JP2018205693A - Photomask and method for manufacturing display device - Google Patents

Abstract

To solve the problem of the conventional photomask in which: when a transfer pattern of a photomask is transferred on a transferred object with a proximity exposure system, it is difficult to form a high definition pattern faithful to the pattern design of the photomask.SOLUTION: A photomask for proximity exposure comprises transfer patterns on a transparent substrate for forming a black matrix on a transferred object. The transfer patterns comprise: a first slit pattern that is formed in a first pattern formation region, substantially consists of a translucent part, and has a part having a constant width W1; a second slit pattern that is formed in a second pattern formation region excluding an intersection region, substantially consists of a semi-translucent part, and has a part having a constant width W2, which is smaller than the constant width W1; and an auxiliary pattern that is not resolved independently, and is used to adjust a shape of the black matrix image formed on the transferred object.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a photomask for manufacturing an electronic device, and more particularly to a photomask suitable for use in manufacturing a flat panel display and a method for manufacturing a display device.

  Patent Document 1 discloses a photomask that can form a line pattern having a fine portion on a transfer object such as a substrate by photolithography. Specifically, it is a photomask used to form a line pattern having a fine portion with a line width of 2 μm to 10 μm and a peripheral region surrounding the line pattern, and corresponds to the light shielding portion and the line pattern. A semi-transparent portion, and a light-transmitting portion that surrounds the light-shielding portion and the semi-transparent portion and corresponds to the peripheral region, and the semi-transparent portion is more than the fine portion of the line pattern. A wide photomask is described in Patent Document 1. According to this, it is said that a fine line pattern can be formed while suppressing an increase in capital investment and a decrease in production efficiency.

Japanese Patent Laying-Open No. 2015-99247

  Along with the rapid market expansion of mobile terminals and the like, the trend of increasing pixel density is progressing against flat panel display (hereinafter referred to as “FPD”) products such as liquid crystal display devices (hereinafter referred to as “LCD”). Yes. In addition, further improvements in performance such as display screen resolution, brightness, power saving, and operation speed are strongly desired.

  As a color filter (hereinafter abbreviated as “CF”) substrate used in an LCD, three primary color filters (red filter, green filter, and blue filter) corresponding to each pixel electrode are arranged on a transparent substrate. In this case, a black matrix (hereinafter abbreviated as “BM”), which is a light shielding portion, is known. The BM shields light from a portion that does not contribute to image display, such as a source wiring of a liquid crystal display element or a gap between a pixel electrode and a source wiring. In order to brighten the liquid crystal display, it is desirable to reduce the light shielding portion by the BM as much as possible, that is, to reduce the line width of the BM.

  FIG. 19A is a schematic diagram illustrating a configuration example of a color filter. In the color filter pattern shown here, three sub-pixels (SP unit patterns) having the same shape are arranged in one pixel (P unit pattern). The three subpixels correspond to R (Red), G (Green), and B (Blue) color filters, respectively. Each subpixel is formed in a rectangular shape and is regularly arranged at a constant pitch.

  Each subpixel is partitioned by BM. The BMs are formed in a lattice shape while crossing each other. One pixel having the sub-pixels for the three colors is regularly arranged at a constant pitch, thereby forming a repeated pattern.

  With the trend of BM miniaturization, there is a need for miniaturization even in a photomask having a transfer pattern for forming a BM. However, the following inconvenience occurs only by simply reducing the size of the pattern provided in the photomask.

  For the production of CF, a method is used in which a photomask transfer pattern is mainly exposed to a negative photosensitive material by a proximity exposure type exposure apparatus (proximity exposure apparatus). FIG. 19B illustrates an existing (before miniaturization) photomask pattern for BM formation. FIG. 19 shows a pattern obtained by miniaturizing the photomask pattern in order to form a higher-definition BM. Illustrated in (c). Such pattern miniaturization is necessary, for example, in a situation where CF of about 300 ppi (pixel per inch) is shifted to a finer standard exceeding 400 ppi.

  When a CF is manufactured by transferring a BM pattern onto a CF substrate using a photomask having the pattern of FIG. 19C, ideally, a BM transfer image as shown in FIG. Is ideal. However, as shown in FIG. 20B, the BM transfer image that is actually transferred to the CF substrate is not sufficiently miniaturized (see Z1 in the figure). There arises a problem that the corner of the opening (see Z2 in the figure) is rounded. Therefore, it was actually difficult to obtain an ideal CF pattern.

  According to the technique described in Patent Document 1, a certain effect can be obtained with respect to the reduction in the line width of the BM. On the other hand, there is still room for improvement in the formation of a BM for manufacturing a more advantageous CF, such as rounding of the corners of the subpixel opening. This is because a complex light intensity distribution is formed by diffracted light generated in a gap (ie, a proximity gap) between a photomask and a transfer object during proximity exposure, and the transfer formed on the transfer object. This is probably because the image does not faithfully reproduce the photomask pattern.

  According to the study of the inventors, depending on the design of the photomask pattern, the light that passes through the photomask is affected by the diffraction action when it reaches the transfer target (here, the CF substrate), and is in an unintended position. It has been found that a local increase in light intensity or a local decrease occurs, and a light intensity distribution having a shape different from that of the photomask pattern is formed. For this reason, it has become clear that it is difficult to form a BM that is faithful to the pattern design of the photomask, and that the above-mentioned tendency becomes more prominent when the pattern is miniaturized.

  On the other hand, in order to control the diffracted light in the proximity gap, which causes the above problem, the proximity gap should be made sufficiently narrow, or the optical conditions (exposure light source wavelength, etc.) should be fundamentally changed. Can be considered. However, in consideration of the production efficiency and cost efficiency of CF manufacturing, it is advantageous to use a photomask having a certain size (a side of 300 mm or more, preferably about 400 to 2000 mm). In order to hold a photomask of this size for proximity exposure, securing a sufficient proximity gap (for example, 30 μm or more, preferably 40 μm or more) can stably produce CF. Desirable above. Further, the proximity exposure method has a great advantage in that the production cost is lower than that of the projection exposure method, and there is a concern that the advantage is remarkably impaired when the apparatus configuration such as optical conditions is changed.

  An object of the present invention is a photomask capable of transferring a high-definition pattern faithful to a target device pattern design when transferring a photomask transfer pattern onto a transfer object by a proximity exposure method, and Another object is to provide a method for manufacturing a display device.

