JP4957140B2 - Photomask for color filter, method for producing color filter, color filter, and liquid crystal display device - Google Patents

Description

  The present invention relates to a technique for forming a pattern constituting a color filter, and in particular, a photomask in which a pattern corner corresponding to a corner of a light-shielding portion of a photomask is not rounded by exposure by proximity exposure. In addition, the present invention relates to a photomask in which pattern corners corresponding to the corners of the light transmitting portion of the photomask are not rounded in exposure by proximity exposure. The present invention also relates to a color filter manufacturing method, a color filter, and a liquid crystal display device.

Since the liquid crystal display device is not a self-luminous display device, the display needs light from the other, for example, a backlight is provided behind the display, and the display is performed by the light from the back. Such a liquid crystal display device is called a transmissive liquid crystal display device, and is mainly used in a dark environment such as indoors.
Further, for example, there is a liquid crystal display device in which a light reflection layer is provided behind the liquid crystal display device, and display is performed by external light from the surroundings when the liquid crystal display device is viewed. Such a liquid crystal display device is called a reflection type liquid crystal display device, and is mainly used in a bright environment such as outdoors.

  A liquid crystal display device called a transflective liquid crystal display device is a liquid crystal display device that has both a transmissive type and a reflective type function in one liquid crystal display device. This transflective liquid crystal display device can be used in a very bright environment such as outdoors or in a dark environment such as indoors, and is used in mobile devices.

  FIG. 3 shows an example of a color filter used in a transflective liquid crystal display device, and is a plan view showing an enlarged portion corresponding to one pixel. FIG. 4 is an explanatory cross-sectional view showing a pixel portion of a transflective liquid crystal display device using the color filter shown in FIG. 3 corresponds to the cross section of the color filter (30) shown in FIG.

As shown in FIGS. 3 and 4, the transflective liquid crystal display device includes a color filter (30), a transparent electrode (14) formed on the color filter, a liquid crystal (50), a TFT element (not shown). ) And the like, and a transparent electrode (41) and a reflective electrode (42) formed on the TFT substrate.
The color filter (30) has a black matrix (12) and colored pixels (13) formed on a glass substrate (11). The transparent electrode (41) and the reflective electrode (42) are connected to the drain electrode of the TFT element.

Except for the black matrix (12), one pixel region (Px) is composed of a light transmission region (Tr) and a light reflection region (Re).
The light transmissive region (Tr) is a region that functions as a transmissive liquid crystal display device, and the light reflective region (Re) is a region that functions as a reflective liquid crystal display device.

The colored layer (15) in one pixel region (Px) and the colored layer (16) having a through hole (opening) are colored layers of the same thickness provided using the same colored layer forming material. . In FIG. 4, for the sake of explanation, the left diagonal line and the right diagonal line are used. In FIG. 4, the upper part of both ends of the reflective electrode (42) is the boundary between the colored layer (15) and the colored layer (16) having a through hole (opening) (17), which is indicated by a chain line. .
In the light transmission region (Tr) of the colored pixel (13), a uniform colored layer (15) having a thickness D1 is formed in the entire region, and external light enters and reflects in the light reflection region (Re). A colored layer (16) having through holes (openings) (17) to be formed is formed.

That is, in a region (Px) of one pixel, a colored layer (16) having a uniform colored layer (15) in the light transmitting region (Tr) and a through hole (opening) (17) in the light reflecting region (Re) (16). ) Constitutes a colored pixel (13). The color density thickness of the colored layer (16) having the through hole (opening) (17) is represented by the average thickness (D2).
Further, when the through hole (opening) (17) of the colored layer (16) is in a state where nothing is provided and the colored layer is missing, the flatness of the surface of the color filter is deteriorated. As a result, the alignment of the liquid crystal is disturbed, which adversely affects the display quality. Therefore, in general, the through-hole (opening) (17) of the colored layer (16) is filled with a colorless and transparent resin to maintain flatness.

