CN114114827A - Photomask, method for manufacturing photomask, and method for manufacturing display device - Google Patents

Abstract

The purpose of the present invention is to gently incline a photosensitive resist from the center to the outside. The photomask (1A) has, on a transparent substrate, a plurality of pattern formation regions A formed by partially overlapping a pattern of the semi-transmissive film and a pattern of the light-shielding film and having a predetermined shape, and a light-transmissive portion (7) in which the pattern formation region A is not formed. When a region having a predetermined area including the center of the pattern forming region (a) is the 1 st region (D1) and a region having a predetermined area at the outer edge of the pattern forming region (a) is the 2 nd region (D2), the transmittance in the 2 nd region (D2) is higher than the transmittance in the 1 st region (D1).

Description

Photomask, method for manufacturing photomask, and method for manufacturing display device

Technical Field

The present invention relates to a photomask, a method for manufacturing the photomask, and a method for manufacturing a display device.

Background

A technique of forming a resist into a desired shape by exposure using a photomask is known. For example, patent document 1 discloses a method for manufacturing a multi-tone photomask having a stepped pattern on at least one layer of the surface of a mask substrate.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent No. 2018-45016

Disclosure of Invention

Problems to be solved by the invention

In the case of forming a resist having an uneven shape or the like on a transfer substrate by exposure using a photomask, it is desirable that the resist in an arbitrary region be gradually inclined from the center of the resist to the outside.

An object of an embodiment of the present invention is to provide a photomask capable of forming a shape gently inclined with respect to a photosensitive resist of a transfer target substrate, a method for manufacturing the photomask, and the like.

Means for solving the problems

In order to solve the above-described problems, a photomask according to one aspect of the present invention includes a plurality of pattern forming regions having a predetermined shape and including at least two regions having different transmittances, on a transparent substrate, and a region having a predetermined area including a central portion of the pattern forming region is a 1 st region, and a region having a predetermined area at an outer edge portion of the pattern forming region is a 2 nd region, and the transmittance in the 2 nd region is higher or lower than the transmittance in the 1 st region.

In order to solve the above-described problems, a method for manufacturing a photomask according to one aspect of the present invention is a method for manufacturing a photomask including a semi-transmissive region formed of a semi-transmissive film on a transparent substrate, a laminated region in which at least the semi-transmissive film and a light-shielding film are laminated on the transparent substrate such that the semi-transmissive film is positioned on the transparent substrate side of the light-shielding film, and a transparent region in which the transparent substrate is exposed, the method including: a step of preparing a mask blank in which at least the semi-permeable film and the light shielding film are laminated on the surface of the transparent substrate such that the semi-permeable film is positioned on the transparent substrate side of the light shielding film; forming a 1 st photoresist pattern by forming a 1 st photoresist film on the surface of the mask blank and drawing the 1 st photoresist film on the 1 st photoresist film by a drawing device to form a 1 st photoresist pattern; a step of removing a part of the light shielding film by using the 1 st photoresist pattern as a mask; removing the exposed semi-permeable film; forming a 2 nd photoresist on the entire surface of the photomask including the light-shielding film, and forming a 2 nd photoresist pattern by drawing the 2 nd photoresist film with a drawing apparatus; and a step of removing a part of the light-shielding film by using the 2 nd photoresist pattern as a mask, wherein when a region having a predetermined area including a central portion of a pattern formation region formed by the light-shielding film and the semi-transmissive film is a 1 st region and a region having a predetermined area in an outer peripheral portion of the pattern formation region is a 2 nd region, the pattern formation region is formed so that a transmittance in the 1 st region is higher than a transmittance in the 2 nd region.

In order to solve the above problem, a method for manufacturing a photomask according to one aspect of the present invention is a method for manufacturing a photomask including: a semi-transmissive region formed of a semi-transmissive film on a transparent substrate, a laminated region formed by laminating a light-shielding film and the semi-transmissive film in this order on the transparent substrate, and a transparent region where the transparent substrate is exposed, the manufacturing method comprising: preparing a mask blank having a light-shielding film formed on a surface of a transparent substrate; forming a 1 st photoresist film on a surface of the mask blank; forming a 1 st photoresist pattern by drawing the 1 st photoresist film with a drawing device; removing a part of the light shielding film using the 1 st photoresist pattern as a mask; forming a semi-transmissive film on the entire surface of the photomask including the light-shielding film; forming a 2 nd photoresist film on a surface of the semi-permeable film; forming a 2 nd photoresist pattern by drawing the 2 nd photoresist film with a drawing device; and a step of removing a part of the semi-permeable film by using the 2 nd photoresist pattern as a mask, wherein when a region having a predetermined area including a central portion of a pattern formation region formed by the light-shielding film and the semi-permeable film is a 1 st region and a region having a predetermined area in an outer peripheral portion of the pattern formation region is a 2 nd region, the pattern formation region is formed so that a transmittance in the 1 st region is higher than a transmittance in the 2 nd region.

In order to solve the above problem, a method for manufacturing a photomask according to one aspect of the present invention is a method for manufacturing a photomask including: a semi-transparent region formed of a semi-transparent film on a transparent substrate, a laminated region in which at least the semi-transparent film and a light-shielding film are laminated on the transparent substrate such that the semi-transparent film is positioned on the transparent substrate side of the light-shielding film, and a transparent region in which the transparent substrate is exposed, the manufacturing method including the steps of: a step of preparing a mask blank in which at least the semi-permeable film and the light-shielding film are laminated on the surface of the transparent substrate such that the semi-permeable film is positioned on the transparent substrate side of the light-shielding film; a step of forming a 1 st photoresist pattern by forming a 1 st photoresist film on the surface of the mask blank and drawing the 1 st photoresist film on the 1 st photoresist film with a drawing device to form a 1 st photoresist pattern; removing a part of the light shielding film using the 1 st photoresist pattern as a mask; removing the exposed semi-permeable film; a step of forming a 2 nd photoresist pattern by forming a 2 nd photoresist film on the entire surface of the photomask including the light shielding film and drawing the 2 nd photoresist film with a drawing device to form a 2 nd photoresist pattern; and removing a part of the semi-permeable film by using the 2 nd photoresist pattern as a mask, wherein when a region having a predetermined area in a central portion of a pattern forming region formed by the light-shielding film and the semi-permeable film is a 1 st region and a region having a predetermined area in an outer peripheral portion of the pattern forming region is a 2 nd region, the pattern forming region is formed so that a transmittance in the 1 st region is lower than a transmittance in the 2 nd region.

In order to solve the above problem, a method for manufacturing a photomask according to one aspect of the present invention is a method for manufacturing a photomask including: a semi-transparent region formed of a semi-transparent film on a transparent substrate, a laminated region formed by laminating a light-shielding film and the semi-transparent film in this order on the transparent substrate, and a transparent region exposed from the transparent substrate, the manufacturing method including the steps of: preparing a mask blank having a light-shielding film formed on a surface of a transparent substrate; forming a 1 st photoresist film on a surface of the mask blank; forming a 1 st photoresist pattern by drawing the 1 st photoresist film with a drawing device; removing a part of the light shielding film using the 1 st photoresist pattern as a mask; forming a semi-transmissive film on the entire surface of the photomask including the light-shielding film; forming a 2 nd photoresist film on a surface of the semi-permeable film; forming a 2 nd photoresist pattern by drawing the 2 nd photoresist film with a drawing device; and removing a part of the semi-permeable film by using the 2 nd photoresist pattern as a mask, wherein when a region having a predetermined area including a central portion of a pattern formation region formed by the light-shielding film and the semi-permeable film is a 1 st region and a region having a predetermined area in an outer peripheral portion of the pattern formation region is a 2 nd region, the pattern formation region is formed so that a transmittance in the 1 st region is lower than a transmittance in the 2 nd region.

ADVANTAGEOUS EFFECTS OF INVENTION

According to an aspect of the present invention, the photosensitive resist in an arbitrary region of the photosensitive resist on the transfer target substrate can be formed into a gently inclined shape.

Drawings

Fig. 1 is a plan view showing a configuration of a photomask according to embodiment 1 of the present invention.

Fig. 2(a) is a view showing a pattern design formed on a pattern forming region of the photomask, and (b) is a cross-sectional view of the photomask obtained by cutting the transparent substrate in a plane perpendicular to the pattern forming region.

Fig. 3(a) is a diagram showing the intensity of light irradiated from the photoresist film when the photoresist film on the transfer substrate is irradiated through the photomask, and (b) is a diagram showing the shape of the photoresist film after exposure and development of the photosensitive photoresist film on the transfer substrate through the photomask.

Fig. 4 is a diagram for explaining the method of manufacturing the photomask.

Fig. 5 is a diagram for explaining the method of manufacturing the photomask.

Fig. 6 is a diagram for explaining the method of manufacturing the photomask.

Fig. 7 is a diagram for explaining the method of manufacturing the photomask.

Fig. 8(a) is a plan view showing a pattern forming region as a modification of the pattern forming region, wherein (b) is a graph showing the intensity of light irradiated to the photoresist film when the photoresist film is irradiated through a photomask having the pattern forming region as the modification, and (c) is a graph showing the shape of the photoresist film after exposure and development of the photosensitive photoresist film through the photomask.

Fig. 9(a) is a plan view showing a pattern forming region as another modification of the pattern forming region, wherein (b) is a graph showing the intensity of light irradiated to the photoresist film when the photoresist film is irradiated with light through a photomask including the pattern forming region as the other modification, and (c) is a graph showing the shape of the photoresist film after exposure and development of the photosensitive photoresist film through the photomask.

Fig. 10(a) is a plan view showing a pattern forming region as another modification of the pattern forming region, wherein (b) is a graph showing the intensity of light irradiated to the photoresist film when the photoresist film is irradiated with light through a photomask including the pattern forming region as the other modification, and (c) is a graph showing the shape of the photoresist film after exposure and development of the photosensitive photoresist film through the photomask.

Fig. 11(a) is a plan view showing a pattern forming region as another modification of the pattern forming region, wherein (b) is a diagram showing the intensity of light irradiated from the photoresist film when the photoresist film is irradiated with light through a photomask having the pattern forming region as the other modification, and (c) is a diagram showing the shape of the photoresist film after exposure and development of the photosensitive photoresist film through the photomask.

Fig. 12(a) is a plan view showing a pattern forming region as a further modification of the pattern forming region, wherein (b) is a graph showing the intensity of light irradiated to the photoresist film when the photoresist film is irradiated with light through a photomask having the pattern forming region as the other modification, and (c) is a graph showing the shape of the photoresist film after exposure and development of the photosensitive photoresist film through the photomask.

Fig. 13(a) is a plan view showing a pattern forming region as another modification of the pattern forming region, wherein (b) is a graph showing the intensity of light irradiated to the photoresist film when the photoresist film is irradiated with light through a photomask including the pattern forming region as the other modification, and (c) is a graph showing the shape of the photoresist film after exposure and development of the photosensitive photoresist film through the photomask.

Fig. 14(a) is a view showing a pattern design formed in a pattern forming region of a photomask including the pattern forming region as the further modification, and (b) is a cross-sectional view showing the photomask cut in a plane perpendicular to the transparent substrate.

Fig. 15(a) is a view showing the intensity of light irradiated to the photoresist film when the photoresist film is irradiated with light through a photomask having a pattern forming region as yet another modification example, and (b) is a view showing the shape of the photoresist film after exposure and development of the photosensitive photoresist film through the photomask.

Fig. 16 is a diagram for explaining the method of manufacturing the photomask.

Fig. 17 is a diagram for explaining the method of manufacturing the photomask.

Fig. 18 is a diagram for explaining the method of manufacturing the photomask.

Fig. 19(a) is a diagram showing a pattern design formed in a pattern forming region of a photomask according to embodiment 2 of the present invention, and (b) is a cross-sectional view of the photomask cut in a plane perpendicular to a transparent substrate.

Fig. 20 is a diagram for explaining the method of manufacturing the photomask.

Fig. 21 is a diagram for explaining the method of manufacturing the photomask.

Fig. 22 is a diagram for explaining the method of manufacturing the photomask.

Fig. 23 is a plan view showing a pattern forming region of a photomask according to embodiment 3 of the present invention.

Fig. 24 is a plan view showing a pattern forming region of a photomask as a modified example of the photomask.

