JP5205933B2 - Method for manufacturing substrate for liquid crystal display device, substrate for liquid crystal display device, and liquid crystal display device - Google Patents

Description

  The present invention relates to a liquid crystal display device, and more particularly to a technique for forming a fine hole pattern in colored pixels on an array substrate.

  A color liquid crystal display device is generally configured by enclosing a liquid crystal 3 between an array substrate 1 and a color filter substrate 2 as shown in FIG. The array substrate 1 includes a TFT (Thin Film Transistor) 12, a transparent electrode 13a, and an alignment film (not shown) formed on a transparent substrate 11a, and a polarizing film 14a is provided on the opposite side. Further, a backlight 18 is disposed on the outer side.

  In the color filter substrate 2, the liquid crystal side of the transparent substrate 11b is divided into a large number of pixel areas, a light shielding film 15 is provided at the boundary between the pixel areas and the colored pixels 16 constituting the color filter are provided in each of the pixel areas. Further, an overcoat layer 17, a transparent electrode 13b, and an alignment film (not shown) are formed thereon. The colored pixel 16 colors transmitted light for each pixel, and generally, three colored pixels of red (R), green (G), and blue (B) corresponding to the three primary colors of light are arranged. The light shielding film 15 is for preventing color mixing of colored transmitted light and blocking unnecessary transmitted light. A polarizing film 14b is arranged on the screen viewer side of the transparent substrate 11b.

  In the liquid crystal display device having such a configuration, a voltage is applied to each pixel between the transparent electrode 13a on the array substrate side and the transparent electrode 13b on the color filter substrate side to control the light transmission amount, and the transmission Light is displayed on the screen as display light.

  In a high-definition liquid crystal display or a liquid crystal display for mobile use, in order to eliminate the influence of parallax and secure a wide viewing angle, as shown in FIG. 2, a color is provided on the side of the array substrate 1 having TFTs for driving the liquid crystal. Adoption of a structure in which a filter is disposed is progressing. The structure shown in FIG. 2 is suitable for a transflective mobile display. The reason is that when the transparent colored layer 16 is disposed on the substrate that opposes the array substrate 1 as shown in FIG. 1, the light 19 having an angle from the backlight 18 and the reflected light 20 in the reflection type are This is because there is a problem that dark pixels and mixed colors are likely to occur because adjacent pixels of different colors are passed.

  However, with the configuration shown in FIG. 2, it is necessary to form a contact hole 21 for electrical connection between the transparent electrode 13 a and the TFT 12. In this case, as represented by a liquid crystal display device for mobile use, in a display that requires high definition, the contact hole 21 itself needs to be miniaturized. For example, if the resolution of a 2.4-inch mobile phone with QVGA (320 × 240 pixels) is 4 times the resolution of VGA (640 × 480 pixels), the width of one pixel of the RGB material layer is about It becomes narrow from 75 μm to about 25 μm. Therefore, the width of the contact hole needs to be smaller than 25 μm. For example, the diameter is about 10 μm, desirably smaller.

  The contact hole affects the image quality in proportion to the opening area (the square of the radius). For mobile devices, a contact hole having a diameter of 10 μm or less is particularly desired in order to avoid adverse effects on image display and absorb alignment errors (± (5 μm to 3 μm)).

A method for forming the transparent colored layer 16 on the color filter substrate 2 includes a printing method and an ink jet method, and a photolithography method is generally used. For the formation of the latent image of the photosensitive composition layer, a batch / proximity exposure method using a proximity aligner is adopted because it is advantageous in terms of manufacturing cost. That is, a photosensitive composition is obtained by separating a quartz mask on which a metal film pattern serving as a light-shielding layer in advance and a substrate for a color filter from each other at intervals of several tens to several hundreds of μm and performing UV irradiation through the quartz mask. This is a method of photocuring.

  While the batch and proximity exposure methods have the advantages of high productivity and low cost, they also have the downside that they are easily affected by the effects of UV light diffraction and the separation distance between the quartz mask and the color filter substrate (hereinafter referred to as the exposure gap). is there. For this reason, the conventional color filter manufacturing method using a photomask pattern has a problem that it is difficult to form a fine opening having a width of 1.0 to 10.0 μm.

  In order to solve the above problem, in the proximity exposure method, exposure is performed by shifting the relative position of the exposure mask having a mask pattern larger than the resolution limit and the substrate coated with the negative photosensitive composition. Thus, a method of forming an opening having a narrow width below the resolution limit is disclosed (for example, Patent Document 1).

