the present embodiment. [Figure 10] 1A to 1C are diagrams (part 1) illustrating the effects of an electroformed product manufactured using an electroformed mold manufactured by a method for manufacturing an electroformed mold using a photomask according to the present embodiment. [Figure 11] FIG. 10 is a diagram (part 2) for explaining the effect of an electroformed product manufactured using an electroformed mold manufactured by the method for manufacturing an electroformed mold using a photomask of the present embodiment. [Figure 12] FIG. 10 is a diagram (part 3) for explaining the effect of an electroformed product manufactured using an electroformed mold manufactured by the method for manufacturing an electroformed mold using a photomask of the present embodiment. [Figure 13] FIG. 10 is a diagram (part 4) for explaining the effect of an electroformed product manufactured using an electroformed mold manufactured by the method for manufacturing an electroformed mold using a photomask of the present embodiment. [Figure 14] FIG. 5 is a diagram (part 5) for explaining the effect of an electroformed product manufactured using an electroformed mold manufactured by the method for manufacturing an electroformed mold using a photomask of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of a method for manufacturing an electroforming mold and a photomask according to the present invention will be described with reference to the drawings.

[0014] Figure 1 is a cross-sectional view showing a schematic flow of an example of a method for manufacturing an electroformed product 200, Figure 2 is a plan view of an example of a photomask 180 conventionally used in the method for manufacturing the electroformed product 200 shown in Figure 1, and Figure 3 is a plan view of an embodiment of a photomask according to the present invention used in the method for manufacturing the electroformed product 200 shown in Figure 1.

[0015] In the manufacturing method of the electroformed product 200 shown in Figure 1, the method using the photomask 80 is a manufacturing method of the electroformed product 200 that applies one embodiment of the manufacturing method of the electroformed mold of the present invention, and the method using the photomask 180 is a manufacturing method of the electroformed product 200 that applies an example of a conventional manufacturing method of the electroformed mold.

[0016] 1, the method for manufacturing the electroformed product 200 involves laminating a photoresist layer 20 on a substrate 10. The substrate 10 may have a conductive substrate body 11, or if the substrate body 11 is not conductive, such as a resin, a conductive film (conductive layer) 12 may be formed on the surface of the substrate body 11 on which the photoresist layer 20 is laminated.

[0017] When the substrate body 11 is conductive, it does not need to be provided with the conductive film 12. When the substrate body 11 is not conductive and the conductive film 12 is not formed, a conductive film may be formed at least in the cavity 23 after the cavity 23 is formed.

[0018] The photoresist layer 20 may be a positive resist in which the portions irradiated with ultraviolet light (ultraviolet light) are soluble and the portions not irradiated are insoluble, or a negative resist in which the portions irradiated with ultraviolet light are insoluble and the portions not irradiated are soluble. The following description will be given assuming that the photoresist layer 20 in the manufacturing method of the electroformed product 200 shown in FIG. 1 is a negative resist.

[0019] The manufacturing method for the electroformed product 200 next involves placing a photomask 80 or a photomask 180 on the surface (top surface as shown) of the photoresist layer 20, and irradiating ultraviolet light L onto the photoresist layer 20 from above through the photomask 80 or the photomask 180.

[0020] Both the photomask 80 and the photomask 180 have a pattern made up of light-transmitting portions 81 that transmit ultraviolet light L and light-shielding portions 82 that do not transmit ultraviolet light L. The pattern forms an electroforming mold corresponding to the contour shape of the electroformed product 200.

[0021] When ultraviolet light L is irradiated through the photomask 80, 180, the portions of the photoresist layer 20 below the light-transmitting portions 81 become insoluble portions 21 due to the ultraviolet light L passing through and being irradiated, and these portions remain even after development. On the other hand, the portions of the photoresist layer 20 below the light-shielding portions 82 become soluble portions 22 due to the ultraviolet light L being blocked and not being irradiated, and these portions are removed by development.

[0022] In this way, the light-shielding portions 82 of the photomasks 80 and 180 form soluble portions 22 in the photoresist layer 20, and the light-transmitting portions 81 form insoluble portions 21 in the photoresist layer 20. Conversely, when the photoresist layer 20 is a positive resist, the light-shielding portions 82 form insoluble portions in the photoresist layer 20, and the light-transmitting portions 81 form soluble portions in the photoresist layer 20.