The spectral transmittance of the uniform colored layer (15) having the thickness D1 shown in FIG. 4 has a spectral transmittance suitable for the over-type liquid crystal display device. In the light transmission region (Tr), white light from the backlight indicated by the white arrow (A) is colored through the TFT substrate (40), the transparent electrode (41), the liquid crystal (50), and the transparent conductive film (14). The light passes through the colored layer (15) in the light transmission region (Tr) of the pixel (13), becomes colored light, and is emitted to the outside as indicated by a thin white arrow (P).
Therefore, when the backlight of this transflective liquid crystal display device is turned on and used as a transmissive liquid crystal display device, a transmissive color display having excellent brightness and saturation as the transmissive liquid crystal display device is obtained.

  In addition, when the backlight of this transflective liquid crystal display device is turned off and used as a reflective liquid crystal display device in a bright environment such as outdoors, a hatched thick arrow (B) in the light reflection region (Re) The external light from the surroundings shown in FIG. 5 passes through the colored layer (16) having the through-hole (opening) (17) of the glass substrate (11) and the average thickness (D2, D2 <D1) to become colored light, which is a reflective electrode The light is reflected at (42) and is emitted to the outside again as indicated by the hatched thin arrow (Q).

The reflected light at this time passes through the colored layer (16) having through holes (openings) (17) having an average thickness (D2) twice, so that the colored pixels used in the transmissive liquid crystal display device It has a spectral transmittance close to the spectral transmittance.
By using such a color filter, a transmissive color display having excellent brightness and saturation as a transmissive liquid crystal display device is obtained, and as a reflective liquid crystal display device, it is not dark and has excellent brightness and saturation. It is possible to display a reflective color display.

  The colored pixel (13) is obtained by photolithography using a negative colored photoresist in which a pigment such as a pigment is dispersed on a glass substrate (11) on which a black matrix (12) is formed, that is, The colored pixels are formed as colored pixels by exposure to a coating film of a colored photoresist through a photomask and development processing. Red, green, and blue colored pixels are sequentially formed.

  For the exposure through the photomask when manufacturing the color filter, a method of performing exposure using a photomask having a size substantially the same as the size of the glass substrate (11) is widely adopted. This is a so-called batch exposure method in which the entire screen of the color filter is collectively performed by one exposure. In this exposure method, a photomask is disposed above a glass substrate on which a photoresist coating film is provided via a proximity exposure gap, and the photomask on which a mask pattern is formed has its film surface below, that is, Proximity exposure that opposes a coating film on a glass substrate has been widely adopted.

The exposure method by the proximity exposure described above prevents scratches caused by sticking the photomask to the glass substrate (11), and prevents the pixels from becoming defective when dust adheres to the photomask. Therefore, the glass substrate on which the photoresist is applied and the photomask are, for example, a method of performing exposure while maintaining an interval of about 50 μm to 100 μm.

FIG. 5 is a cross-sectional view illustrating an example of proximity exposure in the manufacture of a color filter. As shown in FIG. 5, a colored photoresist coating film (47) is formed on a glass substrate (11), and a photomask (PM) is disposed thereabove with a proximity exposure gap (G). Yes.
On the photomask (PM), a pattern corresponding to the formation of the through hole (opening) (17) is formed. The film surface (18) of the photomask faces the coating film (47) of the colored photoresist.

  6A to 6C are plan views showing other examples of color filters used in the transflective liquid crystal display device. In another example shown in FIGS. 6A to 6C, the upper half of the colored pixel (13) in the drawing is a light transmission region (Tr), and a colored layer (15) is provided in the upper half. It has been. The lower half is a light reflection region (Re), and a colored layer (16) having a through hole (opening) (17) is provided in the lower half.

6A shows a circular through hole (opening) (17), FIG. 6B shows a square through hole (opening) (17), and FIG. 6C shows a through hole (opening). ) (17) is an example of two rectangles provided symmetrically in the figure.
Thus, the shape of the through hole (opening) (17) provided in the colored layer (16) is not limited to a circle, and various polygons are used. The shape of the through hole (opening) (17) shown in FIGS. 6A to 6C represents the desired shape of the through hole (opening) (17).

  When the exposure method by proximity exposure is adopted, it is difficult to form a polygonal through hole (opening) (17) in a desired shape as described below. The colored pixel (13) has a width (a) of about 25 μm and a length (b) of about 75 μm, and one side (c) of the square is about 75 μm.

  FIG. 7A is an enlarged plan view showing a part of an example of a color filter photomask used when forming the colored pixels shown in FIG. 6B. This is a case where a negative colored photoresist is used as the photoresist for forming the colored pixels. FIG. 7B is an enlarged plan view showing colored pixels formed using the color filter photomask shown in FIG.