Fig. 25 is a view showing the shape of a negative photoresist film after exposure and development of the negative photoresist film on a transfer substrate through a photomask according to embodiment 1 of the present invention.

Fig. 26(a) is a view showing a pattern design formed in a pattern forming region of a photomask according to embodiment 5 of the present invention, and (b) is a cross-sectional view of the photomask obtained by cutting the transparent substrate in a plane perpendicular to the plane.

Fig. 27 is a view showing the shape of a positive photoresist film after exposure and development of the positive photoresist film on a transfer substrate through the photomask.

Fig. 28 is a view showing the shape of a negative photoresist film on a transfer substrate after exposure and development of the photoresist film through the photomask.

Fig. 29 is a diagram for explaining the method of manufacturing the photomask.

Fig. 30 is a diagram for explaining the method of manufacturing the photomask.

Fig. 31 is a diagram for explaining the method of manufacturing the photomask.

Fig. 32(a) is a view showing a pattern design formed in a pattern forming region of a photomask according to embodiment 6 of the present invention, and (b) is a cross-sectional view of the photomask obtained by cutting the transparent substrate in a plane perpendicular to the plane.

Fig. 33 is a diagram for explaining the method of manufacturing the photomask.

Fig. 34 is a diagram for explaining the method of manufacturing the photomask.

Fig. 35 is a diagram for explaining the method of manufacturing the photomask.

Fig. 36 is a plan view showing a pattern forming region of a photomask as a modified example of the photomask.

Fig. 37 is a plan view showing a pattern forming region of a photomask as a modified example of the photomask.

Fig. 38 is a plan view showing a pattern forming region of a photomask as a modified example of the photomask.

Fig. 39 is a plan view showing a pattern forming region of a photomask as a modified example of the photomask.

Fig. 40 is a plan view showing a pattern forming region of a photomask as a modified example of the photomask.

Fig. 41 is a plan view showing a pattern forming region of a photomask as a modified example of the photomask.

Fig. 42 is a plan view showing a pattern forming region of a photomask as a modified example of the photomask.

Description of the figures

1A-1F photomask; 2 a transparent substrate; 3 a semi-permeable membrane; 4 etching the barrier film; 5 a light shielding film; 7. 85 light-transmitting part; 10. 86, 103 overlap region; 11 a non-overlapping area; 12 a grid pattern area; 14. 17, 70, 80, 88, 90, 102, 110 central region; 16 a light transmissive region; 20. 84 a photoresist film; 30. 50 a mask blank; 40. 60a 1 st photoresist film; 41. 61a 2 nd photoresist film; a pattern forming region; d1 area 1; d2 area 2

Detailed Description

[ embodiment mode 1 ]

An embodiment of the present invention will be described in detail below. Fig. 1 is a plan view showing the structure of a photomask 1A in the present embodiment. Fig. 2(a) is a diagram showing a pattern design of a pattern formation region a formed in the photomask 1A, and fig. 2(b) is a cross-sectional view of the photomask 1A obtained by cutting the transparent substrate 2 in a plane perpendicular to the plane. Fig. 2(b) is an enlarged cross-sectional view of the periphery of the 1 pattern forming region a described later.

As shown in fig. 1 and 2, the photomask 1A is formed by sequentially laminating a transparent substrate 2, a semi-permeable film 3, an etching stopper film 4, and a light-shielding film 5. The semi-transmissive film 3, the etching stopper film 4, and the light-shielding film 5 are not disposed in all regions of the transparent substrate 2, but are preferably disposed in the pattern formation region a as shown in fig. 2 (b).

The transparent substrate 2 is a substrate having optical transparency, and may be made of, for example, quartz glass. The semi-transmissive film 3 is a film that transmits a part of irradiated light, and a chromium-based material such as chromium oxide, chromium nitride, or chromium oxynitride can be used. The etching stopper film 4 is a film for preventing the semi-permeable film 3 from being etched when the light-shielding film 5 is etched. The etching stopper film 4 is made of a material that is not etched by the solvent for etching the light shielding film 5. As the etching stopper film 4, for example, titanium, nickel, molybdenum silicide, or the like can be used. The light-shielding film 5 is a film that does not transmit light, and preferably has an optical density OD of 2.7 or more. As the light shielding film 5, for example, a chromium film can be used.

As shown in fig. 1, the pattern forming region a of the photomask 1A is arranged in a lattice shape. The pattern forming regions a are provided at positions corresponding to the respective pixels of the display device. The region where the pattern forming region a is not formed serves as a light transmitting portion 7 through which light is transmitted.

Next, a pattern design of the pattern forming region a formed in the photomask 1A will be described. In the following description, when designing a pattern of a photomask, the photomask will be described as being viewed from the side opposite to the transparent substrate 2.

As shown in fig. 2(a), the pattern forming region a of the photomask 1A is circular. In the pattern forming region a of the photomask 1A, an overlapping region 10 in which the light-shielding film 5 and the semi-transmissive film 3 overlap each other is formed in a circular shape in a central portion including the center of the pattern forming region a. In the pattern forming region a, a non-overlapping region 11 in which only the semi-permeable film 3 is formed so as to surround the overlapping region 10. In other words, the non-overlapping region 11 is formed at the outer edge of the pattern forming region a. The non-overlap region 11 is formed in a concentric circle shape with respect to the overlap region 10.

In the present disclosure, the transmittance of light in a region of a predetermined area within the pattern forming region a is used as an index indicating the difference in transmittance of light in each portion of the pattern forming region a. A region having a predetermined area including the center of the pattern forming region a is referred to as a 1 st region D1, and a region having a predetermined area in the outer edge of the pattern forming region a is referred to as a 2 nd region D2. The 1 st region D1 and the 2 nd region D2 are regions for explaining the concept of the difference in transmittance between the central portion and the outer edge portion of the pattern forming region a. The center of the 1 st region D1 substantially coincides with the center of the pattern forming region a. Therefore, the 1 st region D1 is a region including at least the overlap region 10. On the other hand, the central portion of the 2 nd region D2 is located at the outer edge portion of the pattern forming region a. Therefore, the 2 nd region D2 is a region including at least the non-overlapping region 11 formed at the outer edge portion of the pattern forming region a. By setting the 1 st region D1 and the 2 nd region D2 in this way, the transmittance in the 2 nd region D2 is higher than the transmittance in the 1 st region D1. When the pattern forming region a is circular, the central portion of the pattern forming region a refers to the center of the circle or a portion near the center.

When the 1 st region D1 and the 2 nd region D2 are rectangular, the size of these regions is, for example, 1 μm × 1 μm or more. In one embodiment of the present invention, the diameter of the overlapping region 10 of the pattern region A of the photomask is 10 to 60 μm, and the width of the non-overlapping region 11 in the diameter direction is 3 to 20 μm. The 1 st region D1 and the 2 nd region D2 may be set so as not to protrude from the pattern forming region a. In the case where there are regions having different transmittances from each other in the 1 st region D1 or the 2 nd region D2, the average transmittance in the regions is set as the transmittance of the 1 st region D1 or the 2 nd region D2.

In the example shown in fig. 2(a), the 1 st region D1 is a rectangular region including only the overlap region 10 in the central portion of the pattern forming region a. The 2 nd region D2 is a region including only the non-overlapping region 11 formed in the outer edge portion. In the example shown in fig. 2(a), although the 1 st and 2 nd regions D1 and D2 are illustrated as rectangles, the 1 st and 2 nd regions D1 and D2 may be circles, polygons, or the like. The setting method of the 1 st region D1 and the 2 nd region D2 is the same as in the modification examples 1 to 7 and embodiment 2 described later.

Fig. 3(a) is a diagram showing the intensity of light irradiated by the photoresist film 20 when the positive photoresist film 20 on the transfer substrate is irradiated with light through the photomask 1A, and fig. 3(b) is a diagram showing the shape of the photoresist film 20 after exposure and development of the photoresist film 20 on the transfer substrate through the photomask 1A. In fig. 3(a), the darker the black color, the lower the intensity of light irradiated to the photoresist film 20. This point is also the same as in fig. 9(a), 11(a), 13(a), 15(a), 17, 19(a), and 21, which will be described later.

As shown in fig. 3(a), the light shielding film 5 is present in the central portion of the pattern forming region a, whereby the intensity of light irradiated to the central portion of the photoresist film 20 becomes small. In addition, since only the semi-transmissive film 3 is present at the outer edge portion of the pattern forming region a so as to surround the overlap region 10, the intensity of the irradiated light increases from the center toward the outer photoresist film 20. This is also true of modifications 1 to 7 described later. As a result, as shown in fig. 3(b), the developed photoresist film 20 has a shape in which the outer edge portion of the photoresist film 20 is gradually inclined, which is a region corresponding to the outer edge portion of the pattern forming region a of the photomask 1A.

As described above, by exposing and developing the photoresist film 20 through the photomask 1A in the present embodiment, the outer edge portion of the photoresist film 20 can be gently inclined. In other words, the photoresist film 20 can be gently inclined from the center toward the outside.

In addition, in the photomask 1A of the present embodiment, the non-overlapping region 11 is formed concentrically with respect to the overlapping region 10. This makes it possible to increase the intensity of light irradiated onto the photoresist film 20 in a stepwise manner while making the light concentric from the center of the photoresist film to the outside.

Next, a method for manufacturing the photomask 1A will be described. Fig. 4 to 7 are diagrams for explaining a method of manufacturing the photomask 1A. As shown in fig. 4, in the production of the photomask 1A, first, a mask blank 30 is prepared in which a semi-transmissive film 3, an etching stopper film 4, and a light-shielding film 5 are sequentially laminated on the surface of a transparent substrate 2 (hereinafter referred to as a 1 st step P1).

Next, a 1 st photoresist film 40 is formed on the surface of the mask blank 30 (hereinafter referred to as a 2 nd step P2). Then, the 1 st photoresist film 40 is drawn by a drawing apparatus (hereinafter referred to as a 3 rd step P3). In the 3 rd step P3, the pattern blank 30 is drawn so that the developed 1 st photoresist film 40 has the shape of the pattern forming region a (i.e., a substantially circular shape) in plan view.

Although not shown, in the 3 rd step P3 and the 10 th step P10 described later, a fiducial mark serving as a reference for alignment may be formed at the same time for alignment, which is called a fiducial mark. More specifically, alignment marks are formed at the corners of the transparent substrate 2.

Next, the 1 st photoresist film 40 is developed to remove the drawn region 40A of the 1 st photoresist film 40, thereby forming a 1 st photoresist pattern (hereinafter referred to as a 4 th step P4). The 3 rd process P3 and the 4 th process P4 are processes of forming the 1 st photoresist pattern.

Next, as shown in fig. 5, the light shielding film 5 is etched using the 1 st photoresist film 40 (i.e., the 1 st photoresist pattern) having the pattern formed thereon as a mask, thereby forming a pattern of the light shielding film 5 (hereinafter referred to as a 5 th step P5). In the 5 th step P5, only the light-shielding film 5 is etched and removed by using a solvent that does not dissolve the etching stopper film 4 as a solvent for etching the light-shielding film 5.

Next, the etching stopper film 4 is removed using the 1 st photoresist pattern and the light-shielding film 5 as masks (hereinafter referred to as a 6 th step P6). Then, the exposed semi-permeable film 3 is removed by removing the etching stopper film 4 (hereinafter referred to as a 7 th step P7). Next, the remaining 1 st photoresist film 40 is removed (hereinafter referred to as 8 th step P8).

Next, as shown in fig. 6, a 2 nd photoresist film 41 is formed on the entire surface of the photomask including the light shielding film 5 (hereinafter, referred to as a 9 th step P9). Then, the 2 nd photoresist film 41 is drawn by a drawing device (hereinafter referred to as a 10 th step P10). In the 10 th step P10, the outer edge portion of the 2 nd photoresist film 41 is drawn in a substantially circular shape in a plan view of the photomask. In the 10 th step P10, the alignment marks formed in the 3 rd step P3 are used to determine the position of the region to be drawn.

Next, the 2 nd photoresist film 41 is developed to remove the drawn region 41A in the 2 nd photoresist film 41, thereby forming a 2 nd photoresist pattern (hereinafter referred to as 11 th step P11). The 9 th, 10 th, and 11 th processes P9, P10, and P11 are processes of forming a 2 nd photoresist pattern.