[0023] When the soluble portion 22 is removed by the development process, the area where the soluble portion 22 was present becomes a hollow portion 23, and in this hollow portion 23, the substrate 10 is exposed, and the pattern of this hollow portion 23 and the insoluble portion 21 becomes a mold (electroforming mold) for forming the electroformed product 200.

[0024] Then, through the electroplating process, a metal such as nickel grows from the substrate 10 in the cavity 23, and an electroformed product 200 of a metal such as nickel is produced that corresponds to the contour shape of the cavity 23. If the substrate 10 is an insulating material that does not have electrical conductivity, it is sufficient to form a conductive film at least in the cavity 23 at this stage.

[0025] Here, the photomask 180 used in the conventional method of manufacturing an electroforming mold will be described as having a pattern consisting of a star-shaped light-shielding portion 82 and a light-transmitting portion 81 surrounding the star-shaped light-shielding portion 82, as shown in Fig. 2. The star shape of the light-shielding portion 82 corresponds to the outline shape of the electroformed product 200 to be manufactured.

[0026] 4 is a diagram showing a typical corner 23a formed in cavity 23 of photoresist layer 20 in a conventional method for manufacturing an electroforming mold using photomask 180. In this case, when photomask 180 has corner 82a (a portion bent at an angle of less than 180 degrees) formed in light-shielding portion 82, corner 23a of cavity 23 that should be formed corresponding to corner 82a, as shown in the left half of FIG. 4, becomes blunt and rounded, and apex 23b at the tip of corner 23a disappears, as shown in the right half of FIG.

[0027] Fig. 5 is a diagram schematically illustrating the state of corners 21a formed in the insoluble portion 21 of the photoresist layer 20 in a conventional method for manufacturing an electroforming mold using a photomask 180. When the photomask 180 has corners (portions bent at an angle of less than 180 degrees) 81a formed in the light-transmitting portion 81 as shown in Fig. 2, the corners 21a of the insoluble portion 21 that should be formed corresponding to the corners 81a as shown in the left half of Fig. 5 become blunt and rounded, and the apex 21b at the tip of the corners 21a disappears, resulting in an expanded cavity 23, as shown in the right half of Fig. 5.

[0028] The reason why the tips of the corners 21a of the insoluble portions 21 become blunt and rounded in this way is presumably because the insoluble portions 21 shrink due to crosslinking between molecules of the insoluble portions 21 during exposure to ultraviolet light L or, if the photoresist layer 20 is a chemically amplified resist, during PEB (Post Exposure Bake: baking after exposure and before development) after exposure.

[0029] In addition, it is presumed that the tip of the corner 23a of the hollow portion 23 becomes blunt and rounded because a pulling force occurs between the two insoluble portions 21 that sandwich the corner 23a of the hollow portion 23 due to contraction caused by cross-linking between molecules, and the stress of this pulling force pulls the insoluble portion 21 in the area opposite the corner 23a across the vertex 23b toward the corner.

[0030] As described above, if the tip of the corner 23a of the hollow portion 23 or the tip of the corner 21a of the insoluble portion 21 becomes blunt, the shape of the hollow portion 23 will no longer reproduce the shape of the intended design, and the dimensions of the electroformed product 200 manufactured using an electroforming mold formed with the pattern of the hollow portion 23 and the insoluble portion 21 will differ from the dimensions of the intended design.

[0031] In contrast, the photomask 80 of this embodiment also has a pattern consisting of a star-shaped light-shielding portion 82 and a light-transmitting portion 81 that is the area surrounding the star-shaped light-shielding portion 82, as shown in Figure 3, and the star shape of the light-shielding portion 82 is the outline shape of the electroformed product 200 to be manufactured.

[0032] When the photomask 80 has a corner (a portion bent at an angle of less than 180 degrees) 82a formed in the shading portion 82, a shading portion angle correction portion 84 is formed in the area facing the corner 82a of the shading portion 82, across the vertex 82b of the corner 82a of the shading portion 82, to suppress a decrease in the sharpness of the corner 82a of the shading portion 82.

[0033] The light-shielding portion angle correction portion 84 is a light-shielding portion that does not allow ultraviolet light to pass therethrough, similar to the light-shielding portion 82. In other words, the light-shielding portion angle correction portion 84 forms a soluble portion angle correction portion 24, which is a soluble portion (cavity), in the photoresist layer 20.

