JP2010072299A - Photomask and method of manufacturing color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photomask that provides a seam area in a screen center of a color filter, the photomask eliminating chipping in alignment control protrusions caused even when a gap is provided between light shielding units of a left random area and a right random area. <P>SOLUTION: The photomask is characterized in that: (1) the photomask includes a left random area 12L, a pattern area 12 and a right random area 12R; (2) a uniform array of mask patterns 32 is formed in the pattern area, while in the right random area, mask patterns are randomly distributed and reduced in number to the right (a right-random state) and in the left random area, mask patterns are randomly distributed and reduced in number to the left (a left-random state), wherein the mask patterns of the right-random state and the left-random state are in a complementary relationship with each other to give a uniform array when combined together; and (3) a light shielding unit 33 is formed in each pixel area 31 having no mask pattern in the right random area and in the left random area, and when the light shielding units are adjoining to each other, the light shielding unit is provided as extended between the light shielding units. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to the manufacture of a color filter, and in particular, when a single photomask is used and a color filter of one screen is manufactured by divided exposure, the photomask is used so that display unevenness is not observed at the joint. The present invention relates to a photomask that can eliminate display unevenness that may occur even if an interval is provided between the light shielding portions.
The present invention also relates to a method for manufacturing a color filter using the photomask.

  As a method of manufacturing a color filter used in a liquid crystal display device, first, a black matrix is formed on a glass substrate, and then a colored pixel is aligned with the black matrix pattern on the glass substrate on which the black matrix is formed. In addition, a method of forming a transparent conductive film, a photo spacer, an alignment control protrusion, and the like by sequentially aligning them is widely used.

  The black matrix has a light-shielding property, determines the position of the colored pixels of the color filter, makes the size uniform, and shields unwanted light when used in a display device. It has a function of making a uniform image with no unevenness and improved contrast. For example, the black matrix is formed by a photolithography method using a black photoresist.

The colored pixels have, for example, red, green, and blue filter functions. For example, a negative photoresist made of a pigment such as a pigment dispersed on a glass substrate on which the black matrix is formed. A method is adopted in which a coating film is provided and colored pixels are formed by exposure and development on the coating film.
The transparent conductive film is formed on a glass substrate on which colored pixels and a black matrix are formed by, for example, forming a transparent conductive film by sputtering using ITO (Indium Tin Oxide).

  In addition, the photo spacer, the alignment control protrusion, and the like are formed by a photolithography method in the same manner as the black matrix or the colored pixel. The photo spacer and the alignment control protrusion are often formed using a positive type photoresist.

A method of performing exposure using a photomask having a size approximately the same as the size of a glass substrate is widely used for exposure when manufacturing a color filter by a photolithography method. This is a so-called batch exposure method in which the entire screen of the color filter is collectively performed by one exposure. In the exposure apparatus used in this batch exposure method, a photomask is disposed above a glass substrate provided with a photoresist coating film through a proximity exposure gap, and the photomask has a film surface below, that is, glass. Proximity exposure that faces the coating film on the substrate is widely adopted.
As an exposure method for producing a color filter by photolithography, this collective exposure method can be said to be an excellent exposure method capable of producing a large number of color filters at low cost.

However, when the size of the glass substrate gradually increases and exceeds 550 mm × 650 mm, for example, about 1 m × 1.3 m, or 1.5 m × 1.8 m, a photomask having a size corresponding to this size is formed. The restrictions in manufacturing and the restrictions in using the photomask become significant.
Therefore, the same photomask is used for exposure to a glass substrate having a size of about 1 m × 1.3 m or 1.5 m × 1.8 m. For example, the color filter screen is divided into left and right parts. An exposure method will be adopted.

FIG. 1 is a plan view showing an outline of an example of a color filter manufactured by a division exposure method. FIG. 1 shows a state in which a black matrix, colored pixels, and a transparent conductive film have already been sequentially formed on a glass substrate (10), and subsequently alignment control protrusions are formed on the entire surface of one screen (11) of the color filter ( (Not shown).
One screen (11) of the color filter is composed of a left screen (11L) and a right screen (11R).

  As shown by dotted lines in FIG. 1, the area indicated by the width (W1) from the right and left center of one screen, the right end of the left screen (11L) to the left end of the right screen (11R) is the left screen (11L). This is a joint area (11a) in one screen (11) provided so that display unevenness that recognizes the presence of a joint is not viewed between the right screen (11R). The orientation control protrusion is formed in each pixel region on the entire surface of the screen (11) including the left screen (11L) and the right screen (11R) including the joint region (11a). The width (W1) of the joint region (11a) is about 100 mm to 150 mm.

Reference numerals (X ₀ ) and (Y ₀ ) represent the X axis at the center of the upper and lower sides and the Y axis at the center of the left and right sides of the color filter (glass substrate (10)) in FIG. Reference sign (A ₀ ) represents left and right alignment marks formed on the glass substrate (10).
Further, the positions of the alignment control protrusions constituting one screen (11) of the color filter are symmetrical with respect to the Y axis (Y ₀ ) of the color filter.