  This color filter photomask is used in a proximity exposure system in which a gap is provided between a photomask and a colored photoresist layer provided on a substrate. As shown in FIGS. 7A and 7B, this photomask is composed of a light transmission part (52) and a light shielding part (51), and the reflection display part (Re) of the light transmission part (52) A square light shielding part (S1) corresponding to a through hole (opening part) (K1) formed in the colored pixel (53) is provided.

  This square light-shielding part (S1) is not connected to the light-shielding part (51), and is a light-shielding part isolated in an island shape in the light transmission part (52). When this photomask is arranged as shown in FIG. 5 and the irradiation light (L) is exposed from above, the light irradiated from above wraps downward at the end of the square light shielding portion (S1) due to the diffraction effect of proximity exposure. In particular, the amount of irradiation below the corners (vertices) (d) of the four corners of the square increases, and the corners of the four corners of the through hole (opening) (K1) are rounded.

The round radius (r1) is, for example, about 5 μm when the side (c) of the square light-shielding portion (S1) is about 12 μm in the proximity exposure using the negative coloring photoresist.
The area of the through hole (opening) (K1) varies depending on the roundness at the corners (vertices) of the four corners of the square, and the average thickness of the colored layer (16) having the through hole (opening) shown in FIG. Affects (D2). That is, the change in the average thickness (D2) causes a change in brightness and saturation in the reflective color display of the reflective liquid crystal display device.

FIG. 8A is an enlarged plan view showing a part of an example of a color filter photomask used for forming the colored pixels shown in FIG.
FIG. 8B is an enlarged plan view showing colored pixels formed using the color filter photomask shown in FIG.
The reflective display part (Re) of the colored pixel (63) is provided with two rectangles symmetrically as through-holes (openings) (K2). The through hole (opening) (K2) is in the colored pixel, but the left side of the left through hole (opening) (K2) and the right side of the right through hole (opening) (K2) are respectively colored pixels. The long side is in contact with the line (f).

  As shown in FIGS. 8A and 8B, this photomask is composed of a light transmission part (62) and a light shielding part (61), and the reflection display part (Re) of the light transmission part (62) A rectangular light shielding portion (S2) corresponding to a through hole (opening portion) (K2) formed in the colored pixel (63) is provided.

  The rectangular light shielding portion (S2) is connected to the light shielding portion (61), and is a light shielding portion in a state where the light shielding portion (61) is extended. When this photomask is arranged as shown in FIG. 5 and the irradiation light (L) is exposed from above, the light irradiated from above wraps downward at the end of the rectangular light shielding portion (S2) due to the diffraction effect of proximity exposure. In particular, the amount of irradiation below the corner (vertex) (d) of the rectangle is increased, and the corner of the through hole (opening) (K2) is the same as in the case of the square light shield (S1) shown in FIG. Is rounded with a radius (r1).

  On the other hand, the amount of light irradiated from above the photomask is particularly low below the corner (vertex) (e) of the light transmitting portion (62), and the corner of the through hole (opening) (K2). The part is rounded.

  As described above, in the case of a photomask in which the rectangular light-shielding portion (S2) in a state where the light-shielding portion (61) is extended in the light-transmitting portion (62) is connected to the light-shielding portion (61). The change in the area of the through hole (opening) (K2) due to the roundness of the corner of the through hole (opening) (K2) below the rectangular corner (vertex) (d) of the rectangular light shielding part (S2) And the change in the area of the through hole (opening) (K2) due to the roundness of the corner of the through hole (opening) (K2) below the corner (vertex) (e) of the light transmitting portion (62). Both of these occur and change the brightness and saturation in the reflective color display of the reflective liquid crystal display device.