[0034] FIG. 6 is a diagram showing details of a light-shielding portion angle correction portion 84 formed opposite a corner 82a of a light-shielding portion 82 of a photomask 80, and FIG. 7 is a diagram showing details of a light-transmitting portion angle correction portion 85 formed opposite a corner 81a of a light-transmitting portion 81 of a photomask 80.

[0035] In addition, Figure 8 is a diagram schematically showing the appearance of a corner 23a formed in a cavity 23 of a photoresist layer 20 in a manufacturing method of an electroformed product 200 to which a manufacturing method of an electroformed mold using the photomask 80 of this embodiment is applied, and Figure 9 is a diagram schematically showing the appearance of a corner 21a formed in an insoluble portion 21 of a photoresist layer 20 in a manufacturing method of an electroformed product 200 to which a manufacturing method of an electroformed mold using the photomask 80 of this embodiment is applied.

[0036] The light-shielding portion angle correction portion 84 is formed in a rectangular shape, for example, as shown in FIG. 6. The length L2 of one side of the rectangle is, for example, 1 μm, but is not limited to 1 μm and may be greater than or less than 1 μm. Furthermore, the light-shielding portion angle correction portion 84 is not limited to a rectangle and may be triangular, other polygonal, circular, or other shapes.

[0037] In short, the shading portion angle correction portion 84 only needs to remove the insoluble portion 21 that is attracted to the vicinity of the vertex 23b of the corner 23a in the area facing the corner 23a across the vertex 23b, even if a pulling action occurs between two insoluble portions 21 that sandwich the corner 23a of the hollow portion 23 formed by the shading portion 82 due to contraction caused by cross-linking between molecules.

[0038] When the light-shielding portion angle correction portion 84 is rectangular or polygonal, it is preferable that its vertex be formed in a direction (posture) facing the corner portion 82a across the vertex 82b in order to alleviate the stress generated in the two insoluble portions 21 that sandwich the corner portion 23a, but the sides of the rectangle or polygon may also be formed in a direction facing the corner portion 82a across the vertex 82b.

[0039] The light-shielding portion angle correction portion 84 may be configured to be in contact with the vertex 82b of the corner 82a of the light-shielding portion 82, so that the light-shielding portion angle correction portion 84 and the light-shielding portion 82 are in contact, or may be configured to be separated from the vertex 82b of the corner 82a of the light-shielding portion 82, so that the light-shielding portion angle correction portion 84 and the light-shielding portion 82 are separated, or may be configured to be overlapped with the vertex 82b of the corner 82a of the light-shielding portion 82, so that the light-shielding portion angle correction portion 84 and the light-shielding portion 82 are connected. When the light-shielding portion angle correction portion 84 and the vertex 82b of the corner 82a of the light-shielding portion 82 are separated from each other, the distance between them is preferably within 10 μm.

[0040] 3, when a corner portion (a portion bent at an angle of less than 180 degrees) 81a is formed in light-transmitting portion 81 of photomask 80, light-transmitting portion angle correction portion 85 that suppresses a decrease in the sharpness of corner portion 81a of light-transmitting portion 81 is formed in a region facing corner portion 81a of light-transmitting portion 81 across vertex 81b of corner portion 81a of light-transmitting portion 81. Light-transmitting portion angle correction portion 85 is a light-transmitting portion that transmits ultraviolet light, similar to light-transmitting portion 81. In other words, light-transmitting portion angle correction portion 85 forms insoluble portion corner correction portion 25, which is an insoluble portion, in photoresist layer 20.

[0041] For example, as shown in FIG. 7, the light-transmitting portion angle correction portion 85 is formed in a rectangular shape. The length L3 of one side of the rectangle is, for example, 1 μm, but is not limited to 1 μm and may be greater than or less than 1 μm. Furthermore, the light-transmitting portion angle correction portion 85 is not limited to a rectangle and may be triangular, other polygonal, circular, or other shapes.

[0042] The light-transmitting portion angle correction portion 85 is configured such that the vertex of the light-transmitting portion angle correction portion 85 and the vertex 81b of the corner 81a of the light-transmitting portion 81 are in contact with each other, or the vertex of the light-transmitting portion angle correction portion 85 and the vertex 81b of the corner 81a overlap with each other, connecting the light-transmitting portion angle correction portion 85 and the light-transmitting portion 81.