FIG. 2 is a plan view schematically showing an example of a photomask used when forming alignment control protrusions as an example of the color filter shown in FIG. As shown in FIG. 2, in the photomask (PM1), the area indicated by reference numeral (12) includes the left screen (11L) excluding the joint area (11a) and the joint area (11a) of the color filter. The pattern area corresponding to the formation of the right screen (11R) is shown.
Each pixel region on the entire surface of the pattern region (12) is provided with a mask pattern for forming alignment control protrusions.

Reference numeral (12R) represents an area corresponding to the formation of the joint area (11a) of the color filter. In each pixel region of the right random region (12R), a mask pattern for forming alignment control protrusions is randomly provided on the right.
Reference numeral (12L) represents a region corresponding to the formation of the joint region (11a) of the color filter. In each pixel region of the left random region (12L), a mask pattern for forming alignment control protrusions is randomly provided on the left.
The right random mask pattern and the left random mask pattern are coupled to each other and have a complementary relationship that is the same as the uniform arrangement of the mask patterns provided in each pixel area of the pattern area (12). .

In FIG. 2, symbols (X ₁ ) and (Y ₁ ) represent the X axis and the Y axis that pass through the center of the pattern region (12) of the photomask (PM1), respectively. The symbol (Y ₃ ) represents the position on the photomask (PM1) corresponding to the center in the X-axis direction of the joint region (11a) of one screen (11) of the color filter obtained by divided exposure.
In FIG. 2, a left shading band (13L) is provided to the left of the left left random area (12L), and a right shading band (13R) is provided to the right of the right random area (12R). Yes. Reference sign (A ₁ ) represents an alignment mark provided on the Y-axis (Y ₁ ) of the photomask (PM1).

FIG. 3 is a plan view for explaining exposure when forming alignment control protrusions on a color filter (glass substrate (10)) using the photomask (PM1) shown in FIG.
First, the first exposure (1st−) is performed by aligning the alignment mark (A ₁ ) on the photomask (PM1) with the left alignment mark (A ₀ ) in FIG. 3 on the color filter (glass substrate (10)). Ex). At this time, the position indicated by the symbol (Y ₃ ) on the right side of the photomask (PM1) matches the Y axis (Y ₀ ) of the color filter (glass substrate (10)).

By this first exposure (1st-Ex), the pattern area (12) of the photomask (PM1) is formed on each pixel area of the left screen (11L) excluding the joint area (11a) on the glass substrate (10). Due to the mask pattern, the alignment control protrusions are exposed and uniformly arranged. In addition, each pixel area of the joint area (11a) is exposed in a state where alignment control protrusions are randomly arranged in the right direction, and in the left random area (11bL) on the left side of the left screen (11L), the alignment control is performed. Exposure is performed with the protrusions randomly arranged on the left.
During this first exposure, the area near the joint area (11a) in the right screen (11R) is shielded by the right shading band (13R) of the photomask (PM1), but the right screen (11R). ) Is not shielded, a blind shutter (not shown) is provided on the light source side of the photomask (PM1) to shield the right screen (11R).

Next, the second exposure (2nd) is performed by aligning the alignment mark (A ₁ ) on the photomask (PM1) with the alignment mark (A ₀ ) on the right side of FIG. 3 on the color filter (glass substrate (10)). -Ex). At this time, the position indicated by the symbol (Y ₃ ) on the left side of the photomask (PM1) matches the Y axis (Y ₀ ) of the color filter (glass substrate (10)).

By this second exposure (2nd-Ex), the pattern area (12) of the photomask (PM1) is formed on each pixel area of the right screen (11R) excluding the joint area (11a) on the glass substrate (10). Due to the mask pattern, the alignment control protrusions are exposed and uniformly arranged. In addition, each pixel region in the joint region (11a) is exposed in a state in which the alignment control protrusions are randomly arranged on the left side, and the right random region (11bR) on the right side of the right screen (11R) is exposed to the alignment control. Exposure is performed in a state where the protrusions are randomly arranged to the right.
During this second exposure, the area near the joint area (11a) in the left screen (11L) is shielded by the left shading band (13L) of the photomask (PM1), but the left screen (11L) ) Is not shielded, a blind shutter (not shown) is provided on the light source side of the photomask (PM1) to shield the left screen (11L).

The double exposure of the first exposure and the second exposure is performed on the joint area (11a).
Thereby, the alignment control projection is exposed to the joint region (11a) randomly at right by the first exposure, and the alignment control projection is randomly exposed to the left by the second exposure. The number of mask patterns of the alignment control protrusions provided in the left random region (12L) and the right random region (12R) of the photomask (PM1) shown in FIG. 2 is the alignment control protrusion provided in the pattern region (12). Half of the number of mask patterns is provided in the left random region (12L) and the right random region (12R), respectively.

