JP2007171333A - Photomask for color filter, method for manufacturing color filter, color filter and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photomask for a color filter and a color filter in which a fine through hole having an opening diameter of 9.0 μm to 0.5 μm can be formed in a pattern even when exposure is carried out via the photomask by a proximity exposure method. <P>SOLUTION: The photomask is characterized in that: a light shielding pattern on the photomask corresponding to an opening K1 is composed of a kernel light shielding pattern (P0) having a circular or polygonal outer shape, an annular light transmitting portion (T1) adjacent to outside the kernel light shielding pattern (P0), and an annular light shielding pattern (P1) adjacent to the outside of the annular light transmitting portion (T1); the outer diameter of the annular light shielding pattern (P1) is 6.0 μm to 15.0 μm; the width of the annular light shielding pattern (P1) is 0.5 μm to 4.0 μm; and the width of the annular light transmitting portion (T1) is 0.5 μm to 4.0 μm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique for forming a through hole (opening) in a pattern constituting a color filter, and in particular, a photomask for a color filter capable of forming a fine through hole by exposure by proximity exposure, and a color Regarding filters.

  A transflective liquid crystal display device (semi-transmissive LCD) has a transmissive display part that transmits light from the light emitting device from a backlight or the like in a relatively dark place where there is little outside light, such as indoors, and the outside, such as outdoors. In a place where light can be obtained, it is a system with a reflective display unit that reflects external light by a reflector provided on the array side and is widely used as a display device for mobile devices that are often used outdoors. .

  FIG. 1 is a cross-sectional view of an example of a liquid crystal cell of a transflective LCD. As shown in FIG. 1, a liquid crystal 7 is sandwiched between a color filter 4 and a substrate (array substrate) 8 on which pixel electrodes, circuits, etc. for driving the liquid crystal are formed. The colored pixels 3 are formed. The colored pixel 3 is to change the light passing through the colored pixel to a predetermined color light, and generally has a colorant such as a color pigment dispersed in a transparent resin.

  In the transflective LCD color filter, one color pixel is composed of a color pixel portion for a transmissive display portion and a color pixel portion for a reflective display portion. In a reflective display unit that includes a reflecting plate 21 on the array side and reflects and displays external light incident on the transflective LCD, the external light incident from the color filter display surface reflects the colored pixel portion constituting the color filter. Since it passes twice, problems such as dark display on the reflective display portion and color purity with the transmissive display portion have occurred.

As a method for solving the above problem, for example, the following methods have been proposed in the prior art.
That is, as shown in FIG. 1, using the same coloring material, colored pixels are simultaneously formed in the transmissive display unit 12 and the reflective display unit 11, but through-holes 13 (colored pixels) are formed in the colored pixel portion of the reflective display unit 11. This is a method of forming a colored pixel having a high transmittance by patterning a penetrating region where no layer is provided. As the shape of the through hole 13 in the colored pixel, a circular pattern, a polygonal pattern, or a stripe pattern that is relatively easy to manage the dimensions is widely used, and the color characteristics of the colored pixel are adjusted by forming the through hole. It is a method to do.

  Next, a manufacturing method of the through hole type transflective LCD color filter will be described. FIG. 2 is a manufacturing process diagram showing an example of a manufacturing method of a color filter for through-hole type transflective LCD. First, a glass substrate 2 for a color filter made of a predetermined material and provided with a metal thin film (for a light shielding film) 19 on the entire surface on one side is put into the process.

(1) First, a predetermined light shielding film pattern 15 is formed on the glass substrate. That is, first, a photosensitive resin is applied on the metal thin film 19 to form a resist layer. Using a light-shielding film photomask having a light-shielding film pattern prepared in advance, a predetermined light source is irradiated and exposed, and a predetermined development process is performed, whereby the resist layer is formed into a resist layer 20 patterned for the light-shielding film.
Next, the exposed metal thin film portion is etched using the patterned resist layer 20 as a mask to form a light shielding film pattern 15 (see FIGS. 2A to 2C). Here, each opening between the light shielding film patterns 15 becomes one pixel portion.

(2) A first colored pixel is formed in the pixel portion. That is, a coloring material of the first color, for example, a red photoresist in which a red pigment is dispersed in a photosensitive resin, is applied to the entire surface of the glass substrate on which the light-shielding film pattern is formed by a predetermined method. A red photoresist coating layer is formed.
Using a photomask provided with a red colored pixel pattern prepared in advance, the coating layer is irradiated and exposed to a predetermined light source. After the pattern is transferred to the coating layer, a predetermined development process is performed to form red colored pixels 16. It forms (refer FIG.2 (d)-(e)). The photomask includes a pattern for red colored pixels. The red colored pixel pattern includes a pixel pattern of a reflective display unit and a pixel pattern of a transmissive display unit each having a predetermined through-hole pattern.

