JP6993530B1 - Photomask, photomask manufacturing method, display device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To gently incline a photosensitive resist from the center to the outside.
SOLUTION: A photomask (1A) has a plurality of pattern forming regions A having a predetermined shape formed by laminating a semi-transmissive film pattern and a light-shielding film pattern so as to partially overlap each other. A translucent portion (7) in which the pattern forming region (A) is not formed is provided on the transparent substrate. When the region having a predetermined area including the central portion of the pattern forming region (A) is defined as the first region (D1) and the region having a predetermined area at the outer edge portion of the pattern forming region (A) is defined as the second region (D2), the first region is used. The transmittance in the second region (D2) is higher than the transmittance in the first region (D1).
[Selection diagram] Fig. 2

Description

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

A technique for 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-gradation photomask having a stepped pattern on at least one layer on the surface of a mask substrate.

Japanese Unexamined Patent Publication No. 2018-4516

When a resist having an uneven shape or the like is formed on a substrate to be transferred by exposure using a photomask, it is desired to gently incline the resist in an arbitrary region from the center to the outside of the resist.

One aspect of the present invention is to provide a photomask capable of forming a gently inclined shape with respect to a photosensitive resist of a substrate to be transferred, a method for producing the same, and the like.

In order to solve the above problems, the photomask according to one aspect of the present invention has a plurality of pattern forming regions having a predetermined shape including at least two regions having different transmittances from each other on the transparent substrate. A region having a predetermined area including the central portion of the pattern forming region is set as a first region, and a region having a predetermined area on the outer edge portion of the pattern forming region is set as a second region, and the second region is higher than the transmittance in the first region. Higher or lower transmittance in the area.

In order to solve the above-mentioned problems, in the method for producing a photomask according to one aspect of the present invention, a semi-transmissive region formed by a semi-transmissive film is formed on a transparent substrate, and at least the semi-transmissive film and a light-shielding film are formed on the transparent substrate. A method for manufacturing a photomask, which comprises a laminated region in which the semi-transmissive film is laminated so as to be located closer to the transparent substrate than the light-shielding film, and a transparent region in which the transparent substrate is exposed. A step of preparing a mask blank formed by laminating at least the semi-transmissive film and the light-shielding film on the surface of the substrate so that the semi-transmissive film is located closer to the transparent substrate than the light-shielding film. A step of forming a first photoresist film on the surface of a mask blank and drawing the first photoresist film on the first photoresist film with a drawing device to form a first photoresist pattern, and the first. Using the photoresist pattern as a mask, a step of removing a part of the light-shielding film, a step of removing the exposed semi-permeable film, and a step of forming a second photoresist on the entire surface of the photomask including the light-shielding film are formed. It includes a step of drawing on the second photoresist film with a drawing device to form the second photoresist pattern, and a step of removing a part of the light-shielding film using the second photoresist pattern as a mask. When a region having a predetermined area including the central portion of the pattern forming region formed by the light-shielding film and the semi-transmissive film is designated as the first region, and a region having a predetermined area on the outer peripheral portion of the pattern forming region is designated as the second region. In addition, the pattern forming region is formed so that the permeability in the second region is higher than the permeability in the first region.

In order to solve the above-mentioned problems, the method for producing a photomask according to one aspect of the present invention comprises a semi-transmissive region formed by a semi-transmissive film on a transparent substrate, and a light-shielding film and the semi-transmissive film on the transparent substrate. A method for manufacturing a photomask having a laminated region in which the transparent substrate is exposed and a transparent region in which the transparent substrate is exposed, the step of preparing a mask blank having a light-shielding film formed on the surface of the transparent substrate, and the mask. A step of forming a first photoresist film on the surface of blanks, a step of drawing on the first photoresist film with a drawing device to form a first photoresist pattern, and using the first photoresist pattern as a mask. , A step of removing a part of the light-shielding film, a step of forming a semi-transmissive film on the entire surface of the photomask including the light-shielding film, and a step of forming a second photoresist film on the surface of the semi-transmissive film. A step of drawing on the second photoresist film with a drawing device to form a second photoresist pattern, and a step of removing a part of the semi-transmissive film using the second photoresist pattern as a mask. The region having a predetermined area including the central portion of the pattern forming region formed by the light-shielding film and the semi-transmissive film is defined as the first region, and the region having a predetermined area on the outer peripheral portion of the pattern forming region is referred to as the second region. When this is done, the pattern forming region is formed so that the permeability in the second region is higher than the permeability in the first region.

In order to solve the above-mentioned problems, in the method for producing a photomask according to one aspect of the present invention, a semi-transmissive region formed by a semi-transmissive film is formed on a transparent substrate, and at least the semi-transmissive film and a light-shielding film are formed on the transparent substrate. A method for manufacturing a photomask, which comprises a laminated region in which the semi-transmissive film is laminated so as to be located closer to the transparent substrate than the light-shielding film, and a transparent region in which the transparent substrate is exposed. A step of preparing a mask blank formed by laminating at least the semi-transmissive film and the light-shielding film on the surface of the substrate so that the semi-transmissive film is located closer to the transparent substrate than the light-shielding film. A step of forming a first photoresist film on the surface of a mask blank and drawing the first photoresist film on the first photoresist film with a drawing device to form a first photoresist pattern, and the first. Using the photoresist pattern as a mask, a step of removing a part of the light-shielding film, a step of removing the exposed semi-permeable film, and a step of forming a second photoresist film on the entire surface of the photomask including the light-shielding film are formed. It includes a step of drawing on the second photoresist film with a drawing device to form a second photoresist pattern, and a step of removing a part of the semi-transmissive film using the second photoresist pattern as a mask. The region having a predetermined area including the central portion of the pattern forming region formed by the light-shielding film and the semi-transmissive film was designated as the first region, and the region having a predetermined area on the outer peripheral portion of the pattern forming region was designated as the second region. Occasionally, the pattern forming region is formed so that the permeability in the second region is lower than the permeability in the first region.

In order to solve the above-mentioned problems, the method for producing a photomask according to one aspect of the present invention comprises a semi-transmissive region formed by a semi-transmissive film on a transparent substrate, and a light-shielding film and the semi-transmissive film on the transparent substrate. A method for manufacturing a photomask having a laminated region in which the transparent substrate is exposed and a transparent region in which the transparent substrate is exposed, the step of preparing a mask blank having a light-shielding film formed on the surface of the transparent substrate, and the mask. A step of forming a first photoresist film on the surface of blanks, a step of drawing on the first photoresist film with a drawing device to form a first photoresist pattern, and using the first photoresist pattern as a mask. , A step of removing a part of the light-shielding film, a step of forming a semi-transmissive film on the entire surface of the photomask including the light-shielding film, and a step of forming a second photoresist film on the surface of the semi-transmissive film. A step of drawing on the second photoresist film with a drawing device to form a second photoresist pattern, and a step of removing a part of the semi-transmissive film using the second photoresist pattern as a mask. The region having a predetermined area including the central portion of the pattern forming region formed by the light-shielding film and the semi-transmissive film is defined as the first region, and the region having a predetermined area on the outer peripheral portion of the pattern forming region is referred to as the second region. When this is done, the pattern forming region is formed so that the permeability in the second region is lower than the permeability in the first region.

According to one aspect of the present invention, it is possible to form a shape gently inclined with respect to the photosensitive resist in an arbitrary region of the photosensitive resist of the substrate to be transferred.

It is a top view which shows the structure of the photomask which concerns on Embodiment 1 of this invention. (A) is a diagram showing a pattern design formed in the pattern forming region of the photomask, and (b) is a cross-sectional view of the photomask cut in a plane perpendicular to the transparent substrate. (A) is a figure which shows the intensity of light which irradiates a photoresist film when light is irradiated to the photoresist film on the photoresist substrate through the said photomask, and (b) is a figure which shows. It is a figure which shows the shape of the photoresist film after the photosensitive photoresist film on the transfer substrate is exposed and developed through the said photomask. It is a figure for demonstrating the manufacturing method of the said photomask. It is a figure for demonstrating the manufacturing method of the said photomask. It is a figure for demonstrating the manufacturing method of the said photomask. It is a figure for demonstrating the manufacturing method of the said photomask. (A) is a plan view showing a pattern forming region as a modification of the pattern forming region, and (b) is for a photoresist film via a photomask provided with the pattern forming region as the modification. It is a figure which shows the intensity of light which irradiates a photoresist film at the time of irradiating with light, and (c) is after exposing and developing a photosensitive photoresist film through the said photomask. It is a figure which shows the shape of a photoresist film. (A) is a plan view showing a pattern forming region as a further modification of the pattern forming region, and (b) is a photoresist via a photomask provided with the pattern forming region as a further modification of the pattern forming region. It is a figure which shows the intensity of the light which irradiates a photoresist film when the film is irradiated with light, and (c) is exposed to the photosensitive photoresist film through the said photomask, and is exposed. It is a figure which shows the shape of the photoresist film after development. (A) is a plan view showing a pattern forming region as a further modification of the pattern forming region, and (b) is a photoresist via a photomask provided with the pattern forming region as a further modification of the pattern forming region. It is a figure which shows the intensity of the light which irradiates a photoresist film when the film is irradiated with light, and (c) is exposed to the photosensitive photoresist film through the said photomask, and is exposed. It is a figure which shows the shape of the photoresist film after development. (A) is a plan view showing a pattern forming region as a further modification of the pattern forming region, and (b) is a photoresist via a photomask provided with the pattern forming region as a further modification of the pattern forming region. It is a figure which shows the intensity of the light which irradiates a photoresist film when the film is irradiated with light, and (c) is exposed to the photosensitive photoresist film through the said photomask, and is exposed. It is a figure which shows the shape of the photoresist film after development. (A) is a plan view showing a pattern forming region as a further modification of the pattern forming region, and (b) is a photoresist via a photomask provided with the pattern forming region as a further modification of the pattern forming region. It is a figure which shows the intensity of the light which irradiates a photoresist film when the film is irradiated with light, and (c) is exposed to the photosensitive photoresist film through the said photomask, and is exposed. It is a figure which shows the shape of the photoresist film after development. (A) is a plan view showing a pattern forming region as a further modification of the pattern forming region, and (b) is a photoresist via a photomask provided with the pattern forming region as a further modification of the pattern forming region. It is a figure which shows the intensity of the light which irradiates a photoresist film when the film is irradiated with light, and (c) is exposed to the photosensitive photoresist film through the said photomask, and is exposed. It is a figure which shows the shape of the photoresist film after development. (A) is a diagram showing a pattern design formed in a pattern forming region of a photomask having a pattern forming region as a further modification of the above, and (b) is a diagram showing a plane perpendicular to a transparent substrate. It is sectional drawing of the said photomask. (A) is a figure which shows the intensity of light irradiated to a photoresist film when the photoresist film is irradiated with light through a photomask provided with a pattern forming region as a further modification. , (B) is a diagram showing the shape of the photoresist film after exposure to the photosensitive photoresist film via the photomask and development. It is a figure for demonstrating the manufacturing method of the said photomask. It is a figure for demonstrating the manufacturing method of the said photomask. It is a figure for demonstrating the manufacturing method of the said photomask. (A) is a diagram showing a pattern design formed in a pattern forming region of the photomask according to the second embodiment of the present invention, and (b) is the above-mentioned photomask cut in a plane perpendicular to a transparent substrate. It is a cross-sectional view of. It is a figure for demonstrating the manufacturing method of the said photomask. It is a figure for demonstrating the manufacturing method of the said photomask. It is a figure for demonstrating the manufacturing method of the said photomask. It is a top view which shows the pattern formation region of the photomask which concerns on Embodiment 3 of this invention. It is a top view which shows the pattern formation region of the photomask as a modification of the said photomask. It is a figure which shows the shape of the photoresist film after the negative type photoresist film on the transfer substrate is exposed and developed through the photomask which concerns on Embodiment 1 of this invention. (A) is a diagram showing a pattern design formed in a pattern forming region of the photomask according to the fifth embodiment of the present invention, and (b) is the above-mentioned photomask cut in a plane perpendicular to a transparent substrate. It is a cross-sectional view of. It is a figure which shows the shape of the photoresist film after the positive type photoresist film on the transfer substrate is exposed and developed through the said photomask. It is a figure which shows the shape of the photoresist film after the negative type photoresist film on the transfer substrate is exposed and developed through the said photomask. It is a figure for demonstrating the manufacturing method of the said photomask. It is a figure for demonstrating the manufacturing method of the said photomask. It is a figure for demonstrating the manufacturing method of the said photomask. (A) is a diagram showing a pattern design formed in a pattern forming region of the photomask according to the sixth embodiment of the present invention, and (b) is the above-mentioned photomask cut in a plane perpendicular to a transparent substrate. It is a cross-sectional view of. It is a figure for demonstrating the manufacturing method of the said photomask. It is a figure for demonstrating the manufacturing method of the said photomask. It is a figure for demonstrating the manufacturing method of the said photomask. It is a top view which shows the pattern formation region of the photomask as a modification of the said photomask. It is a top view which shows the pattern formation region of the photomask as a modification of the said photomask. It is a top view which shows the pattern formation region of the photomask as a modification of the said photomask. It is a top view which shows the pattern formation region of a photomask as a modification of the said photomask. It is a top view which shows the pattern formation region of a photomask as a modification of the said photomask. It is a top view which shows the pattern formation region of the photomask as a modification of the said photomask. It is a top view which shows the pattern formation region of the photomask as a modification of the said photomask.