The mask patterns of the left random region (12L) and the right random region (12R) are combined, and are identical to the uniform arrangement of the mask patterns provided in the pixel regions of the pattern region (12) shown in FIG. They are in complementary relationship with different sequences.
Therefore, even if the first exposure and the second exposure are performed twice, the alignment control protrusions are not overlapped or missing in the joint region (11a). By the first exposure and the second exposure, the same number of alignment control protrusions as the number per unit area of the alignment control protrusions provided in the pattern region (12) are provided in the joint region (11a).

Thereby, uniform alignment control protrusions are provided on the entire surface of one screen (11), and display unevenness that recognizes the presence of a seam between the left screen (11L) and the right screen (11R) is not viewed.
In FIG. 3, only the left random area (11bL) on the left side of the left screen (11L) and the right random area (11bR) on the right side of the right screen (11R) after the first exposure and the second exposure, By selectively performing the third exposure, the alignment control protrusions of the left random region (11bL) and the right random region (11bR) can be erased from the glass substrate (10). The color filter shown in FIG. 1 is an example in which the alignment control protrusions in the left random region (11bL) and the right random region (11bR) are deleted.

FIG. 4 is a plan view illustrating an example of the orientation control protrusion by enlarging a part of the left screen (11L) indicated by reference numeral (S1) in FIG. In FIG. 4, a black matrix, colored pixels, and a transparent conductive film are already formed in sequence on a glass substrate (10) (not shown), and subsequently an alignment control protrusion (22) is formed on the transparent conductive film. Is.
In FIG. 4, a dotted line (21) represents a pixel area of one pixel of the color filter, and the pixel is rectangular. The long side is about 300 to 450 μm, and the short side is about 100 to 150 μm.

  A large number of pixels are provided so as to be uniformly arranged at the same pitch (Px, Py) in the X-axis direction and the Y-axis direction on the entire surface of the left screen (11L). Orientation control protrusions (22) are provided in pairs in the pixel region (21) of each pixel. Therefore, a large number of pairs of alignment control projections (22) are uniformly arranged at the same pitch (Px, Py) in the X-axis direction and the Y-axis direction on the entire surface of the left screen (11L). The pixels are provided at the same pitch (Px, Py) in the right screen (11R) and in the joint region (11a), that is, on the entire surface of one screen (11) of the color filter. The pair of control protrusions (22) is uniformly provided on the entire surface of one screen (11) at the same pitch.

FIG. 4 also serves as a plan view for explaining a mask pattern corresponding to the formation of alignment control protrusions in the pattern region (12) on the photomask (PM1) shown in FIG. The part shown by the code | symbol (S2) in FIG. 2 is expanded.
In FIG. 4, a dotted line (31) represents a pixel area of one pixel on the photomask (PM1), and has the same shape and size as one pixel indicated by the dotted line (21) in FIG. A large number of pairs of mask patterns (32) corresponding to the formation of the alignment control protrusions (22) are arranged at the same pitch (Px, Py) in the X-axis direction and the Y-axis direction on the entire surface of the pattern region (12). Is provided.

FIG. 5 shows a mask pattern (32 in the right random region (12R) on the photomask (PM1) shown in FIG. 2 corresponding to the formation of the alignment control protrusion (22) in the joint region (11a) shown in FIG. It is a top view which expands and shows an example of the arrangement | sequence of ().
5 shows the arrangement of the mask pattern (32) at the left end (c) and the center within the width (W1) from the left end (c) to the right end (d) of the right random region (12R) shown in FIG. a sequence in part (Y _3), illustrates a sequence in the right end (d).

  As shown in FIG. 5, each pixel region (31) is provided with a mask pattern (32) or a light shielding portion (33). At the left end (c), the ratio of the mask pattern (32) is large, and the ratio of the light shielding portion (33) is small. At the right end (d), the ratio of the mask pattern (32) is small, and the ratio of the light shielding portion (33) is large. That is, the ratio of the mask pattern (32) is gradually decreased from the left end (c) to the right end (d), and the ratio of the light shielding part (33) is gradually increased from the left end (c) to the right end (d).

The shape and size of the pixel region (31) of one pixel indicated by the dotted line is the same as the shape and size of the light shielding portion (33) indicated by the solid line. Further, a gap having a width (W2) is provided between the adjacent light shielding portions (33), between the pixel regions (31), or between the light shielding portions (33) and the pixel regions (31). The width (W2) of the gap is about 4 to 5 μm.
Such an arrangement of the mask pattern (32) in the width (W1) direction is referred to as random in the present invention, the random shown in FIG. 5 is the right random, and this region on the photomask (PM1) is the right random region ( 12R).

6 shows a mask pattern in the left random region (12L) on the photomask (PM1) shown in FIG. 2, corresponding to the formation of the alignment control protrusion (22) in the joint region (11a) shown in FIG. It is a top view which expands and shows an example of the arrangement | sequence of (32).
6 shows the arrangement of the mask pattern (32) at the left end (a) and the center within the width (W1) from the left end (a) to the right end (b) of the left random region (12L) shown in FIG. a sequence in part (Y _3), illustrates a sequence in the right end (b).