Next, the light shielding film 5 is patterned using the patterned 2 nd photoresist film 41 (i.e., the 2 nd photoresist pattern) as a mask (hereinafter referred to as a 12 th step P12). In the 12 th step P12, as in the 5 th step P5, only the light-shielding film 5 is etched and removed by using a solvent that does not dissolve the etching stopper film 4 as a solvent for etching the light-shielding film 5.

Next, as shown in fig. 7, the etching stopper film 4 is removed using the 2 nd photoresist pattern and the light-shielding film 5 as masks, and the semi-transmissive film 3 is patterned (hereinafter referred to as 13 th step P13). Finally, the remaining 2 nd photoresist film 41 is removed (hereinafter referred to as 14 th step P14).

Through the above steps, the photomask 1A having the pattern forming region in which the non-overlapping region 11 is formed can be manufactured so as to surround the overlapping region 10 while the overlapping region 10 is formed in a circular shape in the central portion including the center of the pattern forming region a.

In the case where a solvent that does not dissolve the semi-permeable film 3 is used as the solvent for the etching light-shielding film 5, a mask blank that does not include the etching stopper film 4 may be used. For example. By constituting the mask blank with a material in which the light-shielding film 5 and the semi-transmissive film 3 have different etching resistances from each other, it is possible to selectively etch only the light-shielding film 5 even without the etching stopper film 4.

Next, a method for manufacturing a display device using the photomask 1A in the present embodiment will be described. The use of the photomask 1A of the present invention is not limited. In particular, in a substrate for a display device configured by stacking a plurality of layers, the photomask of the present invention can be advantageously applied to a multi-tone photomask in which a resist shape gently inclined from the center of an arbitrary pattern to the outside can be formed by 1 photomask 1A.

For example, the method for manufacturing a display device using the photomask 1A in the present embodiment includes a step of preparing the photomask 1A and a resist forming step of forming a desired resist shape using the photomask 1A. The resist forming step is a step of transferring the transfer pattern of the photomask 1A onto a transfer substrate using an exposure apparatus. The method for manufacturing a display device using the photomask 1A in the present embodiment includes various other necessary steps.

As described above, the photomask 1A of the present invention has a significant advantage in that the resist shape gradually inclined in the direction from the center of the pattern toward the outside can be formed at the outer edge of the pattern forming region a, and thus, a desired pattern can be formed at an arbitrary position of the display device, for example.

The photomask 1A of the present invention can be exposed using a known exposure apparatus for liquid crystal and organic EL. For example, a projection exposure apparatus using exposure light of a single-wavelength or broadband light source having a peak at 300 to 500nm, the Number of Apertures (NA) being 0.08 to 0.12, and the coherence factor (coherence factor, コヒレントファクタ) (σ) having a conventionally known approximately equal magnification optical system, can be used as the exposure apparatus. The number of openings can be 0.12 or more. Of course, the photomask 1A may also be applied as a photomask for proximity exposure.

< modification 1>

A modification of the pattern forming region a of the photomask 1A of embodiment 1 will be described. Fig. 8(a) is a plan view showing the pattern forming region a in the present modification, fig. 8(b) is a graph showing the intensity of light irradiated to the photoresist film 20 when the photoresist film 20 is irradiated through the photomask 1A of the present modification, and fig. 8(c) is a graph showing the shape of the photoresist film 20 after exposure and development of the photoresist film 20 through the photomask 1A of the present modification.

As shown in fig. 8(a), in the present modification, when the pattern forming region a is viewed in plan, a lattice pattern region 12 in which rectangular overlapping regions 10 in which the semi-permeable film 3 and the light-shielding film 5 overlap and rectangular non-overlapping regions 11 in which the light-shielding film 5 does not overlap are formed in an alternating manner is formed. In the present modification, a region where the light-shielding film 5 does not overlap the semi-permeable film 3 is formed on the outer periphery of the lattice pattern region 12. That is, the pattern forming region a of the present modification includes: (1) a mixed region including an overlapping region 10 and a non-overlapping region 11, the overlapping region 10 being formed by laminating a pattern of the semi-transmissive film and a pattern of the light-shielding film so as to overlap each other, the non-overlapping region 11 not overlapping the light-shielding film 5 on the semi-transmissive film 3; and (2) a non-mixed region formed at the outer edge of the mixed region, in which the semi-permeable film 3 does not overlap the light-shielding film 5. The 1 st region D1 in the present modification is present inside the lattice pattern region 12 and is set so as to include at least the rectangular overlap region 10 located at the center of the pattern forming region a. That is, the 1 st region D1 may be a region including only the overlapping region 10 located at the center of the pattern forming region a, or may be a region including the overlapping region 10 and the non-overlapping region 11 around the overlapping region 10. The 2 nd region D2 in the present modification is set in the region outside the lattice pattern region 12, that is, in the non-overlapping region 11 formed in the outer edge portion of the pattern forming region a.

With this configuration, as shown in fig. 8(b), by the light-shielding film 5 being present in the central portion of the pattern formation region a, the intensity of light irradiated to the central portion of the photoresist film 20 becomes smaller as the area ratio of the light-shielding film 5 becomes larger. In addition, since only the semi-transmissive film 3 is present in the outer edge portion of the pattern forming region a so as to surround the overlap region 10, the intensity of light irradiated from the photoresist film 20 increases from the center toward the outside. As a result, as shown in fig. 8(c), the developed photoresist film 20 has a shape in which the outer edge portion is gradually inclined. That is, by using the photomask 1A of the present modification example, the photoresist film 20 can be gently inclined from the center to the outer side.

< modification 2>

Still another modification of the pattern forming region a of the photomask 1A according to embodiment 1 will be described. Fig. 9(a) is a plan view showing the pattern forming region a in the present modification, fig. 9(b) is a graph showing the intensity of light irradiated by the photoresist film 20 when the photoresist film 20 is irradiated through the photomask 1A of the present modification, and fig. 9(c) is a graph showing the shape of the photoresist film 20 after the photoresist film 20 is exposed to light and developed through the photomask 1A of the present modification.

As shown in fig. 9(a), in the present modification, in a plan view of the pattern forming region a, an overlapping region 10 in which the semi-permeable film 3 and the light shielding film 5 overlap is formed in a central region 14 of the pattern forming region a. In the present modification, the region 15 is formed outside the central region 14, and the region 15 includes an overlapping region 10 where the semi-permeable film 3 and the light-shielding film 5 overlap each other, and a plurality of non-overlapping regions 11 where the semi-permeable film 3 does not overlap the light-shielding film 5. In the region 15, the non-overlapping region 11 is formed so that the area increases as it goes toward the outer edge. Further, a region where the semi-permeable film 3 does not overlap the light-shielding film 5 is formed on the outer periphery of the region 15. The 1 st region D1 in the present modification is set inside the central region 14. The 2 nd area D2 in the present modification is set in the non-overlapping area 11 formed in the outer edge portion of the pattern forming area a.

With this configuration, as shown in fig. 9(b), the intensity of light irradiated to the outer edge portion of the photoresist film 20 is greater than the intensity of light irradiated to the central portion of the photoresist film 20. As a result, as shown in fig. 9(c), the developed photoresist film 20 can be formed in a shape in which the outer edge portion is gently inclined. In other words, the photoresist film 20 can be gently inclined from the center to the outside.

< modification 3>

Still another modification of the pattern forming region a of the photomask 1A according to embodiment 1 will be described. Fig. 10(a) is a plan view showing the pattern forming region a in the present modification, fig. 10(b) is a view showing the intensity of light irradiated to the photoresist film 20 when the photoresist film 20 is irradiated through the photomask 1A of the present modification, and fig. 10(c) is a view showing the shape of the photoresist film 20 after the photoresist film 20 is exposed to light and developed through the photomask 1A of the present modification.

As shown in fig. 10(a), in the present modification, when the pattern forming region a is viewed in plan, a rectangular overlapping region 10 in which the semi-transmissive film 3 and the light-shielding film 5 overlap and a rectangular non-overlapping region 11 in which the light-shielding film 5 does not overlap are alternately arranged in the central portion of the pattern forming region a. Further, a region in which only the semipermeable membrane 3 is present is formed outside the region in which the rectangular overlapping region 10 and the rectangular non-overlapping region 11 are alternately arranged. Further, a plurality of rectangular light-transmitting regions 16 in which the light-shielding film 5 and the semi-transmissive film 3 are not present are formed in the outer edge portion of the region where only the semi-transmissive film 3 is present. The 1 st region D1 in the present modification is a region in which the overlapping regions 10 and the non-overlapping regions 11 are alternately arranged, and is set in at least a part thereof so as to be a region including the overlapping regions 10. The 2 nd region D2 in the present modification is a region formed at the outer edge of the pattern forming region a, and is set at least partially so as to include the light-transmitting region 16.

With this configuration, as shown in fig. 10(b), the intensity of light irradiated to the photoresist film 20 is the smallest at the center of the photoresist film 20, and gradually increases from the center toward the outer edge. As a result, as shown in fig. 10(c), the shape of the developed photoresist film 20 can be gradually inclined from the center toward the outer edge.

< modification 4>

Still another modification of the pattern forming region a of the photomask 1A according to embodiment 1 will be described. Fig. 11(a) is a plan view showing the pattern forming region a in the present modification, fig. 11(b) is a view showing the intensity of light irradiated to the photoresist film 20 when the photoresist film 20 is irradiated through the photomask 1A of the present modification, and fig. 11(c) is a view showing the shape of the photoresist film 20 after the photoresist film 20 is exposed to light and developed through the photomask 1A of the present modification.

As shown in fig. 11(a), in the present modification, when the pattern forming region a is viewed in plan, an overlapping region 10 in which the semi-permeable film 3 and the light shielding film 5 are overlapped is formed in a central region 17 of the pattern forming region a. In the modification, a radial region 18 extending radially is formed from the central region 17 to the outer edge overlapping region 10 of the pattern forming region a. The radial region 18 becomes narrower in width as the pattern forming region a proceeds toward the outer edge portion. The 1 st region D1 in the present modification is set inside the central region 17. The 2 nd region D2 in the present modification is a region at the outer edge of the pattern forming region a, and is set so as to include the non-overlapping region 11 at least in part. That is, the pattern forming region a of the present modification includes: (1) a non-mixed region composed of an overlapping region, wherein the overlapping region is formed by laminating a pattern of a semi-transparent film and a pattern of a light-shielding film in an overlapping manner; and (2) a mixed region formed at the outer edge of the non-mixed region and including a region in which the pattern of the semi-permeable film and the pattern of the light-shielding film are laminated so as to overlap, and a non-overlapping region in which the light-shielding film 5 is not overlapped on the semi-permeable film 3.

With this configuration, as shown in fig. 11(b), the intensity of light irradiated to the photoresist film 20 is smallest at the center of the photoresist film 20, and gradually increases from the center toward the outer edge. As a result, as shown in fig. 11(c), the shape of the photoresist film 20 after development can be made gradually inclined from the center toward the outer edge.

< modification 5>

Still another modification of the pattern forming region a of the photomask 1A according to embodiment 1 will be described. Fig. 12(a) is a plan view showing the pattern forming region a in this modification. Fig. 12(b) is a diagram showing the intensity of light irradiated by the photoresist film 20 when the photoresist film 20 is irradiated through the photomask 1A of the present modification, and fig. 12(c) is a diagram showing the shape of the photoresist film 20 after the photoresist film 20 is exposed and developed through the photomask 1A of the present modification.

As shown in fig. 12(a), in the present modification, when the pattern forming region a is viewed in plan, an overlapping region 10 in which the semi-transmissive film 3 and the light shielding film 5 are overlapped is formed in a central region 70 of the pattern forming region a. In the present modification, a spiral region 71 extending in a spiral shape is formed from the central region 70 to the outer edge overlapping region 10 of the pattern forming region a. Between the plurality of swirl regions 71, a non-overlapping region 11 is formed. In the present specification, the phrase "extend in a spiral shape toward the outer edge" actually means "extend in a curved shape toward the outer edge". The radial region 18 may have a width that decreases toward the outer edge of the pattern forming region a. The 1 st region D1 in the present modification is set inside the central region 70. The 2 nd area D2 in the present modification is an area at the outer edge of the pattern forming area a, and is set so as to include the non-overlapping area 11 at least in part.