[0043] In addition, it is preferable that the vertices of the rectangular or polygonal transparent portion angle correction portion 85 are formed in a direction facing the corner portion 81a across the vertex 81b in order to alleviate the stress generated at the corner portion 21a, but the sides of the rectangular or polygonal transparent portion angle correction portion 85 may be formed in a direction facing the corner portion 82a across the vertex 81b.

[0044] When an electroforming mold is manufactured using the photomask 80 of this embodiment configured in this manner in the process shown in Figure 1, as shown in Figure 8, the soluble portion angle correction portion 24 can prevent or suppress a decrease in sharpness (dulling) of the corners 23a of the electroforming mold compared to the case shown in the right half of Figure 4 (when manufactured using a conventional photomask 180).

[0045] In other words, even if a pulling action occurs between two insoluble portions 21 sandwiching the corner 23a of the hollow portion 23 due to contraction caused by cross-linking between molecules, a cavity is formed by the light-shielding portion angle correction portion 84 in the area facing the corner 23a across the vertex 23b, and no insoluble portion 21 (see the area on the right half of Figure 4) is formed that is drawn to the vicinity of the vertex 23b of the corner 23a, reducing the sharpness of the corner 23a.

[0046] Furthermore, when an electroformed product 200 is manufactured using the photomask 80 in the process shown in Figure 1, as shown in Figure 9, the insoluble portion corner correction section 25 can prevent or suppress a decrease in the sharpness of the corners 21a of the electroformed mold, compared to the case shown in the right half of Figure 5 (when manufactured using a conventional photomask 180).

[0047] In other words, a tension occurs between the corner 21a of the insoluble portion 21 and the insoluble portion corner correction portion 25 formed by the transparent portion corner correction portion 85 due to contraction caused by cross-linking between molecules, leaving the vertex 21b of the corner 21a.

[0048] As a result, according to the method for manufacturing an electroforming mold using the photomask 80 of this embodiment, the sharpness of the tip of the corner 23a of the hollow portion 23 is not reduced or is suppressed, and the tip of the corner 21a of the insoluble portion 21 is not reduced or is suppressed, so that the shape of the hollow portion 23 can be made to reproduce the shape of the intended design.

[0049] Therefore, the method for manufacturing an electroformed mold using the photomask 80 of this embodiment can prevent or suppress a decrease in the sharpness of the corners 21a, 23a, compared to a method for manufacturing an electroformed mold using a conventional photomask 180. As a result, the method for manufacturing an electroformed product using the electroformed mold manufacturing method of this embodiment can improve the dimensional accuracy of the manufactured electroformed product 200, compared to a method for manufacturing an electroformed product using a conventional electroformed mold manufacturing method.

[0050] The electroformed mold manufactured by the electroformed mold manufacturing method using the photomask 80 of this embodiment has an insoluble portion corner correction portion 25 formed in the portion corresponding to the light-transmitting portion corner correction portion 85. Therefore, the electroformed product 200 manufactured using the electroformed mold having the insoluble portion corner correction portion 25 has a cavity 210 formed in the portion corresponding to the light-transmitting portion corner correction portion 85, as shown in Figure 10 as an example.

[0051] In other words, if the electroformed product 200 has a corner 220 that is bent at an angle of more than 180 degrees, as shown in Figure 10, a cavity 210 corresponding to the insoluble part angle correction portion 25 shown in Figure 9 will be formed in the corner 220.

[0052] Therefore, the electroformed product 200 can be made lighter in weight by the amount of the cavity 210 compared to electroformed products manufactured by conventional manufacturing methods in which the cavity 210 is not formed, and when this electroformed product 200 is used as a moving object, energy savings can be achieved through the weight reduction.

[0053] Furthermore, an electroformed product 200 having a corner 220 bent at an angle of more than 180 degrees and a cavity 210 formed therein can retain lubricating oil 300 within the cavity 210 and in the corners and other areas surrounding it when lubricating oil 300 is applied to the surface 230 of the electroformed product 200, as shown in Figure 11, for example.