(First aspect)
The first aspect of the present invention is:
A photomask for proximity exposure comprising a transfer pattern on a transparent substrate for forming a black matrix on a transfer object,
The transfer pattern is:
The pattern formation region extending in the first direction is defined as a first pattern formation region, the pattern formation region extending in a second direction intersecting the first direction is defined as a second pattern formation region, and the first pattern formation is performed. When a region where the region and the second pattern formation region intersect is a crossing region,
A first slit pattern formed in the first pattern formation region, which is a slit pattern substantially consisting of a light-transmitting portion and has a portion having a constant width W1,
A second slit formed in the second pattern formation region excluding the intersecting region, which is substantially a semi-translucent portion and has a portion with a constant width W2 smaller than the constant width W1. With patterns,
An auxiliary pattern for adjusting the shape of the black matrix image formed on the transferred body, which is a pattern that does not resolve independently;
A photomask characterized by comprising:
(Second aspect)
The second aspect of the present invention is:
The auxiliary pattern is
The photomask according to the first aspect, characterized in that it includes a pair of convex portions made of a semi-translucent portion that are formed so as to partially protrude on both sides in the width direction of the second slit pattern. is there.
(Third aspect)
The third aspect of the present invention is:
The pair of convex portions suppresses a local decrease in light intensity in the light intensity distribution of a transfer image formed by the second slit pattern on the transfer object when the transfer pattern is subjected to proximity exposure. The photomask according to the second aspect is characterized in that the transmitted light intensity of the second slit pattern is made uniform.
(Fourth aspect)
The fourth aspect of the present invention is:
The auxiliary pattern is
Any one of the first to third aspects, characterized in that it includes an extended portion formed of a semi-translucent portion, which is formed to extend at least in the second direction from the exit of the second slit pattern. Or a photomask according to any one of the above.
(5th aspect)
According to a fifth aspect of the present invention,
The extended portion increases the curvature of a corner portion in a transfer image formed by the second slit pattern on the transfer object when the transfer pattern is subjected to proximity exposure. The photomask according to the fourth aspect.
(Sixth aspect)
The sixth aspect of the present invention is:
The auxiliary pattern is
Including an isolated pattern formed of a semi-translucent part or a light-shielding part, which is located in the middle of the two intersecting areas adjacent in the first direction and is formed in the first pattern forming area, The photomask according to any one of the first to fifth aspects.
(Seventh aspect)
The seventh aspect of the present invention is
The isolated pattern suppresses a local peak of light intensity in a light intensity distribution of a transfer image formed by the first slit pattern on the transfer object when the transfer pattern is subjected to proximity exposure, The photomask according to the sixth aspect, wherein the transmitted light intensity of the first slit pattern is made uniform.
(Eighth aspect)
The eighth aspect of the present invention is
8. The photomask according to the sixth or seventh aspect, wherein the isolated pattern has a rectangular shape.
(Ninth aspect)
The ninth aspect of the present invention provides
Preparing a photomask according to any one of the first to eighth aspects;
Transferring the transfer pattern onto the transfer object using a proximity exposure apparatus; and
A method for manufacturing a display device, comprising:

  ADVANTAGE OF THE INVENTION According to this invention, when transferring the pattern for transfer of a photomask on a to-be-transferred body by a proximity exposure system, the high-definition pattern faithful to the pattern design of the target device can be transferred. Thereby, for example, when a BM is formed using a CF substrate as a transfer target, a high-definition BM can be formed on the transfer target, which can contribute to the production of high-performance CF.

It is a top view which shows the structural example of the photomask which concerns on the reference form of this invention. (A) is HH sectional drawing of FIG. 1, (b) is V1-V1 sectional drawing of FIG. 1, (c) is V2-V2 sectional drawing of FIG. It is a top view which shows the arrangement | positioning relationship of a 1st pattern formation area, a 2nd pattern formation area, and an intersection area | region. (A) is a plan view schematically showing a light intensity distribution of a transfer image obtained on a transfer object when a transfer pattern of a photomask of a reference form is exposed using a proximity exposure apparatus, (B) is a plan view showing a BM image formed on a transfer target (negative photosensitive material) by the light intensity distribution shown in (a) of the figure. (A) is a plan view in which the periphery of the crossing region of the transfer pattern of the photomask shown in FIG. 1 is enlarged, and (b) is the top view of the transfer object when the transfer pattern is exposed by the proximity exposure apparatus. It is a top view which shows typically the light intensity distribution of the transfer image formed in FIG. It is a top view which shows typically ideal light intensity distribution of a transfer image. It is a top view which shows the structural example of the pattern for a transfer with which the photomask which concerns on 1st Embodiment of this invention is provided. It is a top view which shows typically an example of the light intensity distribution of the transfer image obtained when the photomask which concerns on 1st Embodiment of this invention is used. It is a top view which shows the other structural example of the pattern for a transfer with which the photomask which concerns on 1st Embodiment of this invention is provided. FIG. 2 is a plan view schematically showing a light intensity distribution of a transfer image formed on a transfer object when a photomask transfer pattern according to the reference embodiment shown in FIG. 1 is exposed by a proximity exposure apparatus. It is a top view which shows the structural example of the pattern for a transfer with which the photomask which concerns on 2nd Embodiment of this invention is provided. (A)-(e) is a top view which shows the aspect of the expansion part applicable to 2nd Embodiment of this invention. FIG. 2 is a plan view schematically showing a light intensity distribution of a transfer image formed on a transfer object when a photomask transfer pattern according to the reference embodiment shown in FIG. 1 is exposed by a proximity exposure apparatus. It is a top view which shows the structural example of the pattern for a transfer with which the photomask which concerns on 3rd Embodiment of this invention is provided. It is a top view which shows the pattern for transfer of the photomask of a reference form. It is a figure which shows the light intensity distribution of the optical image (transfer image) obtained by exposing the photomask provided with the pattern for transfer shown in the said FIG. 15 on a to-be-transferred body. It is a top view which shows the example which introduce | transduced the auxiliary pattern into the pattern for transfer of a photomask. It is a figure which shows the light intensity distribution of the optical image obtained on a to-be-transferred material by the pattern for a transfer of the said FIG. (A) is a schematic diagram which shows the structural example of a color filter, (b) is a figure which shows the mask pattern before refinement | miniaturization, (c) is a figure which shows the mask pattern after refinement | miniaturization. (A) is a diagram showing a CF pattern by an ideal BM transfer image, and (b) is a diagram showing a CF pattern by an actual BM transfer image.

<Reference form>
FIG. 1 is a plan view showing a configuration example of a photomask according to a reference embodiment of the present invention. 2A is a cross-sectional view taken along line HH in FIG. 1, FIG. 2B is a cross-sectional view taken along line V1-V1 in FIG. 1, and FIG. 2C is a cross-sectional view taken along line V2-V2 in FIG.
The illustrated photomask is a proximity exposure photomask provided with a transfer pattern on a transparent substrate for forming a BM on a transfer target. The photomask transfer pattern includes a first slit pattern 1 substantially composed of a light-transmitting portion 22, a second slit pattern 2 substantially composed of a semi-transparent portion 21, and a substantially light-shielding portion 23. A light-shielding pattern 3.

  The 1st slit pattern 1 and the 2nd slit pattern 2 are formed in the pattern formation area corresponding to each. Specifically, as shown in FIG. 3, a pattern formation region extending in the first direction is defined as a first pattern formation region E1, and a pattern formation region extending in a second direction intersecting the first direction is defined as a second pattern formation region E1. When the first pattern formation region E1 and the second pattern formation region E2 intersect with each other (the hatched region in the figure) is defined as the intersection region E3, the first slit pattern 1 is formed in the first pattern formation region E1, and the second slit pattern 2 is formed in the second pattern formation region E2 excluding the intersection region E3. Here, as an example, the X direction (horizontal direction) is the first direction, and the Y direction (vertical direction) is the second direction. In this case, the first pattern formation region E1 and the second pattern formation region E2 are formed in a lattice shape so as to intersect each other at right angles.