  As shown in FIG. 6, each pixel region (31) is provided with a mask pattern (32) or a light shielding portion (33). At the left end (a), the ratio of the mask pattern (32) is small, and the ratio of the light shielding part (33) is large. At the right end (b), the ratio of the mask pattern (32) is large, and the ratio of the light shielding portion (33) is small. That is, the ratio of the mask pattern (32) gradually increases from the left end (a) to the right end (b), and the ratio of the light shielding portion (33) gradually decreases from the left end (a) to the right end (b).

  Such an arrangement of the mask pattern (32) in the width (W1) direction is referred to as random in the present invention, the random shown in FIG. 6 is left random, and this region on the photomask (PM1) is left random region ( 12L).

When the right random region (12R) shown in FIG. 5 is compared with the left random region (12L) shown in FIG. 6, the position of the light shielding portion (33) at the left end (c) of the right random region (12R). In the left random area (12L), the mask pattern (32) is arranged. Similarly, at the position of the mask pattern (32) at the left end (c) of the right random region (12R), the light shielding portion (33) is arranged in the left random region (12L).
That is, FIG. 5 and FIG. 6 are in a complementary relationship between the light shielding portion (33) and the mask pattern (32). This complementary relationship is maintained over the entire surface of FIGS.

When forming the orientation control protrusion (22) on the color filter (glass substrate (10)), the right random region (12R) shown in FIG. 5 is randomized to the joint region (11a) in the first exposure. The aligned orientation control protrusions (22) are formed. In addition, the left random region (12L) shown in FIG. 6 forms an alignment control protrusion (22) having a left random arrangement in the joint region (11a) in the second exposure.
As shown in FIG. 4, the alignment control protrusion (22) arranged in the right random arrangement and the alignment control protrusion (22) arranged in the left random arrangement are combined to form the alignment control protrusion (22 in the joint area (11a). ) Are arranged uniformly.

  By providing such a joint area (11a) between the left screen (11L) and the right screen (11R), display unevenness that recognizes the presence of a joint between the left screen (11L) and the right screen (11R) is not observed. It will not be seen.

The above-described content is an example of a method for manufacturing a color filter larger than the photomask by a division exposure method in which one screen of the color filter is divided into left and right using one photomask. At this time, in order to prevent the display unevenness that recognizes the presence of the joint from being viewed, a joint area is provided between the left screen and the right screen, and the width shown in FIGS. 5 and 6 is provided between the pixel areas in the joint area. It is assumed that a gap (W2) is provided.
The following is a description of how the gap (W2) shown in FIGS. 5 and 6 is provided between the pixel regions in the joint region.

When the division exposure method is performed using a positive photoresist, the boundary line (PM1) is shifted by the positional deviation of the photomask (PM1) in the first exposure and the positional deviation of the photomask (PM1) in the second exposure. In the vicinity of Y ₅ ), when an unexposed part is left and the resist remains after the development process, or the position of the photomask (PM1) in the first exposure and the position of the photomask (PM1) in the second exposure Due to the deviation, a part of the alignment control protrusion (22) in the vicinity of the boundary line (Y ₅ ) may be double-exposed and a part of the alignment control protrusion (22) may be chipped.

The first exposure will be described with the cross-sectional portion taken along the line AA shown in FIG. 5, and the second exposure will be described with the cross-sectional portion taken along the line BB shown in FIG. ) Between the adjacent light shielding portions (33), between the pixel regions (31), or between the light shielding portion (33) and the pixel region (31) at the boundary line (Y ₅ ). Take an example.

FIG. 7 is a cross-sectional view for explaining the generation of the remaining resist near the boundary line (Y ₅ ). FIG. 7 is an enlarged view of the vicinity of the boundary line (Y ₅ ) of the photomask (PM1) shown in FIGS. FIG. 7 shows that when the divided exposure is performed, the photomask (PM1) is not misaligned in the first exposure and the second exposure, and an unexposed portion does not occur in the vicinity of the boundary line (Y ₅ ). This explains the case where there is no resist residue after the development process.

FIG. 7A corresponds to a cross-sectional portion taken along line AA shown in FIG. As shown to Fig.7 (a), the 1st exposure (L1) through the photomask (PM1) was given to the coating film (15) of the positive type photoresist provided on the glass substrate (10), When the development process is performed, the left alignment control protrusion (22L) is formed.
Subsequently, as shown in FIG. 7B, when the second exposure (L2) through the photomask (PM1) is given and the development process is performed, the right alignment control protrusion (22R) is formed.

In the first exposure and the second exposure, since the photomask (PM1) is not misaligned, a resist residue is generated on the glass substrate (10) in the vicinity of the boundary line (Y ₅ ) indicated by the symbol (M). Not. FIG. 7 shows a cross section of the left alignment control protrusion (22L) and the right alignment control protrusion (22R) after the development processing. FIG. 7B corresponds to a cross-sectional portion taken along line BB shown in FIG.