With this configuration, as shown in fig. 12(b), the intensity of light irradiated to the photoresist film 20 is smallest at the center of the photoresist film 20, and gradually increases from the center toward the outer edge. As a result, as shown in fig. 12(c), the shape of the photoresist film 20 after development can be gradually inclined from the center toward the outer edge.

< modification 6>

Still another modification of the pattern forming region a of the photomask 1A according to embodiment 1 will be described. Fig. 13(a) is a plan view showing the pattern forming region a in this modification. Fig. 13(b) is a diagram showing the intensity of light irradiated by the photoresist film 20 when the photoresist film 20 is irradiated through the photomask 1A of the present modification, and fig. 13(c) is a diagram showing the shape of the photoresist film 20 after the photoresist film 20 is exposed and developed through the photomask 1A of the present modification.

As shown in fig. 13(a), in the present modification, when the pattern forming region a is viewed in plan, an overlapping region 10 in which the semi-transmissive film 3 and the light shielding film 5 are overlapped is formed in a central region 80 of the pattern forming region a. The following regions 81 are formed outside the central region 80: all the regions 81 have: an overlapping region 10 where the semi-permeable film 3 and the light-shielding film 5 are overlapped, and a plurality of light-transmitting regions 16 where the light-shielding film 5 and the semi-permeable film 3 are not present. The region 81 is formed so that the area increases as the light-transmissive region 16 goes to the outside of the pattern forming region a. In addition, a 1 st semi-transmissive portion 82 is formed in a ring shape on the outer periphery of the region 81. In addition, a 2 nd semi-transmissive portion 83 is formed in a ring shape at the outer periphery of the 1 st semi-transmissive portion 82. The 1 st semi-transmissive portion 82 is designed to have a lower transmittance than the 2 nd semi-transmissive portion 83. The 1 st region D1 in the present modification is set inside the central region 80. The 2 nd area D2 in the present modification is set in the non-overlapping area 11 formed in the outer edge portion of the pattern forming area a.

With this configuration, as shown in fig. 13(b), the intensity of light irradiated to the photoresist film 20 is smallest at the center of the photoresist film 20 and gradually increases from the center toward the outer edge. As a result, as shown in fig. 13(c), the shape of the photoresist film 20 after development can be gradually inclined from the center toward the outer edge.

< modification 7>

Still another modification of the pattern forming region a of the photomask 1A according to embodiment 1 will be described. Fig. 14(a) is a plan view showing a pattern design of a pattern forming region a formed in the photomask 1A of the present modification, and fig. 14(b) is a cross-sectional view of the photomask 1A of the present modification cut along a vertical plane with respect to the transparent substrate 2. Fig. 15(a) is a diagram showing the intensity of light irradiated on the photoresist film 20 when the photoresist film 20 is irradiated through the photomask 1A of the present modification, and fig. 15(b) is a diagram showing the shape of the photoresist film 20 after exposure and development of the photoresist film 20 through the photomask 1A of the present modification.

As shown in fig. 14(a), in the present modification, when the pattern forming region a is viewed in plan, an overlapping region 10 in which the semi-transmissive film 3 and the light shielding film 5 are overlapped is formed in a central region 90 of the pattern forming region a. On the outside of the central region 90, a 1 st semi-transmissive portion 91, a 2 nd semi-transmissive portion 92, a 3 rd semi-transmissive portion 93, and a 4 th semi-transmissive portion 94 are formed in a ring shape in this order from the inside. The 1 st, 2 nd, 3 rd, and 4 th semi-permeable parts 91, 92, 93, and 94 are constituted by a semi-permeable membrane 3. As shown in fig. 14(b), of the 1 st, 2 nd, 3 rd, and 4 th half transmission parts 91, 92, 93, and 94, the 1 st half transmission part 91 has the largest film thickness, and the 2 nd, 3 rd, and 4 th half transmission parts 92, 93, and 94 have successively smaller film thicknesses. Thus, the light transmittance of the 1 st half-transmissive portion 91 is minimized, and the light transmittances of the 2 nd half-transmissive portion 92, the 3 rd half-transmissive portion 93, and the 4 th half-transmissive portion 94 are sequentially increased.

With this configuration, as shown in fig. 15(a), the intensity of light irradiated to the photoresist film 20 is smallest at the center of the photoresist film 20 and gradually increases from the center toward the outer edge. As a result, as shown in fig. 15(b), the shape of the developed photoresist film 20 is gradually inclined from the center toward the outer edge.

As described above, the mask 1A of the present modification example has the overlapping region 10 in which the pattern of the semi-transmissive film 3 and the pattern of the light-shielding film 5 are stacked so as to overlap each other in the center of the pattern formation region a. In the photomask 1A of the present modification example, the plurality of semi-transmissive portions having different light transmittances (i.e., the 1 st, 2 nd, 3 rd, and 4 th semi-transmissive portions 91, 92, 93, and 94) are formed toward the outer periphery of the pattern formation region a so as to surround the overlap region 10, and the light transmittances of the plurality of semi-transmissive portions increase toward the outer periphery of the pattern formation region a.

In the photomask 1A, the overlapping region 10 formed in the central region 90 of the pattern forming region a is formed in a circular shape, and the 1 st half transmissive portion 91, the 2 nd half transmissive portion 92, the 3 rd half transmissive portion 93, and the 4 th half transmissive portion 94 are formed in a ring shape, but the invention is not limited to this configuration. That is, the photomask 1A of the present modification example may have the overlapping region 10 in the central portion of the pattern forming region a, and the transmittance gradually increases toward the outer peripheral portion of the pattern forming region a so as to surround the overlapping region 10, so that the plurality of semi-transmissive portions thus obtained are formed. For example, the overlapping area 10 and the plurality of semi-transmissive portions may be elliptical, rectangular, or the like.

In the photomask 1A, the 1 st, 2 nd, 3 rd, and 4 th half- transmissive portions 91, 92, 93, and 94 have the half-transmissive film 3 having the same transmittance, but the photomask 1A of the present modification is not limited to this configuration. The 1 st, 2 nd, 3 rd, and 4 th semi-transmissive portions 91, 92, 93, and 94 may be configured by semi-transmissive films having different transmittances of light from each other, and thus may be configured to have a higher transmittance of light toward the outer periphery of the pattern forming region a.

Next, a method for manufacturing the photomask 1A in the present modification will be described. Fig. 16 to 18 are diagrams で for explaining a method of manufacturing the photomask 1A. As shown in fig. 16, in the production of the photomask 1B, first, a mask blank 50 having a light-shielding film 5 formed thereon is prepared on the surface of the transparent substrate 2 (hereinafter referred to as "1 st step R1"). Next, the light-shielding film 5 formed on the mask blank 50 is patterned. (hereinafter referred to as the 2 nd step R2). In the 2 nd step R2, the light shielding film 5 is patterned to have the shape of the overlapping region 10 (i.e., a circular shape).

Next, the semi-transmissive film 3 is formed on the entire surface of the transparent substrate 2 including the light-shielding film 5 (hereinafter referred to as a 3 rd step R3). Thereafter, in the 3 rd step R3, the semi-permeable film 3 after film formation is patterned (hereinafter referred to as the 4 th step R4). In the 4 th step R4, the shape of the outer edge of the semi-transmissive film 3 is patterned so as to be the shape of the outer edge of the 1 st semi-transmissive portion 91 in a plan view of the transparent substrate 2. Specifically, in the 4 th step R4, a photoresist film is formed on the surface of the semi-transmissive film 3, and the photoresist film is drawn by a drawing device. Then, a photoresist pattern is formed by developing and exposing the photoresist film, and the semi-permeable film 3 is etched with the photoresist pattern as a mask, thereby removing a part of the semi-permeable film to form a pattern of the semi-permeable film 3. Thereafter, the remaining photoresist film is removed.

Next, as shown in fig. 17, a semi-transparent film 3 is further formed on the entire surface of the transparent substrate 2 (hereinafter referred to as a 5 th step R5). In fig. 17, for easy understanding, the semi-permeable film 3 formed in the 5 th step is hatched differently from the semi-permeable film 3 formed in the 3 rd step R3. In this regard, the following steps are also hatched differently. Then, patterning of the semi-permeable film 3 after the film formation in the 5 th step R5 is performed (hereinafter referred to as the 6 th step R6). In the 6 th step R6, the shape of the outer edge of the semi-transmissive film 3 is patterned to be the shape of the outer edge of the 2 nd semi-transmissive portion 92 in a plan view of the transparent substrate 2. The specific method of the 6 th step R6 is the same as that of the 4 th step R4.

Next, the semi-transparent film 3 is further formed on the entire surface of the transparent substrate 2 (hereinafter referred to as a 7 th step R7). Then, patterning of the semi-permeable film 3 formed in the 7 th step R7 is performed (hereinafter referred to as an 8 th step R8). In the 8 th step R8, the outer edge of the semi-transmissive film 3 is patterned so as to have the outer edge of the 3 rd semi-transmissive portion 93 when the transparent substrate 2 is viewed in plan. The specific method of the 8 th step R8 is the same as that of the 4 th step R4.

Next, as shown in fig. 18, a semi-transparent film 3 is further formed on the entire surface of the transparent substrate 2 (hereinafter referred to as a 9 th step R9). Then, patterning of the semi-permeable film 3 after the film formation in the 9 th step R9 is performed (hereinafter referred to as a 10 th step R10). In the 10 th step R10, the transparent substrate 2 is patterned so that the outer edge of the semi-transmissive film 3 has the shape of the outer edge of the 4 th semi-transmissive portion 94 in a plan view. The specific method of the 10 th step R10 is the same as that of the 4 th step R4. Through the above steps, the photomask 1A shown in fig. 14(b) can be manufactured, that is, the photomask 1A in which the film thickness of the 1 st semi-transmissive portion 91 is the largest and the film thicknesses of the 2 nd semi-transmissive portion 92, the 3 rd semi-transmissive portion 93, and the 4 th semi-transmissive portion 94 are sequentially reduced can be manufactured.

Next, the film thickness of the semi-permeable film 3 formed in the 3 rd step R3, the 5 th step R5, the 7 th step R7, and the 9 th step R9 will be described. In the setting of the film thickness, first, the transmittance of the light in the 4 th semi-transmissive portion 94 is set to the film thickness of the semi-transmissive film 3 formed in the 9 th step R9 so that the transmittance becomes a desired transmittance. The transmittance in the region in which a plurality of semipermeable membranes are laminated is represented by the following formula (1).

T＝T₀×exp(-4πkz/λ)…(1)

In the above formula (1), T is the transmittance, T₀Is a value uniquely determined from the optical properties of the substrate glass (i.e., the transparent substrate 2) and the semi-transmissive film, λ is the wavelength of the exposure light, k is the extinction coefficient of the semi-transmissive film, and z is the film thickness of the semi-transmissive film. As shown in the above formula (1), T₀And λ and k are given by a given time, the transmittance of the region in which the plurality of semi-permeable films are laminated is determined by the thickness of the semi-permeable film. In the 9 th step R9, the thickness of the semi-permeable film to be formed is set so that the transmittance calculated by the above formula (1) is the transmittance of the 4 th semi-permeable portion 94. Since the 4 th semi-transmissive section 94 is formed of 1 semi-transmissive film 3, λ in the above formula (1) is the film thickness of the semi-transmissive film 3 formed in the 9 th step R9. The transmittance of the 4 th half-transmissive part 94 formed in the 9 th step R9 is a reference of the transmittance of the photomask 1A in the present modification example。

Next, the thickness of the semi-transmissive film 3 formed in the 7 th step R7 is set so that the transmittance of the light in the 3 rd semi-transmissive section 93 becomes a desired transmittance, and the transmittance of the light in the 3 rd semi-transmissive section 93 is determined by the total thickness of the thicknesses of the semi-transmissive films 3 formed in the 7 th step R7 and the 9 th step R9. That is, in order to set the 3 rd semi-transmissive section 93 to a desired transmittance, the thickness of the semi-transmissive film 3 formed in the 7 th step R7 is set in advance in consideration of the thickness of the semi-transmissive film 3 formed in the 9 th step R9. More specifically, the thickness of the semi-permeable membrane 3 formed in the 9 th step R9 and the thickness of the semi-permeable membrane 3 having a desired transmittance in the 3 rd semi-permeable section 93 are obtained by using the above formula (1), and the thickness of the semi-permeable membrane 3 formed in the 7 th step R7 is calculated from these thicknesses, and the semi-permeable membrane 3 is formed in the 7 th step R7.