  Recently, in addition to the proximity exposure method, color filter manufacturing technology using the same magnification projection method such as mirror projection and lens condensing has been put into practical use, and a pattern can be formed without being influenced by diffraction or exposure gap. It has become possible to form. However, these methods have problems such as high initial cost of the exposure apparatus and low production throughput as compared with the normal proximity exposure method, and there is a high possibility that the cost will not be reduced.

  On the other hand, although it is an exposure method belonging to the proximity exposure method, exposure is performed using a suitable photomask under transfer conditions in which the shape and direction of the mask pattern are not faithfully transferred, and the shape of the pattern transferred using the diffraction effect is corrected. And a technique for improving the resolution is disclosed (Patent Document 2). However, even in this method, there is a problem that the circular opening diameter is 3.0 μm to 12.0 μm, and it cannot reach the extremely small region of 1.0 μm to 3.0 μm.

In addition, some proposals have been made to improve the resolution of the pattern formed on the photosensitive composition layer by giving a characteristic to the correction of the pattern of the photomask. This is not achieved (for example, 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 a color filter layer is formed by an photolithography method on an array substrate on which electrical elements such as TFTs are arranged, the substrate is exposed through a photomask by a collective exposure method. A manufacturing method of a substrate for a liquid crystal display device capable of forming a fine contact hole with a width of 1.0 μm to 10.0 μm in a color filter layer without being subjected to exposure gap variation even when proximity exposure is performed on It is an object to provide a substrate for a liquid crystal display device and a liquid crystal display device .

An aspect of the invention relating to claim 1 for solving the above-described problem is that a color filter is obtained by performing at least the following steps on an array substrate having a switching element for driving liquid crystal and a pixel electrode connected to the switching element. A method of manufacturing a substrate for a liquid crystal display device, characterized in that a contact hole is formed in a layer ,
(A) a step of forming a photosensitive colored layer using a negative photosensitive coloring composition;
(B) a pattern corresponding to the contact hole is divided into nine quadrilaterals and four the angular portion of the quadrilateral is a central quadrilateral cross-shaped pattern is a non-light-shielding portion and the non-light-shielding portion Forming a latent image of a contact hole and a color filter layer having an opening diameter of 1.0 μm to 10.0 μm in the photosensitive colored layer by a proximity exposure method using a photomask having a pattern;
(C) forming a colored pixel having a contact hole with an opening diameter of 1.0 μm to 10 μm by developing and heat-fixing the photosensitive colored layer having the latent image.

The aspect of the invention of claim 2 is a substrate for a liquid crystal display device manufactured by the manufacturing method of the first invention.

According to a third aspect of the present invention, there is provided a liquid crystal display device comprising the liquid crystal display device substrate described above.

  If the method for manufacturing a substrate for a liquid crystal display device according to the present invention and a photomask for proximity exposure are used, even when the batch proximity exposure method is used, the exposure gap is not affected and the width is from 1.0 μm. A colored pixel having a fine contact hole of 10 μm can be formed. By manufacturing an array substrate using this color filter, a high-quality and high-quality liquid crystal display device can be realized.

  First, prior to detailed description of the present invention with reference to the drawings and tables, simulation results of light intensity in the case of proximity exposure using a mask having an L-shaped light shielding portion shown in FIG. 3 will be described.

  FIG. 3A shows a mask pattern used. The shaded part 35 is a light shielding part, and the other part is an opening 34. FIG. 4B shows the light intensity when exposure light having a wavelength of 365 nm is spread from a parallel light source and is irradiated on the mask (a) at an angle of 2 degrees, and the distance between the mask and the photosensitive colored layer, ie, the exposure gap is 100 μm. It is a simulation result. A portion 37 having a high black density is a portion having a low light intensity. According to this, the light intensity of the proximity exposure of the opening 37 sandwiched between the L-shaped portions hits only the same amount of light as that of the light receiving portion of the light-shielding portion that is the least exposed to the light. That is, it is shown that a light shielding property comparable to that of the light shielding portion can be achieved by introducing a plurality of L-shaped openings 37, and the photomask of the present invention has been realized.

  In the proximity exposure simulation, the coherent light from the light source is diffracted at the edge portion of the mask pattern, spreads on the spherical surface using the edge portion as a wave source (FIG. 3C), and interferes with the exposure surface. is there. This is because the spherical waves overlap most in the opening 37, and the effect of weakening as a result of interference increases.