[Embodiment 1]
Hereinafter, one embodiment of the present invention will be described in detail. FIG. 1 is a plan view showing the configuration of the photomask 1A in the present embodiment. FIG. 2A is a diagram showing a pattern design formed in the pattern forming region A of the photomask 1A, and FIG. 2B is a photomask cut in a plane perpendicular to the transparent substrate 2. It is sectional drawing of 1A. Note that FIG. 2B is an enlarged cross-sectional view of the periphery of one pattern forming region A, which will be described later.

As shown in FIGS. 1 and 2, the photomask 1A has a structure in which a transparent substrate 2, a semi-transmissive film 3, an etching stopper film 4, and a light-shielding film 5 are laminated in this order. The semi-transmissive film 3, the etching stopper film 4, and the light-shielding film 5 are not arranged in all the regions of the transparent substrate 2, and are appropriately arranged in the pattern forming region A as shown in FIG. 2 (b). Has been done.

The transparent substrate 2 is a transparent substrate, and can be made of, for example, quartz glass. The semi-transmissive film 3 is a film that transmits a part of the irradiated light, and for example, a chromium-based material such as chromium oxide, chromium nitride, or chromic acid nitride can be used. The etching stopper film 4 is a film for preventing the semi-transmissive 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 a 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 an optical density OD value of 2.7 or more is suitable. As the light-shielding film 5, for example, a chrome film can be used.

As shown in FIG. 1, in the photomask 1A, the pattern forming regions A are arranged in a grid pattern. The pattern forming region A is provided at a position corresponding to each pixel of the display device. The region in which the pattern forming region A is not formed is a translucent portion 7 that allows light to pass through.

Next, the pattern design formed in the pattern forming region A in the photomask 1A will be described. In the following description, in the case of explaining the pattern design of the photomask, the case where the photomask is viewed in a plane from the side opposite to the transparent substrate 2 side will be described.

As shown in FIG. 2A, the pattern forming region A of the photomask 1A has a circular shape. In the pattern forming region A of the photomask 1A, an overlapping region 10 in which the light-shielding film 5 and the transflective film 3 are superimposed is formed in a circular shape in the central portion including the center of the pattern forming region A. Further, in the pattern forming region A, a non-superimposing region 11 in which only the semi-transmissive membrane 3 is formed so as to surround the superimposing region 10 is formed. In other words, the non-superimposing region 11 is formed on the outer edge portion of the pattern forming region A. The non-superimposed region 11 is formed concentrically with respect to the superposed region 10.

In the present disclosure, as an index showing the difference in the light transmittance of each part in the pattern forming region A, the light transmittance in a region of a predetermined area in the pattern forming region A is used. The region having a predetermined area including the central portion of the pattern forming region A is referred to as a first region D1, and the region having a predetermined area at the outer edge portion of the pattern forming region A is referred to as a second region D2. The first region D1 and the second region D2 are conceptual regions for explaining the difference in transmittance between the central portion and the outer edge portion of the pattern forming region A. The central portion of the first region D1 substantially coincides with the central portion of the pattern forming region A. Therefore, the first region D1 is a region including at least the superimposed region 10. On the other hand, the central portion of the second region D2 is located at the outer edge portion of the pattern forming region A. Therefore, the second region D2 is a region including at least the non-superimposing region 11 formed on the outer edge portion of the pattern forming region A. Since the first region D1 and the second region D2 are set in this way, the transmittance in the second region D2 is higher than the transmittance in the first region D1. When the pattern forming region A is circular, the central portion of the pattern forming region A means the center of the circle or a portion near the center.

When the first region D1 and the second region D2 are rectangular, the size of these regions is, for example, 1 μm × 1 μm or more. In one aspect of the present invention, the diameter of the superimposed region 10 of the pattern region A in the photomask is 10 to 60 μm, and the radial width of the non-superimposed region 11 is 3 to 20 μm. The first region D1 and the second region D2 may be set so as not to protrude from the pattern forming region A. When there are regions having different transmittances in the first region D1 or the second region D2, the average transmittance in the regions is defined as the transmittance of the first region D1 or the second region D2.

In the example shown in FIG. 2A, the first region D1 is a rectangular region including only the superposed region 10 in the central portion of the pattern forming region A. The second region D2 is a region including only the non-superimposed region 11 formed on the outer edge portion. In the example shown in FIG. 2A, the first region D1 and the second region D2 are shown as rectangles, but the first region D1 and the second region D2 may be circular, polygonal, or the like. The method for setting the first region D1 and the second region D2 described above is the same for the modified examples 1 to 7 and the second embodiment described later.

FIG. 3A is a diagram showing the intensity of light applied to the photoresist film 20 when the positive photoresist film 20 on the substrate to be transferred is irradiated with light via the photomask 1A. 3 (b) is a diagram showing the shape of the photoresist film 20 after exposure to the photoresist film 20 on the substrate to be transferred via the photomask 1A and development. In FIG. 3A, it is shown that the darker the black region, the smaller the intensity of the light applied to the photoresist film 20. Regarding this point, FIGS. 9 (a), 11 (a), 13 (a), 15 (a), 17 (a), 19 (a), and FIGS. The same applies to (a) of 21.

As shown in FIG. 3A, the presence of the light-shielding film 5 in the central portion of the pattern forming region A reduces the intensity of the light applied to the central portion of the photoresist film 20. Further, since only the semitransparent film 3 is present at the outer edge of the pattern forming region A so as to surround the superposed region 10, the intensity of the light applied to the photoresist film 20 increases from the center to the outside. ing. This point is the same for the modified examples 1 to 7 described later. As a result, as shown in FIG. 3B, the developed photoresist film 20 has a region corresponding to the outer edge of the pattern forming region A of the photomask 1A, that is, the outer edge of the photoresist film 20 is loose. It has a slanted shape.

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

Further, in the photomask 1A of the present embodiment, the non-superimposing region 11 is formed concentrically with respect to the superimposing region 10. As a result, the intensity of the light applied to the photoresist film 20 can be increased concentrically and stepwise from the center to the outside of the photoresist film.

Next, a method for manufacturing the photomask 1A will be described. 4 to 7 are diagrams for explaining a method for manufacturing the photomask 1A. As shown in FIG. 4, in the manufacture of the photomask 1A, first, a mask blank 30 formed by laminating a semi-transmissive film 3, an etching stopper film 4, and a light-shielding film 5 on the surface of a transparent substrate 2 in this order. (Hereinafter referred to as the first step P1).

Next, the first photoresist film 40 is formed on the surface of the mask blanks 30 (hereinafter, referred to as the second step P2). After that, the first photoresist film 40 is drawn by a drawing device (hereinafter, referred to as a third step P3). In the third step P3, drawing is performed so that the first photoresist film 40 after development has the shape of the pattern forming region A (that is, a substantially circular shape) when the mask blanks 30 are viewed in a plan view.

Although not shown, in the third step P3, in the tenth step P10 described later, an alignment mark as a reference for alignment may be formed at the same time in order to perform alignment called alignment. More specifically, alignment marks are formed in each corner of the transparent substrate 2.

Next, the first photoresist film 40 is developed to remove the drawn region 40A of the first photoresist film 40 to form the first photoresist pattern (hereinafter referred to as the fourth step P4). Call). The third step P3 and the fourth step P4 are steps for forming the first photoresist pattern.

Next, as shown in FIG. 5, the pattern of the light-shielding film 5 is formed by etching the light-shielding film 5 using the first photoresist film 40 (that is, the first photoresist pattern) on which the pattern is formed as a mask. (Hereinafter referred to as the fifth step P5). In the fifth 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 the solvent for etching the light-shielding film 5.

Next, the etching stopper film 4 is removed using the first photoresist pattern and the light-shielding film 5 as masks (hereinafter, referred to as the sixth step P6). After that, the semi-transmissive film 3 exposed by removing the etching stopper film 4 is removed (hereinafter, referred to as the seventh step P7). Next, the remaining first photoresist film 40 is removed (hereinafter, referred to as the eighth step P8).

Next, as shown in FIG. 6, the second photoresist film 41 is formed on the entire surface of the photomask including the light-shielding film 5 (hereinafter, referred to as the ninth step P9). After that, the second photoresist film 41 is drawn by a drawing device (hereinafter, referred to as the tenth step P10). In the tenth step P10, when the photomask is viewed in a plane, drawing is performed in a substantially circular shape with respect to the outer edge portion of the second photoresist film 41. Further, in the tenth step P10, the region for drawing is positioned using the alignment mark formed in the third step P3.

Next, the second photoresist film 41 is developed to remove the drawn region 41A of the second photoresist film 41 to form the second photoresist pattern (hereinafter referred to as the eleventh step P11). Call). The ninth step P9, the tenth step P10, and the eleventh step P11 are steps for forming the second photoresist pattern.

Next, the pattern of the light-shielding film 5 is formed using the second photoresist film 41 (that is, the second photoresist pattern) on which the pattern is formed as a mask (hereinafter, referred to as the twelfth step P12). In the twelfth step P12, similarly to the fifth 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 the solvent for etching the light-shielding film 5.

Next, as shown in FIG. 7, the etching stopper film 4 is removed by using the second photoresist pattern and the light-shielding film 5 as masks, and the pattern of the semi-transmissive film 3 is formed (hereinafter referred to as the thirteenth step P13). Call). Finally, the remaining second photoresist film 41 is removed (hereinafter referred to as step 14 P14).

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

When a solvent that does not dissolve the semi-transmissive film 3 is used as the solvent for etching the light-shielding film 5, mask blanks that do not have the etching stopper film 4 can be used. For example, by forming the mask blanks with a substance in which the light-shielding film 5 and the semi-transmissive film 3 have different etching resistances, only the light-shielding film 5 is selectively etched even when the etching stopper film 4 is not provided. Can be done.