FIG. 8 shows that when divided exposure is performed, the photomask (PM1) is displaced to the left in FIG. 8 in the first exposure, and the second exposure in the first exposure. As shown by the white arrow, the photomask (PM1) is displaced to the right in FIG. 8 and an unexposed portion is generated in the vicinity of the boundary line (Y ₅ ). As shown to Fig.8 (a), the 1st exposure (L1) through the photomask (PM1) is given to the coating film (15) of the positive type photoresist provided on the glass substrate (10), When the development process is performed, the left alignment control protrusion (22L) is formed. At the same time, a resist residue (15L) corresponding to the positional deviation (a2) of the light shielding portion (33) is generated.

Subsequently, as shown in FIG. 8B, the second exposure (L2) through the photomask (PM1) is applied to the positive photoresist coating film (15) provided on the glass substrate (10). When the development processing is performed, the right alignment control protrusion (22R) is formed.
At the same time, a resist residue (15R) corresponding to the positional deviation (a2) of the light shielding portion (33) is generated. That is, a resist residue (15L, 15R) is generated in the vicinity of the boundary line (Y ₅ ) on the glass substrate (10). For the sake of explanation, the positional deviation (a2) of the photomask (PM1) in the first exposure and the positional deviation (a2) of the photomask (PM1) in the second exposure are equal in the opposite direction.

FIG. 9 shows the left alignment control protrusion (22L) in the vicinity of the boundary line (Y ₅ ) in the first exposure and the second exposure when the photomask (PM1) is not misaligned during the divided exposure. And a case where no alignment control protrusion is missing in the right alignment control protrusion (22R).

FIG. 9A corresponds to a cross-sectional portion taken along line AA shown in FIG. As shown to Fig.9 (a), the 1st exposure (L1) through the photomask (PM1) was given to the coating film (15) of the positive type photoresist provided on the glass substrate (10), When the development process is performed, the left alignment control protrusion (22L) is formed.
Subsequently, as shown in FIG. 9B, when the second exposure (L2) through the photomask (PM1) is given and the development process is performed, the right alignment control protrusion (22R) is formed.

In the first exposure and the second exposure, since the photomask (PM1) is not misaligned, the left alignment control protrusion (22L) and the right alignment control near the boundary (Y ₅ ) on the glass substrate (10). In the protrusion (22R), the alignment control protrusion is not chipped. FIG. 9B corresponds to a cross-sectional portion taken along line BB shown in FIG.

Further, in FIG. 10, when divided exposure is performed, as shown by a white arrow in the first exposure, the photomask (PM1) is displaced to the right in FIG. During exposure, as shown by the thick white arrow, the photomask (PM1) is displaced to the left in FIG. 10, and the left alignment control protrusion (22L) and the right alignment control in the vicinity of the boundary line (Y ₅ ). This is a case where the alignment control protrusion is missing in the protrusion (22R).

  As shown to Fig.10 (a), the 1st exposure (L1) through the photomask (PM1) was given to the coating film (15) of the positive type photoresist provided on the glass substrate (10), When the development process is performed, the left alignment control protrusion (22L) is formed. At the same time, the alignment control protrusion corresponding to the positional deviation (b1) of the light shielding portion (33) is chipped (16R).

Subsequently, as shown in FIG. 10B, the second exposure (L2) through the photomask (PM1) is applied to the positive photoresist coating film (15) provided on the glass substrate (10). When the development processing is performed, the right alignment control protrusion (22R) is formed. The right alignment control protrusion (22R) is chipped by the first exposure. At the same time, the left alignment control projection (22L) is chipped (16L) corresponding to the positional deviation (b1) of the light shielding portion (33). In other words, so that the missing of the alignment control projection in the left alignment control projection in the vicinity of the glass substrate (10) on the boundary line (Y ₅₎ (22L) and right alignment control protrusions (22R) (16L, 16R) is generated.
For the sake of explanation, the positional deviation (b1) of the photomask (PM1) in the first exposure is equivalent to the positional deviation (b1) of the photomask (PM1) in the second exposure.

As described above, in the vicinity of the boundary line (Y ₅ ), when divided exposure is performed using a positive photoresist, the first exposure and the second photomask (PM1) are caused to be misaligned. Resist residue and chipping of alignment control protrusions occur.

  As a method for solving such a troubled phenomenon, 1) a correction for providing an interval between the adjacent light-shielding portion (33) of the first exposure and the light-shielding portion (33) of the second exposure, and 2 ) Between the adjacent first exposure light-shielding part (33) and the second exposure mask pattern (32), and between the adjacent first exposure mask pattern (32) and the second exposure light-shielding part (33). The correction which provides the space | interval between is adopted.

FIG. 11 illustrates a specific correction. As shown in FIG. 11, this correction is performed by a) providing an interval of 4.5 μm or more between the light shielding part (33) in the right random region (12R) and the light shielding part (33) in the left random region (12L). Provided,
b) A space of 5.0 μm or more is provided between the mask pattern (32) of the right random region (12R) and the light shielding portion (33) of the left random region (12L),
c) An interval of 5.0 μm or more is provided between the mask pattern (32) of the left random region (12L) and the light shielding portion (33) of the right random region (12R), and the correction is 14.5 μm or more in total. Is to do.