Next, the thickness of the semi-transmissive film 3 formed in the 5 th step R5 is set so that the transmittance of the light in the 2 nd semi-transmissive section 92 becomes a desired transmittance, and the transmittance of the light in the 2 nd semi-transmissive section 92 is determined by the total thickness of the thicknesses of the semi-transmissive films 3 formed in the 5 th step R5, the 7 th step R7, and the 9 th step R9. More specifically, the thickness of the semi-permeable film 3 formed in the 7 th step R7 and the 9 th step R9 and the thickness of the semi-permeable film 3 having a desired transmittance in the 2 nd semi-permeable section 92 are obtained by using the above formula (1), and the thickness of the semi-permeable film 3 formed in the 5 th step R5 is calculated from these thicknesses, and the semi-permeable film 3 is formed in the 5 th step R5.

Finally, the thickness of the semi-transmissive film 3 formed in the 3 rd step R3 is set so that the transmittance of the light in the 1 st semi-transmissive section 91 becomes a desired transmittance, and the transmittance of the light in the 1 st semi-transmissive section 91 is determined by the total thickness of the thicknesses of the semi-transmissive films 3 formed in the 3 rd step R3, the 5 th step R5, the 7 th step R7, and the 9 th step R9. More specifically, the thickness of the permeable membrane 3 formed in the 5 th step R5, the 7 th step R7, and the 9 th step R9, and the thickness of the semi-permeable membrane 3 having a desired transmittance in the 1 st semi-permeable section 91 are determined using the above formula (1), and the thickness of the semi-permeable membrane 3 formed in the 3 rd step R3 is calculated from these thicknesses, and the semi-permeable membrane 3 is formed in the 3 rd step R3.

[ embodiment 2 ]

Other embodiments of the present invention will be described below. For convenience of explanation, members having the same functions as those described in the above embodiment are given the same reference numerals, and the explanation thereof will not be repeated.

Fig. 19(a) is a plan view showing a pattern design of a pattern forming region a formed in a photomask 1B in the present embodiment, and fig. 19(B) is a view showing a configuration of the photomask 1B, which is a cross-sectional view of the photomask 1B cut in a plane perpendicular to the transparent substrate 2. Although the photomask 1A in embodiment 1 is a bottom-surface type photomask, the photomask 1B in this embodiment is a top-surface type photomask.

As shown in fig. 19(B), the photomask 1B has a structure including: a region in which the transparent substrate 2, the light-shielding film 5, and the semi-transmissive film 3 are sequentially laminated; and a region in which the semi-permeable film 3 is laminated on the transparent substrate 2. The light-shielding film 5 and the semi-transmissive film 3 are not disposed in all regions of the transparent substrate 2, but are disposed appropriately in the pattern formation region a. The photomask 1B in the embodiment is not limited to the one having the pattern forming region a shown in fig. 19(a), and may have the pattern forming region a described in the above-described modified examples 1 to 7.

In the pattern forming region a of the photomask 1B, the circular light-shielding film 5 is located on the surface of the transparent substrate 2, and the circular semi-transmissive film 3 having a larger diameter than the light-shielding film 5 is formed on the upper surface of the light-shielding film 5 and the upper surface of the transparent substrate 2, with the same position as the center of the light-shielding film 5 as the center, as in the photomask 1A.

Thus, in the pattern forming region a of the photomask 1B, as shown in fig. 19(a), the overlapping region 10 in which the light-shielding film 5 and the semi-transmissive film 3 are overlapped in the center portion including the center of the pattern forming region a is formed in a circular shape. In the pattern forming region a, a non-overlapping region 11 in which only the semi-permeable film 3 is formed so as to surround the overlapping region 10. In other words, the non-overlapping region 11 is formed at the outer edge of the pattern forming region a.

With this configuration, similarly to the photomask 1A in embodiment 1, the transmittance of light is low in the central portion of the pattern forming region a, whereas the transmittance of light is high toward the outer side of the pattern forming region a in the outer edge portion of the pattern forming region a. In other words, when a region having a predetermined area including the center of the pattern forming region a is the 1 st region D1 and a region having a predetermined area at the outer edge of the pattern forming region a is the 2 nd region D2, the transmittance in the 2 nd region D2 is higher than the transmittance in the 1 st region D1.

Next, a method for manufacturing the photomask 1B will be described. Fig. 20 to 22 are diagrams for explaining a method of manufacturing the photomask 1B. As shown in fig. 20, in the production of the photomask 1B, first, a mask blank 50 having a light-shielding film 5 formed thereon is prepared on the surface of a transparent substrate 2 (hereinafter referred to as "1 st step Q1"). Next, a 1 st photoresist film 60 is formed on the surface of the mask blank 50 (hereinafter referred to as a 2 nd step Q2). Then, the 1 st photoresist film 60 is drawn by a drawing device to form a 1 st photoresist pattern (hereinafter referred to as a 3 rd process Q3). In the 3 rd step Q3, the pattern is drawn so that the developed 1 st photoresist film 60 has the shape of the overlapping region 10 (i.e., a circular shape) when the mask blank 50 is viewed from above.

Next, the 1 st photoresist film 60 is developed to remove the region 60A of the 1 st photoresist film 60 where the drawing is performed, thereby forming a 1 st photoresist pattern (hereinafter referred to as a 4 th step Q4). The 3 rd process Q3 and the 4 th process Q4 are processes for forming the 1 st photoresist pattern.

Next, as shown in fig. 21, the light-shielding film 5 is etched using the 1 st photoresist film 60 (i.e., the 1 st photoresist pattern) having the pattern formed thereon as a mask, and a part of the light-shielding film 5 is removed to form a pattern of the light-shielding film 5 (hereinafter referred to as a 5 th step Q5). Next, the remaining 1 st photoresist film 60 is removed (hereinafter referred to as a 6 th step Q6).

Next, the semi-transmissive film 3 is formed on the entire surface of the photomask including the light-shielding film 5 (hereinafter referred to as a 7 th step Q7). Then, a 2 nd photoresist film 61 is formed on the surface of the semi-transmissive film 3 (hereinafter referred to as an 8 th step Q8). Then, as shown in fig. 22, the 2 nd photoresist film 61 is drawn by a drawing device (hereinafter referred to as a 9 th step P9). In the 9 th step P9, the outer edge portion of the 2 nd photoresist film 61 is drawn in a ring shape in a plan view of the photomask.

Next, the 2 nd photoresist film 61 is developed to remove the region 61A of the 2 nd photoresist film 61 where drawing is performed, thereby forming a 2 nd photoresist pattern (hereinafter referred to as a 10 th step Q10). The 9 th process Q9 and the 10 th process Q10 are processes for forming the 2 nd photoresist pattern.

Next, a part of the semi-permeable film 3 is removed using the patterned 2 nd photoresist film 61 (i.e., the 2 nd photoresist pattern) as a mask (hereinafter referred to as 11 th step Q11). Finally, the remaining 2 nd photoresist film 61 is removed (hereinafter referred to as a 12 th step Q12).

Through the above steps, the photomask 1B having the pattern formation region in which the overlapping region 10 is formed in a circular shape in the central portion including the center of the pattern formation region a and the non-overlapping region 11 is formed so as to surround the overlapping region 10 can be manufactured.

< modification 8>

The photomask described as any of the above embodiments or modifications is a photomask utilizing a difference in transmittance between the light-shielding film 5 and the semi-transmissive film 3, a difference in transmittance due to an area ratio between the light-shielding film 5 and the semi-transmissive film 3, and the like, but the photomask of the present invention is not limited thereto, and a phase shift film may be applied instead of the semi-transmissive film 3 or in combination with the semi-transmissive film 3. The application of the phase shift film can be realized by adjusting the phase difference of the phase shift film with respect to the transparent substrate 2 and the transmittance of the phase shift film, and setting the region to which the phase effect is applied.

For example, in the photomask 1A shown in fig. 2(a), the film thickness of the phase shift film is adjusted so that the phase difference with respect to the transparent substrate 2 becomes 100 degrees or less, the phase shift film is disposed between the overlapping region 10 having a low transmittance and the non-overlapping region 11 having a high transmittance, and the exposure light transmitted through the exposure apparatus in the vicinity of the boundary between the overlapping region 10 and the non-overlapping region 11 is adjusted so as to be shifted toward the non-overlapping region 11 side by the phase shift effect.

In the photomask 1A shown in fig. 14(a), a phase shift film may be formed between at least 1 or more adjacent semi-transmissive portions among the plurality of semi-transmissive portions (i.e., the 1 st semi-transmissive portion 91, the 2 nd semi-transmissive portion 92, the 3 rd semi-transmissive portion 93, and the 4 th semi-transmissive portion 94) having different transmittances of light formed in the outer periphery of the overlap region 10, and/or in the vicinity of the boundary between the adjacent semi-transmissive portions.

In the photomask 1A in which a pattern is formed using the overlapping region 10 and the non-overlapping region 11 shown in fig. 8(a), 9(a), 10(a), 11(a), 12(a), or the like, a phase shift film may be formed in the vicinity of the boundary between the overlapping region 10 and the non-overlapping region 11.

As described above, the transmittance can be adjusted more finely by forming the phase shift film. As a result, the resist on the transfer target substrate side formed through the photomask of the present application can be made to have a more gently inclined shape.

Note that, even when a phase shift film is used, the phase shift film can be used without any particular problem because the above-described manufacturing method can be applied by using the same metal type as the material of the phase shift film, the light-shielding film 5, and/or the semi-permeable film 3.

For example, in the photomask 1A of embodiment 1, the overlapping region 10 is overlapped with the light-shielding film 5 and the semi-transmissive film 3, but the phase shift film may be used instead of the light-shielding film 5. That is, the region where the phase shift film is formed may have a lower transmittance than the non-overlapping region 11, that is, may be set to a region where the intensity of the transmitted exposure light is small, and the optical density OD value may be set to 2.7 or more by laminating the semi-transmissive film 3 and the phase shift film.

[ embodiment 3 ]

In the above embodiments, the photomask in which the pattern forming region a is formed in a circular shape is described, but the photomask of the present invention is not limited to this, and the pattern forming region a is formed in a desired shape in accordance with the shape of each pixel of the display device. This will be described with reference to fig. 23.

Fig. 23 is a plan view showing a pattern forming region a of the photomask 1C in the present embodiment. As shown in fig. 23, the pattern forming region a of the photomask 1C is a regular pentagon. In the pattern forming region a of the photomask 1C, an overlapping region 10 in which the light-shielding film 5 and the semi-transmissive film 3 are overlapped in the center portion including the center of the pattern forming region a is formed in a regular pentagon shape. In the pattern forming region a, a non-overlapping region 11 in which only the semi-transmissive film 3 is formed so as to surround the overlapping region 10. The 1 st region D1 in the present modification is set in the overlap region 10. The 2 nd area D2 in the present modification is set in the non-overlapping area 11 formed by the outer edge portion of the pattern forming area a.

With this configuration, if exposure is not performed through the photomask 1C, the intensity of light irradiated to the outer edge portion of the photoresist film 20 is greater than the intensity of light irradiated to the central portion of the photoresist film 20. As a result, as shown in fig. 3(b), the developed photoresist film 20 can be formed such that the outer edge portion thereof is gently inclined. In other words, the photoresist film 20 can be gently inclined from the center toward the outside.

In the present embodiment, the pattern forming region a has a regular pentagonal structure, but the photomask of the present invention is not limited to this. In the photomask according to one aspect of the present invention, the pattern forming region a may have a pentagonal shape other than a regular pentagonal shape, or may have a polygonal shape other than a pentagonal shape (e.g., a triangular shape, a rectangular shape, a hexagonal shape, etc.). In the photomask according to one aspect of the present invention, the pattern forming region a may have a shape including a pair of opposing straight lines and 2 curved lines connecting both ends of the pair of opposing straight lines, and the pair of opposing straight lines and the 2 curved lines may be connected to each other. In the photomask according to one aspect of the present invention, the pattern forming region a may have a polygonal shape, and at least 1 side of the polygon may have a shape formed by a curved line such as an arc.