Next, a method of manufacturing a display device using the photomask 1A in the present embodiment will be described. There is no limitation on the use of the photomask 1A of the present invention. In particular, in a display device substrate configured by stacking a plurality of layers, it is possible to form a resist shape having a gentle inclination from the center of an arbitrary pattern to the outside with one photomask 1A. The photomask of the present invention can be advantageously applied to a key photomask.

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 the substrate to be transferred using an exposure apparatus. The method for manufacturing a display device via the photomask 1A in the present embodiment further includes various other necessary steps.

As described above, the photomask 1A of the present invention makes it possible to form a resist shape having a gentle slope along the direction from the center of the pattern toward the outside at the outer edge portion of the pattern forming region A. Therefore, for example, There is a great merit in that a desired pattern can be formed at an arbitrary position of the display device.

The photomask 1A of the present invention can be exposed using an exposure apparatus known for liquid crystal display and organic EL. For example, as an exposure apparatus, exposure light of a single wavelength or broadband light source having a peak at 300 to 500 nm is used, the numerical aperture (NA) is 0.08 to 0.12, and the coherent factor (σ) is conventionally known. A projection exposure apparatus having the same magnification optical system as described above can be used. The numerical aperture can be applied even if it is 0.12 or more. Of course, the photomask 1A can also be applied as a photomask for proximity exposure.

<Modification 1>
A modification of the pattern forming region A of the photomask 1A of the first embodiment will be described. FIG. 8A is a plan view showing the pattern forming region A in the present modification, and FIG. 8B is a plan view showing light to the photoresist film 20 through the photomask 1A of the present modification. It is a figure which shows the intensity of the light which irradiates the photoresist film 20 at the time of irradiation, and (c) of FIG. 8 is exposed to the photoresist film 20 through the photomask 1A of this modification. It is a figure which shows the shape of the photoresist film 20 after development.

As shown in FIG. 8A, in this modification, when the pattern forming region A is viewed in a plan view, the rectangular overlapping region 10 on which the semi-transmissive film 3 and the light-shielding film 5 are superimposed and the semi-transmissive film A checkered pattern region 12 is formed in which rectangular non-superimposed regions 11 on which the light-shielding film 5 is not superimposed are alternately arranged. Further, in this modification, a region in which the light-shielding film 5 is not superimposed on the semi-transmissive film 3 is formed on the outer periphery of the check pattern region 12. That is, in the pattern forming region A of this modification, (1) the superimposed region 10 in which the pattern of the semi-transmissive film and the pattern of the light-shielding film are overlapped, and the light-shielding film 5 are superimposed on the semi-transmissive film 3. It has a mixed region including the non-superimposed region 11 which is not superimposed, and (2) a non-mixed region formed on the outer edge of the mixed region and in which the light-shielding film 5 is not superimposed on the semi-transmissive film 3. The first region D1 in this modification is set so as to include at least a rectangular overlapping region 10 existing inside the check pattern region 12 and located in the central portion of the pattern forming region A. That is, the first region D1 may be a region including only the superposed region 10 located in the central portion of the pattern forming region A, or a region including the superposed region 10 and the non-superimposed region 11 around the superposed region 10. You may. The second region D2 in this modification is set in the region outside the plaid region 12, that is, in the non-superimposing region 11 formed on the outer edge of the pattern forming region A.

With this configuration, as shown in FIG. 8B, the light-shielding film 5 is present in the central portion of the pattern forming region A, so that the area ratio of the light-shielding film 5 increases and the center of the photoresist film 20 increases. The intensity of the light applied to the part is low. Further, since only the semitransparent film 3 is present at the outer edge of the pattern forming region A so as to surround the superposed region 10, the intensity of the light applied to the photoresist film 20 increases from the center to the outside. ing. As a result, as shown in FIG. 8C, the developed photoresist film 20 has a shape in which the outer edge portion is gently inclined. That is, by using the photomask 1A of this modification, the photoresist film 20 can be gently inclined from the center to the outside.

<Modification 2>
A further modification of the pattern forming region A of the photomask 1A of the first embodiment will be described. FIG. 9A is a plan view showing the pattern forming region A in the present modification, and FIG. 9B is a plan view showing light to the photoresist film 20 through the photomask 1A of the present modification. It is a figure which shows the intensity of the light which irradiates the photoresist film 20 at the time of irradiation, and (c) of FIG. 9 is exposed to the photoresist film 20 through the photomask 1A of this modification. It is a figure which shows the shape of the photoresist film 20 after development.

As shown in FIG. 9A, in this modification, when the pattern forming region A is viewed in a plan view, the semi-transmissive film 3 and the light-shielding film 5 are superimposed on each other in the central region 14 of the pattern forming region A. The overlapping region 10 is formed. Further, in this modification, the region 15 has a superposed region 10 in which the semi-transmissive film 3 and the light-shielding film 5 are superimposed, and a plurality of non-superimposed regions 11 in which the light-shielding film 5 is not superposed on the semi-transmissive film 3. Is formed on the outside of the central region 14. In the region 15, the non-superimposed region 11 is formed so that the area increases toward the outer edge portion. Further, on the outer periphery of the region 15, a region is formed in which the light-shielding film 5 is not superimposed on the semi-transmissive film 3. The first region D1 in this modification is set inside the central region 14. The second region D2 in this modification is set in the non-superimposing region 11 formed on the outer edge of the pattern forming region A.

With this configuration, as shown in FIG. 9B, the intensity of the light radiated to the outer edge portion of the photoresist film 20 becomes higher than the intensity of the light radiated to the central portion of the photoresist film 20. There is. As a result, as shown in FIG. 9 (c), the developed photoresist film 20 can have a shape in which the outer edge portion is gently inclined. In other words, the photoresist film 20 can be gently tilted from the center to the outside.

<Modification 3>
A further modification of the pattern forming region A of the photomask 1A of the first embodiment will be described. FIG. 10A is a plan view showing the pattern forming region A in the present modification, and FIG. 10B is a plan view showing light to the photoresist film 20 through the photomask 1A of the present modification. It is a figure which shows the intensity of the light which irradiates the photoresist film 20 at the time of irradiation, and (c) of FIG. 10 is exposed to the photoresist film 20 through the photomask 1A of this modification. It is a figure which shows the shape of the photoresist film 20 after development.

As shown in FIG. 10A, in this modification, when the pattern forming region A is viewed in a plan view, the central portion of the pattern forming region A is a rectangle in which the transflective film 3 and the light shielding film 5 are superimposed. The superposed region 10 and the rectangular non-superimposed region 11 on which the light-shielding film 5 is not superposed are alternately arranged. Further, a region in which only the semi-transmissive film 3 exists is formed outside the region in which the rectangular superimposition region 10 and the rectangular non-superimposition region 11 are alternately arranged. Further, a plurality of rectangular translucent regions 16 in which the light-shielding film 5 and the semi-transmissive film 3 do not exist are formed on the outer edge of the region in which only the semi-transmissive film 3 exists. The first region D1 in this modification is set so that the superimposing region 10 and the non-superimposing region 11 are alternately arranged, and the superimposing region 10 is included in at least a part thereof. The second region D2 in this modification is a region formed on the outer edge of the pattern forming region A, and is set so as to include a translucent region 16 at least in a part thereof.

With this configuration, as shown in FIG. 10B, the intensity of the light applied to the photoresist film 20 is the smallest in the center of the photoresist film 20, and gradually increases from the center toward the outer edge portion. 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 portion.

<Modification example 4>
A further modification of the pattern forming region A of the photomask 1A of the first embodiment will be described. 11 (a) is a plan view showing the pattern forming region A in the present modification, and FIG. 11 (b) shows light to the photoresist film 20 through the photomask 1A of the present modification. It is a figure which shows the intensity of the light which irradiates the photoresist film 20 at the time of irradiation, and (c) of FIG. 11 is exposed to the photoresist film 20 through the photomask 1A of this modification. It is a figure which shows the shape of the photoresist film 20 after development.

As shown in FIG. 11A, in this modification, when the pattern forming region A is viewed in a plan view, the semi-transmissive film 3 and the light-shielding film 5 are superimposed on each other in the central region 17 of the pattern forming region A. The overlapping region 10 is formed. Further, in this modification, a radial region 18 is formed in which the superimposed region 10 radiates from the central region 17 toward the outer edge portion of the pattern forming region A. The radial region 18 becomes narrower toward the outer edge of the pattern forming region A. The first region D1 in this modification is set inside the central region 17. The second region D2 in this modification is a region of the outer edge portion of the pattern forming region A, and is set so as to include a non-superimposed region 11 at least in a part thereof. That is, the pattern forming region A of this modification is a non-mixed region consisting of (1) a superposed region in which the pattern of the semi-transmissive film and the pattern of the light-shielding film are superposed, and (2) the non-mixed region. A mixed region including a region formed on the outer edge of the semi-transmissive film and laminated so that the pattern of the semi-transmissive film and the pattern of the light-shielding film are superimposed, and a non-overlapping region in which the light-shielding film 5 is not superimposed on the semi-transmissive film 3. have.

With this configuration, as shown in FIG. 11B, the intensity of the light applied to the photoresist film 20 is the smallest in the center of the photoresist film 20, and gradually increases from the center toward the outer edge portion. As a result, as shown in FIG. 11 (c), the shape of the developed photoresist film 20 can be gradually inclined from the center toward the outer edge portion.

<Modification 5>
A further modification of the pattern forming region A of the photomask 1A of the first embodiment will be described. FIG. 12A is a plan view showing the pattern forming region A in this modification. FIG. 12B is a diagram showing the intensity of light applied to the photoresist film 20 when the photoresist film 20 is irradiated with light through the photomask 1A of this modification. 12 (c) is a diagram showing the shape of the photoresist film 20 after exposure to the photoresist film 20 via the photomask 1A of this modification and development.

As shown in FIG. 12A, in this modification, when the pattern forming region A is viewed in a plan view, the semi-transmissive film 3 and the light-shielding film 5 are superimposed on each other in the central region 70 of the pattern forming region A. The overlapping region 10 is formed. Further, in this modification, a spiral region 71 is formed in which the superposed region 10 extends spirally from the central region 70 toward the outer edge portion of the pattern forming region A. A non-superimposed region 11 is formed between the plurality of spiral regions 71. As used herein, "extending in a spiral toward the outer edge" means "extending in a curve toward the outer edge". The radial region 18 may become narrower toward the outer edge of the pattern forming region A. The first region D1 in this modification is set inside the central region 70. The second region D2 in this modification is a region of the outer edge portion of the pattern forming region A, and is set so as to include a non-superimposed region 11 at least in a part thereof.

With this configuration, as shown in FIG. 12B, the intensity of the light applied to the photoresist film 20 is the smallest in the center of the photoresist film 20, and gradually increases from the center toward the outer edge portion. As a result, as shown in FIG. 12 (c), the shape of the developed photoresist film 20 can be gradually inclined from the center toward the outer edge portion.

<Modification 6>
A further modification of the pattern forming region A of the photomask 1A of the first embodiment will be described. FIG. 13A is a plan view showing the pattern forming region A in this modification. FIG. 13B is a diagram showing the intensity of light applied to the photoresist film 20 when the photoresist film 20 is irradiated with light through the photomask 1A of this modification. FIG. 13 (c) is a diagram showing the shape of the photoresist film 20 after exposure to the photoresist film 20 via the photomask 1A of this modification and development.