  The interval (W2) between the adjacent light shielding portions (33) in FIGS. 5 and 6 conforms to the above correction, and the distance between the light shielding portion (33) and the light shielding portion (33) is 4 to 5 μm. It is kept.

However, even if the above correction is performed, in actual work, for example, when a photomask is designed close to the limit of the correction value, the orientation control protrusion in the joint region (11a) of the color filter is used. (22) may not be formed normally and chipping may occur mainly.
As shown in FIG. 12, in the pair of orientation control protrusions (22) formed in the joint region (11a), this phenomenon occurs in the region (23) indicated by the dotted line in FIG. 12, that is, between the pixel regions. This tendency is observed in the two alignment control protrusions (22) adjacent to each other with a space therebetween, in particular, in the linear portion (22a) of the alignment control protrusion.

  Such a chipping tendency is caused by the left screen (11L) excluding the joint region (11a) in which the orientation control protrusion (22) is normally formed in one screen (11) of the color filter shown in FIG. For example, a luminance difference is caused between the right screen (11R) and the joint region (11a) that tends to be chipped, and the presence of the joint region (11a) having the width (W1) is viewed as display unevenness. Will be.

This chipping tendency is caused by the fact that the exposure light travels down to the lower part of the light shielding part (33) due to the diffraction of the exposure light at the end of the light shielding part (33) during the first exposure and the second exposure. It is estimated that this will affect (22).
JP 2004-302439 A JP 2007-34136 A

The present invention has been made to solve the above problems, and a color filter larger than the photomask is manufactured by a division exposure method in which one screen of the color filter is divided into left and right using one photomask. When providing a joint region in the center of the screen so that the display unevenness that recognizes the presence of the joint is not observed, for example, the left random region and the right of the photomask that forms the alignment control protrusion in the joint region. A photo that can eliminate the lack of alignment control protrusions in the joint area, which may occur even if a space is provided between the light-shielding parts in the random area, and can form normal alignment control protrusions on the entire screen of the color filter. It is an object to provide a mask.
Another object of the present invention is to provide a method for manufacturing a color filter using the above-described photomask so that display unevenness is not observed in the joint area of one screen.

The present invention uses an exposure apparatus that performs proximity exposure, and performs two exposures through a single photomask on the left and right of a glass substrate provided with a positive photoresist coating film, so that one screen larger than the photomask is obtained. In a photomask for manufacturing a color filter having a joint region in the left and right central portion of the one screen,
1) The photomask is provided with at least a left random area, a pattern area, and a right random area adjacent to each other in this order,
2) a) A mask pattern is provided in each pixel area of the pattern area to form a uniform array,
b) A mask pattern is randomly provided on each pixel area of the right random area, and a mask pattern is randomly provided on each pixel area of the left random area.
c) The right random mask pattern and the left random mask pattern are combined to form a complementary relationship that is the same as the uniform arrangement of the mask patterns provided in the pixel areas of the pattern area. And
3) A light shielding portion is provided in each pixel region of the right random region and the left random region where no mask pattern is provided, and the light shielding portion extends between the light shielding portions when the light shielding portions are adjacent to each other. The photomask is provided.

  According to the present invention, in the photomask according to the above invention, the mask pattern is a mask pattern for forming alignment control protrusions.

  In the photomask according to the present invention, the right random region of the right random region is an array in which the ratio of the mask pattern gradually decreases and the ratio of the light shielding portion gradually increases from the left end to the right end of the right random region. The left random of the left random area is a photomask characterized in that the ratio of the mask pattern gradually increases and the ratio of the light shielding portion gradually decreases from the left end to the right end of the left random area.

  According to another aspect of the present invention, there is provided a method for producing a color filter, characterized by being produced using the photomask according to claim 1, claim 2, or claim 3.

  In the photomask according to the present invention, 1) a left random area, a pattern area, and a right random area are provided adjacent in this order, and 2) a) a mask pattern is provided in each pixel area of the pattern area. B) A mask pattern is randomly provided in each pixel area of the right random area, and a mask pattern is randomly provided in each pixel area of the left random area. C) The right random mask pattern and the left random mask pattern are combined with each other in a complementary relationship that is the same as the uniform arrangement of the mask pattern provided in each pixel area of the pattern area, 3) A light shielding portion is provided in each pixel region of the right random region and the left random region where no mask pattern is provided, and between the light shielding portions when the light shielding portions are adjacent to each other. Since the light shielding portion is extended, for example, even if an interval is provided between the light shielding portions of the left random region and the right random region of the photomask that forms alignment control protrusions in the joint region, it may occur. A photomask is obtained in which the lack of alignment control protrusions in a certain joint region is eliminated.