[0054] Therefore, when the surface 230 of the electroformed product 200 slides against another object 400, the lubricating oil 300 held in the cavity 210 is supplied to the sliding surface (same as the surface 230) between the electroformed product 200 and the other object 400, thereby retaining the lubricating oil 300 on the sliding surface (surface 230), and improving the durability (extending the lifespan) of the sliding surface (surface 230) between the electroformed product 200 and the other object 400.

[0055] 12, when the electroformed product 200 slides against another object 400 and wear particles are generated by the sliding or foreign matter from other parts adheres to the sliding surface (surface 230) between the two (electroformed product 200 and other object 400) (hereinafter, the wear particles and foreign matter will be referred to as wear particles, etc. 310), the wear particles, etc. 310 will enter the cavity 210 due to the sliding movement. This prevents the wear particles, etc. 310 from remaining on the sliding surface (surface 230), improving the durability (extending the lifespan) of the sliding surface (surface 230) between the electroformed product 200 and other object 400.

[0056] Furthermore, for example, as shown in Figure 13, when an electroformed product 200 is joined to another object 400 with adhesive 500, the adhesive 500 is pre-applied to the surface 230 of the electroformed product 200, but the adhesive 500 can be held within a cavity 210 formed in a corner 220 that is bent at an angle of more than 180 degrees.

[0057] Therefore, when the other object 400 is advanced in the direction of the arrow toward the surface 230 of the electroformed product 200 to join the electroformed product 200 and the other object 400, the adhesive 500 held within the cavity 210 and in the corners around the cavity 210 is supplied between the electroformed product 200 and the other object 400, allowing for a sufficient supply of adhesive 500 between the electroformed product 200 and the other object 400, thereby firmly joining the electroformed product 200 and the other object 400.

[0058] 14, when another object 400 having a width W2 (>W1) that is approximately the same as the width W1 or a width W2 (≈W1) that is wider than the width W1 is inserted into a recess 250 of width W1 formed in an electroformed product 200, both side portions 260, 260 forming the recess 250 are each pressed outward in the width direction by the other object 400 inserted into the recess 250. At this time, the cavities 210, 210 formed in the corner portion 220 of the electroformed product 200 that is bent at an angle exceeding 180 degrees are pushed open, causing the both side portions 260, 260 to be displaced (deformed) outward in the width direction.

[0059] Therefore, another object 400 having a width W2 (≒W1) that is approximately the same as width W1 or a width W2 (>W1) that is wider than width W1 can be inserted into the recess 250 having width W1 formed in the electroformed product 200.

[0060] In the method for manufacturing an electroforming mold of this embodiment, the photoresist layer 20 to be exposed to ultraviolet light L using the photomask 80 is a negative resist, but in the method for manufacturing an electroforming mold of the present invention, the photoresist layer 20 to be exposed to ultraviolet light L using the photomask 80 may be a positive resist.

[0061] In this case, the light-shielding portion 82 of the photomask 80 shown in Figures 6 and 7 forms the insoluble portion of the photoresist layer 20, and the light-transmitting portion 81 forms the soluble portion of the photoresist layer 20. In the photoresist layer 20, the portion indicated by reference numeral 21 in Figures 8 and 9 becomes a soluble portion (cavity), and the portion indicated by reference numeral 25 becomes a soluble portion angle correction portion that becomes a cavity, and 23 The portion indicated by the reference numeral 24 becomes the insoluble portion and the portion indicated by the reference numeral 24 becomes the insoluble portion angle correction portion.

[0062] Therefore, when the electroforming mold manufacturing method of the present invention uses a photoresist layer of a positive resist, the light-shielding portion angle correction portion 84 is configured to be in contact with or connected to the light-shielding portion 82, and the light-transmitting portion angle correction portion 85 is configured to be in contact with or separated from the light-transmitting portion 81 by a distance of 0 to 10 μm, or to be connected to the light-transmitting portion 81.

[0063] The electroforming mold manufacturing method and photomask 80 of the above-described embodiment form an electroforming mold with a pattern in the photoresist layer 20 that has both the corners 23a of the soluble portions 22 (cavities 23) and the corners 21a of the insoluble portions 21. However, the electroforming mold manufacturing method and photomask of the present invention may form a pattern in the photoresist layer that has only the corners of the soluble portions (cavities), or may form a pattern that has only the corners of the insoluble portions.