As shown in FIG. 13A, in this modification, when the pattern forming region A is viewed in a plan view, the semi-transmissive film 3 and the light-shielding film 5 are superimposed on each other in the central region 80 of the pattern forming region A. The overlapping region 10 is formed. On the outside of the central region 80, there is a superposed region 10 on which the semi-transmissive film 3 and the light-shielding film 5 are superimposed, and a plurality of translucent regions 16 in which the light-shielding film 5 and the semi-transmissive film 3 do not exist. The region 81 is formed. The region 81 is formed so that the area of the translucent region 16 increases toward the outside of the pattern forming region A. Further, a first semi-transmissive portion 82 is formed in a ring shape on the outer periphery of the region 81. Further, the second semi-transmissive portion 83 is formed in a ring shape on the outer periphery of the first semi-transmissive portion 82. The first semi-transmissive portion 82 is designed to have a lower transmittance than the second semi-transmissive portion 83. The first region D1 in this modification is set inside the central region 80. The second region D2 in this modification is set in the non-superimposing region 11 formed on the outer edge of the pattern forming region A.

With this configuration, as shown in FIG. 13B, the intensity of the light applied to the photoresist film 20 is the smallest in the center of the photoresist film 20, and gradually increases from the center toward the outer edge portion. As a result, as shown in FIG. 13 (c), the shape of the developed photoresist film 20 can be gradually inclined from the center toward the outer edge portion.

<Modification 7>
A further modification of the pattern forming region A of the photomask 1A of the first embodiment will be described. FIG. 14A is a plan view showing a pattern design formed in the pattern forming region A of the photomask 1A of the present modification, and FIG. 14B is a plane perpendicular to the transparent substrate 2. It is sectional drawing of the photomask 1A of this modification cut in. FIG. 15A is a diagram showing the intensity of light applied to the photoresist film 20 when the photoresist film 20 is irradiated with light through the photomask 1A of this modification. FIG. 15 (b) is a diagram showing the shape of the photoresist film 20 after exposure to the photoresist film 20 via the photomask 1A of this modification and development.

As shown in FIG. 14A, in this modification, when the pattern forming region A is viewed in a plan view, the semi-transmissive film 3 and the light-shielding film 5 are superimposed on each other in the central region 90 of the pattern forming region A. The overlapping region 10 is formed. On the outside of the central region 90, a first semi-transparent portion 91, a second semi-transmissive portion 92, a third semi-transmissive portion 93, and a fourth semi-transmissive portion 94 are formed in a ring shape from the inside in this order. The first semi-transmissive section 91, the second semi-transmissive section 92, the third semi-transmissive section 93, and the fourth semi-transmissive section 94 are composed of the semi-transmissive film 3. As shown in FIG. 14B, the film thickness of the first semi-transmissive portion 91 of the first semi-transmissive portion 91, the second semi-transmissive portion 92, the third semi-transmissive portion 93, and the fourth semi-transmissive portion 94. The film thickness is the largest, and the film thickness is reduced in the order of the second semi-transmissive portion 92, the third semi-transmissive portion 93, and the fourth semi-transmissive portion 94. As a result, the light transmittance of the first semi-transmissive portion 91 is the smallest, and the light transmittance is higher in the order of the second semi-transmissive portion 92, the third semi-transmissive portion 93, and the fourth semi-transmissive portion 94. It has become.

With this configuration, as shown in FIG. 15A, the intensity of the light applied to the photoresist film 20 is the smallest in the center of the photoresist film 20, and gradually increases from the center toward the outer edge portion. As a result, as shown in FIG. 15B, the shape of the developed photoresist film 20 can be gradually inclined from the center toward the outer edge portion.

As described above, the photomask 1A of the present modification has a superimposing region 10 in which the pattern of the semi-transmissive film 3 and the pattern of the light-shielding film 5 are superposed on each other in the central portion of the pattern forming region A. ing. Further, in the photomask 1A of this modification, a plurality of semi-transmissive portions having different light transmittances (that is, a first semi-transmissive portion 91, a second semi-transmissive portion 92, a third semi-transmissive portion 93, and a fourth half). The transmissive portion 94) is formed toward the outer peripheral portion of the pattern forming region A so as to surround the superposed region 10, and the plurality of semi-transmissive portions have a light transmittance toward the outer edge portion of the pattern forming region A. It's getting higher.

In the above-mentioned photomask 1A, the superimposed region 10 formed in the central region 90 of the pattern forming region A is circular, and the first semi-transmissive portion 91, the second semi-transparent portion 92, and the third semi-transparent portion 93, The fourth semi-transmissive portion 94 has a ring-shaped configuration, but the configuration is not limited to this. That is, the photomask 1A of this modification has a superimposing 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 superimposing region 10. It suffices if a plurality of semi-transmissive portions are formed so as to continue. For example, the superimposed region 10 and the plurality of translucent portions may be elliptical, rectangular, or the like.

Further, in the above-mentioned photomask 1A, the first semi-transmissive portion 91, the second semi-transmissive portion 92, the third semi-transmissive portion 93, and the fourth semi-transmissive portion 94 are composed of the semi-transmissive film 3 having the same transmittance. However, the photomask 1A of this modification is not limited to this configuration. The first semi-transmissive portion 91, the second semi-transmissive portion 92, the third semi-transmissive portion 93, and the fourth semi-transmissive portion 94 are formed of semi-transmissive films having different light transmittances, whereby a pattern forming region is formed. It may be configured so that the light transmittance increases toward the outer peripheral portion of A.

Next, a method for manufacturing the photomask 1A in this modification will be described. 16 to 18 are diagrams for explaining a method for manufacturing the photomask 1A. As shown in FIG. 16, in the production of the photomask 1B, first, the mask blanks 50 having the light-shielding film 5 formed on the surface of the transparent substrate 2 are prepared (hereinafter, referred to as the first step R1). Next, the light-shielding film 5 formed on the mask blanks 50 is patterned. (Hereinafter referred to as the second step R2). In the second step R2, patterning is performed so that the light-shielding film 5 has the shape (that is, the circular shape) of the overlapping region 10.

Next, a 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 the third step R3). After that, the semi-transmissive film 3 formed in the third step R3 is patterned (hereinafter referred to as the fourth step R4). In the fourth step R4, patterning is performed so that the shape of the outer edge of the semi-transmissive film 3 becomes the shape of the outer edge of the first semi-transmissive portion 91 when the transparent substrate 2 is viewed in a plan view. Specifically, in the fourth 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. After that, a photoresist pattern is formed by developing and exposing the photoresist film, and by etching the semi-transmissive film 3 using the photoresist pattern as a mask, a part of the semi-transmissive film is removed and the semi-transmissive film 3 is removed. Form a pattern of. Then, the remaining photoresist film is removed.

Next, as shown in FIG. 17, a semi-transmissive film 3 is further formed on the entire surface of the transparent substrate 2 (hereinafter, referred to as the fifth step R5). In FIG. 17, for easy understanding, the semi-transmissive film 3 formed in the fifth step is hatched differently from the semi-transmissive film 3 formed in the third step R3. In this regard, different hatching is applied to the following steps as well. After that, the semi-transmissive film 3 formed in the fifth step R5 is patterned (hereinafter referred to as the sixth step R6). In the sixth step R6, patterning is performed so that the shape of the outer edge of the semi-transmissive film 3 becomes the shape of the outer edge of the second semi-transmissive portion 92 when the transparent substrate 2 is viewed in a plan view. The specific method of the sixth step R6 is the same as that of the fourth step R4.

Next, a semi-transmissive film 3 is further formed on the entire surface of the transparent substrate 2 (hereinafter, referred to as a seventh step R7). After that, the semi-transmissive film 3 formed in the seventh step R7 is patterned (hereinafter referred to as the eighth step R8). In the eighth step R8, patterning is performed so that the shape of the outer edge of the semi-transmissive film 3 becomes the shape of the outer edge of the third semi-transmissive portion 93 when the transparent substrate 2 is viewed in a plan view. The specific method of the eighth step R8 is the same as that of the fourth step R4.

Next, as shown in FIG. 18, a semi-transmissive film 3 is further formed on the entire surface of the transparent substrate 2 (hereinafter, referred to as the ninth step R9). After that, the semi-transmissive film 3 formed in the ninth step R9 is patterned (hereinafter referred to as the tenth step R10). In the tenth step R10, patterning is performed so that the shape of the outer edge of the semi-transmissive film 3 becomes the shape of the outer edge of the fourth semi-transmissive portion 94 when the transparent substrate 2 is viewed in a plan view. The specific method of the tenth step R10 is the same as that of the fourth step R4. Through the above steps, the photomask 1A shown in FIG. 14B, that is, the first semi-transmissive portion 91 has the largest film thickness, and the second semi-transmissive portion 92, the third semi-transmissive portion 93, and the fourth semi-transmissive portion 91 have the largest film thickness. A photomask 1A having a smaller film thickness in the order of parts 94 can be manufactured.

Next, the film thickness of the semi-transmissive film 3 formed in the third step R3, the fifth step R5, the seventh step R7, and the ninth step R9 will be described. In setting the film thickness, first, the film thickness of the semi-transmissive film 3 formed in the ninth step R9 is set so that the light transmittance of the fourth semi-transmissive portion 94 becomes a desired transmittance. Here, the transmittance in the region where a plurality of semi-permeable membranes are laminated is expressed by the following formula (1).
T = T ₀ × exp (-4πkz / λ) ・ ・ ・ (1)
In the above formula (1), T is the transmittance, T ₀ is a value uniquely determined by the optical properties of the substrate glass (that is, the transparent substrate 2) and the semitransmissive film, λ is the wavelength of the exposure light, and k is the semitransmissive. The extinction coefficient of the film, z, is the film thickness of the semi-permeable film. As shown in the above formula (1), when T ₀ , λ, and k are constant, the transmittance in the region where a plurality of semi-permeable membranes are laminated is determined by the film thickness of the semi-transmissive membrane. In the ninth step R9, the film thickness of the semi-transmissive film to be formed is set so that the transmittance calculated from the above formula (1) becomes the transmittance of the fourth semi-transmissive portion 94. Since the fourth semi-transmissive portion 94 is composed of one layer of the semi-transmissive film 3, λ in the above formula (1) is the film thickness of the semi-transmissive film 3 formed in the ninth step R9. The transmittance of the fourth semi-transmissive portion 94 formed in the ninth step R9 serves as a reference for the transmittance of the photomask 1A in this modification.

Next, the light transmittance of the third semi-transmissive portion 93, which is determined by the total thickness of the semi-transmissive films 3 formed in the seventh step R7 and the ninth step R9, is the desired transmittance. As described above, the film thickness of the semi-transmissive film 3 formed in the seventh step R7 is set. That is, in order to make the third semi-transmissive portion 93 have a desired transmittance, the semi-transmissive film 3 formed in the seventh step R7 in advance in consideration of the film thickness of the semi-transmissive film 3 formed in the ninth step R9. The film thickness of the transmission film 3 is set. More specifically, using the above formula (1), the film thickness of the semi-transmissive film 3 formed in the ninth step R9 and the semi-transmissive film 3 in which the third semi-transmissive portion 93 has a desired transmittance. The film thickness is obtained, the film thickness of the semi-transmissive film 3 to be formed in the seventh step R7 is calculated from these film thicknesses, and the semi-transmissive film 3 is formed in the seventh step R7.

Next, the light transmittance of the second semi-transmissive portion 92, which is determined by the total thickness of the semi-transmissive films 3 formed in the fifth step R5, the seventh step R7, and the ninth step R9, is desired. The thickness of the semi-transmissive film 3 to be formed in the fifth step R5 is set so as to have the transmittance of. More specifically, using the above formula (1), the film thickness of the semi-transmissive film 3 formed in the 7th step R7 and the 9th step R9 and the second semi-transmissive portion 92 have desired transmittances. The film thickness of the semi-transmissive film 3 is obtained, the film thickness of the semi-transmissive film 3 to be formed in the fifth step R5 is calculated from these film thicknesses, and the semi-transmissive film 3 is formed in the fifth step R5.