(3) Next, a second color pixel is formed. That is, a second color material, for example, a green photoresist in which a green pigment is dispersed in a photosensitive resin, is applied to the entire surface of the glass substrate on which the red colored pixels 16 are formed by a predetermined method. Then, a green photoresist coating layer is formed.
Using a photomask having a reflective display pixel pattern having a through hole pattern for green coloring pixels and a pixel pattern of a transmissive display portion prepared in advance, the coating layer is irradiated with a predetermined light source and exposed to the coating layer. After transferring the pattern, a predetermined development process is performed to form green colored pixels 17 (see FIG. 2F). The green colored pixel is formed in the pixel portion adjacent to the red colored pixel 16.

(4) Next, in the step of forming the third color pixel, the third color material, for example, blue in which a blue pigment is dispersed in a photosensitive resin on the entire surface of the glass substrate on which the green color pixel is formed. A photoresist is applied by a predetermined method, and a blue photoresist coating layer is formed on the entire surface of the glass substrate.
The coating layer is irradiated with a predetermined light source using a photomask having a pixel pattern of a reflective display unit and a pixel pattern of a transmissive display unit, each of which is prepared in advance. After transferring the pattern to the layer, a predetermined development process is performed to form blue colored pixels 18 (see FIG. 2G).

  The blue colored pixel 18 is formed in a pixel portion between the red colored pixel 16 and the green colored pixel 17. As described above, the colored pixel 3 in which the red colored pixel 16, the green colored pixel 17, and the blue colored pixel 18 are arranged in order is formed.

A through hole 13 is formed in the reflective display portion 11 of the colored pixel 3. FIG. 3 is a cross-sectional view in the direction perpendicular to the plane of the drawing, taken along the line ZZ in FIG. FIG. 4 is a plan view thereof. As shown in FIGS. 3 and 4, a through hole 13 is formed in the reflective display portion 11 of the red colored pixel 16 formed on the glass substrate 2.
The photomask used for forming the red colored pixel 16 includes a red colored pixel pattern composed of a pixel pattern of a reflective display unit having a through-hole pattern and a pixel pattern of a transmissive display unit. A through hole 13 is formed corresponding to the through hole pattern.

  (5) Next, the optical path difference adjusting layer 6 made of a transparent resin layer is formed on the reflective display portion 11 of the colored pixel 3, and the transparent electrode layer 5 is further formed on the entire surface of the glass substrate on which the optical path difference adjusting layer is formed. The through-hole type transflective LCD color filter is formed (see FIG. 1).

As described above, a photolithographic method is generally used for manufacturing a color filter for a through-hole type transflective LCD. Proximity aligner proximity is used in terms of production throughput and manufacturing equipment initial cost. In many cases, colored pixels are formed by an exposure method. That is, a quartz mask provided with a metal thin film pattern serving as a light shielding layer in advance and a glass substrate were brought close to each other at intervals of several tens to several hundreds of μm, and were applied to the glass substrate by UV irradiation through the quartz mask. The photo-curing of the colored photoresist is performed.
A high pressure mercury lamp is generally used as an exposure light source for UV irradiation. The main wavelengths include 302 nm, 312 nm, 334 nm, 365 nm, 405 nm, and the like. The colored photoresist composition is adjusted by blending appropriate amounts of a photopolymerization initiator that is sensitive to these wavelengths and a photophotopolymerizable monomer.

  While the proximity exposure method has advantages such as higher production throughput and lower initial cost of manufacturing equipment, it has the effect of diffraction of UV light and the gap amount between the quartz mask and the color filter. Since it is easily affected, it is difficult to form a fine through hole having an aperture diameter of 6.0 μm or less by the conventional color filter photomask and color filter manufacturing method.

  Transflective LCDs are widely used as display devices for mobile devices such as mobile phones and digital still cameras. However, in recent years, as the display devices have become higher definition, the reflective display portion of the color filter for transflective LCDs. It is also necessary to increase the definition of through-holes. For example, when a 2.4 inch type mobile phone has a resolution of QVGA (320 × 240 pixels) and a resolution of VGA (640 × 480 pixels), the width of one color pixel is It will be narrowed from about 75 μm to about 25 μm. Therefore, a smaller through hole formed in a pixel having a width of 25 μm is required.

  Recently, in addition to the proximity exposure method, an exposure device for manufacturing color filters of the same size projection method using mirror projection or lens condensing has been put into practical use, and a pattern can be formed without being influenced by diffraction or gap amount. It has become possible to form.

  In the proximity exposure method, the exposure mask having a mask pattern larger than the resolution limit and the substrate coated with the negative photoresist are subjected to exposure while shifting the relative position to narrow the width below the resolution limit. A method for forming an opening has been proposed (Patent Document 1).

  These methods that require special functions in the exposure apparatus often have problems such as an increase in initial cost of the exposure apparatus and a decrease in production throughput as compared with a normal proximity exposure system, and this often does not lead to cost reduction of the color filter. .