  The first slit pattern 1 is a slit-like pattern formed with the X direction as the length direction and the Y direction as the width direction, and is arranged at a predetermined pitch P1 in the Y direction. The second slit pattern 2 is a slit-like pattern formed with the X direction as the width direction and the Y direction as the length direction, and is arranged at a predetermined pitch P2 in the X direction. The light shielding pattern 3 is a pattern surrounded by the first slit pattern 1 and the second slit pattern 2. FIG. 1 shows a part of the transfer pattern of the photomask. Actually, the first slit pattern 1 and the second slit pattern 2 are formed at a repetition period of a predetermined pitch P1, P2, respectively. .

  The first slit pattern 1 is composed of a light transmitting portion 22 where the surface of the transparent substrate 30 is exposed. The second slit pattern 2 includes a semi-transparent portion 21 formed by forming a semi-transparent film 31 on the transparent substrate 30. The semi-transmissive film 31 is a semi-transmissive film that transmits part of the exposure light. The light shielding pattern 3 includes a light shielding portion 23 formed by forming a light shielding film 32 on the transparent substrate 30. In FIG. 2, the light shielding portion 23 is a laminated film in which the semi-transparent film 31 and the light shielding film 32 are laminated in this order. However, the lamination order may be reversed, or a single layer film of the light shielding film 32. There may be.

  FIG. 4A is a plan view schematically showing a light intensity distribution of a transfer image obtained on a transfer target when the transfer pattern of the photomask of the above-described reference form is exposed using a proximity exposure apparatus. It is. FIG. 4B is a plan view showing a BM image formed on the transfer target (negative photosensitive material) by the light intensity distribution shown in FIG. In FIG. 4B, the portion surrounded by the first BM pattern 41 corresponding to the first slit pattern 1 and the second BM pattern 42 corresponding to the second slit pattern 2 corresponds to the light shielding pattern 3. It becomes the opening part 43 to do. The line width of the first BM pattern 41 is represented by L1, and the line width of the second BM pattern 42 is represented by L2.

  According to the light intensity distribution shown in FIG. 4A, the following three phenomena appear in the shape of the transfer image obtained on the transfer target by the photomask transfer pattern.

  (1) The vicinity of the intersection region E3 of the first pattern formation region E1 and the second pattern formation region E2 and the end portion in the length direction of the second slit pattern 2 (A portion in FIG. 4A) In the vicinity, a dark spot (hereinafter referred to as “light quantity reduced spot”) in which the light intensity of the exposure light is locally reduced appears. Due to the decrease in the light intensity that appears here, in the BM image formed on the transfer target, the line width L2 of the second BM pattern 42 is partially smaller than the design value, or in some cases, the wire breaks. It is easy to become.

  (2) As shown in FIG. 4B, the corners of the opening 43 of the BM image are rounded instead of being a right angle. Further, the shape of the contour line of the amount of light is also wavy due to fluctuations in the straight line portion in the photomask transfer pattern (B portion in FIG. 4A). For this reason, the corners of the opening 43 of the BM image formed on the transfer medium are rounded, and the opening area is reduced.

  (3) In the first slit pattern 1, a strong light quantity peak appears in the middle of two intersecting regions E3 adjacent in the X direction (C portion in FIG. 4A). For this reason, an unnecessary intensity is generated in the light intensity of the exposure light transmitted through the first slit pattern 1. Accordingly, there is a risk that locally strong cured portions 44 are generated in the BM image formed on the transfer target corresponding to the first slit pattern 1, thereby causing irregularities in the three-dimensional structure of the BM.

  Under the present circumstances, it is a problem to solve problems that may occur when a CF is produced by exposing a BM photosensitive material on a transfer object by using a transfer image whose pattern shape has deteriorated due to the three phenomena described above. It has become. Hereinafter, the embodiment corresponding to the problem caused by the phenomenon of (1) is the first embodiment, the embodiment corresponding to the problem caused by the phenomenon of (2) is the second embodiment, and the phenomenon of (3) is caused. An embodiment corresponding to the problem will be described as a third embodiment.

<First Embodiment>
First, the phenomenon (1) will be examined.
FIG. 5A is an enlarged plan view of the periphery of the crossing region of the transfer pattern of the photomask shown in FIG. 1, and FIG. 5B is a plan view when the transfer pattern is exposed by the proximity exposure apparatus. It is a top view which shows typically the light intensity distribution of the transfer image formed on a transfer body.

  In FIG. 5A, the first slit pattern 1 has a portion with a constant width W1, and the second slit pattern 2 has a portion with a constant width W2 (W2 <W1). A portion of the first slit pattern 1 having a constant width W1 is parallel to the X direction, and a portion of the second slit pattern 2 having a constant width W2 is parallel to the Y direction.

  The intersecting region E3 is a polygonal region (rectangle in FIG. 5A) partitioned between the second slit patterns 2 adjacent in the Y direction. The intersection area E3 is specified as a polygonal area in which each corner YE is connected by a straight line when the corners of the second slit pattern 2 facing each other via the intersection area E3 in the Y direction are each YE. It is possible. With respect to a certain second slit pattern 2, a line segment connecting the corners YE of the second slit pattern 2 paired in the X direction with a straight line corresponds to the exit of the second slit pattern 2. The exit of the second slit pattern 2 is a boundary between the intersecting region E3 and the second slit pattern 2 and is in contact with the intersecting region E3 in the second direction (Y direction in this embodiment). The edge of 2. The corner portion YE of the second slit pattern 2 is an inflection portion where the line width or edge shape of the second slit pattern 2 changes abruptly at the boundary portion between the intersecting region E3 and the second slit pattern 2, for example. Can be specified.

  As described above, the first slit pattern 1 includes the translucent portion 22, and the second slit pattern 2 includes the semi-transparent portion 21. Further, in FIG. 5A, hatching is performed to indicate the range of the intersecting region E <b> 3, but the intersecting region E <b> 3 becomes a part of the first slit pattern 1. For this reason, the intersection region E <b> 3 includes the transparent portion 22 formed by exposing the transparent substrate 30, as in the first slit pattern 1. In addition, regarding the intersection region E3, hatching may be applied even in drawings other than FIG. The light shielding pattern 3 is a pattern corresponding to the opening of the BM, and includes a light shielding portion 23. The light shielding pattern 3 is formed so as to be positioned between the second slit patterns 2 adjacent in the X direction and between the first slit patterns 1 adjacent in the Y direction.

  In FIG. 5B, the portion corresponding to the second slit pattern 2 has a light quantity at a position separated by a distance d1 (μm) in the Y direction from the boundary between the intersecting region E3 and the second slit pattern 2. A drop spot 45 is formed. In FIG. 5B, the light amount reduction spot generated in the portion A of FIG. 4A is emphasized. The formation of the light quantity reduction spot 45 is not preferable because, in the step of forming the BM, as described above, the line width of the BM is reduced and the risk of disconnection occurs. That is, the intensity of the light formed on the transfer medium by the exposure light transmitted through the second slit pattern 2 is made more uniform, and as a result, an ideal light intensity distribution as shown in FIG. 6 can be obtained. desirable. In the light intensity distribution shown in FIG. 6, the light quantity reduction spot 45 does not occur.