Finally, the light of the first semi-transmissive portion 91 determined by the total film thickness of the semi-transmitt film 3 formed in the third step R3, the fifth step R5, the seventh step R7 and the ninth step R9, respectively. The film thickness of the semi-transmissive film 3 to be formed in the third step R3 is set so that the transmittance of the film becomes a desired transmittance. More specifically, using the above formula (1), the film thickness of the semi-transmissive film 3 formed in the fifth step R5, the seventh step R7 and the ninth step R9, and the first semi-transmissive portion 91 are desired. The film thickness of the semi-transmissive film 3 to be the transmittance of Form a film.

[Embodiment 2]
Other embodiments of the present invention will be described below. For convenience of explanation, the same reference numerals are given to the members having the same functions as the members described in the above-described embodiment, and the description thereof will not be repeated.

FIG. 19A is a plan view showing a pattern design formed in the pattern forming region A of the photomask 1B in the present embodiment, and FIG. 19B is a diagram showing the configuration of the photomask 1B. It is a cross-sectional view of a photomask 1B cut in a plane perpendicular to the transparent substrate 2. The photomask 1A in the first embodiment is a bottom type photomask, but the photomask 1B in the present embodiment is a top type photomask.

As shown in FIG. 19B, the photomask 1B has a region in which the transparent substrate 2, the light-shielding film 5, and the semi-transmissive film 3 are laminated in this order, and the semi-transmissive film 3 is laminated on the transparent substrate 2. It has a structure with an area. The light-shielding film 5 and the semi-transmissive film 3 are not arranged in all the regions of the transparent substrate 2, but are appropriately arranged in the pattern forming region A. The photomask 1B in the embodiment is not limited to the one having the pattern forming region A shown in FIG. 19A, and may have the pattern forming region A described in the above modified examples 1 to 7.

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

As a result, as shown in FIG. 19A, the light-shielding film 5 and the transflective film 3 are superimposed on the central portion including the center of the pattern-forming region A in the pattern-forming region A of the photomask 1B. The region 10 is formed in a circular shape. Further, in the pattern forming region A, a non-superimposing region 11 in which only the semi-transmissive membrane 3 is formed so as to surround the superimposing region 10 is formed. In other words, the non-superimposing region 11 is formed on the outer edge portion of the pattern forming region A.

With this configuration, the light transmittance is low in the central portion of the pattern forming region A, as in the photomask 1A in the first embodiment, whereas the outer edge portion of the pattern forming region A has the pattern forming region A. The transmittance of light increases toward the outside of. In other words, when the region having a predetermined area including the central portion of the pattern forming region A is defined as the first region D1 and the region having a predetermined area at the outer edge portion of the pattern forming region A is defined as the second region D2, the first region D1 The transmittance in the second region D2 is higher than the transmittance in the inside.

Next, a method for manufacturing the photomask 1B will be described. 20 to 22 are diagrams for explaining a method for manufacturing the photomask 1B. As shown in FIG. 20, in the production of the photomask 1B, first, the mask blanks 50 having the light-shielding film 5 formed on the surface of the transparent substrate 2 are prepared (hereinafter, referred to as the first step Q1). Next, the first photoresist film 60 is formed on the surface of the mask blanks 50 (hereinafter, referred to as the second step Q2). After that, the first photoresist film 60 is drawn with a drawing device to form the first photoresist pattern (hereinafter, referred to as the third step Q3). In the third step Q3, drawing is performed so that the first photoresist film 60 after development has the shape (that is, a circular shape) of the superimposed region 10 when the mask blanks 50 are viewed in a plan view.

Next, the first photoresist film 60 is developed to remove the drawn region 60A of the first photoresist film 60 to form the first photoresist pattern (hereinafter referred to as the fourth step Q4). Call). The third step Q3 and the fourth step Q4 are steps for forming the first photoresist pattern.

Next, as shown in FIG. 21, a part of the light-shielding film 5 is removed by etching the light-shielding film 5 using the first photoresist film 60 (that is, the first photoresist pattern) on which the pattern is formed as a mask. The pattern of the light-shielding film 5 is formed (hereinafter, referred to as the fifth step Q5). Next, the remaining first photoresist film 60 is removed (hereinafter, referred to as the sixth 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 the seventh step Q7). After that, the second photoresist film 61 is formed on the surface of the semi-transmissive film 3 (hereinafter referred to as the eighth step Q8). After that, as shown in FIG. 22, the second photoresist film 61 is drawn by a drawing apparatus (hereinafter, referred to as a ninth step P9). In the ninth step P9, when the photomask is viewed in a plane, drawing is performed so as to form a ring with respect to the outer edge portion of the second photoresist film 61.

Next, the second photoresist film 61 is developed to remove the drawn region 61A of the second photoresist film 61 to form the second photoresist pattern (hereinafter referred to as the tenth step Q10). Call). The ninth step Q9 and the tenth step Q10 are steps for forming the second photoresist pattern.

Next, a part of the semi-transmissive membrane 3 is removed using the second photoresist film 61 (that is, the second photoresist pattern) on which the pattern is formed as a mask (hereinafter, referred to as the eleventh step Q11). Finally, the remaining second photoresist film 61 is removed (hereinafter referred to as the twelfth step Q12).

By the above steps, a photomask having a pattern forming region in which the superimposing region 10 is formed in a circular shape in the central portion including the center of the pattern forming region A and the non-superimposing region 11 is formed so as to surround the superimposing region 10. 1B can be produced.

<Modification 8>
The photomask described as any of the above embodiments or modifications utilizes the difference in transmittance between the light-shielding film 5 and the semi-transmissive film 3, the difference in transmittance due to the area ratio between the light-shielding film 5 and the semi-transmissive film 3, and the like. However, the photomask of the present invention is not limited to this, and it is also possible to apply a phase shift film in place of the semi-transmissive membrane 3 or in combination with the semi-transmissive membrane 3. The application of the phase shift film is possible 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 a region to which the phase effect is applied.

For example, in the photomask 1A shown in FIG. 2A, the film thickness of the phase shift film is adjusted so that the phase difference with respect to the transparent substrate 2 is 100 degrees or less, and the superimposed region 10 having low transmittance and the transmittance are adjusted. A phase shift film is arranged between the high non-superimposition region 11 so that the exposure light of the exposure apparatus transmitting near the boundary between the superimposition region 10 and the non-superimposition region 11 is shifted to the non-superimposition region 11 side by the phase effect. May be adjusted to.

Further, in the photo mask 1A shown in FIG. 14A, a plurality of semi-transmissive portions (that is, the first semi-transmissive portion 91 and the second semi-transmissive portion) formed on the outer periphery of the superimposed region 10 and having different light transmittances (that is, the first semi-transmissive portion 91 and the second semi-transmissive portion). A phase shift film is formed between at least one or more adjacent semi-transmissive portions of 92, the third semi-transmissive portion 93, and the fourth semi-transmissive portion 94) and / or near the boundary of the adjacent semi-transmissive portions. You may.

Further, the superimposed region 10 and the non-superimposed region 11 shown in (a) of FIG. 8, (a) of FIG. 9, (a) of FIG. 10, (a) of FIG. 11, (a) of FIG. In the photomask 1A on which the pattern is formed, a phase shift film may be formed in the vicinity of the boundary between the superposed region 10 and the non-superimposed region 11.

As described above, by forming the phase shift film, finer transmittance adjustment becomes possible. As a result, it becomes possible to make the resist shape on the transfer substrate side formed through the photomask of the present application a gentler inclined shape.

Even when the phase shift film is applied, the above-mentioned manufacturing method can be applied by using the same kind of metal as the material of the phase shift film and the light-shielding film 5 and / or the semi-transmissive film 3, which is a particular problem. It is possible to adopt a phase shift film without.

Further, for example, in the photomask 1A of the first embodiment, the superimposed region 10 is configured such that the light-shielding film 5 and the semi-transmissive film 3 are superimposed, but the phase shift film may be applied instead of the light-shielding film 5. That is, it suffices if the region forming the phase shift film can be set to a region having a lower transmittance than the non-superimposed region 11, in other words, a region where the intensity of the transmitted exposure light is small, and the semitransmissive film 3 and the phase shift film Adaptation is possible if the optical density OD value can satisfy 2.7 or more by stacking.

[Embodiment 3]
In each of the above-described embodiments, the photomask in which the pattern forming region A has a circular shape has been described, but the photomask of the present invention is not limited to this, and the pattern forming region is matched to the shape of each pixel of the display device. A can be formed into a desired shape. This will be described with reference to FIG. 23.

FIG. 23 is a plan view showing the 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 transflective film 3 are superimposed is formed in a regular pentagonal shape in the central portion including the center of the pattern forming region A. Further, in the pattern forming region A, a non-superimposing region 11 in which only the semi-transmissive membrane 3 is formed so as to surround the superimposing region 10 is formed. The first region D1 in this modification is set in the superimposed region 10. The second region D2 in this modification is set in the non-superimposing region 11 formed on the outer edge of the pattern forming region A.

With this configuration, when exposure is performed through the photomask 1C, the intensity of the light radiated to the outer edge portion of the photoresist film 20 becomes higher than the intensity of the light radiated to the central portion of the photoresist film 20. As a result, as shown in FIG. 3B, the developed photoresist film 20 can have a shape in which the outer edge portion is gently inclined. In other words, the photoresist film 20 can be gently tilted from the center to the outside.

In the present embodiment, the configuration in which the pattern forming region A is a regular pentagon has been described, but the photomask of the present invention is not limited to this. In the photomask of one aspect of the present invention, the pattern forming region A may be a pentagon other than a regular pentagon, or a polygon other than a pentagon (for example, a triangle, a rectangle, a hexagon, etc.). Further, in the photomask of one aspect of the present invention, the pattern forming region A has a pair of opposing straight lines and two curves connecting both ends of the pair of opposing straight lines, and the pair of opposing straight lines. It may be a shape formed by the above two curves. Further, in the photomask of one aspect of the present invention, the pattern forming region A may have a polygonal shape, and at least one corner of the polygon may have a shape formed by a curve such as an arc.

<Modification 9>
In the photomask of one aspect of the present invention, the pattern forming region A may be elliptical. This will be described with reference to FIG. 24.

FIG. 24 is a plan view showing the pattern forming region A of the 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 transflective film 3 are superimposed is formed in an elliptical shape in the central portion including the center of the pattern forming region A. Further, in the pattern forming region A, a non-superimposing region 11 in which only the semi-transmissive membrane 3 is formed so as to surround the superimposing region 10 is formed. The first region D1 in this modification is set in the superimposed region 10. The second region D2 in this modification is set in the non-superimposing region 11 formed on the outer edge of the pattern forming region A.

With this configuration, in the photomask 1D, the intensity of the light radiated to the outer edge portion of the photoresist film 20 is higher than the intensity of the light radiated to the central portion of the photoresist film 20. As a result, the photoresist film 20 after development can be formed into a shape in which the outer edge portion is gently inclined, as in the cross section shown in FIG. 3B. In other words, the photoresist film 20 can be gently tilted from the center to the outside.

[Embodiment 4]
In the above description, the configuration of forming a convex resist shape with respect to the substrate to be transferred by exposing the positive photoresist film through the photomask of the present invention has been described. The photomask can also be used for a negative photoresist film. In this case, the resist shape formed is concave with respect to the substrate to be transferred. The concave shape has a shape in which the outer edge portion is gently inclined. The configuration will be described in detail below.