  Further, in the proximity exposure method, a photomask and an exposure method that are suitable for use under transfer conditions where the shape of the opening pattern of the exposure mask is not faithfully transferred have been proposed. This method utilizes the diffraction effect and is effective when the aperture diameter is 3.0 μm to 12.0 μm. However, the problem in the area of 3.0 μm or less cannot be solved (Patent Document 2).

In addition, some proposals have been made to improve the resolution of the pattern formed on the colored pixels by giving a characteristic to the photomask for the color filter. However, these proposals cannot solve the problems in the present application. No (Patent Documents 3, 4, and 5).
JP 2005-107356 A JP 2005-202345 A JP 2005-173384 A Japanese Patent Laying-Open No. 2005-084492 Japanese Patent Application Laid-Open No. 2003-065589

The present invention has been made in view of the above circumstances, and when forming a pattern constituting a color filter on a glass substrate by a photolithography method, even if exposure through a photomask is performed by a proximity exposure method, It is an object of the present invention to provide a photomask for a color filter that can form a fine through hole (opening) having an opening diameter of 9.0 to 0.5 μm in a pattern, for example, a colored pixel.
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 present invention relates to a photomask used for forming a pattern constituting a color filter by proximity exposure using a negative photoresist, and corresponding to an opening formed in the pattern simultaneously with the formation of the pattern. The upper light-shielding pattern includes a nuclear light-shielding pattern (P0) having a circular or polygonal outer shape, an annular light transmission part (T1) adjacent to the outside of the nuclear light-shielding pattern (P0), and the annular light transmission part (T1). ) Is a light-shielding pattern composed of an annular light-shielding pattern (P1) adjacent to the outside of the photomask for color filters.

  The present invention is also the color filter photomask according to the invention, wherein the pattern is a colored pixel.

  In the color filter photomask according to the present invention, the outer shape of the annular light transmission part (T1) and the annular light shielding pattern (P1) is similar to the outer shape of the nuclear light shielding pattern (P0). A photomask for a color filter.

  Further, according to the present invention, in the photomask for a color filter according to the above invention, the outer diameter of the annular light shielding pattern (P1) is 6.0 μm to 15.0 μm, and the width of the annular light shielding pattern (P1) is 0.5 μm to 4. A photomask for a color filter, characterized in that 0 μm and the width of the annular light transmission part (T1) are 0.5 μm to 4.0 μm.

  Further, the present invention is the color filter photomask according to the above invention, wherein the i-th annular light transmitting portion (Ti) and the i-th annular light transmitting portion (Ti) are adjacent to the outside of the annular light shielding pattern (P1). The color filter photomask is characterized in that one or more pairs (i = 2 to n) of the i-th annular light-shielding patterns (Pi) adjacent to the outside are sequentially adjacent to each other.

  In the color filter photomask according to the present invention, the outer shapes of the i-th annular light transmitting portion (Ti) and the i-th annular light shielding pattern (Pi) are similar to the outer shape of the annular light shielding pattern (P1). It is a photomask for a color filter characterized by being.

  In the color filter photomask according to the present invention, the width of the i-th annular light transmitting portion (Ti) is 0.5 μm to 4.0 μm, and the width of the i-th annular light shielding pattern (Pi) is 0.00. A photomask for a color filter, wherein the photomask is 5 μm to 4.0 μm.

Moreover, this invention uses the photomask for color filters of any one of Claims 1-7, and the opening diameter is 9.0 micrometers-0.5 micrometer in the pattern which comprises a color filter. A color filter manufacturing method is characterized by forming a portion.

  In addition, the present invention is a color filter manufactured using the method for manufacturing a color filter according to claim 8.

  The present invention also provides a liquid crystal display device comprising the color filter according to claim 9.

  The present invention relates to a photomask used for forming a pattern constituting a color filter by proximity exposure using a negative photoresist, and corresponding to an opening formed in the pattern simultaneously with the formation of the pattern. The upper light-shielding pattern includes a nuclear light-shielding pattern (P0) having a circular or polygonal outer shape, an annular light transmission part (T1) adjacent to the outside of the nuclear light-shielding pattern (P0), and the annular light transmission part (T1). ) On the outside of the annular light shielding pattern (P1) adjacent to the outside of the pattern, for example, a fine through hole (opening) having an opening diameter of 9.0 to 0.5 μm is formed in the colored pixel, for example, The color filter photomask can be used.

  In addition, since the present invention uses the photomask for a color filter, a method for producing a color filter that can form fine through holes (openings) having an opening diameter of 9.0 to 0.5 μm in the pattern, for example, colored pixels. The formed color filter and the liquid crystal display device are obtained.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 5A is an enlarged plan view showing a part of the pattern of one embodiment of the color filter photomask 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. 5B is an enlarged plan view showing colored pixels formed using the color filter photomask shown in FIG.