  Therefore, the present inventors examined the introduction of an auxiliary pattern that increases the uniformity of the light intensity of the BM transfer image formed on the transfer target by the first slit pattern 1 and the second slit pattern 2. This auxiliary pattern is a pattern that is not resolved independently when the transfer pattern of the photomask is transferred onto the transfer object using the proximity exposure apparatus. Here, “a pattern that is not independently resolved” means that the transferred image of the pattern can be identified by the CD and transmittance of the photomask pattern under the exposure conditions of the exposure apparatus for manufacturing the display device. This refers to a pattern that cannot be formed. CD is an abbreviation for Critical Dimension and has the meaning of pattern width. The auxiliary pattern is a pattern introduced for the purpose of bringing the BM image formed on the transferred body close to an ideal shape as shown in FIG. 6, and the shape of the BM image formed on the transferred body is changed. Plays an auxiliary role in arranging.

(Photomask of the first embodiment)
FIG. 7 is a plan view showing a configuration example of a transfer pattern included in the photomask according to the first embodiment of the present invention.

  The illustrated photomask can be applied as a photomask for forming a BM on a transfer object by being exposed by a proximity exposure method. The photomask according to the first embodiment has the same pattern as the photomask of the reference mode shown in FIG. 1 except that the transfer pattern includes an auxiliary pattern. Specifically, the first slit pattern 1 formed in the first pattern formation region E1, the second slit pattern 2 formed in the second pattern formation region E2 excluding the intersection region E3, and the first A transfer pattern including a light shielding pattern 3 surrounded by the slit pattern 1 and the second slit pattern 2.

  The first slit pattern 1 has a constant width W1 (μm) portion, and the second slit pattern 2 has a narrower constant width W2 (μm) portion. The pitch (repetition period) in the Y direction of the first slit pattern 1 is P1 (μm), and the pitch (repetition period) in the X direction of the second slit pattern 2 is P2 (μm). It is preferable that the first slit pattern 1 is substantially composed of the translucent part 22, and the second slit pattern 2 is substantially composed of the semi-translucent part 21. The translucent part 22 can be one in which the transparent substrate 30 is exposed, and the semi-translucent part 21 can be formed by forming the semi-transparent film 31 on the semi-transparent film 31. The exposure light transmittance of the semi-translucent portion 21 is preferably 30 to 70%, more preferably 40 to 60%, when that of the transparent substrate is taken as 100%. Further, the phase shift amount of the semi-transmissive film 31 with respect to the exposure light is preferably within ± 90 degrees, and more preferably within ± 60 degrees. The intersecting region E3 is substantially composed of the light transmitting portion 22.

  In this embodiment, the “substantial” region is a region other than the auxiliary pattern when there is an auxiliary pattern that is not resolved independently but is introduced to improve the transferability of the BM pattern. Say. For example, the case where an isolated pattern made of a semi-light-transmitting portion is introduced as an auxiliary pattern in the first slit pattern 1 made of a light-transmitting portion is included as will be described later. In this case, the meaning that the first slit pattern 1 is “substantially” made of a light-transmitting portion means that the first slit pattern 1 made of the light-transmitting portion and the auxiliary pattern made of the semi-light-transmitting portion are added together. Is 100%, the area occupied by the first slit pattern 1 is 65% or more, preferably 80% or more. Similarly for the second slit pattern 2, the meaning that the second slit pattern 2 is “substantially” composed of a semi-translucent portion means that the area occupied by the second slit pattern 2 is 65% or more, preferably 80%. % Or more. Further, the case where the intersecting region E3 substantially consists of a light transmitting portion means that, for example, an auxiliary pattern having optical characteristics different from that of the intersecting region E3 is introduced into the intersecting region E3 as described in a second embodiment described later. In this case, the portion excluding the auxiliary pattern is a translucent portion.

  Further, light shielding patterns 3 are formed in portions corresponding to the windows of the lattice formed by the first slit pattern 1 and the second slit pattern 2. The light shielding pattern 3 includes a light shielding portion 23 in which a light shielding film 32 is formed on a transparent substrate 30. The first slit pattern 1 and the second slit pattern 2 constitute a lattice pattern corresponding to the BM to be formed on the transfer target. The light shielding pattern 3 surrounded by the first slit pattern 1 and the second slit pattern 2 constitutes a pattern corresponding to the opening of the BM. In the case of manufacturing a CF for an LCD, after forming a BM on a transparent CF substrate, filters of corresponding colors (R, G, B) are formed in each opening portion of the BM.

  Although not shown, a light-transmitting portion in which no light shielding portion is formed can be provided in the vicinity of the outer periphery of the photomask transfer pattern. This translucent portion corresponds to a frame region on the outer edge of the display portion of the liquid crystal display device, and has a width that is sufficiently wider than the first and second slit patterns.

  The width dimension W1 (μm) in the constant width portion of the first slit pattern 1 is preferably 15 ≦ W1 ≦ 40, and the width dimension W2 (μm) of the constant width portion of the second slit pattern 2 is preferably Is 4 ≦ W2 ≦ 12. The pitch P1 (μm) of the first slit pattern 1 is preferably 400 ≦ P1 ≦ 100, and the pitch P2 (μm) of the second slit pattern 2 is preferably 10 ≦ P2 ≦ 35. is there.

  In the present embodiment, the case where the first pattern formation region E1 and the second pattern formation region E2 intersect at right angles is described as an example. However, the present invention is not limited to this. is not. For example, the angle at which the first pattern formation region E1 and the second pattern formation region E2 intersect can be within 90 ± 45 degrees, and more preferably within 90 ± 30 degrees. In any case, the first slit pattern 1 is formed in the first pattern formation region E1, and the second slit pattern 2 is formed in the second slit pattern 2 excluding the intersection region E3.

  Further, the first slit pattern 1 may not have a constant width in all portions, and may have a constant width portion of W1. Similarly, the second slit pattern 2 may not have a constant width in all portions, and may have a constant width portion of W2. Therefore, for example, the first slit pattern 1 may have a part that is partially widened. Moreover, it is preferable that the 1st slit pattern 1 and the 2nd slit pattern 2 have the part of the said fixed width W1, W2 in the ratio of 50% or more of length, respectively.

  The auxiliary pattern provided in the photomask transfer pattern according to the first embodiment of the present invention will be described below with reference to FIG.

  The second slit pattern 2 is formed with a pair of convex portions 5 as an auxiliary pattern. The pair of convex portions 5 are formed so as to partially protrude on both sides in the width direction of the second slit pattern 2, whereby a part of the second slit pattern 2 has a wider portion 6 having a wider line width than other portions. It has become. Each convex portion 5 is formed with a protruding amount of α1 (μm) in the X direction and a protruding width of β1 (μm) in the Y direction. The pair of convex portions 5 are formed at corresponding positions on both sides in the width direction of the second slit pattern 2 and are preferably provided symmetrically in the width direction. In addition, the pair of convex portions 5 are preferably formed at equidistant positions in the Y direction from the boundary between the intersection region E3 and the second slit pattern 2.

  The wide portion 6 formed by the pair of convex portions 5 is preferably disposed in the vicinity of the intersection region E3. Specifically, in the Y direction, the distance D1 from the boundary between the intersecting region E3 and the second slit pattern 2 to the center of gravity of the wide portion 6 is the length of the second slit pattern 2 (P1-W1). It is preferable that it is within 1/4. In this case, a preferable range of the distance D1 is β1 ÷ 2 ≦ D1 ≦ 0.25 × (P1−W1). Further, it is preferable that the distance D1 satisfies β1 ÷ 2 <D1, that is, the convex portion 5 is arranged away from the boundary between the intersecting region E3 and the second slit pattern 2.