FIG. 25 is a diagram showing the shape of the photoresist film 84 after exposure to the negative photoresist film 84 on the substrate to be transferred via the photomask 1A described in the first embodiment and development. As described in the first embodiment, in the photomask 1A, the transmittance is low in the central portion of the pattern forming region A, and the transmittance increases from the central portion toward the outside. By exposing and developing the negative type photoresist film 84 using the photomask 1A having the above configuration, as shown in FIG. 25, the developed photoresist film 84 is irradiated with the intensity of light. In the central part where is small, it is removed by development. Further, since the intensity of the emitted light increases from the central portion toward the outer edge portion, the solubility of the photoresist film 84 in the developing solution decreases, and the thickness of the remaining photoresist film 84 increases. In other words, by using the photomask 1A for the negative-type photoresist film 84, the shape of the photoresist film 84 after development is made concave with respect to the substrate to be transferred, and the light-shielding region and the light-transmitting region are transmitted. The region between the region and the region can be gently inclined.

[Embodiment 5]
In each of the above-described embodiments, the photomask in which the pattern forming region A is formed so that the intensity of the light applied to the photoresist film 20 increases from the center to the outside has been described. However, the photomask of the present invention has been described. Is not limited to this. The photomask of one aspect of the present invention may have a configuration in which the pattern forming region A is formed so that the intensity of the light applied to the photoresist film 20 decreases from the center to the outside. This will be described with reference to FIG.

FIG. 26A is a diagram showing a pattern design formed in the pattern forming region A of the photomask 1E in the present embodiment, and FIG. 26B is a plane perpendicular to the transparent substrate 2. It is sectional drawing of the cut photomask 1E.

As shown in FIG. 26 (a), the pattern forming region A of the photomask 1E has a circular shape. In the pattern forming region A of the photomask 1E, a translucent portion 85 that transmits light is formed in a circular shape in a central portion including the center of the pattern forming region A. Further, as shown in FIGS. 26 (a) and 26 (b), a non-superimposed region 11 in which only the semi-transmissive film 3 is formed so as to surround the translucent portion 85 is formed in the pattern forming region A. .. As a result, when the region having a predetermined area including the central portion of the pattern forming region A is designated as the first region D1 and the region having a predetermined area at the outer edge portion of the pattern forming region A is designated as the second region D2, the region within the first region D1 is used. The transmittance in the second region D2 is lower than the transmittance of. In the region outside the pattern forming region A, a superposed region 10 in which the light-shielding film 5, the etching stopper film 4, and the semi-transmissive film 3 are superimposed is formed, and is a light-shielding region.

In the photomask 1E having the above configuration, since the translucent portion 85 is present in the central portion of the pattern forming region A, the intensity of the light applied to the central portion of the photoresist film 20 is increased. Further, since the non-superimposed region 11 is formed so as to surround the translucent portion 85, the intensity of the light applied to the photoresist film 20 decreases from the center to the outside.

FIG. 27 is a diagram showing the shape of the photoresist film 20 after exposure to the positive photoresist film 20 on the substrate to be transferred via the photomask 1E and development. As shown in FIG. 27, by exposing and developing a positive photoresist film 20 on a transfer substrate via a photomask 1E, the developed photoresist film 20 is exposed to light. The central part, which has high intensity, is removed by development. Further, since the intensity of the emitted 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 for the positive photoresist film 20, the shape of the developed photoresist film 20 is made concave with respect to the substrate to be transferred, as well as a light-shielding region and light transmission. The region between the region and the region can be gently inclined.

FIG. 28 is a diagram showing the shape of the photoresist film 84 after exposure to the negative photoresist film 84 on the substrate to be transferred via the photomask 1E and development. As shown in FIG. 28, by exposing and developing a negative photoresist film 84 on a substrate to be transferred via a photomask 1E, the developed photoresist film 84 is gently exposed to an outer edge portion. It can have an inclined shape. In other words, the photoresist film 84 can be gently tilted from the center to the outside.

Next, a method for manufacturing the photomask 1E will be described. 29 to 31 are diagrams for explaining the manufacturing method of the photomask 1E. As shown in FIG. 29, in the manufacture of the photomask 1A, first, the mask blanks 30 formed by laminating a semi-transmissive film 3, an etching stopper film 4, and a light-shielding film 5 on the surface of the transparent substrate 2 in this order. (Hereinafter referred to as the first step S1).

Next, the first photoresist film 40 is formed on the surface of the mask blanks 30 (hereinafter, referred to as the second step S2). After that, the first photoresist film 40 is drawn by a drawing device (hereinafter, referred to as a third step S3). In the third step S3, when the mask blanks 30 are viewed in a plan view, drawing is performed so that the first photoresist film 40 in the region corresponding to the pattern forming region A is removed by development.

Next, the first photoresist film 40 is developed to remove the drawn region 40A of the first photoresist film 40 to form the first photoresist pattern (hereinafter referred to as the fourth step S4). Call). The third step S3 and the fourth step S4 are steps for forming the first photoresist pattern.

Next, as shown in FIG. 30, the pattern of the light-shielding film 5 is formed by etching the light-shielding film 5 using the first photoresist film 40 (that is, the first photoresist pattern) on which the pattern is formed as a mask. (Hereinafter referred to as the fifth step S5). In the fifth 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 the solvent for etching the light-shielding film 5.

Next, the etching stopper film 4 is removed using the first photoresist pattern and the light-shielding film 5 as masks (hereinafter, referred to as the sixth step S6). After that, the remaining first photoresist film 40 is removed (hereinafter, referred to as the seventh step S7).

Next, the second photoresist film 41 is formed on the entire surface of the photomask including the light-shielding film 5 (hereinafter, referred to as the eighth step S8).

Next, as shown in FIG. 31, the second photoresist film 41 is drawn by a drawing apparatus (hereinafter, referred to as a ninth step S9). In the ninth step S9, when the photomask is viewed in a plan view, drawing is performed so that only the second photoresist film 41 in the region corresponding to the superimposed region 10 and the non-superimposed region 11 remains after development. At this time, it is also important to reflect the margin considering the misalignment of the pattern due to the misalignment of the drawing device in the design pattern in advance to minimize the influence of the misalignment of the pattern.

Next, the second photoresist film 41 is developed to remove the drawn region 41A of the second photoresist film 41 to form the second photoresist pattern (hereinafter referred to as the tenth step S10). Call). The eighth step S8, the ninth step S9, and the tenth step S10 are steps for forming the second photoresist pattern.

Next, the pattern of the semi-transmissive film 3 is formed by etching the semi-transmissive film 3 using the second photoresist film 41 (that is, the second photoresist pattern) on which the pattern is formed as a mask (hereinafter,). 11th step (referred to as S11). Finally, the remaining second photoresist film 41 is removed (hereinafter referred to as step 12 P12).

By the above steps, the pattern forming region A in which the translucent portion 85 is formed in a circular shape in the central portion including the center of the pattern forming region A and the non-superimposing region 11 is formed so as to surround the translucent portion 85 is formed. The photomask 1E having can be produced.

[Embodiment 6]
In the fifth embodiment, the bottom type photomask 1E having a translucent region in the central portion of the pattern forming region A and a non-superimposed region formed so as to surround the translucent region has been described. Photomasks are not limited to this. The photomask of one aspect of the present invention is a top-type photomask having a translucent region in the central portion of the pattern forming region A and a non-superimposed region formed so as to surround the translucent region. May be good. This will be described in detail below.

FIG. 32 (a) is a diagram showing a pattern design formed in the pattern forming region A of the photomask 1F in the present embodiment, and FIG. 32 (b) is a plane perpendicular to the transparent substrate 2. It is sectional drawing of the cut photomask 1F.

As shown in FIG. 32 (a), in the pattern forming region A of the photomask 1F, a translucent portion 85 that transmits light is formed in a circular shape in the central portion including the center of the pattern forming region A. .. Further, as shown in FIGS. 32 (a) and 32 (b), a non-superimposed region 11 in which only the semi-transmissive film 3 is formed so as to surround the translucent portion 85 is formed in the pattern forming region A. .. Further, on the outside of the pattern forming region A, a superposed region 10 in which the light-shielding film 5 and the semi-transmissive film 3 are superposed is formed so as to surround the non-superimposed region 11.

With this configuration, the light transmittance is high in the central portion of the pattern forming region A as in the photomask 1E in the fifth embodiment, whereas the pattern forming region A is formed in the outer edge portion of the pattern forming region A. The light transmittance decreases toward the outside of. In other words, when the region having a predetermined area including the central portion of the pattern forming region A is defined as the first region D1 and the region having a predetermined area at the outer edge portion of the pattern forming region A is defined as the second region D2, the first region D1 The transmittance in the second region D2 is lower than the transmittance in the inside.

Next, a method for manufacturing the photomask 1F will be described. FIGS. 33 to 35 are diagrams for explaining a method for manufacturing the photomask 1F. As shown in FIG. 33, in the production of the photomask 1B, first, the mask blanks 50 having the light-shielding film 5 formed on the surface of the transparent substrate 2 are prepared (hereinafter, referred to as the first step T1). Next, the first photoresist film 60 is formed on the surface of the mask blanks 50 (hereinafter, referred to as the second step T2). After that, the first photoresist film 60 is drawn with a drawing apparatus to form the first photoresist pattern (hereinafter, referred to as the third step T3). In the third step T3, when the mask blanks 50 are viewed in a plan view, drawing is performed so that the first photoresist film 60 in the region corresponding to the pattern forming region A is removed by development.

Next, the first photoresist film 60 is developed to remove the drawn region 60A of the first photoresist film 60 to form the first photoresist pattern (hereinafter referred to as the fourth step T4). Call). The third step T3 and the fourth step T4 are steps for forming the first photoresist pattern.

Next, as shown in FIG. 34, a part of the light-shielding film 5 is removed by etching the light-shielding film 5 using the first photoresist film 60 (that is, the first photoresist pattern) on which the pattern is formed as a mask. The pattern of the light-shielding film 5 is formed (hereinafter, referred to as the fifth step T5). Next, the remaining first photoresist film 60 is removed (hereinafter, referred to as the sixth 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 the seventh step T7). After that, the second photoresist film 61 is formed on the surface of the semi-transmissive film 3 (hereinafter, referred to as the eighth step T8). After that, as shown in FIG. 35, the second photoresist film 61 is drawn by a drawing apparatus (hereinafter, referred to as a ninth step T9). At this time, it is also important to reflect the margin considering the misalignment of the pattern due to the misalignment of the drawing device in the design pattern in advance to minimize the influence of the misalignment of the pattern. In the ninth step T9, when the photomask is viewed in a plan view, drawing is performed so that only the second photoresist film 61 in the region corresponding to the superimposed region 10 and the non-superimposed region 11 remains.

Next, the second photoresist film 61 is developed to remove the drawn region 61A of the second photoresist film 61 to form the second photoresist pattern (hereinafter referred to as the tenth step T10). Call). The ninth step T9 and the tenth step T10 are steps for forming the second photoresist pattern.

Next, a part of the semi-transmissive membrane 3 is removed using the second photoresist film 61 (that is, the second photoresist pattern) on which the pattern is formed as a mask (hereinafter, referred to as the eleventh step T11). Finally, the remaining second photoresist film 61 is removed (hereinafter referred to as step 12 T12).

By the above steps, the translucent portion 85 is formed in a circular shape in the central portion including the center of the pattern forming region A, and the pattern forming region A in which the non-superimposing region 11 is formed so as to surround the superimposing region 10 is provided. The photomask 1F can be produced.