In the photomask according to the present invention, since the mask pattern is a mask pattern for forming alignment control protrusions, the photomask is suitable as a photomask for manufacturing a color filter for a liquid crystal display device. It becomes.
In the photomask according to the present invention, the right random region of the right random region is an array in which the ratio of the mask pattern gradually decreases and the ratio of the light shielding portion gradually increases from the left end to the right end of the right random region. Yes, left random in the left random area is an array in which the ratio of the mask pattern gradually increases and the ratio of the light shielding part gradually decreases from the left end to the right end of the left random area, so a joint area is provided in the center of the screen. In this case, the display unevenness that recognizes the presence of the seam is not preferably observed.
In addition, since the present invention is a method for manufacturing a color filter manufactured using the photomask according to the above-described invention, for example, the left random region and the right random region of a photomask that forms alignment control protrusions in the joint region are shielded. The color filter manufacturing method eliminates the chipping of the orientation control protrusions in the joint region, which may occur even if a space is provided between the portions.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 13 shows a mask pattern (32) in the left random region (12L) on the photomask (PM2) according to the present invention corresponding to the formation of the alignment control protrusion (22) in the joint region (11a) shown in FIG. It is a top view which expands and shows an example of this arrangement | sequence.
FIG. 13 shows the arrangement of the mask pattern (32) at the left end (a) within the width (W1) from the left end (a) to the right end (b) of the left random region (12L).

  As shown in FIG. 13, at the left end (a) of the left random region (12L), the mask pattern (32) is provided in the two pixel regions (31), and light shielding is performed between the light shielding portions of the other pixel regions. A continuous light-shielding part (53) in which the part is extended and the light-shielding part is integrated is provided.

Compared with an example of the arrangement of the mask pattern (32) in the left random region (12L) on the photomask (PM1) shown in FIG. 6, the left end (a) of the left random region (12L) shown in FIG. Sixteen pixel regions (31) are shown, of which two pixel regions (31) are provided with a mask pattern (32), and fourteen pixel regions (31) are provided with a light shielding portion (33). ing.
That is, the left end (a) is a portion where the ratio of the mask pattern (32) is small and the ratio of the light shielding portion (33) is large. An interval of width (W2) is provided between the light shielding portions (33).

As described above, this interval is as follows: 1) When the divided exposure method is performed using a positive photoresist, the positional deviation of the photomask (PM1) in the first exposure and the photomask in the second exposure (PM1) misalignment in the vicinity of the boundary line (Y ₅ ) resulting in an unexposed portion and resist remaining after development processing 2) or the photomask (PM1) misalignment in the first exposure, In addition, due to the misalignment of the photomask (PM1) in the second exposure, a part of the alignment control protrusion (22) in the vicinity of the boundary line (Y ₅ ) is double exposed, and a part of the alignment control protrusion (22) is missing. This correction is made between the light-shielding portions (33) in order to eliminate the phenomenon in which the phenomenon occurs.

In the present invention, in order to eliminate the wraparound due to diffraction of the exposure light at the end of the light shielding portion (33) in this interval, the light shielding portion (33) is extended to this interval.
The inventor of the present invention is exposed by the same exposure at the interval where the light shielding part (33) and the light shielding part (33) are adjacent to each other, so that the positional deviation of the light shielding part (33) as shown in FIGS. Focusing on the fact that this is not the case, the present invention has been achieved.

In the orientation control protrusion (22) formed in the joint region (11a) shown in FIG. 12 by extending the light shielding portion (33), the region (23) indicated by the dotted line in FIG. The tendency of chipping of the alignment control protrusions (22) observed in the two alignment control protrusions (22) adjacent to each other with a gap therebetween, in particular, the linear portion (22a) of the alignment control protrusions is eliminated.
As shown in FIG. 6, in the left random area (12L), the ratio gradually decreases to the light shielding part (33) toward the right end (b), so that the light shielding part (33) and the light shielding part (33) The area of the continuous light-shielding part (53), which is integrated by extending the light-shielding part in the interval, decreases toward the right end (b).

FIG. 14 shows a mask pattern (32) in the right random region (12R) on the photomask (PM2) according to the present invention corresponding to the formation of the alignment control protrusion (22) in the joint region (11a) shown in FIG. It is a top view which expands and shows an example of this arrangement | sequence.
FIG. 14 shows the arrangement of the mask pattern (32) at the right end (d) within the width (W1) from the left end (c) to the right end (d) of the right random region (12R).

  As shown in FIG. 14, at the right end (d) of the right random region (12R), the mask pattern (32) is provided in the two pixel regions (31), and light shielding is performed between the light shielding portions of the other pixel regions. A continuous light-shielding part (53) in which the part is extended and the light-shielding part is integrated is provided.

Compared with an example of the arrangement of the mask pattern (32) in the right random region (12R) on the photomask (PM1) shown in FIG. 5, the right end (d) of the right random region (12R) shown in FIG. Sixteen pixel regions (31) are shown, of which two pixel regions (31) are provided with a mask pattern (32), and fourteen pixel regions (31) are provided with a light shielding portion (33). ing.
That is, the right end (d) is a portion where the ratio of the mask pattern (32) is small and the ratio of the light shielding portion (33) is large. An interval of width (W2) is provided between the light shielding portions (33).