  The color filter photomask according to the present invention is used in the proximity exposure method in which a gap is provided between the photomask and the colored photoresist layer provided on the substrate. The gap varies depending on the size of the pattern to be formed, but is usually in the range of 50 μm to 400 μm, preferably in the range of 100 μm to 200 μm.

As shown in FIGS. 5A and 5B, this photomask is composed of a light transmitting portion 52 and a light shielding portion 51. The light transmitting portion 52 is a rectangle having a width a of about 25 μm and a length b of about 75 μm. The shape of the desired colored pixel 53 is obtained.
The reflection display unit 11 of the light transmission unit 52 includes a nuclear light shielding pattern (P0) having a circular or polygonal outer shape as a light shielding pattern corresponding to the opening K1 formed in the colored pixel 53, and the nuclear light shielding pattern ( A light shielding pattern composed of an annular light transmitting portion (T1) adjacent to the outside of P0) and an annular light shielding pattern (P1) adjacent to the outside of the annular light transmitting portion (T1) is provided. At the center of the nuclear light shielding pattern (P0), there are the centers of the annular light transmission part (T1) and the annular light shielding pattern (P1), which are arranged concentrically. Further, the center of the nuclear light-shielding pattern (P0) corresponds to the center of the opening K1 of the colored pixel 53. FIG. 5 shows an example in which the outer shape of the nuclear light shielding pattern (P0) is circular.

FIG. 7A is an enlarged plan view showing a part of a conventional pattern that does not use the color filter photomask according to the present invention. FIG. 7B is an enlarged plan view showing the colored pixel 73 formed using the photomask shown in FIG.

  The reflective display unit 11 of the light transmission unit 72 shown in FIG. 7A is provided with a circular light shielding pattern P corresponding to the opening K of the colored pixel 73. This circular light-shielding pattern P is faithfully reproduced by exposure, and a desired circular opening K is formed in FIG. 7B. Light irradiated from above is caused by the diffraction effect of proximity exposure. Since it goes down at the end of the light shielding pattern and reaches the colored photoresist layer below the light shielding pattern, if the outer diameter of the light shielding pattern P is less than a certain size, the light shielding pattern P does not function as a light shielding portion. As shown by the dotted line in FIG. 7B, the opening K is not formed. The outer diameter of the certain size is about 6 μm in proximity exposure using a negative coloring photoresist.

  In the photomask for a color filter according to the present invention shown in FIG. 5A, the light radiated downward from the outer peripheral edge of the annular light shielding pattern P1 among the light irradiated from above, and the annular light transmitting portion (T1). ) May interfere with the light intensity at the center of the colored photoresist layer surface. That is, the central portion of the colored photoresist layer surface where the light intensity is weakened is not cured, and the opening K1 is formed by development processing.

  The present inventor has determined that the opening diameter of the opening K1 formed in the colored pixel 53, that is, the light intensity of the colored photoresist layer surface, the core light shielding pattern (P0) constituting the light shielding pattern, and the annular light transmitting portion (T1). As a result of the simulation of the relationship between the shape of the annular light shielding pattern (P1), specifically, the outer diameter D1 of the annular light shielding pattern (P1) is 6.0 μm to 15.0 μm, and the annular light shielding pattern (P1) It has been found that a fine opening K1 is formed when the width W1 is 0.5 μm to 4.0 μm and the width W2 of the annular light transmission portion (T1) is 0.5 μm to 4.0 μm.

For example, when the outer diameter D1 of the annular light shielding pattern (P1) is 6.0 μm, the width W1 of the annular light shielding pattern (P1) is 0.5 μm to 4.0 μm, and the width W2 of the annular light transmission part (T1) is 0. .5 μm to 4.0 μm. Further, for example, when the outer diameter D1 of the annular light shielding pattern (P1) is 15.0 μm, the width W1 of the annular light shielding pattern (P1) is 0.5 μm to 4.0 μm, and the width W2 of the annular light transmission part (T1). Is from 0.5 μm to 4.0 μm.
By providing the light-shielding pattern having the above shape, the opening K1 having an opening diameter of 9.0 μm to 0.5 μm can be formed in the colored pixel 53.
Further, if the outer shape of the annular light transmission part (T1) and the annular light shielding pattern (P1) is similar to the outer shape of the core light shielding pattern (P0), the light intensity in the central portion of the colored photoresist layer surface tends to be uniform.

  FIG. 6A is an enlarged plan view showing a part of a pattern of an embodiment of a color filter photomask according to the invention of claim 5. FIG. 6B is an enlarged plan view showing colored pixels formed using the color filter photomask shown in FIG.