< modification 9>

The pattern forming region a of the photomask according to an aspect of the present invention may have an elliptical shape. This will be described with reference to fig. 24.

Fig. 24 is a plan view showing a pattern forming region a of a photomask 1D in the present embodiment. As shown in fig. 24, the pattern forming region a of the photomask 1D has an elliptical shape. In the pattern forming region a of the photomask 1D, an overlapping region 10 in which the light-shielding film 5 and the semi-transmissive film 3 are overlapped is formed in an elliptical shape in a central portion including the center of the pattern forming region a. In the pattern forming region a, a non-overlapping region 11 in which only the semi-permeable film 3 is formed so as to surround the overlapping region 10. The 1 st region D1 in the present modification is set in the overlap region 10. The 2 nd area D2 in the present modification is set in the non-overlapping area 11 formed by the outer edge portion of the pattern forming area a.

With this configuration, in the photomask 1D, the intensity of light irradiated to the outer edge portion of the photoresist film 20 is greater than the intensity of light irradiated to the central portion of the photoresist film 20. Thus, the photoresist film 20 after development can be formed to have a shape in which the outer edge portion thereof is gradually inclined, as in the cross section shown in fig. 3 (b). In other words, the photoresist film 20 can be gently inclined from the center to the outside.

[ embodiment 4 ]

In the above description, the configuration is described in which a resist shape convex to a transfer target substrate is formed by exposing a positive type photoresist film through the photomask of the present invention, but the photomask of the present invention may be used for a negative type photoresist film. In this case, the resist is formed in a concave shape with respect to the transfer substrate. The concave shape is a shape in which the outer edge portion is gently inclined. This structure will be described in detail below.

Fig. 25 is a view showing the shape of a negative photoresist film 84 on a transfer substrate after exposure and development of the photoresist film 84 through the photomask 1A described in embodiment 1. As described in embodiment 1, in the photomask 1A, the transmittance in the central portion of the pattern forming region a is low, and the transmittance increases from the central portion to the outer side. By exposing and developing the negative photoresist film 84 using the photomask 1A having the above-described configuration, the developed photoresist film 84 is removed by development at the central portion where the intensity of the irradiated light is low, as shown in fig. 25. Further, since the intensity of the irradiated light increases from the central portion to the outer edge portion, the solubility of the developer in the photoresist film 84 decreases, and the thickness of the remaining photoresist film 84 increases. In other words, by using the photomask 1A for the negative photoresist film 84, the shape of the photoresist film 84 after development can be made concave with respect to the substrate to be transferred, and the region between the light blocking region and the light transmitting region can be made gently inclined.

[ embodiment 5 ]

In the above embodiments, the photomask in which the pattern forming region a is formed so that the intensity of light irradiated to the photoresist film 20 increases from the center toward the outside is described, but the photomask of the present invention is not limited thereto. A photomask according to an aspect of the present invention may have the following configuration: that is, the pattern forming region a is formed so that the intensity of light irradiated from the photoresist film 20 becomes smaller from the center toward the outside. This will be described with reference to fig. 26.

Fig. 26(a) is a diagram showing a pattern design formed in the pattern forming region a of the photomask 1E in the present embodiment, and fig. 26(b) is a cross-sectional view of the photomask 1E cut in a plane perpendicular to the transparent substrate 2.

As shown in fig. 26(a), the pattern forming region a of the photomask 1E is circular. In the pattern forming region a of the photomask 1E, a light transmitting portion 85 that transmits light is formed in a circular shape in a central portion including the center of the pattern forming region a. As shown in fig. 26(a) and (b), the pattern forming region a is formed with the non-overlapping region 11 in which only the semi-permeable film 3 is formed so as to surround the light-transmitting portion 85. Accordingly, when a region having a predetermined area including the central portion of the pattern forming region a is the 1 st region D1 and a region having a predetermined area in the outer edge portion of the pattern forming region a is the 2 nd region D2, the transmittance in the 2 nd region D2 is lower than the transmittance in the 1 st region D1. In the region outside the pattern forming region a, an overlapping region 10 is formed by overlapping the light-shielding film 5, the etching stopper film 4, and the semi-permeable film 3, and serves as a light-shielding region.

In the photomask 1E having the above configuration, the light transmitting portion 85 is present in the central portion of the pattern forming region a, whereby the intensity of light irradiated to the central portion of the photoresist film 20 is increased. Further, by forming the non-overlap region 11 so as to surround the light transmitting portion 85, the intensity of light irradiated to the photoresist film 20 decreases from the center toward the outside.

Fig. 27 is a view showing the shape of the positive photoresist film 20 after exposure and development of the positive photoresist film 20 on the transfer substrate through the photomask 1E. As shown in fig. 27, the positive type photoresist film 20 on the transfer substrate is exposed to light through a photomask 1E and developed, and the developed photoresist film 20 is removed by development at the central portion where the intensity of the irradiated light is increased. In addition, since the intensity of the irradiated light decreases from the central portion toward the outer edge portion, the thickness of the remaining photoresist film 20 increases. In other words, by using the photomask 1E along with the positive photoresist film 20, the shape of the photoresist film 20 after development can be made concave with respect to the substrate to be transferred, and the region between the light blocking region and the light transmitting region can be made gently inclined.

Fig. 28 is a view showing the shape of a negative photoresist film 84 on a transfer substrate after exposure and development of the photoresist film 84 through a photomask 1E. As shown in fig. 28, the negative photoresist film 84 on the transfer substrate is exposed to light through the photomask 1E and developed, whereby the developed photoresist film 84 is formed so that the outer edge portion thereof is gradually inclined. In other words, the photoresist film 84 can be gently inclined from the center to the outside.

Next, a method for manufacturing the photomask 1E will be described. Fig. 29 to 31 are diagrams for explaining a method of manufacturing the photomask 1E. As shown in fig. 29, in the production of the photomask 1A, first, a mask blank 30 is prepared in which a semi-transmissive film 3, an etching stopper film 4, and a light-shielding film 5 are sequentially laminated on the surface of a transparent substrate 2 (hereinafter, referred to as a 1 st step S1).

Next, a 1 st photoresist film 40 is formed on the surface of the mask blank 30 (hereinafter referred to as a 2 nd step S2). Thereafter, the 1 st photoresist film 40 is drawn by a drawing device (hereinafter referred to as the 3 rd step S3). In step S3, when mask blank 30 is viewed in plan, the 1 st photoresist film 40 in the region corresponding to pattern formation region a is drawn so as to be removed by development.

Next, the 1 st photoresist film 40 is developed to remove the region 40A drawn in the 1 st photoresist film 40, thereby forming a 1 st photoresist pattern (hereinafter referred to as a 4 th step S4). The 3 rd and 4 th processes S3 and S4 are processes for forming the 1 st photoresist pattern.

Next, as shown in fig. 30, the light shielding film 5 is etched using the 1 st photoresist film 40 (i.e., the 1 st photoresist pattern) having the pattern formed thereon as a mask, thereby forming a pattern of the light shielding film 5 (hereinafter referred to as a 5 th step S5). In the 5 th step S5, only the light-shielding film 5 is etched and removed by using a solvent that does not dissolve the etching stopper film 4 as a solvent for etching the light-shielding film 5.

Next, the etching stopper film 4 is removed using the 1 st photoresist pattern and the light shielding film 5 as masks (hereinafter referred to as a 6 th step S6). Then, the remaining 1 st photoresist film 40 is removed (hereinafter referred to as a 7 th step S7).

Next, a 2 nd photoresist film 41 is formed on the entire surface of the photomask including the light shielding film 5 (hereinafter, referred to as an 8 th step S8).

Next, as shown in fig. 31, the 2 nd photoresist film 41 is drawn by a drawing device (hereinafter referred to as a 9 th step S9). In step S9, in a plan view of the photomask, the 2 nd photoresist film 41 is drawn so that only the regions corresponding to the overlapping region 10 and the non-overlapping region 11 remain after development. In this case, it is important to reflect a margin in consideration of the misalignment of the pattern due to the difference in alignment of the drawing device in the design pattern, and to minimize the influence of the misalignment of the pattern.

Next, the 2 nd photoresist film 41 is developed to remove the drawn region 41A in the 2 nd photoresist film 41, thereby forming a 2 nd photoresist pattern (hereinafter referred to as a 10 th step S10). The 8 th, 9 th, and 10 th processes S8, S9, and S10 are processes of forming a 2 nd photoresist pattern.

Next, the semi-permeable film 3 is etched using the patterned 2 nd photoresist film 41 (i.e., the 2 nd photoresist pattern) as a mask, thereby forming a pattern of the semi-permeable film 3 (hereinafter referred to as the 11 th step S11). Finally, the remaining 2 nd photoresist film 41 is removed (hereinafter referred to as a 12 th step P12).

Through the above steps, the photomask 1E having the pattern forming region a in which the light transmitting portion 85 is formed in a circular shape in the central portion including the center of the pattern forming region a and the non-overlapping region 11 is formed so as to surround the light transmitting portion 85 can be manufactured.

[ embodiment 6 ]

In embodiment 5, a description will be given of a bottom-surface type photomask 1E in which a light-transmitting region is formed in the center of the pattern forming region a and a non-overlapping region is formed so as to include the light-transmitting region, but the photomask of the present invention is not limited to this. The photomask according to an aspect of the present invention may be a top-surface type photomask having a light-transmitting region in a central portion of the pattern forming region a and a non-overlapping region surrounding the light-transmitting region. This will be described in detail below.

Fig. 32(a) is a diagram showing a pattern design of a pattern forming region a formed in the photomask 1F in the present embodiment, and fig. 32(b) is a cross-sectional view of the photomask 1F cut in a plane perpendicular to the transparent substrate 2.

As shown in fig. 32(a), in the pattern forming region a of the photomask 1F, a light transmitting portion 85 for transmitting light is formed in a circular shape in a central portion including the center of the pattern forming region a. As shown in fig. 32(a) and (b), the pattern forming region a is formed with a non-overlapping region 11 in which only the semi-transmissive film 3 is formed so as to surround the light-transmissive portion 85. Further, an overlapping region 10 in which the light shielding film 5 and the semi-transmissive film 3 are overlapped is formed outside the pattern forming region a so as to surround the non-overlapping region 11.

With this configuration, similarly to the photomask 1E in embodiment 5, the transmittance of light is high in the central portion of the pattern forming region a, whereas the transmittance of light is low toward the outer side of the pattern forming region a in the outer edge portion of the pattern forming region a. In other words, when a region having a predetermined area including the center of the pattern forming region a is the 1 st region D1 and a region having a predetermined area in the outer edge of the pattern forming region a is the 2 nd region D2, the transmittance in the 2 nd region D2 is lower than the transmittance in the 1 st region D1.

Next, a method for manufacturing the photomask 1F will be described. FIGS. 33 to 35 are views for explaining a method of manufacturing the photomask 1F. As shown in fig. 33, in the production of the photomask 1B, first, a mask blank 50 in which a light-shielding film 5 is formed on the surface of a transparent substrate 2 is prepared (hereinafter, referred to as a 1 st step T1). Next, a 1 st photoresist film 60 is formed on the surface of the mask blank 50 (hereinafter referred to as a 2 nd step T2). Then, the 1 st photoresist film 60 is drawn by a drawing device to form a 1 st photoresist pattern (hereinafter referred to as a 3 rd step T3). In the 3 rd step T3, when the mask blank 50 is viewed in plan, the 1 st photoresist film 60 in the region corresponding to the pattern forming region a is removed by development, and thus drawing is performed.

Next, the 1 st photoresist film 60 is developed to remove the region 60A drawn in the 1 st photoresist film 60, thereby forming a 1 st photoresist pattern (hereinafter referred to as a 4 th step T4). The 3 rd process T3 and the 4 th process T4 are processes for forming the 1 st photoresist pattern.

Next, as shown in fig. 34, the light shielding film 5 is etched using the 1 st photoresist film 60 (i.e., the 1 st photoresist pattern) having the pattern formed thereon as a mask, thereby removing a part of the light shielding film 5 to form a pattern of the light shielding film 5 (hereinafter referred to as a 5 th step T5). Then, the remaining 1 st photoresist film 60 is removed (hereinafter referred to as a 6 th step T6).