  The width of the wide portion 6 is represented by W2 + (2 × α1). In that case, the protruding amount α1 of the convex portion 5 is preferably 0 <α1 ≦ 0.3 × W2, and more preferably 0.04 × W2 ≦ α1 ≦ 0.25 × W2. Further, the protruding width β1 of the convex portion 5 is preferably 0 <β1 ≦ 0.15 × (P1−W1).

  According to the study by the present inventors, it was confirmed that the formation of the light amount reduction spot 45 (FIG. 5B) is suppressed by providing the wide portion 6 in the second slit pattern 2. That is, when a photomask for BM formation having the transfer pattern of FIG. 7 is exposed, the drop in light intensity is eliminated in the transfer image of the second slit pattern 2 as shown in FIG. It turned out to be uniform. That is, the light intensity distribution can be made uniform as compared with the case where the wide portion 6 is not provided.

  In the present embodiment, the wide portion 6 is formed at a position away from the boundary between the intersecting region E3 and the second slit pattern 2 by the distance D1, but the position of the wide portion 6 specified by the distance D1 The position of the light amount reduction spot 45 specified by the distance d1 shown in FIG. That is, D1 = d1 is not always satisfied, and D1> d1 or D1 <d1 may be satisfied. The optimum position of the wide portion 6, that is, the position of the wide portion 6 where the light intensity distribution in the transfer image of the second slit pattern 2 is most stable can be confirmed by optical simulation.

  Further, the number of the wide portions 6 provided in the second slit pattern 2 is not limited to one. That is, the convex portions 5 introduced into the second slit pattern 2 are not limited to a pair. For example, as a result of providing the wide portion 6 in the vicinity of the boundary between the intersecting region E3 and the second slit pattern 2, in the transfer image of the second slit pattern 2, as shown in FIG. May be formed. The light amount reduction spot 45b is generated at a position separated from the boundary between the intersecting region E3 and the second slit pattern 2 by a distance d2 in the Y direction.

  Therefore, in order to eliminate this light quantity drop and to make the light intensity distribution of the transfer image of the second slit pattern 2 more uniform, the second wide width in addition to the wide portion 6 as shown in FIG. Part 6b can be introduced. The wide portion 6b is formed in the second slit pattern 2 by a pair of convex portions 5b.

  In the transfer pattern shown in FIG. 9, a wide portion (hereinafter also referred to as “main wide portion”) 6 is provided at a position separated by a distance D1 (μm) from the boundary between the intersecting region E3 and the second slit pattern 2. Further, a wide portion 6b is provided at a position away from the boundary by a distance of D2 (μm). In this case, the distance D2 in the Y direction represents the distance from the boundary between the intersecting region E3 and the second slit pattern 2 to the center of gravity of the wide portion 6b, similar to the distance D1, and the relationship of D2> D1 is satisfied. Fulfill. Further, the relationship between the protruding amount α1 (μm) of the convex portion 5 in the wide portion 6 and α2 (μm) of the protruding amount of the convex portion 5b in the wide portion 6b is preferably α1 ≧ α2, more preferably α1. > Α2.

  When providing only the wide part 6 in the 2nd slit pattern 2, or providing both the wide part 6 and the wide part 6b, it is preferable that the protruding shape of the convex parts 5 and 5b is a rectangle. Further, the number of the wide portions 6 provided in the second slit pattern 2 may be three or more. In that case, if the protruding amounts of the wide portions 6 are α1, α2, α3, α4,... In order from the boundary between the intersecting region E3 and the second slit pattern 2, these relationships are preferably α1. ≧ α2 ≧ α3 ≧ α4... More preferably, α1> α2> α3> α4. However, this condition is applied to a section from the boundary between the intersecting region E3 and the second slit pattern 2 to the middle portion in the length direction of the second slit pattern 2.

  The number N of the wide portions 6 arranged from one end to the other end in the length direction of the second slit pattern 2 is preferably 1 ≦ N ≦ 5. In that case, it is preferable to arrange the main wide portion 6 in the vicinity of the intersection region E3.

  Regarding the light amount reduction spot 45b, the position of the wide portion 6b specified by the distance D2 does not necessarily match the position of the light amount reduction spot 45b specified by the distance d2. That is, D2 = d2 is not always satisfied, and D2> d2 or D2 <d2 may be satisfied. The same applies to the case where three or more wide portions 6 are provided in the second slit pattern 2 (in the case of D3 or less).

In the photomask according to the first embodiment of the present invention, the wide slit 6 is formed by the pair of convex portions 5 in the second slit pattern 2, so that when the transfer pattern is subjected to proximity exposure, the second slit is formed. In the light intensity distribution of the transferred image formed by the pattern 2 on the transfer object, local decrease in light intensity (occurrence of the light amount reduction spot 45) is suppressed, and the transmitted light intensity of the second slit pattern 2 is made uniform. can do. Thereby, the light intensity distribution of the transfer image of the second slit pattern 2 formed on the transfer target can be brought close to the ideal light intensity distribution shown in FIG. As a result, when the CF is manufactured in the manufacturing process of the display device, the dimension (particularly, the pattern width) of the BM formed on the CF substrate is within a predetermined range, and the risk of disconnection can be reduced.
Further, in this embodiment, the light shielding pattern corresponding to the opening of the BM provided in the conventional photomask is partially replaced with a semi-transparent portion below the resolution limit (not independently resolved), thereby transferring the light. It can also be considered to reduce the risk of image thinning and disconnection.

Second Embodiment
The photomask according to the second embodiment of the present invention solves the problem caused by the phenomenon (2).

  FIG. 10 is a plan view schematically showing the light intensity distribution of a transfer image formed on a transfer object when the photomask transfer pattern according to the reference embodiment shown in FIG. 1 is exposed by a proximity exposure apparatus. is there. Here, the portion B shown in FIG. 4A (rounded corners and waviness of contour lines) is emphasized. That is, even if the corner portion K (FIG. 5A) of the light shielding pattern 3 is angular, if it is transferred as a transfer image onto the transfer target, the portion corresponding to the corner portion K of the light shielding pattern 3 (FIG. 10). (J section) is rounded and enters the inside of the opening region where the color filter is to be arranged. At the same time, the contours (S part in the figure) formed on the outer edge of the bright band (Q part in FIG. 10) formed as a transfer image of the first slit pattern 1 composed of the translucent part are waved and waved (in the figure). , See dotted ellipses). Due to these phenomena, there is a possibility that the opening area of the opening portion (region where the color filter is arranged) of the CF manufactured using the photomask is reduced, and the brightness of the display is impaired.

(Photomask of the second embodiment)
FIG. 11 is a plan view illustrating a configuration example of a transfer pattern included in the photomask according to the second embodiment of the present invention.

  Similar to the photomask according to the first embodiment, the photomask according to the second embodiment of the present invention includes the first slit pattern 1, the second slit pattern 2, and the light shielding pattern 3. The difference from the embodiment is that the auxiliary pattern has the following extended portion instead of the wide portion (or on the wide portion).