<Modification 10>
A modified example of the pattern forming region A of the photomask 1F of the sixth embodiment will be described. FIG. 36 is a plan view showing the pattern forming region A in this modification. As shown in FIG. 36, in this modification, when the pattern forming region A is viewed in a plan view, the rectangular translucent portion 85 in which the semi-transmissive film 3 and the light-shielding film 5 do not exist, and the semi-transmissive film 3 have a light-shielding film. A checkered pattern region 12 is formed in which rectangular non-superimposed regions 11 on which 5 is not superimposed are alternately arranged. Further, in this modification, a region in which the light-shielding film 5 is not superimposed on the semi-transmissive film 3 is formed on the outer periphery of the check pattern region 12. That is, the pattern forming region A of this modification is (1) a translucent portion 85 in which the semi-transmissive film 3 and the light-shielding film 5 do not exist, and a non-superimposed region in which the light-shielding film 5 is not superimposed on the semi-transmissive film 3. It has a mixed region including 11 and (2) a non-mixed region formed on the outer edge of the mixed region and in which the light-shielding film 5 is not superimposed on the semi-transmissive film 3. The first region D1 in this modification is set so as to include at least a rectangular translucent portion 85 that exists inside the check pattern region 12 and is located in the central portion of the pattern forming region A. That is, the first region D1 may be a region including only the translucent portion 85 located in the central portion of the pattern forming region A, or a region including the translucent portion 85 and the non-superimposed region 11 around the translucent portion 85. May be. The second region D2 in this modification is set in the region outside the plaid region 12, that is, in the non-superimposing region 11 formed on the outer edge of the pattern forming region A.

With this configuration, since the translucent portion 85 is present in the central portion of the pattern forming region A, the intensity of the light applied to the central portion of the photoresist film 20 increases as the area ratio of the transmissive portion 85 increases. It's getting bigger. Further, since only the semi-transmissive film 3 is present at the outer edge of the pattern forming region A so as to surround the check pattern region 12, the intensity of the light applied to the photoresist film 20 decreases from the center to the outside. It has become. As a result, the photoresist film 20 after development has a shape in which the outer edge portion is gently inclined. That is, by using the photomask of this modification, the photoresist film 20 can be gently inclined from the center to the outside.

<Modification 11>
A further modification of the pattern forming region A of the photomask 1F of the sixth embodiment will be described. FIG. 37 is a plan view showing the pattern forming region A in this modification. As shown in FIG. 37, in this modification, when the pattern forming region A is viewed in a plan view, the translucent portion 85 in which the semi-transmissive film 3 and the light-shielding film 5 do not exist is formed in the central region 14 of the pattern forming region A. It is formed. Further, in this modification, the region 15 has a translucent portion 85 in which the semi-transmissive film 3 and the light-shielding film 5 do not exist, and a plurality of non-superimposed regions 11 in which the light-shielding film 5 is not superimposed on the semi-transmissive film 3. Is formed on the outside of the central region 14. In the region 15, the non-superimposed region 11 is formed so that the area increases toward the outer edge portion. Further, on the outer periphery of the region 15, a region is formed in which the light-shielding film 5 is not superimposed on the semi-transmissive film 3. The first region D1 in this modification is set inside the central region 14. The second region D2 in this modification is set in a region outside the region 15, that is, in a non-superimposing region 11 formed on the outer edge of the pattern forming region A.

With this configuration, since the translucent portion 85 is formed in the central region 14, the intensity of the light radiated to the central portion of the photoresist film 20 is increased. Further, as the area ratio of the non-superimposed region 11 increases toward the outside from the central region 14, the intensity of the light applied to the photoresist film 20 decreases. As a result, the developed photoresist film 20 can be formed into a shape in which the outer edge portion is gently inclined. In other words, the photoresist film 20 can be gently tilted from the center to the outside.

<Modification 12>
A further modification of the pattern forming region A of the photomask 1F of the sixth embodiment will be described. FIG. 38 is a plan view showing the pattern forming region A in this modification. As shown in FIG. 38, in this modification, when the pattern forming region A is viewed in a plan view, the central portion of the pattern forming region A is a rectangular translucent portion 85 in which the semitransmissive film 3 and the light shielding film 5 do not exist. And the rectangular non-superimposed region 11 on which the light-shielding film 5 is not superposed on the semi-transmissive film 3 are alternately arranged. Further, a region in which only the semi-transmissive film 3 exists is formed outside the region in which the rectangular translucent portion 85 and the rectangular non-superimposed region 11 are alternately arranged. Further, a plurality of rectangular overlapping regions 86 on which the light-shielding film 5 and the semi-transmissive film 3 are superimposed are formed on the outer edge of the region where only the semi-transmissive film 3 exists. The first region D1 in this modification is set so that the translucent region 85 and the non-superimposed region 11 are alternately arranged, and the region includes at least a part of the translucent portion 85. To. The second region D2 in this modification is a region formed on the outer edge portion of the pattern forming region A, and is set so as to include a superposed region 86 at least in a part thereof.

According to this configuration, the translucent portions 85 and the non-superimposed regions 11 are alternately arranged in the central portion of the pattern forming region A, and the region where only the semitransmissive film 3 exists at the outer edge portion of the pattern forming region A. Since it is formed, the intensity of the light applied to the photoresist film 20 is the largest at the center of the photoresist film 20, and gradually decreases from the center toward the outer edge portion. As a result, the shape of the developed photoresist film 20 can be made to be gently inclined from the center toward the outer edge portion.

<Modification 13>
A further modification of the pattern forming region A of the photomask 1F of the sixth embodiment will be described. FIG. 39 is a plan view showing the pattern forming region A in this modification. As shown in FIG. 39, in this modification, when the pattern forming region A is viewed in a plan view, the translucent portion 85 in which the semi-transmissive film 3 and the light-shielding film 5 do not exist is formed in the central region 17 of the pattern forming region A. It is formed. Further, in this modification, a radial region 87 is formed in which the translucent portion 85 extends radially from the central region 17 toward the outer edge portion of the pattern forming region A. The radial region 87 becomes narrower toward the outer edge of the pattern forming region A. The first region D1 in this modification is set inside the central region 17. The second region D2 in this modification is a region of the outer edge portion of the pattern forming region A, and is set so as to include a non-superimposed region 11 at least in a part thereof. That is, the pattern forming region A of this modification is formed on (1) a non-mixed region (translucent portion 85) in which the semi-transmissive film 3 and the light-shielding film 5 do not exist, and (2) the outer edge of the non-mixed region. It has a mixed region 78 including a region in which the semi-transmissive film 3 and the light-shielding film 5 do not exist, and a non-superimposed region in which the light-shielding film 5 is not superimposed on the semi-transmissive film 3.

Due to this configuration, the translucent portion 85 is formed in the central region 17 of the pattern forming region A, and the translucent portion 85 extends radially from the central region 17 toward the outer edge portion of the pattern forming region A. The intensity of the light applied to the resist film 20 is the highest in the center of the photoresist film 20, and gradually decreases from the center toward the outer edge portion. As a result, the shape of the developed photoresist film 20 can be made to be gently inclined from the center toward the outer edge portion.

<Modification 14>
A further modification of the pattern forming region A of the photomask 1F of the sixth embodiment will be described. FIG. 40 is a plan view showing the pattern forming region A in this modification. As shown in FIG. 40, in this modification, when the pattern forming region A is viewed in a plan view, the translucent portion 85 in which the semi-transmissive film 3 and the light-shielding film 5 do not exist is formed in the central region 88 of the pattern forming region A. It is formed. Further, in this modification, a spiral region 89 is formed in which the translucent portion spirally extends from the central region 88 toward the outer edge portion of the pattern forming region A. A non-superimposed region 11 is formed between the plurality of spiral regions 89. The spiral region 89 may become narrower toward the outer edge of the pattern forming region A. The first region D1 in this modification is set inside the central region 88. The second region D2 in this modification is a region of the outer edge portion of the pattern forming region A, and is set so as to include a non-superimposed region 11 at least in a part thereof.

According to this configuration, the translucent portion 85 is formed in the central region 88 of the pattern forming region A, and the translucent portion 85 extending spirally from the central region 88 toward the outer edge portion of the pattern forming region A is formed. Therefore, the intensity of the light applied to the photoresist film 20 is the largest at the center of the photoresist film 20, and gradually decreases from the center toward the outer edge portion. As a result, the shape of the developed photoresist film 20 can be made to be gently inclined from the center toward the outer edge portion.

<Modification 15>
A further modification of the pattern forming region A of the photomask 1F of the sixth embodiment will be described. FIG. 41 is a plan view showing the pattern forming region A in this modification. As shown in FIG. 41, in this modification, when the pattern forming region A is viewed in a plan view, the translucent portion 85 in which the semi-transmissive film 3 and the light-shielding film 5 do not exist is formed in the central region 102 of the pattern forming region A. It is formed. On the outside of the central region 102, there is a region having a superposed region 10 on which the semi-transmissive film 3 and the light-shielding film 5 are superimposed, and a plurality of translucent portions 85 in which the light-shielding film 5 and the semi-transmissive film 3 do not exist. 103 is formed. The region 103 is formed so that the area of the superimposed region 10 increases toward the outside of the pattern forming region A. Further, the first semi-transmissive portion 100 is formed in a ring shape on the outer periphery of the region 103. Further, the second semi-transmissive portion 101 is formed in a ring shape on the outer periphery of the first semi-transmissive portion 100. The first semi-transmissive portion 100 is designed to have a higher transmittance than the second semi-transmissive portion 101. The first region D1 in this modification is set inside the central region 102. The second region D2 in this modification is set in the non-superimposing region 11 formed on the outer edge of the pattern forming region A.

According to this configuration, the translucent portion 85 is formed in the central region 102 of the pattern forming region A, and the region 103 having the superposed region 10 and the translucent portion 85 is formed outside the central region 102. Since the first semi-transmissive portion 100 is formed on the outer periphery of the photoresist film 20, the intensity of the light applied to the photoresist film 20 is the largest in the center of the photoresist film 20, and gradually decreases from the center toward the outer edge portion. .. As a result, the shape of the developed photoresist film 20 can be made to be gently inclined from the center toward the outer edge portion.

<Modification 16>
A further modification of the pattern forming region A of the photomask 1F of the sixth embodiment will be described. FIG. 42 is a plan view showing a pattern design formed in the pattern forming region A of the photomask of the present modification. As shown in FIG. 42, in this modification, when the pattern forming region A is viewed in a plan view, the translucent portion 85 in which the semi-transmissive film 3 and the light-shielding film 5 do not exist is formed in the central region 110 of the pattern forming region A. It is formed. On the outside of the central region 110, a first semi-transparent portion 111, a second semi-transmissive portion 112, a third semi-transmissive portion 113, and a fourth semi-transmissive portion 114 are formed in a ring shape from the inside in this order. The first semi-transmissive section 111, the second semi-transmissive section 112, the third semi-transmissive section 113, and the fourth semi-transmissive section 114 are composed of the semi-transmissive film 3. Of the first semi-transmissive section 111, the second semi-transmissive section 112, the third semi-transmissive section 113, and the fourth semi-transmissive section 114, the film thickness of the first semi-transmissive section 111 is the smallest, and the second semi-transmissive section 112, The film thickness increases in the order of the third semi-transmissive portion 113 and the fourth semi-transmissive portion 114. As a result, the light transmittance of the first semi-transmissive portion 111 is the highest, and the light transmittance is lower in the order of the second semi-transmissive portion 112, the third semi-transmissive portion 113, and the fourth semi-transmissive portion 114. It has become.