Next, the semi-transmissive film 3 is formed on the entire surface of the photomask including the light-shielding film 5 (hereinafter referred to as a 7 th step T7). Then, a 2 nd photoresist film 61 is formed on the surface of the semi-transmissive film 3 (hereinafter referred to as 8 th step T8). Thereafter, as shown in fig. 35, the 2 nd photoresist film 61 is drawn by a drawing apparatus (hereinafter referred to as a 9 th step T9). In this case, it is also important that the margin of misalignment of the pattern due to the difference in alignment of the drawing device to be considered is reflected in the design pattern in advance, and the influence of the misalignment of the pattern can be minimized. In step 9T 9, the photomask is viewed in plan, and the drawing is performed so that only the 2 nd photoresist film 61 remains in the region corresponding to the overlap region 10 and the non-overlap region 11.

Next, the 2 nd photoresist film 61 is developed to remove the region 61A of the 2 nd photoresist film 61 where drawing is performed, thereby forming a 2 nd photoresist pattern (hereinafter referred to as a 10 th step T10). The 9 th process T9 and the 10 th process T10 are processes for forming the 2 nd photoresist pattern.

Next, a part of the semi-permeable film 3 is removed using the patterned 2 nd photoresist film 61 (i.e., the 2 nd photoresist pattern) as a mask (hereinafter referred to as 11 th step T11). Finally, the remaining 2 nd photoresist film 61 is removed (hereinafter referred to as a 12 th step T12).

Through the above steps, the photomask 1F having the pattern forming region a in which the light transmitting portion 85 is formed in a circular shape in the central portion including the center of the pattern forming region a and the non-overlapping region 11 is formed so as to surround the overlapping region 10 can be manufactured.

< modification 10>

A modification of the pattern forming region a of the photomask 1F according to embodiment 6 will be described. Fig. 36 is a plan view showing the pattern forming region a in the present modification. As shown in fig. 36, in the present modification, when the pattern forming region a is viewed in plan, the lattice pattern region 12 in which the rectangular light transmitting portions 85 and the rectangular non-overlapping regions 11 are alternately arranged is formed, the semi-transmissive film 3 and the light-shielding film 5 do not exist in the rectangular light transmitting portions 85, and the light-shielding film 5 does not overlap the rectangular non-overlapping regions 11 in the semi-transmissive film 3. In the present modification, a region where the light-shielding film 5 does not overlap the semi-permeable film 3 is formed on the outer periphery of the lattice pattern region 12. That is, the pattern forming region a of the present modification includes: (1) a mixed region including a light-transmitting portion 85 where the semi-transmissive film 3 and the light-shielding film 5 do not exist, and a non-overlapping region 11 where the light-shielding film 5 does not overlap the semi-transmissive film 3; and (2) a non-mixed region formed at the outer edge of the mixed region and in which the light-shielding film 5 does not overlap the semi-permeable film 3. The 1 st region D1 in this modification is set so as to be present inside the lattice pattern region 12 and to include at least the rectangular light-transmitting portion 85 located at the center of the pattern forming region a. That is, the 1 st region D1 may be a region including only the light transmitting portion 85 located at the center of the pattern forming region a, or may be a region including the light transmitting portion 85 and the non-overlapping region 11 around the light transmitting portion 85. The 2 nd region D2 in the present modification is set in the region outside the lattice pattern region 12, that is, in the non-overlapping region 11 formed in the outer edge portion of the pattern forming region a.

With this configuration, since the light transmitting portion 85 is present in the central portion of the pattern forming region a, the intensity of light irradiated to the central portion of the photoresist film 20 increases as the area ratio of the light transmitting portion 85 increases. Further, since only the semi-transmissive film 3 is present at the outer edge portion of the pattern forming region a so as to surround the lattice pattern region 12, the intensity of light irradiated to the photoresist film 20 decreases from the center toward the outside. Thus, the developed photoresist film 20 has a shape in which the outer edge portion is gradually inclined. That is, by using the photomask of the present modification, the photoresist film 20 can be gently inclined from the center to the outside.

< modification 11>

Still another modification of the pattern forming region a of the photomask 1F according to embodiment 6 will be described. Fig. 37 is a plan view showing the pattern forming region a in the present modification. As shown in fig. 37, in the present modification, a light transmitting portion 85 where the semi-permeable film 3 and the light shielding film 5 are not present is formed in the central region 14 of the pattern forming region a when the pattern forming region a is viewed in plan. In the present modification, the region 15 is formed outside the central region 14, and the region 15 includes a light transmitting portion 85 where the semi-transmissive film 3 and the light-shielding film 5 are not present, and a plurality of non-overlapping regions 11 where the light-shielding film 5 does not overlap the semi-transmissive film 3. In the region 15, the non-overlapping region 11 is formed so that the area increases toward the outer edge. Further, a region where the light-shielding film 5 does not overlap the semi-transmissive film 3 is formed on the outer periphery of the region 15. The 1 st region D1 in the present modification is set inside the center region 14. The 2 nd area D2 in the present modification is set in an area outside the area 15, that is, in the non-overlapping area 11 formed by the outer edge portion of the pattern forming area a.

With this configuration, since the light transmitting portion 85 is formed in the central region 14, the intensity of light irradiated to the central portion of the photoresist film 20 is increased. Further, as the area ratio of the non-overlapping region 11 increases from the central region 14 toward the outside, the intensity of light irradiated by the photoresist film 20 decreases. This allows the developed photoresist film 20 to have a shape in which the outer edge portion is gradually inclined. In other words, the photoresist film 20 can be gently inclined from the center to the outside.

< modification example 12>

Still another modification of the pattern forming region a of the photomask 1F according to embodiment 6 will be described. Fig. 38 is a plan view showing the pattern forming region a in the present modification. As shown in fig. 38, in the present modification, when the pattern forming region a is viewed in plan, rectangular light transmitting portions 85 and rectangular non-overlapping regions 11 are alternately arranged in the central portion of the pattern forming region a, the semi-transmissive film 3 and the light-shielding film 5 are not present in the rectangular light transmitting portions 85, and the light-shielding film 5 is not overlapped on the semi-transmissive film 3 in the rectangular non-overlapping regions 11. Further, a region where only the semi-permeable film 3 exists is formed outside the region where the rectangular light-transmitting portion 85 and the rectangular non-overlapping region 11 are alternately arranged. Further, a plurality of rectangular overlapping regions 86 in which the light-shielding film 5 and the semi-permeable film 3 overlap each other are formed at the outer edge portion of the region where only the semi-permeable film 3 exists. The 1 st region D1 in this modification is a region in which the light transmitting portions 85 and the non-overlapping region 11 are alternately arranged, and is set at least partially so as to include the region of the light transmitting portions 85. The 2 nd area D2 in the present modification is an area formed at the outer edge of the pattern forming area a, and is set to include the overlap area 86 at least partially.

With this configuration, since the light-transmitting portions 85 and the non-overlapping regions 11 are alternately arranged at the central portion of the pattern forming region a and the region where only the semi-transmissive film 3 exists is formed at the outer edge portion of the pattern forming region a, the intensity of light irradiated to the photoresist film 20 is maximized at the center of the photoresist film 20 and gradually decreases from the center toward the outer edge portion. Thus, the shape of the developed photoresist film 20 is gradually inclined from the center toward the outer edge.

< modification example 13>

Still another modification of the pattern forming region a of the photomask 1F according to embodiment 6 will be described. Fig. 39 is a plan view showing a pattern forming region a in the present modification. As shown in fig. 39, in the present modification, when the pattern forming region a is viewed in plan, the light transmitting portion 85 in which the semi-permeable film 3 and the light shielding film 5 are not present is formed in the central region 17 of the pattern forming region a. In the present modification, a radial region 87 extending radially is formed in the light transmission portion 85 from the central region 17 to the outer edge of the pattern forming region a. The width of the radial region 87 decreases toward the outer edge of the pattern forming region a. The 1 st region D1 in the present modification is set inside the central region 17. The 2 nd area D2 in the present modification is an area at the outer edge of the pattern forming area a, and is set at least partially so as to include the non-overlapping area 11. That is, the pattern forming region a of the present modification includes: (1) a non-mixed region (light-transmitting portion 85) where the semi-transmissive film 3 and the light-shielding film 5 are not present; and (2) a mixed region 78 formed on the outer edge of the non-mixed region and including a region where the semi-permeable film 3 and the light-shielding film 5 are not present and a non-overlapping region where the light-shielding film 5 does not overlap the semi-permeable film 3.

With this configuration, the light transmitting portion 85 is formed in the central region 17 of the pattern forming region a, and extends radially from the central region 17 to the light transmitting portion 85 at the outer edge of the pattern forming region a, and the intensity of light irradiated to the photoresist film 20 is maximized at the center of the photoresist film 20 and gradually decreases from the center toward the outer edge. Thus, the shape of the developed photoresist film 20 is gradually inclined from the center toward the outer edge.

< modification 14>

Still another modification of the pattern forming region a of the photomask 1F according to embodiment 6 will be described. Fig. 40 is a plan view showing the pattern forming region a in the present modification. As shown in fig. 40, in the present modification, a light transmitting portion 85 where the semi-permeable film 3 and the light shielding film 5 are not present is formed in a central region 88 of the pattern forming region a when the pattern forming region a is viewed in plan. In the present modification, a spiral region 89 extending spirally is formed in the light-transmitting portion from the central region 88 to the outer edge of the pattern forming region a. Between the plurality of swirling regions 89, a non-overlapping region 11 is formed. The width of the spiral region 89 may be narrowed toward the outer edge of the pattern forming region a. The 1 st region D1 in the present modification is set inside the central region 88. The 2 nd area D2 in the present modification is an area at the outer edge of the pattern forming area a, and is set so as to include the non-overlapping area 11 at least in part.

With this configuration, the light transmitting portion 85 is formed in the central region 88 of the pattern forming region a, and the light transmitting portion 85 extending spirally from the central region 88 to the outer edge of the pattern forming region a is formed, so that the intensity of light irradiated to the photoresist film 20 is maximized at the center of the photoresist film 20 and gradually decreases from the center toward the outer edge. Thus, the shape of the developed photoresist film 20 is gradually inclined from the center toward the outer edge.

< modification 15>

Still another modification of the pattern forming region a of the photomask 1F according to embodiment 6 will be described. Fig. 41 is a plan view showing a pattern forming region a in the present modification. As shown in fig. 41, in the present modification, in a plan view of the pattern forming region a, the light transmitting portion 85 in which the semi-permeable film 3 and the light shielding film 5 are not present is formed in the central region 102 of the pattern forming region a. An overlapping region 10 and a region 103 are formed outside the central region 102, the overlapping region 10 overlapping the semi-permeable film 3 and the light-shielding film 5; the region 103 has a plurality of light-transmitting portions 85 where the light-shielding film 5 and the semi-transmissive film 3 are not present. The region 103 forms the overlap region 10 so that the area increases toward the outside of the pattern forming region a. In addition, a 1 st semi-transmissive portion 100 is formed in a ring shape on the outer periphery of the region 103. In addition, a 2 nd semi-transmissive portion 101 is formed in a ring shape at the outer circumference of the 1 st semi-transmissive portion 100. The 1 st semi-transmissive portion 100 is designed to have a higher transmittance than the 2 nd semi-transmissive portion 101. The 1 st region D1 in the present modification is set inside the central region 102. The 2 nd area D2 in the present modification is set in the non-overlapping area 11 formed by the outer edge portion of the pattern forming area a.

With this configuration, since the light transmitting portion 85 is formed in the central region 102 of the pattern forming region a, the region 103 having the overlapping region 10 and the light transmitting portion 85 is formed outside the central region 102, and the 1 st semi-transmissive portion 100 is formed on the outer periphery of the region 103, the intensity of light irradiated to the photoresist film 20 is maximized at the center of the photoresist film 20 and gradually decreases from the center toward the outer periphery. Thus, the shape of the developed photoresist film 20 is gradually inclined from the center toward the outer edge.