Note that the four corners (g) of the light transmission part (52) of the photomask shown in FIG. 7A and the four corners (g) of the light transmission part (62) of the photomask shown in FIG. Although the rounding phenomenon of the colored pixels occurs below the corners (vertices) (e) of the light transmission part (62), the light transmission part (52) or Since the black matrix (12) similar in shape to the four corners of the light transmission part (62) is provided, the influence of the roundness phenomenon in this part is small.
JP 2005-173384 A JP 2005-202345 A JP 2005-181516 A Japanese Patent Laying-Open No. 2005-084492 Japanese Patent Application Laid-Open No. 2003-065589

  The present invention has been made to solve the above problems, and when a pattern constituting a color filter is formed on a glass substrate by a photolithography method, even if exposure through a photomask is performed by a proximity exposure method. Another object of the present invention is to provide a photomask in which the corners of the pattern corresponding to the corners of the light-shielding part of the photomask are not rounded.

  In addition, when a pattern constituting a color filter is formed on a glass substrate by photolithography, a pattern corresponding to the corner of the light transmission portion of the photomask even if exposure through a photomask is performed by proximity exposure. It is an object of the present invention to provide a photomask whose corners are not rounded.

  It is another object of the present invention to provide a color filter manufacturing method, a color filter, and a liquid crystal display device using the color filter photomask.

The first invention in the present invention has a transmissive display portion and a reflective display portion, and the reflection display portion is provided with two rectangles symmetrically as through-holes (openings), and the through-holes (openings) are A rectangular color that is in the colored pixel, and the left side of the left through-hole (opening) and the right side of the right through-hole (opening) are in contact with a line that extends the long side of the colored pixel. the pattern constituting the filter, using a negative photoresist, the photomask used at the time of Rikatachi formed by the proximity exposure, the corner of the light shielding portion of the photomask corresponding to the corner portion of the through hole in the coloring in the pixel A polygonal correction light-shielding pattern is provided in contact with the apex , and a polygonal correction aperture pattern is provided at the apex at the corner of the light transmitting portion of the photomask corresponding to the through-hole corner outside the colored pixel. Touching A photomask for a color filter, wherein the digit.

  Further, the present invention is the color filter photomask according to the first invention, wherein an inner angle of a corner portion of the light shielding portion is in a range of 70 ° to 120 °. .

  Further, according to the present invention, in the color filter photomask according to the first aspect of the present invention, the lengths of two sides with the vertex of the polygonal correction light-shielding pattern as intersections are both in the range of 0.5 μm to 6.0 μm. It is a photomask for a color filter characterized by being.

Further, the present invention is the color filter photomask according to the first invention, wherein an inner angle of a corner portion of the light transmitting portion is in a range of 70 ° to 120 °. is there.

According to the present invention, in the color filter photomask according to the first aspect of the present invention, the lengths of two sides having the vertexes of the polygonal correction aperture pattern as intersections are both in the range of 0.5 μm to 6.0 μm. It is a photomask for a color filter characterized by being.

According to a second aspect of the present invention, a color filter is formed by using the color filter photomask according to any one of claims 1 to 5 to form a pattern constituting the color filter. It is a manufacturing method.

A third aspect of the present invention is a color filter manufactured using the method for manufacturing a color filter according to claim 6 .

According to a fourth aspect of the present invention, there is provided a liquid crystal display device comprising the color filter according to the seventh aspect.

  The first aspect of the present invention is a color filter photomask in which a polygonal correction light-shielding pattern is provided at the corner of the light-shielding part of the photomask in contact with the apex thereof. A photomask whose pattern corners corresponding to the corners of the light-shielding portion of the photomask are not rounded even when exposure is performed through the photomask by the proximity exposure method when forming the pattern constituting the color filter. It becomes.

Further , the first invention in the present invention is a color filter photomask in which a polygonal correction aperture pattern is provided in contact with the apex at the corner of the light transmitting portion of the photomask. When forming a pattern constituting a color filter on a substrate, the pattern corner corresponding to the corner of the light transmitting portion of the photomask is rounded even if exposure is performed through a photomask by the proximity exposure method. It becomes a photomask without any.

  In addition, since the present invention uses the photomask, the present invention provides a method for producing a color filter in which the pattern corners constituting the color filter are not rounded. In addition, a color filter and a liquid crystal display device that do not cause changes in lightness and saturation in reflective color display are obtained.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1A is an enlarged plan view showing a part of a pattern of a reference example of a photomask for a color filter according to the present invention. This color filter photomask is for forming colored pixels, and is obtained when a negative colored photoresist is used as a photoresist for forming colored pixels. FIG. 1B is an enlarged plan view showing the colored pixels formed using the color filter photomask shown in FIG.

  The color filter photomask according to the present invention is used in a proximity exposure method in which a gap is provided between a photomask and a colored photoresist layer provided on a substrate. The gap varies depending on the size of the pattern to be formed, but is usually in the range of 50 μm to 100 μm.

As shown in FIGS. 1A and 1B, this photomask is composed of a light transmission part (22) and a light shielding part (21). The light transmission part (22) has a width (a) of about 25 μm and a length. (B) A rectangle of about 75 μm and a desired colored pixel (23) shape.
One reference example shown in FIG. 1 is to explain in correspondence to the photomask and the color pixels for a color filter shown in FIG. 7.

The reflection display portion (Re) of the light transmission portion (22) of the photomask is provided with a square light shielding portion (S3) corresponding to a through hole (opening portion) (K3) formed in the colored pixel (23). This is an example.
This square light-shielding part (S3) is not connected to the light-shielding part (21), and is a light-shielding part isolated in an island shape within the light transmission part (22).

FIG. 2 is an explanatory view showing the square light shielding portion (S3) in an enlarged manner. As shown in FIG. 2, the correction light-shielding pattern (H3) is provided on the light transmitting part (22) side of each corner (h) of the square even part of the square light-shielding part (S3). In this example, an isosceles triangle is used as the shape of the correction light-shielding pattern (H3).
The isosceles triangular correction light-shielding pattern (H3) is provided with its apex in contact with each corner (h) of the quadrant of the square light-shielding part (S3). The correction light-shielding pattern (H3) is provided symmetrically with respect to the bisector (k) of the inner angle (θ) of the corner (h).

  When this photomask is arranged as shown in FIG. 5 and the irradiation light (L) is exposed from above, the light irradiated from above wraps downward at the end of the square light-shielding portion (S3) due to the diffraction effect of proximity exposure. However, wraparound at the corner (h) is suppressed by the corrected light-shielding pattern (H3), and in particular, the amount of irradiation below the corner (h) of the four corners of the square does not increase. Therefore, the corner portions (h ′) at the four corners of the through hole (opening) (K3) are not rounded.

That is, there is no change in the area of the through hole (opening) (K3) due to roundness.
Therefore, the average thickness (D2) of the colored layer (16) having the through hole (opening) shown in FIG. 4 is not affected, and the brightness and saturation in the reflective color display of the reflective liquid crystal display device are not affected. No change is brought about.

The square light-shielding portion (S3) shown in FIGS. 1 and 2 is a photomask corresponding to the through-hole (opening) (K3), taking a square through-hole (opening) formed in the colored pixel (23) as an example. The upper shading part is demonstrated.
The inner angle (θ) of the corner (h) of the square light-shielding portion (S3) is 90 °, but in the present invention, the inner angle of the corner of the light-shielding portion on the photomask is 70 ° to 120 °. It is characterized by that.

When the inner angle of the corner is 120 ° or more, the influence of the irradiation light wrapping around the corner is small, and therefore it is not necessary to provide the correction light-shielding pattern (H3) at the corner of the light-shielding portion.
Moreover, it is rare to use a light-shielding portion having a corner portion with an inner angle of 70 ° or less.
Therefore, it is effective to provide the correction light-shielding pattern (H3) when the inner angle of the corner of the light-shielding part on the photomask is in the range of 70 ° to 120 °.

  In the present invention, it is preferable that the lengths of two sides having the vertexes of the polygonal correction light-shielding pattern as intersections are in the range of 0.5 μm to 6.0 μm. That is, in FIG. 1 and FIG. 2, the lengths (i, j) of two sides with the vertex of the isosceles correction light-shielding pattern (H3) as an intersection are both in the range of 0.5 μm to 6.0 μm. It is preferable.

The roundness (r1) of the corner portion of the through hole (opening portion) (K1) shown in FIG. 7 is the inner angle of the corner portion of the light shielding portion (S1), the gap amount of proximity exposure, the resolution of the photoresist, and the like. The area of the correction light-shielding pattern that suppresses the occurrence of roundness is appropriately set. If the length of one side of the correction light-shielding pattern is 6.0 μm or more, the correction light-shielding pattern is It may be resolved and the shape of the corner may deteriorate. In addition, it is difficult to create a corrected light-shielding pattern having a side length of 0.5 μm or less due to restrictions on photomask manufacturing equipment.
In general, preferable results are obtained when the thickness is in the range of 0.5 μm to 6.0 μm.

FIG. 9A is an enlarged plan view showing a part of the pattern of one embodiment of the color filter photomask according to the present invention. FIG. 9B is an enlarged plan view showing the colored pixels formed using the color filter photomask shown in FIG.
As shown in FIGS. 9A and 9B, this photomask is composed of a light transmission part (32) and a light shielding part (31), and the light transmission part (32) has a width (a) of about 25 μm and a length. (B) A rectangle of about 75 μm and a desired color pixel (33) shape.
The embodiment shown in FIG. 9 explains the present invention in correspondence with the color filter photomask and the colored pixels shown in FIG.

  The reflective display part (Re) of the colored pixel (33) is provided with two rectangles symmetrically as through-holes (openings) (K4). The through hole (opening) (K4) is in the colored pixel, but the left side of the left through hole (opening) (K4) and the right side of the right through hole (opening) (K4) are respectively colored pixels. The long side is in contact with the line (f).

The reflection display part (Re) of the light transmission part (32) of the photomask is provided with a rectangular light shielding part (S4) corresponding to a through hole (opening part) (K4) formed in the colored pixel (33). This is an example.
The rectangular light shielding portion (S4) is connected to the light shielding portion (31) and is a light shielding portion in a state where the light shielding portion (31) is extended.

FIG. 10 is an explanatory view showing the rectangular light shielding portion (S4) in an enlarged manner. As shown in FIG. 10, the correction aperture pattern (H4) is provided on the light shielding part (31) side of each corner (l) of the light transmission part (32). This is an example in which a regular hexagon is used as the shape of the correction opening pattern (H4).
The regular hexagonal correction opening pattern (H4) is provided with its apex in contact with the corner (l) of the light transmission part (32). The correction aperture pattern (H4) is provided symmetrically with respect to the bisector (k) of the inner angle (θ) of the corner (l).

  When this photomask is arranged as shown in FIG. 5 and the irradiation light (L) is exposed from above, the light irradiated from above wraps downward at the end of the rectangular light shielding portion (S4) due to the diffraction effect of proximity exposure. However, the correction aperture pattern (H4) reinforces the wraparound at the corner (1), and the amount of irradiation below the corner (1) of the light transmitting portion (32) is not particularly reduced. Accordingly, the corner portion (l ') of the through hole (opening) (K4) is not rounded.

That is, there is no change in the area of the through hole (opening) (K4) due to roundness.
Therefore, the average thickness (D2) of the colored layer (16) having the through hole (opening) shown in FIG. 4 is not affected, and the brightness and saturation in the reflective color display of the reflective liquid crystal display device are not affected. No change is brought about.

  On the other hand, the light irradiated from above the photomask wraps downward at the end of the rectangular light shielding portion (S4) due to the diffraction effect of the proximity exposure, but as in the example shown in FIGS. 1 and 2, the corrected light shielding pattern (H3). Therefore, the wraparound at the corner (h) is suppressed, and the irradiation amount below the corner (h) is not particularly increased. Therefore, the corner portion (h ′) of the through hole (opening) (K4) is not rounded.

As described above, in the photomask in which the light shielding part (32) is provided with the rectangular light shielding part (S4) in a state where the light shielding part (31) is extended in the light transmitting part (32). There is no change in the area of the through hole (opening) (K4) due to the roundness of the corner of the through hole (opening) (K4) below the rectangular corner (h) of the rectangular light shielding part (S4). In addition, the area of the through hole (opening) (K4) changes due to the roundness of the corner of the through hole (opening) (K4) below the corner (l) of the light transmission part (32). There is nothing.
Accordingly, there is no change in brightness and saturation in the reflective color display of the reflective liquid crystal display device.

Note that the four corners (g) of the light transmission part (22) of the photomask shown in FIG. 1A and the four corners (g) of the light transmission part (32) of the photomask shown in FIG. The rounded phenomenon of the colored pixels occurs below the corner (l) of the light transmission part (32).
Below the four corners (g), a black matrix (12) similar to the shape of the four corners of the light transmitting part (22) or the light transmitting part (32) is provided. However, if there is a concern about the relationship between the width of the black matrix (12) and the radius of roundness, the correction aperture pattern (in the four corners of the light transmitting portion (22) or the light transmitting portion (32)). H4) is preferably provided.

The rectangular light shielding portion (S4) shown in FIGS. 9 and 10 corresponds to the through hole (opening) (K4) by taking a rectangular through hole (opening) (K4) formed in the colored pixel (33) as an example. The light-shielding part on the photomask was explained.
The inner angle (θ) of the light transmitting portion on the photomask is 90 °, but in the present invention, the inner angle of the light transmitting portion on the photomask is 70 ° to 120 °. It is characterized by.

When the inner angle of the corner is 120 ° or more, there is little influence of the irradiation light wrapping around the corner, so that it is not necessary to provide the correction aperture pattern (H4) at the corner of the light shielding portion.
In addition, it is rare to use a light transmission portion having a corner portion with an inner angle of 70 ° or less.
Therefore, it is effective to provide the correction light-shielding pattern (H3) when the inner angle of the corner of the light transmitting portion on the photomask is in the range of 70 ° to 120 °.

  In the present invention, it is preferable that the lengths of the two sides having the vertexes of the polygonal correction aperture pattern as intersections are both in the range of 0.5 μm to 6.0 μm. That is, in FIGS. 9 and 10, the lengths (i, j) of the two sides having the vertex of the regular hexagonal correction opening pattern (H4) as the intersection are both in the range of 0.5 μm to 6.0 μm. Is preferred.

The roundness (r2) of the corner portion of the through hole (opening) (K2) shown in FIG. 8 is the inner angle of the corner portion of the light transmission portion (62), the gap amount of the proximity exposure, and the resolution of the photoresist. The area of the correction aperture pattern that suppresses the occurrence of roundness is appropriately set. If the length of one side of the correction aperture pattern is 6.0 μm or more, the correction aperture pattern May be resolved to form a corrected aperture pattern. In addition, it is difficult to create a correction opening pattern having a side length of 0.5 μm or less due to restrictions of photomask manufacturing equipment.
In general, preferable results are obtained when the thickness is in the range of 0.5 μm to 6.0 μm.

FIGS. 11A and 11B are explanatory views showing an example in which the present invention is applied to a photomask used when forming a black matrix as a pattern constituting a color filter. FIG. 11B is an enlarged plan view showing an example of another black matrix corresponding to the colored pixel, for example, the colored pixel (13) shown in FIG.
The black matrix (74) is composed of a matrix portion (73A) that separates the colored pixels and a TFT light shielding portion (73B) that shields the TFT elements, and the two are integrally connected. The TFT light-shielding part (73B) is in a state of protruding into the colored pixel.

FIG. 11A is a plan view showing an example of a photomask for forming the black matrix 74 shown in FIG. As shown in FIG. 11A, the photomask is composed of a light transmission part (72) and a light shielding part (71) corresponding to the formation of the matrix part (73A) and the TFT light shielding part (73B).
At the corner (m) of the light shielding part (71), a corrected light shielding pattern (H3) is provided on the light transmitting part (72) side of the corner (m). Further, in the corner part (n) of the light transmission part (72), a correction aperture pattern (H4) is provided on the light shielding part (71) side of the corner part (n).

  By using such a photomask, the formed black matrix TFT light shielding portion (73B) is not rounded at each corner.

(A) is a top view which expands and shows a part of pattern of one reference example of the photomask for color filters by this invention. FIG. 2B is an enlarged plan view showing a colored pixel formed using the color filter photomask shown in FIG. It is explanatory drawing which expands and shows a square light-shielding part. FIG. 2 is a plan view showing an example of a color filter used in a transflective liquid crystal display device and showing an enlarged portion corresponding to one pixel. FIG. 4 is a cross-sectional explanatory diagram illustrating a pixel portion of a transflective liquid crystal display device using the color filter for the transflective liquid crystal display device illustrated in FIG. 3. It is sectional drawing explaining an example of proximity | contact exposure in manufacture of a color filter. (A) is an example in which the through hole (opening) is circular. (B) is an example in which the through hole (opening) is square. (C) is an example of two rectangles in which through holes (openings) are provided symmetrically in the drawing. (A) is a top view which expands and shows a part of pattern of an example of the photomask for color filters used when forming the colored pixel shown in FIG.6 (b). FIG. 7B is an enlarged plan view showing colored pixels formed using the color filter photomask shown in FIG. (A) is a top view which expands and shows a part of pattern of an example of the photomask for color filters used when forming the colored pixel shown in FIG.6 (c). (B) is an enlarged plan view showing colored pixels formed using the photomask for color filter shown in FIG. 8 (a). (A) is a top view which expands and shows a part of pattern of one Example of the photomask for color filters by this invention. FIG. 10B is an enlarged plan view showing colored pixels formed using the color filter photomask shown in FIG. It is explanatory drawing which expands and shows a rectangular light-shielding part. (A) is a top view which shows an example of the photomask for forming the black matrix shown in (b). (B) is an enlarged plan view showing an example of another black matrix corresponding to the colored pixels.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Glass substrate 12, 74 ... Black matrix 13, 23, 33, 53, 63 ... Colored pixel 14 ... Transparent conductive film 15 ... Uniform colored layer 16 of a light transmissive area | region ... Colored layer 17 which has the opening part of a light reflection area | region ... through hole (opening)
21, 31, 51, 61, 71... Light-shielding part 22, 32, 52, 62, 72 .. light transmission part 30... Color filter 40 used in a transflective liquid crystal display device. ... Transparent electrode 42 formed on TFT substrate ... Reflective electrode 47 formed on TFT substrate ... Colored photoresist coating film 50 ... Liquid crystal 73A ... Matrix part 73B ... TFT light shielding part A ... White light B from backlight Ambient light D1 from the surroundings D1 thickness of the colored layer D2 average thickness G of the colored layer having an opening G proximity gap H3 correction light-shielding pattern H4 correction aperture patterns K1, K2, K3, K4 through Hall (opening)
L ... Irradiation light L1 ... External light L2 ... Reflected light PM ... Photomask Px ... 1 pixel area Re ... Light reflection area P ... Light transmission area color light Q ... Light reflection area color light S1, S3 ... Square light shielding part S2, S4 ... rectangular light shielding portion Tr ... light transmission region a ... colored pixel width b ... colored pixel length c ... square side d, h ... square corners (vertices)
e ... Corner (vertex) of light transmitting part
f: line obtained by extending the long side of the colored pixel g: four corners i and j of the light transmission part of the photomask: the length r2 of two sides with the apex of the regular hexagonal correction aperture pattern: the round radius of the transmission part r2 ... Round radius of the light shielding part θ ... Inner angle of the corner of the square light shielding part

Claims (8)

A transmissive display portion and a reflective display portion;
The reflection display part is provided with two rectangles symmetrically as through-holes (openings), the through-holes (openings) are in the colored pixels, the left side of the left through-hole (opening), and the right through-hole The right side of each (opening) is a rectangular shape that is in contact with a line extending the long side of the colored pixel.
The pattern that makes up the color filter
A photomask for use in using a negative photoresist, which Rikatachi formed by the proximity exposure,
A polygonal correction light-shielding pattern is provided in contact with the apex at the corner of the light-shielding part of the photomask corresponding to the corner of the through hole in the colored pixel ,
A color filter photo, characterized in that a polygonal correction aperture pattern is provided in contact with the apex at the corner of the light transmission portion of the photomask corresponding to the corner of the through hole outside the colored pixel. mask.   The color filter photomask according to claim 1, wherein an inner angle of a corner portion of the light shielding portion is in a range of 70 ° to 120 °.   3. The color filter photo according to claim 1, wherein the lengths of two sides having the vertexes of the polygonal correction light-shielding pattern as intersections are in the range of 0.5 μm to 6.0 μm. mask. Interior angle of the corner portion of the light transmitting portions, color photo mask filter according to claim 1, wherein the range of 70 ° to 120 °. 5. The color filter photo according to claim 1 , wherein the lengths of two sides having the vertexes of the polygonal correction aperture pattern as intersections are both in the range of 0.5 μm to 6.0 μm. mask. A method for producing a color filter, wherein a pattern constituting the color filter is formed using the photomask for color filter according to any one of claims 1 to 5 . A color filter manufactured using the method for manufacturing a color filter according to claim 6 . A liquid crystal display device comprising the color filter according to claim 7 .

Images