Due to this configuration, the film thickness of the semitransmissive film increases from the center to the outside in the pattern forming region A, so that the intensity of the light applied to the photoresist film 20 is the highest in the center of the photoresist film 20. It is large and gradually decreases from the center to the outer edge. As a result, the shape of the developed photoresist film 20 can be made to be gently inclined from the center toward the outer edge portion.

As described above, the photomask of the present modification has a translucent portion 85 in the central portion of the pattern forming region A, in which the semi-transmissive film 3 and the light-shielding film 5 do not exist. Further, in the photomask of this modification, a plurality of semi-transmissive portions having different light transmittances (that is, a first semi-transmissive portion 91, a second semi-transmissive portion 92, a third semi-transmissive portion 93, and a fourth semi-transmissive portion). Part 94) is formed toward the outer peripheral portion of the pattern forming region A so as to surround the translucent portion 85, and the plurality of semi-transmissive portions have a light transmittance toward the outer edge portion of the pattern forming region A. It's getting low.

In the above-mentioned photomask 1A, the superimposed region 10 formed in the central region 110 of the pattern forming region A is circular, and the first semi-transmissive portion 111, the second semi-transparent portion 112, and the third semi-transparent portion 113 have a circular shape. The fourth semi-transmissive portion 114 has a ring-shaped configuration, but the configuration is not limited to this. That is, the photomask of this modification has a translucent portion 85 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 translucent portion 85. It suffices if a plurality of semi-transmissive portions are formed so as to increase in height. For example, the translucent portion 85 and the plurality of translucent portions may be elliptical, rectangular, or the like.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

1A-1F Photomask 2 Transparent substrate 3 Semi-transmissive film 4 Etching stopper film 5 Light-shielding film 7,85 Transmissive part 10, 86, 103 Superimposed area 11 Non-superimposed area 12 Plaid area 14, 17, 70, 80, 88, 90, 102, 110 Central region 16 Translucent region 20, 84 Photoresist film 30, 50 Mask blanks 40, 60 First photoresist film 41, 61 Second photoresist film A Pattern formation region D1 First region D2 Second region

Claims (18)

A photomask used to form a desired resist shape on a substrate to be transferred in the manufacture of a display device.
A plurality of pattern-forming regions having a predetermined shape including at least two regions having different transmittances from each other are provided on the transparent substrate.
A region having a predetermined area including the central portion of the pattern forming region is defined as a first region, and a region having a predetermined area at the outer edge portion of the pattern forming region is designated as a second region.
The pattern forming region is formed by laminating at least a semi-transmissive film pattern and a light-shielding film pattern so as to partially overlap each other.
It has a translucent portion on which the pattern forming region is not formed on the transparent substrate.
A photomask in which the transmittance in the second region is higher than the transmittance in the first region. A photomask used to form a desired resist shape on a substrate to be transferred in the manufacture of a display device.
A plurality of pattern-forming regions having a predetermined shape including at least two regions having different transmittances from each other are provided on the transparent substrate.
A region having a predetermined area including the central portion of the pattern forming region is defined as a first region, and a region having a predetermined area at the outer edge portion of the pattern forming region is designated as a second region.
In the pattern forming region, at least a translucent portion and a semi-transmissive portion formed by a semi-transmissive film are formed.
In the region where the pattern forming region is not formed, a light-shielding portion formed by laminating the semi-transmissive film and the light-shielding film is formed on the transparent substrate.
A photomask in which the transmittance in the second region is lower than the transmittance in the first region. The photomask according to claim 1 or 2 , wherein the second region is formed concentrically with respect to the first region. The photomask according to claim 1 or 2 , wherein an arc is included in at least a part of the outer edge shape when the pattern forming region is viewed in a plan view. The photomask according to claim 1 or 2 , wherein the pattern forming region has a polygonal shape. When the pattern-forming region is viewed in a plan view, the superposed region in which the semi-transmissive film and the light-shielding film are superimposed extends radially or spirally from the central portion of the pattern-forming region toward the outer edge portion. The photomask according to claim 1 . When the pattern forming region is viewed in a plan view, the semi-transmissive film has a plurality of non-superimposed regions having a predetermined shape in which the light-shielding film is not superimposed.
The photomask according to claim 1 , wherein the non-superimposed region is formed so that the area increases toward the outer edge portion. When the pattern forming region is viewed in a plan view, a rectangular overlapping region in which the semi-transmissive film and the light-shielding film are superimposed, and a rectangular non-superimposition region in which the light-shielding film is not superimposed on the semi-transmissive film. The photo according to claim 1 , wherein plaid regions in which are alternately arranged are formed, and a region in which the light-shielding film is not superimposed on the semi-transmissive film is formed on the outer periphery of the plaid region. mask. The photomask according to claim 1 , wherein the light-transmitting portion in which the light-shielding film and the semi-transmissive film do not exist is formed on the outer edge portion of the pattern-forming region when the pattern-forming region is viewed in a plan view. When the pattern-forming region is viewed in a plan view, the light-transmitting portion in which the light-shielding film and the semi-transmissive film do not exist extends radially or spirally from the central portion of the pattern-forming region toward the outer edge portion. Item 2. The photomask according to item 2. When the pattern forming region is viewed in a plan view, the semi-transmissive film has a plurality of non-superimposed regions having a predetermined shape in which the light-shielding film is not superimposed.
The photomask according to claim 2 , wherein the non-superimposed region is formed so that the area increases toward the outer edge portion. When the pattern forming region is viewed in a plan view, the light-transmitting portion in which the light-shielding film and the semi-transmissive film do not exist and the rectangular non-superimposed region in which the light-shielding film is not superimposed on the semi-transmissive film alternate. The photomask according to claim 2 , wherein a checkered pattern region is formed in the checkered pattern region, and the non-superimposed region is formed on the outer periphery of the checkered pattern region. The photomask according to claim 2 , wherein a superposed region in which the semi-transmissive film and the light-shielding film are superimposed is formed on the outer edge of the pattern-forming region when the pattern-forming region is viewed in a plan view. A semi-transmissive region formed by a semi-transmissive film is laminated on the transparent substrate, and at least the semi-transmissive film and the light-shielding film are laminated on the transparent substrate so that the semi-transmissive film is located closer to the transparent substrate than the light-shielding film. A method for manufacturing a photomask including a laminated region and a transparent region where the transparent substrate is exposed.
A step of preparing a mask blank formed by laminating at least the semi-transmissive film and the light-shielding film on the surface of the transparent substrate so that the semi-transmissive film is located closer to the transparent substrate than the light-shielding film. ,
A step of forming a first photoresist film on the surface of the mask blanks and drawing the first photoresist film on the first photoresist film with a drawing device to form a first photoresist pattern.
A step of removing a part of the light-shielding film using the first photoresist pattern as a mask,
The step of removing the exposed semi-permeable membrane and
A second photoresist film is formed on the entire surface of the photomask including the light-shielding film, the margin of alignment deviation is reflected in the design pattern for the second photoresist film, and the second photoresist is drawn by a drawing device. The process of forming the pattern and
A step of removing a part of the light-shielding film using the second photoresist pattern as a mask is included.
The region having a predetermined area including the central portion of the pattern forming region formed by the light-shielding film and the semi-transmissive film is defined as the first region, and the region having a predetermined area on the outer peripheral portion of the pattern forming region is the first region. The pattern forming region is such that the transmittance in the second region is higher than the transmittance in the first region when the region formed concentrically with respect to the second region is used as the second region. A method of manufacturing a photomask to form a photomask. A photomask having a semi-transmissive region formed by a semi-transmissive film on a 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 in which the transparent substrate is exposed. It ’s a manufacturing method,
The process of preparing mask blanks with a light-shielding film formed on the surface of the transparent substrate, and
The step of forming the first photoresist film on the surface of the mask blanks and
A step of drawing on the first photoresist film with a drawing apparatus to form a first photoresist pattern,
A step of removing a part of the light-shielding film using the first photoresist pattern as a mask,
A step of forming a semi-transmissive film on the entire surface of the photomask including the light-shielding film, and
A step of forming a second photoresist film on the surface of the semi-permeable membrane,
A step of drawing on the second photoresist film with a drawing device, reflecting a margin of alignment deviation in the design pattern, and forming a second photoresist pattern.
A step of removing a part of the semi-permeable membrane using the second photoresist pattern as a mask is included.
The region having a predetermined area including the central portion of the pattern forming region formed by the light-shielding film and the semi-transmissive film is defined as the first region, and the region having a predetermined area on the outer peripheral portion of the pattern forming region is the first region. The pattern forming region is such that the transmittance in the second region is higher than the transmittance in the first region when the region formed concentrically with respect to the second region is used as the second region. A method of manufacturing a photomask to form a photomask. A semi-transmissive region formed by a semi-transmissive film is laminated on the transparent substrate, and at least the semi-transmissive film and the light-shielding film are laminated on the transparent substrate so that the semi-transmissive film is located closer to the transparent substrate than the light-shielding film. A method for manufacturing a photomask including a laminated region and a transparent region where the transparent substrate is exposed.
A step of preparing a mask blank formed by laminating at least the semi-transmissive film and the light-shielding film on the surface of the transparent substrate so that the semi-transmissive film is located closer to the transparent substrate than the light-shielding film. ,
A step of forming a first photoresist film on the surface of the mask blanks and drawing the first photoresist film on the first photoresist film with a drawing device to form a first photoresist pattern.
A step of removing a part of the light-shielding film using the first photoresist pattern as a mask,
The step of removing the exposed semi-permeable membrane and
A second photoresist film is formed on the entire surface of the photomask including the light-shielding film, the margin of alignment deviation is reflected in the design pattern for the second photoresist film, and the second photoresist is drawn by a drawing device. The process of forming the pattern and
A step of removing a part of the semi-permeable membrane using the second photoresist pattern as a mask is included.
The region having a predetermined area including the central portion of the pattern forming region formed by the light-shielding film and the semi-transmissive film is defined as the first region, and the region having a predetermined area on the outer peripheral portion of the pattern forming region is the first region. The pattern forming region is such that the transmittance in the second region is lower than the transmittance in the first region when the region formed concentrically with respect to the second region is used as the second region. A method of manufacturing a photomask to form a photomask. A photomask having a semi-transmissive region formed by a semi-transmissive film on a 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 in which the transparent substrate is exposed. It ’s a manufacturing method,
The process of preparing mask blanks with a light-shielding film formed on the surface of the transparent substrate, and
The step of forming the first photoresist film on the surface of the mask blanks and
A step of drawing on the first photoresist film with a drawing apparatus to form a first photoresist pattern,
A step of removing a part of the light-shielding film using the first photoresist pattern as a mask,
A step of forming a semi-transmissive film on the entire surface of the photomask including the light-shielding film, and
A step of forming a second photoresist film on the surface of the semi-permeable membrane,
A step of reflecting the margin of misalignment in the design pattern of the second photoresist film and drawing with a drawing device to form the second photoresist pattern.
A step of removing a part of the semi-permeable membrane using the second photoresist pattern as a mask is included.
The region having a predetermined area including the central portion of the pattern forming region formed by the light-shielding film and the semi-transmissive film is defined as the first region, and the region having a predetermined area on the outer peripheral portion of the pattern forming region is the first region. The pattern forming region is such that the transmittance in the second region is lower than the transmittance in the first region when the region formed concentrically with respect to the second region is used as the second region. A method of manufacturing a photomask to form a photomask. A method for manufacturing a display device, comprising a resist forming step of forming a desired resist shape on a substrate to be transferred using the photomask according to any one of claims 1 to 10 .
The resist forming step is
An exposure step of exposing the resist via the photomask,
A method for manufacturing a display device, comprising a step of forming the desired resist shape by developing the exposed resist.

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