An example in which a correction pattern is provided on a photomask is generally known (for example, Document 3). However, providing an unevenness or a complex pattern of about several μm requires time and cost for designing and manufacturing a photomask. In practice, this is not preferred because of the inconveniences such as poor resolution and reproducibility of the produced pattern and variation in the surface of the photomask. Further, in the method of providing a correction pattern on the mask, the dependency of the exposure gap tends to increase and there is a problem in the process margin.

  However, according to the suggestion of the present invention, there is an advantage that the above-described problems can be solved by a simple method of combining a plurality of simple L-shaped light shielding patterns. Furthermore, as will be described later, by optimizing the pattern, it is possible to transfer the pattern with an excellent process margin without receiving variations in the exposure gap.

Hereinafter, an example of the embodiment will be described.
[Photomask]
FIG. 4 shows an example of a light shielding pattern of a color filter photomask, and is an enlarged plan view showing a portion corresponding to a contact hole. In any of the figures, the exposed portion of the mask corresponding to the contact hole is divided into nine parts, and the portion of the mask is used as the light shielding portion, and the black portion is the light shielding portion. . Further, the figure shape is for convenience and does not correspond to the actual dimensions.

  (I) in FIG. 4 has a simple cross-shaped light-shielding portion, (ii) has a hollow that has a light-shielding portion in the periphery, and (iii) has a mosaic-type light-shielding portion having an opening in the center. is there. In the figure, a, b, and c are parameters indicating the length of the corresponding part. Note that the photomask includes a portion (not explicitly shown) for forming colored pixels, and is used when a negative photosensitive coloring composition is used as a photoresist.

  Next, Tables 1 to 3 show the resolution results of through holes formed by changing the above parameters using the patterns shown in (i) to (ii) of FIG. In the table, when the exposure gap between the mask and the resist is three levels of 80 μm, 120 μm, and 150 μm, ○ is completely resolved, Δ is partially unresolved, and X is hardly resolved. It is shown that. All numbers are in microns.

Table 1 shows the case of the cross-shaped light-shielding portion shown in FIG. 4 (i), which was resolved when the line width a was increased, and was stably resolved by increasing the wing length b.

  Table 2 shows the resolution state when the line width a and the width c of the central transmission part are changed in the hollow pattern shown in (ii) of FIG. Resolution is facilitated by increasing the line width a, but resolution is difficult when the width c of the transmission part is increased.

  Tables 3-1 to 3-3 show the resolving states when c is fixed in (iii) of FIG. 4 and the line width a and length b are changed. Table 3-1 shows the case where c = 2, Table 3-2 shows the case where c = 4, and Table 3-3 shows the case where c = 5. As in Table 1, when the line width a is increased, the resolution becomes easier. It can also be seen that when the wing length b is increased, the exposure gap dependency is reduced and the resolution becomes easier. It can also be seen that resolution increases as c is increased.

As described above, a fine contact hole can be formed by combining at least four openings by combining simple L-shaped light-shielding portions and further optimizing the pattern. The process is excellent in process margin without receiving exposure gap variations. As a result, a color filter layer can be provided on the array substrate side, and a high-quality liquid crystal display device can be provided.

In addition, the member in which a fine opening is formed using the photomask is not limited to the color filter portion but may be a light shielding layer, a protective layer, or the like. Here, typical photosensitive coloring compositions will be described below.
[Photosensitive coloring composition]
A photosensitive coloring composition suitable for use in the present invention contains a photopolymerizable monomer, a non-photosensitive resin and / or a photosensitive resin, a polymerization initiator, and a solvent, and these are used for UV exposure and Deep UV exposure. Any curing method may be used.

(Photopolymerizable monomer)
A photopolymerizable monomer is blended in the photosensitive coloring composition suitable for use in the present invention. As the photopolymerizable monomer, it is preferable to use 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)
The photosensitive coloring composition suitable for use in the present invention contains a non-photosensitive resin and / or a photosensitive resin. 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 acrylic resins, α-olefin / (anhydrous) maleic acid copolymers, and styrene / styrene sulfonic acid copolymers is preferable. Among these, acrylic resins are preferably used because of their high heat resistance and transparency.

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

  In combination with the organic pigment, an inorganic pigment may be used in combination in order to ensure good coatability, sensitivity, developability and the like while balancing 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. Although the addition amount of a dispersing agent is not specifically limited, It is preferable to set it as 1-10 mass% with respect to 100 mass% of compounding quantities of a pigment.

(Polymerization initiator)
Polymerization initiators suitable for use in the photosensitive coloring 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, benzyldimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone Benzophenone compounds such as acrylated 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) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxy-naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- Triazine compounds such as (piperonyl) -6-triazine and 2,4-trichloromethyl (4'-methoxystyryl) -6-triazine, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], O- (acetyl) -N- (1-phenyl-2-oxo-2- (4′-methoxy-naphthyl) ethylidene) hydroxylamine and other oxime ester compounds such as bis (2, Phosphine compounds such as 4,6-trimethylbenzoyl) phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 9,10-phena Surenkinon, 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 and others)
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 coloring composition used in the present invention is mixed with a solvent such as water or an organic solvent in order to enable uniform coating on the substrate. In addition, when the photosensitive coloring composition is for a colored layer or a light shielding layer of a color filter, the solvent also has a function of uniformly dispersing the pigment.

[Method for preparing photosensitive coloring composition]
The photosensitive coloring composition used for this invention can be prepared by a well-known method. For example, a photosensitive blue coloring composition comprising a photopolymerizable monomer, a photosensitive resin, a pigment, a dispersant, and a solvent can be prepared by 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 photosensitive resin, or a solution obtained by dissolving these in a solvent, a pigment 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.
[Formation of photosensitive colored layer on array substrate]
Hereinafter, the formation method of the photosensitive colored layer using the photomask for color filters of this invention is demonstrated. First, a transparent substrate provided with a light-shielding film at a portion between pixels is prepared. A glass substrate is preferable as the array substrate on which active elements such as TFTs are arranged. Further, a resin such as polycarbonate, polymethyl methacrylate, or polyethylene phthalate can be used as the substrate. The light shielding film as a black matrix for ensuring contrast may be a metal thin film. Further, as the black matrix, a resin film in which a black pigment is mixed can be used. For a reflective or projection type liquid crystal display, a semiconductor substrate such as silicon can be used.

  Next, the photosensitive coloring composition is uniformly applied on the array substrate by a spray coating method, a spin coating method, a roll coating or the like and dried. The layer formed in this step is referred to as “photosensitive colored layer”.

  Next, the formed photosensitive colored layer is patterned by photolithography. That is, the pattern corresponding to the contact hole of the present invention is divided into nine quadrilaterals, and at least four or more of the quadrilaterals are non-light-shielding portions or the central quadrilateral is a non-light-shielding portion. After exposure by irradiating active energy rays such as ultraviolet rays and electron beams through a photomask having an omission pattern, 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 colored layer, a solution of a water-soluble or alkaline water-soluble resin (for example, polyvinyl alcohol or water-soluble acrylic resin) is applied and dried to polymerize with oxygen. Exposure may be performed after forming a film that suppresses inhibition. 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 layer, a light-shielding layer, a columnar convex portion 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, although the Example and comparative example which concern on this invention are described concretely, in the range which does not deviate from the meaning of this invention, it is not limited to this.
Example 1
[Preparation of photosensitive coloring composition]
The red photosensitive coloring composition used for color filter preparation was prepared as follows.
-Red coloring composition A mixture of 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 m filter to prepare a red pigment dispersion.

Red pigment: C.I. I. Pigment Red 254 18 parts ("Ilgar Forred B-CF" manufactured by Ciba Specialty Chemicals)
Dispersant (“Ajisper PB821” manufactured by Ajinomoto Fine Techno Co., Ltd.) 2 parts Acrylic varnish (solid content 20%) 108 parts Thereafter, the mixture having the following composition was stirred and mixed so as to be uniform, then filtered through a 5 μm filter and red. A colored composition was obtained.

The above dispersion 38 parts by weight Acrylic varnish 16 parts by weight Polyfunctional urethane acrylate (1) 6 parts by weight Photopolymerization initiator (“Irgacure-369” manufactured by Ciba Geigy Co.) 0.3 parts by weight Photosensitizer (manufactured by Hodogaya Chemical Co., Ltd. “ EAB-F ") 0.2 parts by mass Cyclohexanone 27 parts by mass [Photomask]
A pattern having openings at the four corners in the cross-shaped light shielding portion shown in FIG. The mask line width a is 4 μm, and the wing length is 6 μm. In FIG. 5, the numbers juxtaposed to the 13 mask patterns indicate dimensions in microns.
(Example 2)
(2) to (10) in FIG. 5 were used as photomasks. The other steps are the same as those in the first embodiment. Table 4 summarizes the results of making contact holes in the color filter using these masks. A fine opening having an opening width of 1.0 μm to 12.0 μm could be formed. In particular, when the mask patterns are (5), (6), and (7), contact holes of 1 μm to 3 μm can be formed. This indicates that the mask pattern suitable for an ultrafine opening is mosaic or hollow.
(Comparative Example 1)
As a photomask for a color filter, a pattern having no transmission part sandwiched between L-shaped light shielding parts as shown in (11) to (13) of FIG. 5 was used. Example 1 other than this
In the same manner as described above, the color filter of the present invention was produced.

  In these cases, since the L-shaped light-shielding portion is not provided, the overlapping of spherical waves is less than the pattern shown in the embodiment, so that the effect of weakening due to interference is reduced, and the image is not resolved.

As described in detail above, the color filter photomask of the present invention stably forms a fine opening having a width of 1.0 to 10.0 μm in the photosensitive colored layer even by the collective / close exposure method. Therefore, a transflective liquid crystal display device with higher definition and higher image quality can be provided.
[Application of photosensitive coloring composition to array substrate]
The blue photosensitive coloring composition described above was applied by spin coating on an array substrate on which TFT elements were disposed, and dried to form a 2 μm blue coating film. After pre-baking at 70 ° C. for 10 minutes, proximity exposure was performed using the photomask shown in FIG. A blue color filter having a contact hole with a diameter of 8 μm was formed on a TFT element of 1/3 pixel by development with an organic alkali. After the development process, hardening was performed at 200 ° C. for 30 minutes to obtain a blue color filter.

  Using the array substrate on which the blue color filter was formed, a green color filter having a contact hole with a diameter of 8 μm was formed by using the green coloring composition on the TFT element of 1/3 pixel in the same process as blue. A red color filter having a contact hole with a diameter of 8 μm was formed using the red photosensitive coloring composition on the remaining 1/3 color-imparting portion on the array substrate on which the two color filters were formed.

  Next, a conductive film which is a mixed oxide of indium oxide and tin oxide was formed on the entire surface by using a sputtering apparatus, and a pattern was formed as a transparent electrode for each TFT pixel by a photolithography technique.

  FIG. 6 shows a liquid crystal display device in which the liquid crystal 3 is sandwiched between the array substrate 1 and the counter substrate 2 according to the manufacturing method of the present invention. A contact hole having a diameter of 8 μm is formed in the transparent colored layer 16 on the array substrate 1.

   In the above embodiment, the transparent electrode is arranged directly on the color filter, but a transparent resin may be formed on the color filter in advance. Alternatively, a pattern of a light-reflective metal thin film such as aluminum may be partially formed as a reflective electrode on the array substrate on which the color filter is disposed. Further, a transparent resin or a transparent inorganic film may be formed before forming the color filter.

Sectional drawing explaining the structure of the conventional color liquid crystal display. Sectional drawing explaining the structure of the color liquid crystal display in connection with this invention. The figure which illustrates typically an L-shaped mask and a simulation result. 6 is a diagram schematically illustrating an example of a light shielding pattern of a photomask for a color filter. The figure which illustrates typically the light-shielding pattern used for exposure experiment. Sectional drawing explaining the structure of the color liquid crystal display with a through hole in connection with this invention.

Explanation of symbols

1. Array substrate 2, color filter substrate 3, liquid crystal 12, TFT
11a, 13a, transparent electrodes 14a, 14b, polarizing film 15, light shielding film 16, transparent colored layer 17, overcoat layer 18, backlight 19, transmitted light 20, reflected light 21, contact holes 34, 36, pattern opening 35 , Mask shading part 37, L-shaped opening

Claims (3)

A substrate for a liquid crystal display device , wherein a contact hole is formed in a color filter layer by performing at least the following steps on an array substrate having a switching element for driving liquid crystal and a pixel electrode connected to the switching element. Manufacturing method.
(A) a step of forming a photosensitive colored layer using a negative photosensitive coloring composition;
(B) a pattern corresponding to the contact hole is divided into nine quadrilaterals and four the angular portion of the quadrilateral is a central quadrilateral cross-shaped pattern is a non-light-shielding portion and the non-light-shielding portion Forming a latent image of a contact hole and a color filter layer having an opening diameter of 1.0 μm to 10.0 μm in the photosensitive colored layer by a proximity exposure method using a photomask having a pattern;
(C) by performing a heating and fixing process and developing the photosensitive wearing color layer having the latent image, the step of opening diameter to form colored pixels having a contact hole of 10.0μm from 1.0 .mu.m.   A substrate for a liquid crystal display device manufactured by the manufacturing method according to claim 1. A liquid crystal display device comprising the substrate for a liquid crystal display device according to claim 2 .