  In the photomask shown in FIG. 11, the extended portion 7 is formed by extending in the Y direction from the exit of the second slit pattern 2. In addition, the extension portion 7 extends in the X direction from the outlet of the second slit pattern 2. Here, the X direction is a direction parallel to the constant width W1 portion of the first slit pattern 1, and the Y direction is a direction parallel to the constant width W2 portion of the second slit pattern 2. Further, as described above, the exit of the second slit pattern 2 is a boundary between the intersecting region E3 and the second slit pattern 2, and enters the intersecting region E3 in the second direction (Y direction in this embodiment). The end side of the 2nd slit pattern 2 which touches is said. The extension part 7 consists of a semi-translucent part. The extended portion 7 extends so as to project from the boundary between the intersecting region E3 and the second slit pattern 2 to the intersecting region E3 side, and further expands so as to project to both sides of the intersecting region E3.

  Here, if the expansion amount in the Y direction of the expansion unit 7 is γ1 (μm) and the expansion amount in the X direction is γ2 (μm), the expansion amount γ1 in the Y direction is the intersection region E3 and the second slit pattern 2 The expansion amount γ2 in the X direction is defined based on the position of the corner YE of the second slit pattern 2. The extension portion 7 projects symmetrically with an extension amount of γ2 (μm) on one side and the other side in the X direction with respect to the center in the width direction of the second slit pattern 2. For this reason, the width W3 (μm) of the extension portion 7 in the X direction is larger than the width W2 of the second slit pattern 2. The width W3 of the extended portion 7 is W3 (= W2 + 2 × γ2)> W2 in relation to the width W2 of the second slit pattern 2. The extension portion 7 is formed in a rectangular shape having a short side having a dimension of γ1 and a long side having a dimension of W3.

  The dimension of γ1 (μm) of the expanded portion 7 is preferably 0 <γ1 <0.5 × W1, more preferably 0 <γ1 <0.1 × P1 <0.5 × W1. In addition, the dimension of γ2 (μm) of the expanded portion 7 is preferably 0 <γ2 <0.5 × (P2−W2), more preferably 0 <γ2 <0.3 × (P2−W2). .

  In the photomask transfer pattern according to the second embodiment, the second slit pattern 2 is made of a semi-translucent portion, and the extension portion 7 is also made of the semi-transparent portion, like the second slit pattern 2. It is preferable to become. Further, it is more preferable that the extended portion 7 is a semi-transparent portion having the same light transmittance formed by the same semi-transparent film as the second slit pattern 2.

  In the photomask according to the second embodiment of the present invention, the extended portion 7 extending in the X direction and the Y direction from the exit of the second slit pattern 2 is formed. The curvature of the corner (J portion in FIG. 10) in the transfer image formed by the second slit pattern 2 on the transfer object can be increased, and curling of the corner can be suppressed. In other words, the extended portion can increase the curvature of the corner portion in the transferred image formed on the transfer target, as compared with the case where the extended portion is not provided. For example, the curvature R2 of the corner portion J in the transfer image of FIG. 10 can be made close to the curvature R1 (> R2) shown in FIG. Furthermore, it is possible to suppress fluctuations in contour lines (S portion in FIG. 10) in the transfer image of the first slit pattern 1 composed of the light transmitting portion. Thereby, the light intensity distribution of the transfer image formed on the transfer target can be brought close to the ideal light intensity distribution shown in FIG. As a result, when the CF is manufactured in the manufacturing process of the display device, it is possible to suppress a decrease in the opening area of the BM and obtain a brighter CF.

In addition to the configuration shown in FIG. 11, various types of expansion units are conceivable, for example, as shown in FIGS. 12 (a) to (e).
In FIG. 11 described above, the expansion unit 7 has an aspect (XY expansion type) expanded in both the X direction and the Y direction. On the other hand, in FIG. 12A, the extended portion 7 is in a mode (Y-expanded type) expanded only in the Y direction with the same width as the width W2 of the second slit pattern 2. Further, in FIG. 12 (b), the end of the expansion portion 7 expanded in the Y direction is in a form protruding in a convex shape (Y convex expansion type), and in FIG. 12 (c), it is expanded in the Y direction. The extended portion 7 has a concave shape (Y-concave expansion type). Further, in FIG. 12 (d), the end of the extended portion 7 extended in both the X direction and the Y direction has a form protruding in a convex shape (XY convex extended type), and in FIG. The tip of the extended portion 7 that extends in both the X direction and the Y direction is recessed (XY concave extended type). Among these, in the convex shape shown in FIGS. 12B and 12D, the expansion amount on both sides of the convex portion is smaller than the expansion amount γ1 at the center of the convex portion (here, “small” Includes a case of zero). In addition, in the concave shape shown in FIGS. 12C and 12E, the expansion amount at the center of the concave portion is smaller than the expansion amount γ1 on both sides of the concave portion (here, “small” means zero. Including some cases).

  In addition, the aspect of the extended part may be an aspect in which a plurality of the shapes illustrated in FIGS. 11 and 12 are combined. In addition, the optimal shape of the extension may vary depending on the width and light transmittance settings of the first slit pattern 1 and the second slit pattern 2, and a better shape should be selected by optical simulation. Can do. Further, the shape of the extended portion is not limited to the shape exemplified above, and can be determined according to the design pattern of the BM. Moreover, in the extended part 7 illustrated above, although it has a symmetric shape with respect to the center in the width direction of the second slit pattern 2, the shape is not limited to this and may be an asymmetric shape.

In the second embodiment of the present invention, the first slit pattern 1 and the second slit pattern 2 are exemplified as a pattern having a right angle. However, the first slit pattern 1 and the second slit pattern are exemplified. Even when the angle formed by the pattern 2 is not a right angle, the above-described extension portion can be provided. That is, the extension portion can be extended in the Y direction from the exit of the second slit pattern 2 (the boundary between the intersection region E3 and the second slit pattern 2), and can be extended in the X direction as necessary. it can.
In this embodiment, a part of the translucent part corresponding to the intersecting region provided in the conventional photomask is replaced with a semi-translucent part below the resolution limit (not independently resolved), thereby The profile can be improved.

<Third Embodiment>
The photomask according to the third embodiment of the present invention solves the problem caused by the phenomenon (3).

  FIG. 13 is a plan view schematically showing a light intensity distribution of a transfer image formed on a transfer object when the photomask transfer pattern according to the reference embodiment shown in FIG. 1 is exposed by a proximity exposure apparatus. is there. Here, the C part (appearance of a strong light intensity peak) shown in FIG. That is, there is a case where a peak having a strong light amount is formed at a position in the vicinity of the width center of the first slit pattern 1 and corresponding to the middle of two intersecting regions E3 adjacent in the X direction. When such a peak appears, the BM or the like (for example, a negative photosensitive resin) formed on the transfer body is locally hardened, and there is a risk that the height of the three-dimensional structure may be uneven. .

(Photomask of the third embodiment)
FIG. 14 is a plan view showing a configuration example of a transfer pattern included in the photomask according to the third embodiment of the present invention.

  Similar to the photomask according to the first embodiment, the photomask according to the third embodiment of the present invention includes the first slit pattern 1, the second slit pattern 2, and the light shielding pattern 3. The difference from the embodiment or the second embodiment is that the auxiliary pattern has the following isolated pattern instead of having the wide portion or the extended portion (or on the upper portion having the wide portion or the extended portion). It is in.