[0064] The method for manufacturing an electroforming mold of this embodiment is a method for manufacturing an electroforming mold in which a photomask 80 having a pattern formed thereon with light-shielding portions 82 that block ultraviolet light L and light-transmitting portions 81 that transmit ultraviolet light L is used to form an electroforming mold with a pattern of soluble portions 22 and insoluble portions 21 (in the case of a photoresist layer 20 of a positive resist, the soluble portions and insoluble portions are reversed) in a photoresist layer 20 that is a negative resist, but the method for manufacturing an electroforming mold according to the present invention is not limited to exposing a photoresist layer using a photomask.

[0065] That is, in the method for manufacturing an electroforming mold according to the present invention, the areas of the photoresist layer to be exposed by the light transmitting portions of the photomask (soluble portions and soluble portion corner correction portions in a positive resist, and insoluble portions and insoluble portion corner correction portions in a negative resist) are scanned with, for example, a laser beam without using a photomask, and the areas of the photomask are Interception The present invention may also be a manufacturing method for manufacturing an electroforming mold with a pattern consisting of soluble and insoluble portions by preventing laser light from irradiating areas of a photoresist layer that should be shielded by light portions (insoluble portions and insoluble portion corner correction portions in a positive resist, and soluble portions and soluble portion corner correction portions in a negative resist).

[0066] This application claims priority based on Patent Application No. 2021-054711, filed with the Japan Patent Office on March 29, 2021, the entire disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A method for manufacturing an electroforming mold, comprising forming a pattern consisting of soluble and insoluble portions in a photoresist layer formed by laminating on a substrate, and then removing the soluble portions to form cavities, When a corner is formed in the soluble portion, a soluble portion corner correction portion formed from the soluble portion is formed in an area facing the corner of the soluble portion across the apex of the corner of the soluble portion, the soluble portion being spaced apart from the apex of the corner of the soluble portion and suppressing a decrease in sharpness of the corner of the soluble portion. A manufacturing method of an electroforming mold.

2. A method for manufacturing an electroforming mold as described in Claim 1, wherein the soluble portion angle correction portion is formed in a polygonal or circular shape.

3. 3. The method for manufacturing an electroforming mold according to claim 1, wherein when a corner is formed in the insoluble portion, an insoluble portion corner correction portion is formed in a region facing the corner of the insoluble portion across the apex of the corner of the insoluble portion, the insoluble portion being arranged in contact with or overlapping the apex of the corner of the insoluble portion and suppressing a decrease in sharpness of the corner of the insoluble portion.

4. A method for manufacturing an electroforming mold, comprising forming a pattern consisting of soluble and insoluble portions in a photoresist layer formed by laminating on a substrate, and then removing the soluble portions to form cavities, When a corner portion is formed in the insoluble portion, an insoluble portion corner correction portion formed from the insoluble portion is formed in a region facing the corner portion across the apex of the corner portion, and is arranged in contact with or overlapping the apex of the corner portion of the insoluble portion, thereby suppressing a decrease in the sharpness of the corner portion.

5. A method for manufacturing an electroforming mold as described in claim 3 or 4, wherein the insoluble part angle correction portion is formed in a polygonal or circular shape.

6. A photomask used to form a pattern consisting of soluble and insoluble portions in a photoresist layer formed by laminating it on a substrate and used to form an electroforming mold, comprising: A pattern consisting of a light-shielding portion and a light-transmitting portion is formed, When a corner is formed in the light-shielding portion, a light-shielding portion angle correction portion is formed in the light-shielding portion in an area facing the corner of the light-shielding portion across the apex of the corner of the light-shielding portion, the light-shielding portion being spaced apart from the apex of the corner of the light-shielding portion and suppressing a decrease in sharpness of the corner of the light-shielding portion.

7. 7. The photomask according to claim 6, wherein, when a corner is formed in the light-transmitting portion, a light-transmitting portion corner correction portion formed of the light-transmitting portion is formed in a region facing the corner of the light-transmitting portion across an apex of the corner of the light-transmitting portion, the light-transmitting portion corner correction portion suppressing a decrease in sharpness of the corner of the light-transmitting portion.

8. A photomask as described in claim 6 or 7, wherein the light-shielding portion angle correction portion is spaced apart from the vertex of the corner of the light-shielding portion by a distance of 10 μm or less.

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