In the present invention, in order to eliminate the wraparound due to diffraction of the exposure light at the end of the light shielding portion (33) in this interval, the light shielding portion (33) is extended to this interval. As a result, the alignment control protrusion (22) formed in the joint region (11a) shown in FIG. 12 is adjacent to the region (23) indicated by the dotted line in FIG. The tendency of chipping of the alignment control protrusions (22) observed in the two alignment control protrusions (22), particularly the linear portion (22a) of the alignment control protrusions is eliminated.
As shown in FIG. 5, in the right random region (12R), since the ratio gradually decreases to the light shielding portion (33) toward the left end (c), the light shielding portion (33) and the light shielding portion (33) are reduced. The area of the continuous light-shielding part (53), which is integrated by extending the light-shielding part in the interval, decreases toward the left end (c).

  As described above, in the present application, the mask pattern of the alignment control protrusion is described as an example of the mask pattern. However, the mask pattern is not limited to the alignment control protrusion. In addition, the color filter having one screen larger than the photomask has been described as an example by performing exposure twice through one photomask to the left and right of the glass substrate. However, the present invention is limited to two exposures to the left and right. It is not something.

It is a top view which shows the outline of an example of the color filter manufactured with the division | segmentation exposure method. It is a top view which shows the outline of an example of the photomask used when forming the alignment control protrusion of an example of the color filter shown in FIG. It is a top view explaining the exposure at the time of forming alignment control protrusion on a color filter (glass substrate). FIG. 6 is a plan view illustrating an example of an orientation control protrusion by enlarging a part of the left screen. It is a top view which expands and shows an example of the arrangement | sequence of the mask pattern in the right random area | region on a photomask. It is a top view which expands and shows an example of the arrangement | sequence of the mask pattern in the left random area | region on a photomask. It is sectional drawing explaining generation | occurrence | production of the resist residue in the vicinity of a boundary line. This is a case where when the divided exposure is performed, a positional shift occurs in the photomask and a resist residue is generated in the vicinity of the boundary line. This is a case where there is no positional deviation in the photomask when the divided exposure is performed, and the alignment control protrusions near the boundary line are not missing. This is a case where a positional shift occurs in the photomask when the divided exposure is performed, and the alignment control protrusion is missing. This is an example of specific correction. It is explanatory drawing of the area | region where a chip | tip occurs. It is a top view which expands and shows an example of the arrangement | sequence of the mask pattern in the left random area | region on the photomask by this invention. It is a top view which expands and shows an example of the arrangement | sequence of the mask pattern in the right random area | region on the photomask by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Glass substrate 11 ... Color filter 1 screen 11a ... Joint area | region 11L ... Left screen 11R ... Right screen 12 ... Pattern area | region 12L ... Left random area | region 12R ... Right random area 13L ... Left light shielding band 13R ... Right light shielding bands 15L, 15R ... Resist remaining 16L, 16R ... Missing alignment control protrusion 21 ... Pixel area 22 of one pixel of color filter ... alignment control protrusion 22L ... left alignment control protrusion 22R ... right alignment control protrusion 31 ... pixel area 32 of one pixel on the photomask ... mask pattern 33 ... light shielding portion A ₀ alignment marks on · · Y axis of the left and right alignment marks a ₁ · · · photomask on the glass substrate PM1 · · · photomask PM2 · · · photomask Px according to the invention, Py · ·・ Pitch W1 of the pixel area... W2 of the joint area... Space Y ₃ between the light shielding parts... Position on the photomask corresponding to the center of the joint area in the X-axis direction.

Claims (4)

Using an exposure apparatus that performs a proximity exposure, with a double exposure through one photomask to the left and right of a glass substrate provided with a positive type photoresist coating film, it has one screen larger than the photomask, In a photomask for manufacturing a color filter having a joint area in the left and right center part of the one screen,
1) The photomask is provided with at least a left random area, a pattern area, and a right random area adjacent to each other in this order,
2) a) A mask pattern is provided in each pixel area of the pattern area to form a uniform array,
b) A mask pattern is randomly provided on each pixel area of the right random area, and a mask pattern is randomly provided on each pixel area of the left random area.
c) The right random mask pattern and the left random mask pattern are combined to form a complementary relationship that is the same as the uniform arrangement of the mask patterns provided in the pixel areas of the pattern area. And
3) A light shielding portion is provided in each pixel region of the right random region and the left random region where no mask pattern is provided, and the light shielding portion extends between the light shielding portions when the light shielding portions are adjacent to each other. A photomask characterized by being provided.   2. The photomask according to claim 1, wherein the mask pattern is a mask pattern for forming alignment control protrusions.   The right random of the right random area is an array in which the ratio of the mask pattern gradually decreases and the ratio of the light-shielding portion gradually increases from the left end to the right end of the right random area. 3. The photomask according to claim 1, wherein the mask pattern ratio is gradually increased from the left end toward the right end, and the ratio of the light shielding portions is gradually decreased.   A method for producing a color filter, comprising producing the photomask according to claim 1, claim 2, or claim 3.

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