  In the photomask shown in FIG. 14, the isolated pattern 8 is provided in the first pattern formation region E1 where the first slit pattern 1 is formed. The isolated pattern 8 is formed so as to be located in the middle of two intersecting regions E3 adjacent in the X direction. Here, the “isolated pattern” refers to a pattern isolated in an island shape. For example, as illustrated in FIG. 14, it refers to an island-shaped pattern surrounded by a transparent portion where a transparent substrate is exposed.

  As shown in the figure, the isolated pattern 8 is arranged near the center in the width direction of the first slit pattern 1 and in the middle of a straight line connecting the centroids of the intersecting regions E3 adjacent in the X direction. Here, one isolated pattern 8 is arranged in the middle of the intersecting region E3 adjacent in the X direction, but it may be arranged separately into a plurality of isolated patterns. When arranging a plurality of isolated patterns, the plurality of isolated patterns can be arranged in the width direction of the first slit pattern 1 at an intermediate point between the intersecting regions E3 adjacent in the X direction. In either case, the center of gravity of the isolated pattern 8 is preferably equidistant from the intersecting region E3. Specifically, the position of the isolated pattern 8 can be set, for example, to a position separated from the center of gravity of the intersection region E3 by a distance D3 (= 1 / 2Py) in the X direction. The isolated pattern 8 can lower the local light intensity peak.

The isolated pattern 8 can be a rectangular pattern made of a semi-translucent portion. However, the shape of the isolated pattern 8 may be a shape other than a rectangle. Further, the isolated pattern 8 may be a light shielding portion that does not substantially transmit light. The phrase “light does not substantially transmit” preferably refers to a case where the optical density OD satisfies the condition of OD ≧ 3. When the isolated pattern 8 is a semi-transparent portion, the isolated pattern 8 is preferably formed of a semi-transparent portion (semi-transmissive film) having the same light transmittance as that of the second slit pattern 2.
It is preferable to form the isolated pattern 8 by a semi-translucent portion because it is easier to select dimensions that are not resolved independently.
Also in the third embodiment, the size, shape, exposure light transmittance (in the case of a semi-translucent portion), arrangement position, number, etc. of the isolated pattern 8 can be selected by optical simulation.

In the photomask according to the third embodiment of the present invention, the first pattern formation region E1 includes a semi-translucent portion or a light-shielding portion so as to be positioned between two adjacent regions E3 adjacent in the X direction. The formation of the isolated pattern 8 suppresses local peaks of light intensity in the light intensity distribution of the transferred image formed by the first slit pattern 1 on the transfer object when the transfer pattern is subjected to proximity exposure. To do. And compared with the case where there is no isolated pattern 8, the transmitted light intensity of the 1st slit pattern 1 can be equalize | homogenized. As a result, in the transfer image of the first slit pattern 1 formed on the transfer target, unnecessary vertical movement of light intensity (generation of intensity) is reduced, and a transfer image with more uniform light intensity is obtained. Therefore, the light intensity distribution of the transfer image formed on the transfer target can be brought close to the ideal light intensity distribution shown in FIG. As a result, when the CF is manufactured in the manufacturing process of the display device, an unnecessary height variation of the BM can be suppressed.
Then, the photomask of this aspect has a light-transmitting portion corresponding to the slit pattern (first slit pattern) included in the conventional photomask, or a light-shielding portion or half of the resolution limit (not independently resolved). By partially replacing the light transmitting portion, unevenness of light intensity in the transferred image can be reduced.

  In the first embodiment, the second embodiment, and the third embodiment described above, the auxiliary pattern for adjusting the shape of the BM image is shown in order to improve the transferability of the lattice pattern. That is, the first embodiment illustrates a pair of convex portions 5 (wide portions 6) as the auxiliary pattern, the second embodiment shows the extended portion 7 as the auxiliary pattern, and the third embodiment uses the isolated pattern 8 as the auxiliary pattern. Illustrated. These auxiliary patterns may be applied independently in designing a photomask transfer pattern, or any two auxiliary patterns may be combined, or all auxiliary patterns may coexist. .

  In addition, as exemplified in the first to third embodiments, the photomask of the present invention has an auxiliary pattern that is not independently resolved on the transfer target, thereby forming a BM image formed on the transfer target. This makes it possible to increase the uniformity of the light intensity of the light source and thereby form a finer BM more precisely.

The photomask of the present invention can be manufactured, for example, by the following method.
First, a photomask blank is prepared in which a semi-transparent film 31 and a light-shielding film 32 are laminated on a transparent substrate 30 made of quartz or the like, and a photoresist film is further formed thereon. The semi-transparent film 31 can be a film containing any of Cr, Ta, Zr, Si, and Mo, or a compound thereof (oxide, nitride, carbide, oxynitride, carbonitride, Appropriate ones can be selected from oxynitride carbides and the like. Alternatively, a Si compound (SiON or the like), a transition metal silicide (MoSi or the like), or a compound thereof (oxide, nitride, oxynitride, oxynitride carbide, or the like) can be used. The exposure light transmittance of the semi-transparent film 31 is preferably 30 to 70%, more preferably 40 to 60%. The material of the light shielding film 32 can also be selected from the above. If there is no etching selectivity between the semi-transparent film 31 and the light-shielding film 32, the semi-transparent film 31 is sandwiched between these films and an etching stopper film having etching selectivity as necessary. And the light shielding film 32 may be laminated.

  Next, the photomask blank of the present invention can be obtained by drawing a desired pattern on the photomask blank using a laser drawing apparatus or the like, and performing this drawing and etching as many times as necessary. As the etching, wet etching can be suitably applied.

  The photomask of the present invention manufactured by the above method has at least a light transmitting part 22 and a light shielding part 23, and preferably has a semi-light transmitting part 21. The translucent part 22 is formed by exposing the transparent substrate 30, the light-shielding part 23 is formed by forming at least a light-shielding film 32 on the transparent substrate 30, and the semi-translucent part 21 is semi-translucent on the transparent substrate 30. The film 31 may be formed.

  Further, the photomask of the present invention can transfer a transfer pattern onto a transfer target (liquid crystal panel substrate, CF substrate, etc.) by performing exposure using a proximity exposure apparatus. In that case, a light source having a wavelength of exposure light including 365 nm, 405 nm, and 436 nm can be preferably used. The proximity gap applied to the proximity exposure is preferably about 40 to 300 μm, and more preferably 100 to 150 μm.

  The photomask of the present invention can be used for BM formation as described above. In that case, the relationship between the dimension of the transfer pattern of the photomask and the dimension of the lattice-like BM formed by transferring the transfer pattern onto the transfer target is as follows. That is, the width of the first slit pattern 1 in the photomask transfer pattern is W1 (μm), the width of the second slit pattern 2 is W2 (μm), and is formed corresponding to the first slit pattern 1. When the line width of the BM pattern is L1 (μm) and the line width of the BM pattern formed corresponding to the second slit pattern 2 is L2 (μm), preferably L1 ≦ W1 and L2 ≦ W2. More preferably, L2 <W2, and still more preferably 1.2 ≦ W2 / L2 ≦ 3.