< modification 16>

Still another modification of the pattern forming region a of the photomask 1F according to embodiment 6 will be described. Fig. 42 is a plan view showing a pattern design formed in the photomask pattern forming region a according to the present modification. As shown in fig. 42, in the present modification, a light transmitting portion 85 where the semi-transmissive film 3 and the light shielding film 5 are not present is formed in a central region 110 of the pattern forming region a when the pattern forming region a is viewed in plan. The 1 st, 2 nd, 3 rd, and 4 th semi-transmissive portions 111, 112, 113, and 114 are formed in a ring shape in order from the inside at the outside of the central region 110. The 1 st, 2 nd, 3 rd, and 4 th semi-transmissive portions 111, 112, 113, and 114 are composed of a semi-permeable membrane 3. The film thickness of the 1 st semi-transmissive portion 111 among the 1 st semi-transmissive portion 111, the 2 nd semi-transmissive portion 112, the 3 rd semi-transmissive portion 113, and the 4 th semi-transmissive portion 114 is the smallest, and the film thicknesses of the 2 nd semi-transmissive portion 112, the 3 rd semi-transmissive portion 113, and the 4 th semi-transmissive portion 114 are sequentially increased. Thus, the transmittance of light in the 1 st half-transmissive portion 111 becomes maximum, and the transmittances of light in the 2 nd half-transmissive portion 112, the 3 rd half-transmissive portion 113, and the 4 th half-transmissive portion 114 become lower in order.

With this configuration, since the thickness of the semi-permeable film in the pattern formation region a increases from the center toward the outside, the intensity of light irradiated to the photoresist film 20 is maximized at the center of the photoresist film 20 and gradually decreases from the center toward the outer edge. This allows the shape of the developed photoresist film 20 to be gradually inclined from the center toward the outer edge.

As described above, the photomask of the present modification example has the light transmitting portion 85 where the semi-transmissive film 3 and the light shielding film 5 are not present in the center portion of the pattern forming region a. In the photomask of the present modification, the plurality of semi-transmissive portions having different transmittances of light (i.e., the 1 st semi-transmissive portion 91, the 2 nd semi-transmissive portion 92, the 3 rd semi-transmissive portion 93, and the 4 th semi-transmissive portion 94) are formed toward the outer peripheral portion of the pattern forming region a so as to surround the light-transmissive portion 85, and the transmittance of light in the plurality of semi-transmissive portions becomes lower toward the outer peripheral portion of the pattern forming region a.

In the photomask 1A, the overlapping region 10 formed in the central region 110 of the pattern forming region a is circular, and the 1 st, 2 nd, 3 rd and 4 th semi-transmissive portions 111, 112, 113 and 114 are annular, but the configuration is not limited thereto. That is, the photomask of the present modification preferably has a light transmitting portion 85 at the center of the pattern forming region a, and a plurality of semi-transmissive portions are preferably formed so as to surround the light transmitting portion 85 and gradually increase in transmittance toward the outer periphery of the pattern forming region a. For example, the light-transmitting portion 85 and the plurality of semi-transmitting portions may be elliptical, rectangular, or the like.

The present invention is not limited to the above embodiments, and various modifications are possible within the scope indicated by the claims, and embodiments obtained by appropriately combining technical means disclosed in the respective embodiments are also included in the technical scope of the present invention.

Claims (19)

1. A kind of photo mask is disclosed, which has a mask body,

a plurality of pattern forming regions having a predetermined shape and including at least two regions having different transmittances from each other are provided on a transparent substrate,

a region of a predetermined area including a central portion of the pattern forming region is defined as a 1 st region, a region of a predetermined area in an outer edge portion of the pattern forming region is defined as a 2 nd region,

the transmittance in the 2 nd region is higher or lower than the transmittance in the 1 st region.

2. The photomask of claim 1,

the 2 nd region is formed in a concentric circle shape with respect to the 1 st region.

3. The photomask of claim 1,

when the pattern forming area is overlooked, at least a part of the outer edge shape comprises a circular arc.

4. The photomask of claim 1,

the pattern forming region is polygonal in shape.

5. The photomask according to any one of claims 1 to 4,

the pattern forming region is formed by laminating in such a manner that at least the pattern of the semi-transmissive film partially overlaps the pattern of the light-shielding film,

a light-transmitting portion on the transparent substrate, wherein the pattern forming region is not formed,

the transmittance in the 2 nd region is higher than the transmittance in the 1 st region.

6. The photomask of claim 5,

when the pattern forming area is overlooked, the overlapped area where the semi-permeable film and the light shielding film are overlapped extends in a radial or spiral shape from the central part to the outer edge part of the pattern forming area.

7. The photomask of claim 5,

a plurality of non-overlapping regions having a predetermined shape and not overlapping the light-shielding film are formed on the semi-transmissive film in a plan view of the pattern formation region,

the non-overlapping region is formed in such a manner that the area thereof increases toward the outer edge portion.

8. The photomask of claim 5,

in a plan view of the pattern formation region, a rectangular overlapping region in which the semi-permeable film and the light-shielding film are overlapped and a rectangular non-overlapping region in which the light-shielding film is not overlapped on the semi-permeable film are formed so as to be alternately arranged, and a region in which the light-shielding film is not overlapped on the semi-permeable film is formed on an outer periphery of the lattice pattern region.

9. The photomask of claim 5,

a light-transmitting portion where the light-shielding film and the semi-transmissive film are not present is formed at an outer edge portion of the pattern forming region when the pattern forming region is viewed in a plan view.

10. The photomask according to any one of claims 1 to 4,

the pattern forming region is formed with at least a light transmitting portion and a semi-transmitting portion formed of a semi-transmitting film,

a light-shielding portion formed by laminating the semi-transmissive film and the light-shielding film is formed on the transparent substrate in a region where the pattern forming region is not formed,

the transmittance in the 2 nd region is lower than the transmittance in the 1 st region.

11. The photomask of claim 10,

when the pattern forming area is overlooked, the light-shielding film and the light-transmitting part of the semi-transmitting film do not extend radially or spirally from the central part to the outer edge part of the pattern forming area.

12. The photomask of claim 10,

a plurality of non-overlapping regions having a predetermined shape and not overlapping the light-shielding film on the semi-transmissive film when the pattern forming region is viewed from above,

the non-overlapping region is formed in such a manner that the area thereof increases toward the outer edge portion.

13. The photomask of claim 10,

a lattice pattern region in which a light-transmitting portion and a rectangular non-overlapping region are alternately arranged, the light-shielding film and the semi-transmissive film being absent in the light-transmitting portion, and the light-shielding film being not overlapped with the rectangular non-overlapping region, is formed in a plan view of the pattern forming region,

the non-overlapping region is formed on the outer periphery of the lattice pattern region.

14. The photomask of claim 10,

an overlapping region in which the semi-permeable film and the light-shielding film overlap each other is formed at an outer edge portion of the pattern formation region when the pattern formation region is viewed in plan.

15. A method for manufacturing a display device, comprising a resist forming step of forming a desired resist shape on a transfer substrate using the photomask according to any one of claims 1 to 14,

the resist forming process includes:

an exposure step of exposing the resist through the photomask, and

and forming the desired resist shape by developing the resist after exposure.

16. A method for manufacturing a photomask, comprising: a semi-transmissive region formed of a semi-transmissive film on the transparent substrate; a lamination region in which at least the semi-transmissive film and the light shielding film on the transparent substrate are laminated such that the semi-transmissive film is positioned on the transparent substrate side of the light shielding film; and a transparent region exposed from the transparent substrate,

the manufacturing method comprises the following steps:

preparing a mask blank formed by laminating at least the semi-transmissive film and the light shielding film on a surface of the transparent substrate so that the semi-transmissive film is positioned on the transparent substrate side of the light shielding film;

forming a 1 st photoresist pattern by forming a 1 st photoresist film on a surface of the mask blank and drawing the 1 st photoresist film on the 1 st photoresist film with a drawing device to form a 1 st photoresist pattern;

removing a part of the light shielding film using the 1 st photoresist pattern as a mask;

removing the exposed semi-permeable film;

forming a 2 nd photoresist pattern by forming a 2 nd photoresist film on the entire surface of the photomask including the light shielding film and drawing the 2 nd photoresist film with a drawing device to form a 2 nd photoresist pattern; and

a step of removing a part of the light shielding film using the 2 nd photoresist pattern as a mask,

wherein, when a region having a predetermined area including a central portion of a pattern formation region formed by the light-shielding film and the semi-transmissive film is a 1 st region and a region having a predetermined area in an outer peripheral portion of the pattern formation region is a 2 nd region, the pattern formation region is formed so that a transmittance in the 2 nd region is higher than a transmittance in the 1 st region.

17. A method for manufacturing a photomask, comprising: a semi-transmissive region formed of a semi-transmissive film on the transparent substrate; a laminated region in which a light-shielding film and the semi-transmissive film are laminated in this order on the transparent substrate; and a transparent region exposed from the transparent substrate,

the manufacturing method comprises the following steps:

preparing a mask blank having a light-shielding film formed on a surface of a transparent substrate;

forming a 1 st photoresist film on a surface of the mask blank;

forming a 1 st photoresist pattern by drawing the 1 st photoresist film with a drawing device;

removing a part of the light shielding film using the 1 st photoresist pattern as a mask;

forming a semi-transmissive film over the entire surface of the photomask including the light-shielding film;

forming a 2 nd photoresist film on a surface of the semi-permeable film;

forming a 2 nd photoresist pattern by drawing the 2 nd photoresist film with a drawing device; and

a step of removing a part of the semi-permeable film using the 2 nd photoresist pattern as a mask,

wherein, when a region having a predetermined area including a central portion of a pattern formation region formed by the light-shielding film and the semi-transmissive film is a 1 st region and a region having a predetermined area in an outer peripheral portion of the pattern formation region is a 2 nd region, the pattern formation region is formed so that a transmittance in the 2 nd region is higher than a transmittance in the 1 st region.

18. A method for manufacturing a photomask, comprising: a semi-transmissive region formed of a semi-transmissive film on the transparent substrate; a lamination region in which at least the semi-transmissive film and the light shielding film are laminated on the transparent substrate such that the semi-transmissive film is positioned on the transparent substrate side of the light shielding film; and a transparent region exposed from the transparent substrate,

the manufacturing method comprises the following steps:

preparing a mask blank formed by laminating at least the semi-transmissive film and the light shielding film on a surface of the transparent substrate so that the semi-transmissive film is positioned on the transparent substrate side of the light shielding film;

forming a 1 st photoresist pattern by forming a 1 st photoresist film on a surface of the mask blank and drawing the 1 st photoresist film on the 1 st photoresist film with a drawing device to form a 1 st photoresist pattern;

removing a part of the light shielding film using the 1 st photoresist pattern as a mask;

removing the exposed semi-permeable film;

forming a 2 nd photoresist pattern by forming a 2 nd photoresist film on the entire surface of the photomask including the light shielding film and drawing the 2 nd photoresist film with a drawing device to form a 2 nd photoresist pattern; and

a step of removing a part of the semi-permeable film using the 2 nd photoresist pattern as a mask,

wherein, when a region having a predetermined area including a central portion of a pattern formation region formed by the light-shielding film and the semi-transmissive film is a 1 st region and a region having a predetermined area in an outer peripheral portion of the pattern formation region is a 2 nd region, the pattern formation region is formed so that a transmittance in the 2 nd region is lower than a transmittance in the 1 st region.

19. A method for manufacturing a photomask, comprising: a semi-transmissive region formed of a semi-transmissive film on the transparent substrate; a laminated region in which a light-shielding film and the semi-transmissive film are laminated in this order on the transparent substrate; and a transparent region exposed from the transparent substrate,

preparing a mask blank having a light-shielding film formed on a surface of a transparent substrate;

forming a 1 st photoresist film on a surface of the mask blank;

forming a 1 st photoresist pattern by drawing the 1 st photoresist film with a drawing device;

removing a part of the light shielding film using the 1 st photoresist pattern as a mask;

forming a semi-transmissive film on the entire surface of the photomask including the light-shielding film;

forming a 2 nd photoresist film on a surface of the semi-permeable film;

forming a 2 nd photoresist pattern by drawing the 2 nd photoresist film with a drawing device; and

a step of removing a part of the semi-permeable film using the 2 nd photoresist pattern as a mask,

wherein, when a region having a predetermined area including a central portion of a pattern formation region formed by the light-shielding film and the semi-transmissive film is a 1 st region and a region having a predetermined area in an outer peripheral portion of the pattern formation region is a 2 nd region, the pattern formation region is formed so that a transmittance in the 2 nd region is lower than a transmittance in the 1 st region.

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