As shown in FIGS. 6A and 6B, this photomask is composed of a light transmitting portion 62 and a light shielding portion 61. The light transmitting portion 62 is a rectangle having a width a of about 25 μm and a length b of about 75 μm. The desired colored pixel 63 has the shape.
The reflection display unit 11 of the light transmission unit 62 has a second annular light transmission part (T2) adjacent to the outside of the annular light shielding pattern (P1) as a light shielding pattern corresponding to the opening K2 formed in the colored pixel 63. And a light shielding pattern in which the second annular light shielding pattern (P2) adjacent to the outside of the second annular light transmission portion (T2) is paired.
The example shown in FIG. 6 is an example in which there is one pair of the i-th annular light transmission part (Ti) and the i-th annular light shielding pattern (Pi).
When the width W4 of the second annular light transmission part (T2) is 0.5 μm to 4.0 μm and the width W3 of the second annular light shielding pattern (P2) is 0.5 μm to 4.0 μm, a fine opening K2 is formed. Is done.

  The light shielding pattern composed of the nuclear light shielding pattern (P0), the annular light transmitting portion (T1), and the annular light shielding pattern (P1) according to claims 1 to 4 shown in FIG. This is suitable when the opening diameter φ1 of the opening K1 to be formed is 6 μm or less. Further, the second annular light transmission part (T2) and the second annular light transmission part (T2) are paired outside the annular light shielding pattern (P1) according to claims 5 to 7 shown in FIG. The formed light shielding pattern is suitable when the opening diameter φ2 of the opening K2 formed in the colored pixel 63 is 6 μm or more.

The pattern in which the opening is formed using the color filter photomask according to the present invention may be not only in the colored pixels but also in, for example, a light shielding film or a protective layer. Moreover, in this invention, you may have another process as needed other than the process of forming the pattern which comprises a color filter using the said photomask for color filters. With respect to such steps and materials used for the color filter of the present invention, the same materials and manufacturing methods used for general color filters can be used.
Here, a typical photoresist (hereinafter referred to as a photosensitive composition) will be described below.

[Photosensitive composition]
A photosensitive composition suitable for use in the present invention is a negative photosensitive composition comprising a photopolymerizable monomer, a non-photosensitive resin and / or a photosensitive resin, a polymerization initiator, and a solvent. For these, any of curing methods of UV exposure and Deep UV exposure may be used.

(Photopolymerizable monomer)
In the photosensitive composition suitable for use in the present invention, a photopolymerizable monomer is blended. The photopolymerizable monomer is characterized by using a polyfunctional urethane acrylate having a (meth) acryloyl group obtained by reacting a polyfunctional isocyanate with a (meth) acrylate having a hydroxyl group. The combination of the (meth) acrylate having a hydroxyl group and the polyfunctional isocyanate is arbitrary and is not particularly limited. Moreover, one type of polyfunctional urethane acrylate may be used alone, or two or more types may be used in combination.

(Non-photosensitive resin and / or photosensitive resin)
In the photosensitive composition suitable for use in the present invention, a non-photosensitive resin and / or a photosensitive resin is blended. At present, from the viewpoint of environmental problems, organic solvents are hardly used as a developer, and alkali development has become the mainstream, but when employing alkali development, it is preferable to include an alkali-soluble non-photosensitive resin. . Here, the alkali-soluble non-photosensitive resin means a resin that is soluble in an alkaline aqueous solution and does not have radical crosslinkability. For example, an acidic functional group such as a carboxyl group or a sulfone group. And a resin having a mass average molecular weight of 1,000 to 500,000, preferably 5,000 to 100,000.

  Specifically, acrylic resin, α-olefin / (anhydrous) maleic acid copolymer, styrene / (anhydrous) maleic acid copolymer, styrene / styrene sulfonic acid copolymer, ethylene / (meth) acrylic acid copolymer And isobutylene / (anhydrous) maleic acid copolymer. Among these, at least one resin selected from an acrylic resin, an α-olefin / (anhydrous) maleic acid copolymer, and a styrene / styrene sulfonic acid copolymer is preferable. Among these, acrylic resins are preferably used because of their high heat resistance and transparency.

(Pigment)
When the photosensitive composition layer is for a colored pixel of a color filter or for a light shielding film, it is necessary to further contain a pigment. For the formation of colored pixels, known organic pigments can be used in the photosensitive composition. Although the compounding quantity of a pigment is not specifically limited, It is preferable that it is about 1-20 weight% with respect to 100 weight% of a photosensitive composition. Also, a plurality of pigments can be used in combination for spectral adjustment of the color filter.

  Further, in combination with the organic pigment, an inorganic pigment can be used in combination in order to ensure good coatability, sensitivity, developability and the like while balancing the saturation and lightness. Inorganic pigments include yellow lead, zinc yellow, red bean (red iron oxide (III)), cadmium red, ultramarine, bitumen, chromium oxide green, cobalt green, and other metal oxide powders, metal sulfide powders, metal powders, etc. Can be mentioned. Furthermore, for color matching, a dye can be contained within a range that does not lower the heat resistance.

(Dispersant)
When the pigment is contained, it is necessary to contain a dispersant for dispersing the pigment. As the dispersant, a surfactant, an intermediate of pigment, an intermediate of dye, Solsperse, or the like is used. The addition amount of the dispersant is not particularly limited, but is preferably 1 to 10% by weight with respect to 100% by weight of the pigment.

(Polymerization initiator)
Suitable polymerization initiators for use in the photosensitive composition used in the present invention include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2- Acetophenone compounds such as hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, benzoin, Benzoin compounds such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether and benzyldimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, Benzophenone compounds such as lysed benzophenone and 4-benzoyl-4′-methyldiphenyl sulfide, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, etc. Thioxanthone compounds, 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloro) Methyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2-pienyl-4,6-bis (trichloromethyl) -s-triazine, 2,4 -Bis (trichloromethyl) -6-styryl s-triazine, 2- (naphth-1-yl)- , 6-Bis (trichloromethyl) -s-triazine, 2- (4-methoxy-naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) ) -6-triazine, 2,4-trichloromethyl (4'-methoxystyryl) -6-triazine and other triazine compounds, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O -Benzoyloxime)], O- (acetyl) -N- (1-phenyl-2-oxo-2- (4′-methoxy-naphthyl) ethylidene) hydroxylamine, and the like, bis (2,4,4) 6-trimethylbenzoyl) phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and other phosphine compounds, 9,10-phenance Nkinon, camphorquinone, quinone-based compounds such as ethyl anthraquinone, borate compounds, carbazole compounds, imidazole compounds, titanocene compounds, and the like.
These can be used singly or in combination of two or more.

(Photosensitizer, other)
Moreover, it is preferable to use together a polymerization initiator and a photosensitizer. Furthermore, the photosensitive composition can contain a polyfunctional thiol that functions as a chain transfer agent. The polyfunctional thiol may be a compound having two or more thiol groups. For example, hexanedithiol, decanedithiol, 1,4-butanediol bisthiopropionate, 1,4-butanediol bisthioglycolate, ethylene Glycol bisthioglycolate, ethylene glycol bisthiopropionate, trimethylolpropane tristhioglycolate, trimethylolpropane tristhiopropionate, trimethylolpropane tris (3-mercaptobutyrate), pentaerythritol tetrakisthioglycolate, Pentaerythritol tetrakisthiopropionate, tris (2-hydroxyethyl) isocyanurate trimercaptopropionate, 1,4-dimethylmercaptobenzene, 2,4,6-trimercapto-s-to Azine, 2- (N, N- dibutylamino) -4,6-dimercapto -s- triazine. These polyfunctional thiols can be used alone or in combination.

(solvent)
The photosensitive composition used in the present invention is blended with a solvent such as water or an organic solvent in order to enable uniform coating on the substrate. Further, when the photosensitive composition used in the present invention is for a colored pixel of a color filter or a light shielding film, the solvent also has a function of uniformly dispersing the pigment.

[Method for Preparing Photosensitive Composition]
The photosensitive composition used in the present invention can be prepared by a known method.
For example, the photosensitive coloring composition used for this invention which consists of a photopolymerizable monomer, photosensitive resin, a dispersing agent, a pigment, and a solvent can be prepared with the following method.

  (1) A pigment composition prepared by mixing a pigment and a dispersant in advance is added to a photopolymerizable monomer and / or photosensitive resin, or a solution in which these are dissolved in a solvent, and dispersed, and the remaining components are added. To do. (2) A pigment and a dispersant are separately added and dispersed in a photopolymerizable monomer and / or photosensitive resin, or a solution in which these are dissolved in a solvent, and then the remaining components are added. (3) A pigment is dispersed in a photopolymerizable monomer and / or a photosensitive resin, or a solution in which these are dissolved in a solvent, a dispersant is added, and the remaining components are added. (4) Prepare two types of photopolymerizable monomer and / or photosensitive resin, or a solution in which these are dissolved in a solvent, disperse the pigment and the dispersant separately in advance, and then mix the remaining components. Added. One of the pigment and the dispersant may be dispersed only in the solvent.

  Here, the dispersion of the pigment or dispersant in the photopolymerizable monomer and / or photosensitive resin, or a solution in which these are dissolved in a solvent, is a three roll mill, a two roll mill, a sand mill, a kneader, a dissolver, a high speed mixer, It can be carried out using various dispersing devices such as a homomixer and an attritor. Moreover, in order to perform dispersion | distribution favorably, you may add and disperse | distribute various surfactants. In addition, when preparing a pigment composition by previously mixing a pigment and a dispersant, the powder pigment and the powder dispersant may be simply mixed, but (a) a kneader, a roll, an attritor, a super mill, etc. Mix mechanically with various pulverizers, (b) Disperse the pigment in the solvent, add a solution containing the dispersant, and adsorb the dispersant on the pigment surface. (C) Strong dissolving power such as sulfuric acid It is preferable to employ a mixing method in which the pigment and the dispersant are co-dissolved in the solvent that is held and then co-precipitated using a poor solvent such as water.

  Below, the formation method of the colored pixel using the photomask for color filters of this invention is demonstrated. First, a photosensitive coloring composition is uniformly applied on a substrate by a spray coating method, a spin coating method, a roll coating or the like and dried. As the substrate to be used, a transparent substrate is preferable, and specifically, a resin substrate such as a glass plate, polycarbonate, polymethyl methacrylate, polyethylene phthalate, or the like is preferably used.

  Next, the formed photosensitive coloring composition layer is patterned. That is, after exposure by irradiating active energy rays such as ultraviolet rays and electron beams through the photomask having the light-shielding pattern shown in FIG. 5 or FIG. 6, development is performed using a developer such as an organic solvent or an alkaline aqueous solution. . Here, in the exposure step, the photopolymerizable monomer in the portion irradiated with the active energy ray is polymerized and cured. Further, when a photosensitive resin is contained, the resin is also crosslinked and cured.

  In order to improve exposure sensitivity, after forming a photosensitive coloring composition layer, a solution of a water-soluble or alkaline water-soluble resin (for example, polyvinyl alcohol, water-soluble acrylic resin, etc.) is applied and dried. The film may be exposed after forming a film that suppresses polymerization inhibition due to. Then, in the development process, the portion not irradiated with the active energy ray is washed away with the developer. As the developer, an alkaline developer such as an aqueous solution such as sodium carbonate or caustic soda, or an organic alkali solution such as dimethylbenzylamine or triethanolamine is mainly used.

  Moreover, as a developing solution, what added the antifoamer and surfactant was used as needed. By baking at the end, a colored pixel, a light-shielding film, a columnar protrusion for making the cell gap of the liquid crystal display device uniform, and a raised layer for forming a step in the cell gap can be formed on the substrate. .

  Next, examples and comparative examples of the present invention will be specifically described, but the present invention is not limited to these examples without departing from the spirit of the present invention.

<Example 1>
[Preparation of photosensitive coloring composition]
The red photosensitive coloring composition used for preparation of a color filter was prepared in the following manner.
1) A mixture having the following composition was uniformly stirred and mixed, then dispersed in a sand mill for 5 hours using a glass bead having a diameter of 1 mm, and then filtered through a 5 μm filter to prepare a red pigment dispersion.
-Red pigment: C.I. I. Pigment Red 254 18 parts by weight (“Ilgar For Red B-CF” manufactured by Ciba Specialty Chemicals)
-Dispersant ("Ajisper PB821" manufactured by Ajinomoto Fine Techno Co., Ltd.) 2 parts by weight-Acrylic varnish (solid content 20%) 108 parts by weight 2) Thereafter, a mixture of the following composition was stirred and mixed to be uniform, Filtration through a filter gave a red photosensitive coloring composition.
-38 parts by weight of the above dispersion-16 parts by weight of acrylic varnish-6 parts by weight of polyfunctional urethane acrylate (1)-Photopolymerization initiator ("Irgacure-369" manufactured by Ciba Geigy) 0.3 parts by weight-Photosensitizer ( "EAB-F" manufactured by Hodogaya Chemical Co., Ltd.) 0.2 parts by weight, cyclohexanone 27 parts by weight [Photomask]
In the photomask shown in FIG. 5A, the outer diameter D1 of the annular light shielding pattern (P1) provided on the reflective display portion 11 of the light transmitting portion 52 is 9.0 μm, and the width W1 of the annular light shielding pattern (P1) is 3. One having a thickness of 0.0 μm and a width W2 of the annular light transmission portion (T1) of 3.0 μm was used.

[Production of color filter]
The red photosensitive coloring composition was applied to a color filter substrate to form a photosensitive composition layer having a thickness of 2.0 μm. Using a high-pressure mercury lamp, the gap amount is 100 μm through the photomask.
The pattern portion was cured by proximity exposure at. Thereafter, alkali development and post-baking at 230 ° C. for 1 hour were performed. As a result, a pattern having a fine circular opening K1 having a film thickness of 1.6 μm and an opening diameter of 3.0 μm was formed.

<Comparative Example 1>
The photomask for the color filter is a photomask having a circular light shielding pattern P shown in FIG. 7A, and the circular light shielding pattern P provided on the reflective display portion 11 of the light transmitting portion 72 has an outer diameter D. A color filter was produced in the same manner as in Example 1 except that 4.0 μm was used.
As a result, due to the influence of diffraction, the light also travels to the light shielding portion, and the desired opening K is not formed.

<Comparative example 2>
In the photomask shown in FIG. 5A, the outer diameter D1 of the annular light shielding pattern (P1) provided on the reflective display portion 11 of the light transmission portion 52 is 75.0 μm, and the width W1 of the annular light shielding pattern (P1) is A color filter was produced in the same manner as in Example 1 except that 15.0 μm and the width W2 of the annular light transmission part (T1) was 15.0 μm. The result is a non-colored layer with an outer diameter of 15.0 μm in the center, which is similar to the photomask pattern, and an annular colored layer with an outer diameter of 45.0 μm and a width of 15.0 μm in the periphery. An annular non-colored layer having an outer diameter of 75.0 μm and a width of 15.0 μm was formed.

  As described above in detail, when the color filter photomask of the present invention forms colored pixels of a color filter on a glass substrate by a photolithography method, even if exposure is performed through a photomask by a proximity exposure method, A fine circular or polygonal opening having a width of 9.0 to 0.5 μm can be formed in the colored pixel. Therefore, a higher definition liquid crystal display device can be provided.

It is sectional drawing of an example of the liquid crystal cell of transflective LCD. It is a manufacturing process figure which shows an example of the manufacturing method of the color filter substrate for through-hole type transflective LCDs. It is sectional drawing of the paper surface perpendicular direction in the ZZ line of FIG.2 (g). It is a top view of the paper surface perpendicular direction in the ZZ line of Drawing 2 (g). (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. (B) is an enlarged plan view showing colored pixels formed using the color filter photomask shown in (a). (A) is a top view which expands and shows a part of pattern of one Example of the photomask for color filters by the invention concerning Claim 5. FIG. (B) is an enlarged plan view showing colored pixels formed using the color filter photomask shown in (a). (A) is a top view which expands and shows a part of conventional photomask pattern. (B) is a top view which expands and shows the colored pixel formed using the photomask shown to (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 9 ... Polarizing plate 2 ... Glass substrate 3, 53, 63, 73 ... Colored pixel 4 ... Color filter 5 ... Transparent electrode layer 6 ... Optical path difference adjusting layer 7 ...・ Liquid crystal 8: substrate on which pixel electrodes and circuits are formed (array substrate)
DESCRIPTION OF SYMBOLS 10 ... Backlight 11 ... Reflection display part 12 ... Transmission display part 13 ... Through hole (opening part)
DESCRIPTION OF SYMBOLS 15 ... Light shielding film pattern 16 ... Red colored pixel 17 ... Green colored pixel 18 ... Blue colored pixel 19 ... Metal thin film 20 ... Patterned resist layer 21 ... Reflector 51, 61, 71... Photomask light shielding portions 52, 62, 72... Photomask light transmitting portion D1... Outer diameters K, K1, K2. )
P0: Nuclear light shielding pattern P1 in the present invention: annular light shielding pattern P2 in the present invention: second annular light shielding pattern T1: annular light transmitting portion T2 in the present invention: second annular light transmitting portion W1 ... width W2 of the annular light shielding pattern ... width W3 of the annular light transmission part ... width W4 of the second annular light shielding pattern ... widths φ, φ1, φ2 of the second annular light transmission part Aperture diameter

Claims (10)

  A photomask used for forming a pattern constituting a color filter by proximity exposure using a negative photoresist, and a light shielding pattern on the photomask corresponding to an opening formed in the pattern simultaneously with the formation of the pattern Is a nuclear light shielding pattern (P0) having a circular or polygonal outer shape, an annular light transmission part (T1) adjacent to the outside of the nuclear light shielding pattern (P0), and an outer side of the annular light transmission part (T1). A photomask for a color filter, which is a light-shielding pattern composed of adjacent annular light-shielding patterns (P1).   The color filter photomask according to claim 1, wherein the pattern is a colored pixel.   The color filter photomask according to claim 1 or 2, wherein the outer shape of the annular light transmission part (T1) and the annular light shielding pattern (P1) is similar to the outer shape of the nuclear light shielding pattern (P0). .   The outer diameter of the annular light shielding pattern (P1) is 6.0 μm to 15.0 μm, the width of the annular light shielding pattern (P1) is 0.5 μm to 4.0 μm, and the width of the annular light transmission part (T1) is 0.5 μm to 4. The color filter photomask according to claim 1, wherein the color filter photomask is 4.0 [mu] m.   A pair of the i-th annular light transmission part (Ti) adjacent to the outside of the annular light-shielding pattern (P1) and the i-th annular light-shielding pattern (Pi) adjacent to the outside of the i-th annular light transmission part (Ti). 5. The color filter photomask according to claim 1, wherein the photomask is one or more pairs (i = 2 to n) sequentially adjacent to each other.   6. The photomask for a color filter according to claim 5, wherein the outer shape of the i-th annular light transmitting portion (Ti) and the i-th annular light shielding pattern (Pi) is similar to the outer shape of the annular light shielding pattern (P1). .   The width of the i-th annular light transmission part (Ti) is 0.5 μm to 4.0 μm, and the width of the i-th annular light shielding pattern (Pi) is 0.5 μm to 4.0 μm. The photomask for a color filter according to claim 6.   An opening having an opening diameter of 9.0 μm to 0.5 μm is formed in the pattern constituting the color filter using the photomask for color filter according to claim 1. A method for producing a color filter.   A color filter manufactured using the method for manufacturing a color filter according to claim 8.   A liquid crystal display device comprising the color filter according to claim 9.

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