By using such a photomask of the present invention, for example, a BM with L2 of 2 to 10 μm, and further 2 to 8 μm can be formed. Further, by using the photomask of the present invention, a high-definition BM can be stably formed. This is because, in the optical image formed on the transfer object, unnecessary fluctuations and irregularities are difficult to be formed in the light intensity distribution, and the width of the BM is less likely to vary with respect to the proximity gap. This is because excellent effects can be obtained.
The photomask of the present invention may have an additional optical film or a functional film as long as the function and effect are not hindered. For example, a reflection reducing film, an etching stopper film, or a conductive film may be added as necessary.

<Example>
As an example of the present invention, optical simulation was performed on a proximity exposure photomask for BM formation.

FIG. 15 is a plan view showing a transfer pattern of a photomask of a reference form serving as a reference. As shown in FIG. 1, the illustrated transfer pattern includes a first slit pattern 1 composed of a translucent portion, a second slit pattern 2 composed of a semi-translucent portion, and a light shielding pattern composed of a light shielding portion. 3. The first slit pattern 1 has a portion having a constant width W1 (μm), and the second slit pattern 2 has a portion having a constant width W2 (μm) smaller than the W1. The pitch P1 in the Y direction of the first slit pattern 1, the pitch P2 in the X direction of the second slit pattern 2, the width W1 of the first slit pattern 1, and the width W2 of the second slit pattern 2 are as follows: It was.
P1 = 19 μm
P2 = 57 μm
W1 = 15μm
W2 = 9μm

It was assumed that a subpixel BM pattern having the following dimensions was formed on the transfer target (negative photosensitive material) by the transfer pattern.
L1 = 15 μm (target)
L2 = 5μm (target)

FIG. 16 is a diagram showing a light intensity distribution of an optical image (transfer image) obtained by exposing a photomask having the transfer pattern shown in FIG. The conditions of the optical simulation applied when obtaining the illustrated light intensity distribution are as follows. Note that Gap in the figure indicates a proximity gap value. The light intensity (%) is shown as a relative value.
Exposure wavelength (λ): 365 nm (single line)
Collimation angle: 2.0 deg.
Proximity gap: {100, 110, 120, 130, 140} μm
Transmissivity of semi-transparent film: 53%
Phase shift amount of semi-translucent film: 0 deg.

Next, as shown in FIG. 17, an auxiliary pattern was introduced into the transfer pattern and an optical simulation was performed in the same manner as described above. The transfer pattern of FIG. 17 introduces two wide portions (6, 6b), an extended portion 7 (Y-convex extended type), and an isolated pattern 8 as auxiliary patterns with respect to the transfer pattern of FIG. It is common, and other than that. The dimensions of the auxiliary pattern applied here are as follows.
D1 = 4.8 μm
α1 = 1.0μm
β1 = 4.0μm
D2 = 13.5 μm
α2 = 0.5μm
β2 = 4.0μm
γ1 = 4.0 μm (expansion amount 2.5 μm on both sides of the convex part, wide part width 3.0 μm)
D3 = 9.5 μm
δ1 = 6μm
δ2 = 4μm

  FIG. 18 is a diagram showing a light intensity distribution of an optical image obtained on the transfer object by the transfer pattern shown in FIG. The following became clear from FIG.

  (I) In FIG. 18, the amount of light (light intensity) of the transfer image of the second slit pattern 2 is increased as compared with FIG. This means that the risk of disconnection of the BM pattern formed corresponding to the second slit pattern 2 is reduced.

  (II) In FIG. 18, the roundness due to the drop in the amount of light at the opening corner of the BM image seen in FIG. 16 is suppressed, and the curvature of the opening corner is increased. Further, in FIG. 18, the undulation of the contour line along the BM pattern in the X direction is suppressed as compared with FIG. As a result, the opening shape of the BM image approaches a rectangle, and the area with a light intensity of 30% or more increases. This means that a bright CF with a large opening area of the BM can be obtained.

  (III) In FIG. 18, the strong light quantity peak of the transfer image in the BM pattern in the X direction seen in FIG. 16 is suppressed, and a uniform light quantity distribution is obtained over the entire X direction. This means that unnecessary unevenness is less likely to occur in the three-dimensional structure of the BM.

  From the result of the above optical simulation, it was confirmed that the photomask of the present invention has an excellent effect.

DESCRIPTION OF SYMBOLS 1 ... 1st slit pattern 2 ... 2nd slit pattern 3 ... Light-shielding pattern 5 ... Convex part 6 ... Wide part 7 ... Expanding part 8 ... Isolated pattern 21 ... Semi-translucent part 22 ... Translucent part 23 ... Light-shielding part 30 ... Transparent substrate 31 ... Semi-transmissive film 32 ... Light shielding film E1 ... First pattern formation region E2 ... Second pattern formation region E3 ... Intersection region

Claims (9)

A photomask for proximity exposure comprising a transfer pattern on a transparent substrate for forming a black matrix on a transfer object,
The transfer pattern is:
The pattern formation region extending in the first direction is defined as a first pattern formation region, the pattern formation region extending in a second direction intersecting the first direction is defined as a second pattern formation region, and the first pattern formation is performed. When a region where the region and the second pattern formation region intersect is a crossing region,
A first slit pattern formed in the first pattern formation region, which is a slit pattern substantially consisting of a light-transmitting portion and has a portion having a constant width W1,
A second slit formed in the second pattern formation region excluding the intersecting region, which is substantially a semi-translucent portion and has a portion with a constant width W2 smaller than the constant width W1. With patterns,
An auxiliary pattern for adjusting the shape of the black matrix image formed on the transferred body, which is a pattern that does not resolve independently;
A photomask comprising: The auxiliary pattern is
2. The photomask according to claim 1, comprising a pair of convex portions formed of a semi-translucent portion, which are formed to partially protrude on both sides in the width direction of the second slit pattern.   The pair of convex portions suppresses a local decrease in light intensity in the light intensity distribution of a transfer image formed by the second slit pattern on the transfer object when the transfer pattern is subjected to proximity exposure. The photomask according to claim 2, wherein the transmitted light intensity of the second slit pattern is made uniform. The auxiliary pattern is
The extended part which consists of a semi-translucent part formed at least by extending in the said 2nd direction from the exit of the said 2nd slit pattern, It is any one of Claims 1-3 characterized by the above-mentioned. The photomask described in 1.   The extended portion increases the curvature of a corner portion in a transfer image formed by the second slit pattern on the transfer object when the transfer pattern is subjected to proximity exposure. The photomask according to claim 4. The auxiliary pattern is
Including an isolated pattern formed of a semi-translucent part or a light-shielding part, which is located in the middle of the two intersecting areas adjacent in the first direction and is formed in the first pattern forming area, The photomask according to claim 1.   The isolated pattern suppresses a local peak of light intensity in a light intensity distribution of a transfer image formed by the first slit pattern on the transfer object when the transfer pattern is subjected to proximity exposure, The photomask according to claim 6, wherein the transmitted light intensity of the first slit pattern is made uniform.   8. The photomask according to claim 6, wherein the isolated pattern has a rectangular shape. Preparing the photomask according to any one of claims 1 to 8,
Transferring the transfer pattern onto the transfer object using a proximity exposure apparatus; and
A method for manufacturing a display device, comprising: