JP2004334226A - Method for manufacturing liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase a production yield by decreasing a man-hour although color filters etc., are formed on a thin-film transistor side substrate. <P>SOLUTION: The method for manufacturing a liquid crystal display device including the thin-film transistor side substrate having thin-film transistors, a counter substrate having a counter electrode, and a liquid crystal element held between the thin-film transistor side substrate and the counter substrate includes a process of forming a pixel electrode material as a material for pixel electrodes selectively driven by the thin-film transistors, a process of forming a colored layer on the pixel electrode material, and a process of patterning the pixel electrode material by using the colored layer as a mask. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing an active matrix liquid crystal display device using thin film transistors.

  2. Description of the Related Art Conventionally, an active matrix type liquid crystal display device (liquid crystal display) having a structure in which a thin film transistor side substrate, a counter substrate, and a TN (twisted nematic) liquid crystal or a ferroelectric liquid crystal as an electro-optical modulation material are sandwiched between these substrates. Panel) is known. In this liquid crystal display device, a thin film transistor (TFT) and a pixel electrode selectively driven by the thin film transistor are provided on a thin film transistor side substrate, and a counter electrode is provided on a counter substrate. In order to realize color display in such a liquid crystal display device, it is necessary to arrange a transmission type color filter having red (R), green (G), and blue (B) colors for each display pixel.

  FIG. 1 shows an example of a conventional liquid crystal display device having such a color filter. (In the drawings shown below, in order to clearly show the structure of the thin film transistor, the size of the thin film transistor is made larger than the actual size. Is also greatly expressed). A liquid crystal 103 is sealed between a thin film transistor-side substrate 101 and a counter substrate 102 provided to face each other. On the counter substrate 102, a black matrix 104 made of a light-shielding film of chrome or the like, and red, green, and blue color filter portions 105, 106, and 107 made of gelatin dyed red, green, and blue are formed. A protective insulating film 108 and a counter electrode 109 made of a transparent conductive film are formed thereon. On the other hand, a thin film transistor 110 and a pixel electrode 111 composed of a transparent conductive film selectively driven by the thin film transistor 110 are provided inside the thin film transistor side substrate 101. On the pixel electrode 111 and the counter electrode 109, alignment films 112 and 113 are stacked and rubbed. Note that an insulating film 116 serving as a protective film is formed over the source electrode 115. Above the pixel electrode 111, the insulating film is removed and a window is opened. Thus, the source electrode 115 can be protected, and the situation where the voltage applied to the liquid crystal is reduced by the presence of the insulating film can be prevented.

  However, the conventional example has the following problems.

  That is, in the above conventional example, the color filter and the black matrix are provided not on the thin film transistor side substrate but on the opposite substrate. For this reason, a step of forming a color filter or the like is required in manufacturing the counter substrate, and there is a problem that the cost of the counter substrate becomes extremely high. Further, when laminating the thin film transistor side substrate and the counter substrate, it is difficult to accurately align the pixel electrode formed on the thin film transistor side substrate with the color filter and the black matrix formed on the counter substrate. there were.

  For example, Japanese Patent Application Laid-Open No. 2-207222 discloses a method of forming a light-shielding layer to be a black matrix on a thin film transistor-side substrate. Further, Japanese Patent Application Laid-Open Nos. Hei 4-253028 and Hei 6-242433 disclose a method of forming a color filter or the like on a thin film transistor side substrate. According to these methods, since a color filter and a black matrix can be provided on the thin film transistor side substrate, the problem of increasing the cost of the opposing substrate and the problem of alignment accuracy can be solved. However, these methods require a new step of forming a color filter or the like on the thin film transistor-side substrate, and the addition of this new step has a problem that the production yield of the liquid crystal display device is reduced.

  Further, in a conventional reflection type liquid crystal display device, it is not known that a color filter is built in a thin film transistor side substrate. Further, in a reflection type liquid crystal display device, since there is no backlight or the like, improvement of an aperture ratio or the like is a major technical problem.

Further, as shown in FIG. 1, in the conventional example, there is a problem that a step of removing the insulating film above the pixel electrode 111 is required after forming the insulating film 116 serving as a protective film.
JP-A-2-207222 JP-A-4-253028 JP-A-6-242433

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-described technical problems, and an object of the present invention is to provide an active device having a small number of steps and a high production yield while forming a color filter or the like on a thin film transistor side substrate. An object of the present invention is to provide a method for manufacturing a matrix type liquid crystal display device.

In order to solve the above problems, the present invention provides a method of manufacturing a liquid crystal display device including a thin film transistor side substrate having a thin film transistor, a counter substrate having a counter electrode, and a liquid crystal element sandwiched between the thin film transistor side substrate and the counter substrate. And
Forming a pixel electrode material, which is a material of a pixel electrode selectively driven by the thin film transistor, on the thin film transistor side substrate;
Forming a colored layer on the pixel electrode material;
Patterning the pixel electrode material using the coloring layer as a mask.

  In the method for manufacturing a liquid crystal display device according to the present invention, the colored layer is formed of a color resist, and a color filter for color display can be formed.

  In the method for manufacturing a liquid crystal display device according to the present invention, the coloring layer may include a conductive substance.

  Further, in the method for manufacturing a liquid crystal display device according to the present invention, a ratio of a solid component containing the coloring matter and the conductive material in the color layer in the color resist may be 30% or less.

  In the method for manufacturing a liquid crystal display device according to the present invention, the colored layer may be made of a resist in which a pigment is dispersed.

  In the method for manufacturing a liquid crystal display device according to the present invention, the colored layer may include a dyed polymer material.

  In the method for manufacturing a liquid crystal display device according to the present invention, the colored layer may be made of ink.

  In the method for manufacturing a liquid crystal display device according to the present invention, the pixel electrode may be made of a non-translucent material.

(1) An active matrix type liquid crystal display device including a thin film transistor side substrate having a thin film transistor, a counter substrate having a counter electrode, and a liquid crystal element sandwiched between the thin film transistor side substrate and the counter substrate.
An active matrix liquid crystal display, wherein a conductive coloring layer is provided on the thin film transistor side substrate as a color filter for color display, and the conductive coloring layer also functions as a pixel electrode selectively driven by the thin film transistor. apparatus.

(2) In the invention of (1),
An active matrix liquid crystal display device, wherein the conductive coloring layer is formed by dyeing a dyeing medium in which a conductive substance is dispersed.

(3) In the invention of (1),
An active matrix liquid crystal display device, wherein the conductive colored layer is a conductive color resist formed by dispersing a dye and a conductive substance in a resist.

(4) In the invention of (3),
An active matrix liquid crystal display device, wherein a ratio of a solid component containing the dye and the conductive material in the color resist is 30% or less.

(5) In the invention of (3) or (4),
A black matrix formed by an insulating film formed in a region where the pattern of the color resist is not formed, wherein the insulating film of the black matrix is saturated with a compound containing at least one substance constituting an insulating substance; An active matrix type liquid crystal display device, wherein a film is formed by adding a light-shielding dye to an aqueous solution, making the saturated aqueous solution supersaturated, and depositing the insulating substance.

(6) In the invention of (5),
An active matrix liquid crystal display device, wherein the insulating film is formed of a silicon oxide film.

(7) In any one of the inventions of (1) to (6),
An active matrix liquid crystal display device, wherein a conductive layer for contacting the drain region and the conductive coloring layer is interposed between the drain region of the thin film transistor and the conductive coloring layer.

(8) In the invention of (7),
An active matrix liquid crystal display device, wherein the conductive layer is formed of the same material as a source line connected to a source region of the thin film transistor.

(9) In the invention of (7) or (8),
The active matrix type liquid crystal display device, wherein the conductive layer is formed around the pixel electrode.

(10) In any one of the inventions of (7) to (9),
The active matrix type liquid crystal display device, wherein the conductive layer is a part of a black matrix serving as a light shielding layer.

(11) A reflective active matrix liquid crystal display device including a thin film transistor side substrate having a thin film transistor, a counter substrate having a counter electrode, and a liquid crystal element sandwiched between the thin film transistor side substrate and the counter substrate.
A conductive coloring layer is provided on the thin film transistor side substrate as a color filter for color display, and a pixel electrode selectively driven by the thin film transistor is provided below the coloring layer, and the pixel electrode is non-translucent. A reflection type active matrix type liquid crystal display device comprising:

(12) In the invention of (11),
The reflective active matrix liquid crystal display device, wherein the pixel electrode is formed of the same material as a source line connected to a source region of the thin film transistor.

(13) In the invention of (11) or (12),
The reflection type active matrix type liquid crystal display device, wherein the liquid crystal element is a polymer dispersion type liquid crystal element.

(14) In any one of the inventions of (11) to (13),
The reflection type active matrix liquid crystal display device, wherein the conductive coloring layer is formed by dyeing a dyeing medium in which a conductive substance is dispersed.

(15) In any one of the inventions of (11) to (13),
A reflective active matrix liquid crystal display device, wherein the conductive colored layer is a conductive color resist formed by dispersing a dye and a conductive substance in a resist.

(16) In the invention of (15),
A reflection type active matrix type liquid crystal display device, wherein a ratio of a solid component containing the dye and the conductive material in the color resist is 30% or less.

(17) An active matrix liquid crystal display device including a thin film transistor side substrate having a thin film transistor, a counter substrate having a counter electrode, and a liquid crystal element sandwiched between the thin film transistor side substrate and the counter substrate.
A color resist is provided on the thin film transistor side substrate as a color filter for color display, and a pixel electrode selectively driven by the thin film transistor is provided below the color resist, and the pixel electrode uses the color resist as a mask. An active matrix type liquid crystal display device characterized by being patterned.

(18) In the invention of (17),
A black matrix formed by an insulating film formed in a region where the pattern of the color resist is not formed, wherein the insulating film of the black matrix is saturated with a compound containing at least one substance constituting an insulating substance; An active matrix type liquid crystal display device, wherein a film is formed by adding a light-shielding dye to an aqueous solution, making the saturated aqueous solution supersaturated, and depositing the insulating substance.

(19) In the invention of (18),
An active matrix liquid crystal display device, wherein the insulating film is formed of a silicon oxide film.

(20) In any one of the inventions of (17) to (19),
An active matrix liquid crystal display device, wherein the color resist is a conductive colored layer formed by dispersing a dye and a conductive substance in the resist.

(21) In the invention of (20),
An active matrix liquid crystal display device, wherein a ratio of a solid component containing the dye and the conductive material in the color resist is 30% or less.

(22) In any one of the inventions of (1) to (16) and (20) and (21),
An active matrix liquid crystal display device, wherein the specific resistance of the conductive colored layer is 1 × 10 7 Ω · cm or less.

(23) In any one of the inventions of (1) to (16) and (20) and (21),
An active matrix liquid crystal display device, wherein the specific resistance of the conductive colored layer is 1 × 10 6 Ω · cm or less.

(24) In any one of the inventions of (1) to (16) and (20) and (21),
An active matrix type liquid crystal display device, wherein the conductive colored layer is formed by dispersing conductive fine particles having a dish shape into the colored layer.

(25) In any one of the inventions of (1) to (16) and (20) and (21),
The active matrix type liquid crystal display device, wherein the conductive colored layer is formed by dispersing conductive fine particles having a rod shape in the colored layer.

(26) In any one of the inventions of (1) to (16) and (20) to (25),
An active matrix liquid crystal display device, wherein the conductive colored layer is formed by dispersing conductive fine particles subjected to a hydrophobic treatment with a coupling agent into the colored layer.

(27) An active matrix liquid crystal display device including a thin film transistor side substrate having a thin film transistor, a counter substrate having a counter electrode, and a liquid crystal element sandwiched between the thin film transistor side substrate and the counter substrate.
A pixel electrode selectively driven by the thin film transistor, a resist provided on the pixel electrode and used for patterning the pixel electrode, and an insulating film formed in a region where the resist pattern is not formed, An active matrix type liquid crystal display device, wherein the insulating film is formed by supersaturating a saturated aqueous solution of a compound containing at least one substance constituting an insulating substance and depositing the insulating substance.

(28) A method for manufacturing an active matrix liquid crystal display device including a thin film transistor-side substrate having a thin film transistor, a counter substrate having a counter electrode, and a liquid crystal element sandwiched between the thin film transistor side substrate and the counter substrate.
Forming a contact hole for making contact with the drain region of the thin film transistor;
Forming a conductive colored layer, which is connected to the drain region through the contact hole, on the thin film transistor-side substrate through a color filter for a color display. Device manufacturing method.

(29) In the invention of (28),
The conductive color layer is a conductive color resist formed by dispersing a dye and a conductive substance in the resist,
In a region where the pattern of the color resist is not formed, a light-shielding dye is added to a saturated aqueous solution of a compound containing at least one substance constituting an insulating material to make the saturated aqueous solution supersaturated, thereby depositing the insulating material. A method for manufacturing an active matrix type liquid crystal display device, comprising a step of forming an insulating film serving as a black matrix by a film forming method to be performed.

(30) In any one of the inventions of (28) or (29),
Forming a conductive layer for contacting a drain region of the thin film transistor and the conductive colored layer between the step of forming the contact hole and the step of forming the conductive colored layer. A method for manufacturing an active matrix type liquid crystal display device.

(31) A method of manufacturing a reflective active matrix liquid crystal display device including a thin film transistor side substrate having a thin film transistor, a counter substrate having a counter electrode, and a liquid crystal element sandwiched between the thin film transistor side substrate and the counter substrate. So,
Forming a pixel electrode made of a non-translucent material selectively driven by the thin film transistor;
Forming a conductive colored layer serving as a color filter for color display on the pixel electrode. A method for manufacturing a reflective type active matrix liquid crystal display device.

(32) A method for manufacturing an active matrix type liquid crystal display device including a thin film transistor side substrate having a thin film transistor, a counter substrate having a counter electrode, and a liquid crystal element sandwiched between the thin film transistor side substrate and the counter substrate.
Forming a pixel electrode material to be a material of a pixel electrode selectively driven by the thin film transistor,
Forming a color resist to be a color filter for color display on the pixel electrode material,
Patterning the pixel electrode material using the color resist as a mask.

(33) In the invention of (32),
In a region where the pattern of the color resist is not formed, a light-shielding dye is added to a saturated aqueous solution of a compound containing at least one substance constituting an insulating material to supersaturate the saturated aqueous solution to deposit the insulating material. A method for manufacturing an active matrix type liquid crystal display device, comprising a step of forming an insulating film serving as a black matrix by a film forming method to be performed.

(34) A method for manufacturing an active matrix type liquid crystal display device including a thin film transistor side substrate having a thin film transistor, a counter substrate having a counter electrode, and a liquid crystal element sandwiched between the thin film transistor side substrate and the counter substrate.
Forming a pixel electrode material to be a material of a pixel electrode selectively driven by the thin film transistor,
Forming a resist for pixel electrode patterning on the pixel electrode material,
Patterning the pixel electrode material using the color resist as a mask,
An insulating film serving as a protective film by a film forming method of supersaturating a saturated aqueous solution of a compound containing at least one substance constituting an insulating substance into a region where the resist pattern is not formed to deposit the insulating substance. Forming an active matrix type liquid crystal display device.

  According to the invention of (1) or (28), the conductive colored layer serving as a color filter is provided on the thin film transistor-side substrate. This eliminates the need to form a color filter on the opposing substrate, and eliminates the need to match the opposing substrate with the thin film transistor-side substrate. Further, according to the present invention, the conductive coloring layer also functions as a pixel electrode. Therefore, a step of forming a pixel electrode material such as ITO and a step of patterning the pixel electrode material can be omitted. Further, in the configuration in which the color filter is formed on the pixel electrode material, there arises a problem that the effective voltage applied to the liquid crystal decreases and a problem that a margin for matching the pixel electrode and the color filter is required. Can effectively prevent this problem.

  According to the invention of (2), a conductive coloring layer is formed by dyeing a dyeing medium such as gelatin in which a conductive substance is dispersed with a predetermined dyeing solution. According to the present invention, since a colored layer is formed by a dyeing method, color purity (color characteristics) can be increased as compared with a method of dispersing a pigment or the like.

  According to the invention of (3), the color filter is formed by the conductive color resist. This makes it possible to employ a method of selectively forming an insulating film by the LPD method using the conductive color resist as a mask.

  According to the invention of (4), the secondary aggregation of the solid component contained in the conductive color resist is prevented, and the pot life can be improved.

  According to the invention of (5) or (29), the black matrix can be formed by a method using the LPD method. Therefore, the formation of an insulating film serving as a black matrix can be performed at a low temperature of about room temperature, an insulating film to which a dye is added can be easily formed, and an inorganic insulating film having higher heat resistance and chemical resistance than gelatin or the like. Can be obtained. Further, since the present invention utilizes the LPD method, an insulating film serving as a black matrix can be selectively formed with respect to a conductive color resist pattern. Thus, the step of etching the insulating film can be omitted, and the black matrix can be formed with high accuracy in a self-aligned manner with respect to the color resist. Further, according to the present invention, since the black matrix is formed of the insulating film to which the dye is added, problems such as glare and cracks can be solved. Further, according to the present invention, it is possible to prevent the problem of the conventional example using the wiring layer and the like as a black matrix, that is, the problem caused by the parasitic capacitance between the pixel electrode and the gate line.

  According to the invention of (6), the insulating film serving as the black matrix can be formed of the silicon oxide film which is compatible with the manufacturing process of the thin film transistor. This facilitates selection of chemicals and the like used in the manufacturing process. Further, even when the insulating film and the black matrix in the thin film transistor have a multilayer structure, since they are formed of the same material, the adverse effect of distortion caused by stress or the like can be reduced.

  According to the invention of (7) or (30), good contact can be obtained between the conductive coloring layer serving as the pixel electrode and the drain region of the thin film transistor, and the contact resistance can be reduced. Thereby, the effective voltage applied to the liquid crystal element can be increased.

  According to the invention (8), since the conductive layer is formed of the same material as the source line, it is not necessary to add a new photo and etching process for forming the conductive layer.

  According to the invention (9), the parasitic resistance between the drain region of the thin film transistor and each part of the pixel electrode can be reduced.

  According to the invention of (10), the conductive layer provided in the peripheral portion can be effectively used as a black matrix.

  According to the invention of (11) or (31), a reflection type active filter is formed by forming a color filter comprising a conductive coloring layer on a pixel electrode formed of a non-translucent (light reflecting) material. A matrix liquid crystal display device can be realized. According to the present invention, since the color filter is formed on the thin film transistor side substrate, the aperture ratio can be improved. In addition, since the color filter has conductivity, it is possible to prevent a problem of voltage division caused by the interposition of the color filter between the pixel electrode and the liquid crystal element.

  According to the invention (12), since the pixel electrode and the source line can be formed in the same step, the steps can be simplified and the cost can be reduced.

  According to the invention (13), the use of the polymer-dispersed liquid crystal element makes it possible to eliminate the need for a polarizing plate, and to provide a favorable reflection-type liquid crystal display device and the like.

  According to the invention of (17) or (32), the pixel electrode made of ITO or the like is arranged below the color resist. Therefore, even if the color resist has a high resistance, it is possible to effectively prevent the effective voltage applied to the liquid crystal from being reduced due to the high resistance. Further, according to the present invention, since the patterning of the pixel electrode material is performed using the color resist as a mask, the step of forming a resist for patterning the pixel electrode can be omitted.

  According to the invention of (18) or (33), the black matrix is formed by a method utilizing the LPD method. Therefore, low-temperature formation of an insulating film serving as a black matrix, selective formation of an insulating film for a color resist, and the like can be performed.

  According to the invention of (22), a good liquid crystal driving operation can be performed on a liquid crystal panel having a relatively small size and loose specifications.

  According to the invention of (23), a good liquid crystal driving operation can be performed even on a large-scale liquid crystal panel having strict specifications.

  According to the invention of (24) or (25), the overlapping area between the conductive fine particles in the coloring layer can be increased, and the specific resistance of the conductive coloring layer can be reduced.

  According to the invention of (26), it is possible to prevent the occurrence of secondary aggregation of the hydrophilic conductive fine particles and to obtain a uniform dispersion state.

  According to the invention of (27) or (34), an insulating film serving as a protective film can be formed by using the LPD method using a resist for patterning a pixel electrode material. This makes it possible to omit the step of removing the insulating film above the pixel electrode, which is required in the conventional example. Further, since the present invention utilizes the LPD method, it is possible to form an insulating film serving as a protective film at a low temperature, selectively form an insulating film on a resist, and the like.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1. First Embodiment The first embodiment is an embodiment in which a conductive coloring layer is provided as a color filter on a thin film transistor-side substrate, and this conductive coloring layer is also used as a pixel electrode. 2A to 2C show an example of a process cross-sectional view of the first embodiment. The thin film transistor 202 is formed inside the thin film transistor side substrate 201. The thin film transistor 202 includes a gate line 203, a source line 204, an insulating film 205, and the like (FIG. 2A).

  Next, a contact hole is opened, and thereafter, a pattern of a red color resist 206, a green color resist 207, and a blue color resist 208 is sequentially formed (FIG. 2B). As such a color resist, for example, a pigment-dispersed resist formed by dispersing a pigment in the resist can be used.

In this embodiment, the color resists 206 to 208 serving as color filters have a conductive property. The color resist having conductivity can be formed by, for example, mixing fine particles such as ITO (indium oxide) and SnO ₂ (tin oxide), which are materials of the transparent conductive film, with the color resist. By imparting conductivity to the color resists 206 to 208 in this manner, these color resists are used as color filters provided on the thin film transistor-side substrate and used as pixel electrodes for driving liquid crystal elements. It becomes possible. Therefore, the conductive color resists 206 to 208 are connected to the drain region 209 of the thin film transistor 202 via the contact hole.

  After forming the conductive color resists 206 to 208 which also serve as a color filter and a pixel electrode in this manner, an insulating film 220 serving as a protective film for the source line 204 is formed as necessary. Next, preferably, the insulating film formed on the color resist is removed. This is because if an insulating film is provided on the color resist, the effective voltage applied to the liquid crystal is reduced, and the image quality is reduced. After that, the alignment film 222 is laminated and rubbed. On the other hand, the opposing substrate 217 has a structure in which the opposing electrode 218 made of a transparent conductive film and the alignment film 221 are only provided inside. Liquid crystal 219 is sealed between the thin film transistor-side substrate 201 and the counter substrate 217 (FIG. 2C).

  Note that a black matrix serving as a light-blocking layer may be formed on the counter substrate 217, or a part or all of the gate lines 203, the source lines 204, and the like may be used as the black matrix. Further, the black matrix may be formed on the thin film transistor-side substrate by using any method.

  According to this embodiment, a color filter made of a conductive color resist is provided on the thin film transistor side substrate. This eliminates the need to form a color filter on the opposing substrate, and can reduce the manufacturing cost of the opposing substrate. In addition, the problem of the margin of bonding accuracy between the thin film transistor side substrate and the counter substrate can be solved.

  Further, according to the present embodiment, since the conductive color resist serving as the color filter also serves as the pixel electrode, the step of forming the ITO serving as the pixel electrode and the step of patterning the ITO can be omitted. As a result, cost can be reduced and the yield can be improved. Also, this embodiment has the following advantages as compared with a configuration in which a color filter made of a color resist or the like is formed on a pixel electrode made of ITO, for example. That is, in the configuration in which a color filter is formed above the pixel electrode, a voltage at the time of driving the liquid crystal is applied to the color filter, and the voltage (effective voltage) applied to the liquid crystal element is reduced by voltage division, which results in lower image quality. Cause. On the other hand, in the present embodiment, since the conductive color resists 206 to 208 also serve as a pixel electrode and a color filter, it is possible to effectively prevent such a problem of image quality deterioration. Further, according to this embodiment, the aperture ratio can be increased as compared with the configuration in which the color filter is formed above the pixel electrode. That is, according to the configuration in which the color filter is formed above the pixel electrode, a margin for matching the pixel electrode and the color filter is required, but according to the present embodiment, the aperture ratio is increased by the amount that such a margin for matching is not required. be able to.

(1) Conductive Colored Layer The conductive colored layer may be formed by dispersing a dye such as a pigment and a conductive substance such as ITO in a resist as in the above-described embodiment. For example, it can be formed by dyeing a dyeing medium such as gelatin (polymer material) in which a conductive substance is dispersed, or by mixing a conductive substance into printing ink or the like.

  When dispersing a dye and a conductive substance in a resist, it is necessary to suppress the ratio of solid components such as the dye and the conductive substance to a certain value or less. This is because if the proportion of the solid component in the resist solution is high, the pot life (time during which a usable liquid state is maintained) is shortened. That is, solid components such as a dye and a conductive substance are aggregated, making it impossible to use a resist solution, which hinders production in a factory or the like. FIG. 13 shows an example of the relationship between the solid component ratio and the pot life. For example, to make the pot life 3 months or more, the solid component ratio needs to be about 30% or less, and to make it 6 months or more, it needs to be about 25% or less. Therefore, in order to make the pot life more reasonable, the solid component ratio is desirably about 30% or less, and more desirably about 25% or less. In order to reduce the solid component ratio, it is only necessary to reduce the amount of the conductive substance contained in the resist. However, if the ratio is too small, the specific resistance of the conductive coloring layer increases. Therefore, the solid component ratio needs to be the most balanced in consideration of the relationship between the pot life and the specific resistance.

  When a pigment or the like is dispersed in the resist, there is no particular limitation. Examples of the red pigment include perylene pigments, anthraquinone pigments, dianthraquinone pigments, azo pigments, diazo pigments, quinacridone pigments, and anthracene pigments. Examples of green pigments include halogenated phthalocyanine pigments. Examples of the blue pigment include metal phthalocyanine pigments, indanthrone pigments, and indophenol pigments. In addition, violet, yellow, cyanine, and magenta pigments can be used in combination. Further, the color resist of this embodiment may be not only a negative type but also a positive type. Examples of the negative type resist include solvents (ethyl-3-ethoxypropionate, methoxypropyl acetate, cyclohexane, 3-methoxybutyl acetate, etc.). And a resin (such as a methacrylic resin) and a monomer (such as a multifunctional acrylic monomer).

  The technique of forming a conductive coloring layer by dyeing a dyeing medium in which a conductive substance is dispersed has the advantage that the color purity of the conductive coloring layer can be increased as compared with the technique of dispersing a pigment or the like in a resist. That is, when a pigment or the like is used, the more the pigment or the like is dispersed, the lower the transmittance is. In order to compensate for this decrease in transmittance, it is necessary to widen the wavelength range of transmitted light. For example, when expressing a green color, a yellow pigment or the like is mixed. For this reason, color purity (color characteristics) deteriorates. On the other hand, according to the method of forming a colored layer by dyeing gelatin or the like, the above problem does not occur, and as a result, the color purity can be further increased.

  As the dyeing medium (chromosomes), in addition to gelatin, use is made of casein, fish glue, polyvinyl alcohol, polyvinyl pyrovidone, polyvinyl alcohol, polyimide, polyamide, polyurea, polyurethane, polycinnamic acid, acrylic resin and derivatives thereof. it can. Acid dyes, reactive dyes and the like can be used as the dyeing solution. Kayanol Milling Red RS (manufactured by Nippon Kayaku) + acetic acid + water as the red dyeing solution, and brilliant indian blue (green dyeing solution) as the green dyeing solution. Hoechst) + Suminol Yellow MR (Sumitomo Chemical) + acetic acid + water; as the blue dye solution, Kayanol Sayanin 6B (Nippon Kayaku) + acetic acid + water can be used. However, the dye solution is not limited to these. There are various techniques for forming a colored layer (color filter) by a dyeing method. In general, for example, a dyeing medium is patterned by exposure and development, and then immersed in a red dyeing solution to form a red colored layer. The same applies to blue and green colored layers.

(2) Conductivity The conductive coloring layer in this embodiment also has a predetermined impedance component (specific resistance and capacitance component). Therefore, the problem that the effective voltage applied to the liquid crystal is reduced due to the presence of the conductive coloring layer between the drain region and the liquid crystal is not limited. Therefore, it is desirable that the specific resistance of the conductive colored layer be as small as possible. For example, FIGS. 14A to 14C show a liquid crystal panel considered to have the strictest specifications, that is, a diagonal length of 30 cm (about 12 inches), an XGA (for example, 1024 × RGB × 768 pixels and a dot clock of 65 MHz). 3) shows the relationship (simulation result) between the specific resistance and the effective value of the liquid crystal panel. FIGS. 14A, 14B, and 14C respectively show the specific resistance and effective resistance of a pixel at a position closest to a driver circuit for driving a panel, a pixel at a center position, and a pixel at a farthest position. This is the relationship with the value difference. Here, the “difference in effective value” refers to the effective voltage value applied to the liquid crystal element when the conductive coloring layer does not exist, and the effective voltage value applied to the liquid crystal element when the conductive coloring layer exists. Is the difference. As shown in FIGS. 14A to 14C, when the specific resistance is about 1 × 10 ⁶ Ω · cm or less, the difference between the effective values increases, and the display characteristics deteriorate. As is clear from the figure, the degree of deterioration of the display characteristics is larger in the case of black display than in the case of gray display / white display. As described above, the specific resistance is desirably about 1 × 10 ⁶ Ω · cm or less in order to normally perform the liquid crystal driving operation in the liquid crystal panel whose specifications are considered to be the strictest.

However, depending on the panel, normal operation may be possible even if the specific resistance is larger than 1 × 10 ⁶ Ω · cm. For example, FIGS. 15A and 15B show a liquid crystal panel whose specifications are considered to be relatively loose. That is, the relationship between the specific resistance and the difference between the effective value and the liquid crystal panel of a VGA (for example, 640 × RGB × 480 pixels and a dot clock of about 25.2 MHz) having a diagonal length of 15 cm (about 6 inches) is shown. FIGS. 15A and 15B show the relationship between the specific resistance and the effective value difference of the pixel located at the center position and the pixel located at the farthest position from the driver circuit for driving the panel, respectively. As is apparent from this figure, in order to normally perform the liquid crystal driving operation in this liquid crystal panel, the specific resistance should be about 1 × 10 ⁷ Ω · cm or less.

From the above, the specific resistance of the conductive colored layer depends on the size of the liquid crystal panel, the intended display characteristics, and the like, but is preferably about 1 × 10 ⁷ Ω · cm or less, and preferably 1 × 10 ⁶ Ω · cm. More preferably, it is not more than the degree.

(3) Shape of conductive fine particles, etc. The conductive substance contained in the coloring layer is preferably in the form of fine particles. This is to minimize the decrease in the transmittance of the color resist due to the inclusion of the conductive material. For the same reason, it is desirable that the conductive material to be dispersed has transparency. For this reason, ITO (indium oxide), SnO ₂ (tin oxide) or the like is optimal as the conductive material. Alternatively, a mixed material of these materials with carbon, gold, and silver can also be used.

  When the conductive substance is formed into fine particles, it is preferable that the fine particles have a dish-like or rod-like shape rather than a spherical shape. The reason for this is that, if the shape is dish-shaped or rod-shaped, the overlapping area between the adjacent fine particles can be increased, and as a result, the current can be more easily flown and the specific resistance can be reduced. That is, the specific resistance can be lowered by increasing the ratio of the conductive fine particles to be dispersed. However, if the ratio is too high, for example, the transmittance decreases, the color characteristics deteriorate, and the above-described problems such as the pot life occur. If the shape is such that the overlap area between adjacent fine particles, such as a dish shape or a rod shape, can be increased, the specific resistance can be reduced without increasing the ratio of the conductive fine particles so much.

  In addition, in order to realize a uniform dispersion state of the conductive substance, it is preferable that the conductive fine particles are subjected to a hydrophobic treatment to make the surface hydrophobic. That is, when the conductive fine particles have a hydrophilic surface, since many of the pigments such as pigments have a hydrophobic surface, secondary aggregation of the hydrophilic conductive fine particles occurs, and a uniform dispersion state is obtained. There is no possibility. The hydrophobic treatment can be realized by using, for example, a coupling agent, and various coupling agents such as silane, titanate, and chromium can be used.

2. Second Embodiment The second embodiment shows an example of a method in which a black matrix is built in a thin film transistor-side substrate in the first embodiment. The difference from the first embodiment is that the black matrix 310 is formed using the LPD method in FIG. The LPD method has a feature that a silicon oxide film is not deposited on a resist pattern. Using this property, a silicon oxide film can be formed selectively with respect to the pattern of the conductive color resist. Therefore, after forming the conductive color resists 306 to 308 in FIG. 3B, the patterns of the conductive color resists 306 to 308 are selectively formed by using the LPD method in FIG. A silicon oxide film to which a dye such as black is added is formed, and this silicon oxide film is used as a black matrix 310. This makes it possible to incorporate the black matrix 310 into the thin film transistor-side substrate by a simple method.

Next, the details of the LPD method will be described using a case where a silicon oxide film is formed as an example. In the LPD method, silica is dissolved in hydrosilicofluoric acid (H ₂ SiF ₆ ) to prepare a saturated aqueous solution, and the substrate is immersed in the aqueous solution. Thereafter, a supersaturated state is formed by adding aluminum, aluminum chloride, boron, boric acid, and the like, and a silicon oxide film is deposited and grown on the substrate surface.

For example, in the above chemical formulas (1) and (2), by adding boric acid (H ₃ BO ₃ ) as an additive, the chemical reaction of chemical formula (2) proceeds rightward, and hydrofluoric acid (HF) Is consumed. Thereby, the chemical reaction of the chemical formula (1) proceeds rightward, and a silicon oxide film (SiO ₂ ) is deposited. As described above, in the LPD method, a saturated aqueous solution of at least one substance constituting the insulating substance, for example, a compound containing silicon (Si) is prepared. Then, the saturated aqueous solution is brought into a supersaturated state by adding an additive, for example, and an insulating material is deposited to form an insulating film. At this time, in the present embodiment, a dye such as black is contained in the saturated aqueous solution, whereby an insulating film to which a dye such as black is added, that is, a black matrix can be obtained.

  In addition, the chemical formula in the case of using aluminum as an additive is shown below.

In the above formula, the chemical reaction of the chemical formula (4) proceeds rightward by adding aluminum (Al) as an additive, and hydrofluoric acid (HF) is consumed. Thus, the chemical reaction of the chemical formula (3) proceeds rightward, and a silicon oxide film (SiO ₂ ) is deposited.

  As described above, in this embodiment, since the insulating film serving as the black matrix is formed by the method using the LPD method, the insulating film can be formed at a low temperature of about room temperature. When the insulating film can be formed at a low temperature, damage to the glass substrate during the formation of the insulating film can be reduced, so that an inexpensive glass substrate can be employed and product cost can be reduced. In addition, it is possible to prevent a situation in which device characteristics of the thin film transistor are degraded due to a heating temperature at the time of forming the black matrix.

  Further, in this embodiment, since the LPD method is used, it is possible to easily form an insulating film having a dye added therein. For example, when an insulating film is formed, a chemical vapor deposition (CVD) method is generally used. However, a pigment such as a pigment is usually a solid, and it is not easy to add the solid pigment to an insulating film by a CVD method. On the other hand, if the LPD method is used, an insulating film in which a dye is added can be easily obtained simply by dissolving the solid dye in a saturated aqueous solution. A major feature of the present embodiment is that the formation of a black matrix that requires coloring is performed using the LPD method that can easily add a dye.

  Further, since the insulating film of this embodiment formed using the LPD method is an inorganic insulating film, an insulating film having higher heat resistance and chemical resistance than gelatin and resist can be obtained.

  In this embodiment, since the LPD method is used, it is possible to selectively form an insulating film on a conductive color resist pattern. That is, the LPD method has a feature that the insulating substance is not deposited on the resist. This is because the surface of the resist has water repellency. When this feature is used, an etching step at the time of pattern formation is not required, and the cost of the product can be reduced. Further, since the black matrix can be formed in a self-aligned manner with respect to the color resist, the black matrix can be formed with high accuracy, and the aperture ratio can be improved.

  The black matrix in this embodiment is arranged between color filters arranged in a pattern such as a stripe type, a mosaic type, a triangle type, and a four-pixel arrangement type, and serves as a light shielding layer. Conventionally, this black matrix is formed of a light-shielding film made of chromium or the like. For this reason, there have been problems such as cracks due to stress and glare due to reflection of chrome or the like. On the other hand, in the present embodiment, since the black matrix is formed of the insulating film to which the dye is added, it is possible to solve the problems such as the occurrence of cracks and glare.

  Further, according to the present embodiment, since the problem that occurs in the conventional example in which the wiring layer and the like are a black matrix, that is, the problem of the parasitic capacitance between the pixel electrode and the gate line does not occur, it is possible to prevent a decrease in image quality and the like.

  In this embodiment, the insulating film constituting the black matrix is preferably a silicon oxide film. This is because a silicon oxide film is generally used as an insulating film in a manufacturing process of a thin film transistor, an LSI, or the like, and has excellent heat resistance and chemical resistance. That is, as compared with the material used for the conventional black matrix, the compatibility with the manufacturing process of the thin film transistor and the like is better. Particularly when the black matrix is formed on the thin film transistor side substrate, this compatibility becomes a problem. In this case, the black matrix is formed by the same manufacturing process as the thin film transistor. Therefore, if a silicon oxide film or the like generally used in the manufacture of a thin film transistor is used as the material of the black matrix, it is not necessary to consider so much about the etchant, temperature, etc. used after the black matrix forming step. This facilitates selection of chemicals and the like used in the manufacturing process. Further, even when the insulating film and the black matrix in the thin film transistor have a multilayer structure, they are formed of the same material, so that the adverse effect of distortion caused by stress or the like can be reduced. In addition, the silicon oxide film constituting the black matrix can be used also as an insulating film (a protective film for the source line) of the thin film transistor.

  In this embodiment, not only the silicon oxide film but also a film made of a material equivalent to the silicon oxide film, a titanium oxide film, or the like can be employed. Things can be adopted.

  When the insulating film is a silicon oxide film, a silicon oxide film may be formed by adding an additive made of aluminum or an aluminum compound, or an additive made of boron or a boron compound to hydrofluoric acid. desirable. Elements constituting the additive used by the LPD method remain in the insulating film as impurities. Therefore, it is desired that the remaining elements do not adversely affect, for example, a thin film transistor or the like. Aluminum and the like are commonly used in processes such as thin film transistors. An insulating film containing boron or the like is used as an insulating film called BPSG in an LSI process. Therefore, even if these elements remain in the insulating film, it is considered that there is little adverse effect on the thin film transistor and the like.

  In the present embodiment, a pigment is desirably used as the dye contained in the insulating film. This is because pigments have relatively high heat resistance, and therefore, when the heat resistance of a color filter or the like is increased, it is desirable to increase the heat resistance of the dye accordingly. However, the dye contained in the insulating film is not limited to this, and for example, a dye or the like may be used. As the black pigment to be included in the insulating film in this embodiment, a carbon-based pigment or the like can be considered. As the pigment used in the LPD method, a water-soluble pigment is preferable.

3. Third Embodiment A third embodiment is an embodiment in which a conductive layer such as a metal is interposed between a conductive colored layer (color resist) and a drain region of a thin film transistor. 4A to 4D show an example of a process sectional view of the third embodiment. The difference from the first embodiment is that, in FIG. 4B, a conductive layer 411 for making contact between the drain region 409 and the pixel electrode is formed after opening a contact hole. This conductive layer 411 is made of metal or the like. Then, after the conductive layer 411 is formed, conductive color resists 406 to 408 serving both as a color filter and a pixel electrode are formed as shown in FIG.

  According to the present embodiment, good contact can be obtained between the conductive color resists 406 to 408 serving as pixel electrodes and the drain region 409, and the contact resistance can be reduced. As a result, the effective voltage applied to the liquid crystal element can be increased, and the display characteristics can be improved. In this case, the material of the conductive layer 411 is desirably a material that can sufficiently reduce the contact resistance with the drain region and the contact resistance with the conductive color resist.

  For example, FIGS. 5A to 5C show an example in which a conductive layer is formed using the same material as a source line. That is, in FIG. 5A, when forming the source line 504 by patterning, the conductive layer 512 of the same material as the source line 504 is also formed by patterning. After that, conductive color resists 506 to 508 are formed as shown in FIG. According to the method of forming the conductive layer 512 using the same material as the source line 504 in this manner, it is not necessary to add a new photo and etching step to form the conductive layer, thereby reducing the number of steps and improving the yield. Can be achieved.

  FIG. 6 is a plan view showing the structure of this embodiment. As shown in FIG. 6, in the present embodiment, the conductive layer 512 made of metal or the like is drawn out of the contact hole 513, and the conductive layer 512 and the conductive color resist 506 are connected so that the contact resistance with the conductive color resist is sufficiently low. The size of the contact area is determined. However, in the case where the conductive layer 512 is made of a non-translucent material, if the contact area is too large, the aperture ratio decreases, so that the size of the contact area depends on the required contact resistance and aperture ratio. Need to decide.

  FIG. 7 shows an example in which the conductive layer 512 is formed around the conductive color resist 506 to be a pixel electrode. That is, in the structure of FIG. 6 in which the conductive layer 512 is formed only in the peripheral portion of the contact hole 513, for example, the parasitic resistance between the point K in FIG. 7 and the drain region 509 of the thin film transistor increases. If the parasitic resistance becomes large, for example, the effective voltage applied to the liquid crystal at the position of the point K becomes low, which causes a problem of deterioration of image quality. On the other hand, when the conductive layer 512 is formed around the conductive color resist 506 as shown in FIG. 7, the parasitic resistance between the drain region 509 and the point K can be reduced, and the image quality as described above can be reduced. The problem of deterioration can be prevented.

  With the structure shown in FIG. 7, the conductive layer 512 provided in the peripheral portion can also be used as a part of the black matrix. This is because the conductive color resist 506 serves as a color filter, and the black matrix is formed around the color filter. In this case, the gate line 503, the source line 504, the black matrix provided on the thin film transistor side substrate, or the black matrix provided on the counter electrode becomes another part of the black matrix. Further, according to the configuration in which the conductive layer 512 in the peripheral portion is a part of the black matrix as shown in FIG. 7, the conductive layer 512 and the conductive color resist 506 are accurately aligned by an optical device or the like. It is possible to accurately arrange the black matrix with respect to the resist 506.

4. Fourth Embodiment A fourth embodiment shows an example in which a black matrix is built in a thin film transistor side substrate in the third embodiment, and FIGS. 8A to 8D show the steps. A sectional view is shown. Unlike the third embodiment, in the fourth embodiment, a black matrix 810 is selectively formed on the color resists 806 to 808 by using the LPD method in FIG. 8C. The method of forming the black matrix 810 by the LPD method and the effect of using this method are as already described in the second embodiment, and a description thereof will be omitted. FIGS. 8A to 8D show an example in which the conductive layer 812 is formed using the same material as the source line. However, the conductive layer may be formed using a material different from the source line.

5. Fifth Embodiment The fifth embodiment relates to a reflection type active matrix liquid crystal display device in which a conductive coloring layer is formed on a non-light-transmitting (light-reflecting) pixel electrode. (A) to (C) show sectional views of the process. First, after a thin film transistor 902 and an insulating film 905 are formed in FIG. 9A, a non-light-transmitting conductive layer such as a metal is patterned to form a source line 904 and a pixel electrode 912. The pixel electrode 912 is in contact with the drain region 909. Further, it is desirable that the material of the conductive layer has as high a reflectivity as possible. Next, as shown in FIG. 9B, red, green, and blue color filters 906, 907, and 908, which are conductive coloring layers, are formed on the pixel electrodes by patterning using a light exposure technique or the like. Subsequent steps are the same as in the first embodiment.

  In the conventional reflection type liquid crystal display device, the color filter is formed on the counter substrate side. However, in the reflection type liquid crystal display device, since only the reflected light serves as a light source, it is desired to further increase the aperture ratio. In this embodiment, the aperture ratio can be improved by incorporating a color filter in the thin film transistor-side substrate 901. Further, by making the color filter conductive, it is possible to prevent the problem of voltage division caused by the interposition of the color filter between the pixel electrode and the liquid crystal element.

  Note that the conductive coloring layer of this embodiment may be formed by dispersing a dye such as a pigment and a conductive substance such as ITO in a resist, or may be formed by dispersing a conductive substance such as gelatin. And the like, or by mixing a conductive material into a printing ink or the like.

  9A to 9C, the source line 904 and the pixel electrode 912 are formed of the same material, thereby simplifying the process and reducing the cost. However, it is naturally possible to form the source line and the pixel electrode with different materials.

  The liquid crystal element 919 sealed in this embodiment is preferably a polymer dispersed liquid crystal (PDLC). Unlike the TN liquid crystal, the PDLC has an advantage that the transmission of light can be controlled by the scattering intensity, and a polarizing plate is not required. By eliminating the need for a polarizing plate, the aperture ratio can be improved and the manufacturing cost of the device can be reduced. PDLC can be realized by dispersing liquid crystal molecules on the order of μm in a polymer or by including liquid crystal in a network polymer.

When the conductive colored layer is a color resist, it is desirable that the proportion of the solid components such as the dye and the conductive material contained in the color resist is 30% or less as in the first embodiment. The specific resistance of the conductive colored layer is desirably 1 × 10 ⁷ Ω · cm or less, and more desirably 1 × 10 ⁶ Ω · cm or less. When the conductive fine particles are dispersed, the shape thereof is desirably dish-like or rod-like, and the surface of the conductive fine particles is preferably subjected to a hydrophobic treatment with a coupling agent or the like.

6. Sixth Embodiment A sixth embodiment is an embodiment in which a color resist is formed on a pixel electrode, and the pixel electrode is patterned by using the color resist as a mask. FIGS. The process sectional view is shown. First, after forming a thin film transistor 1002 and an insulating film 1005 in FIG. 10A, as shown in FIG. 10B, a contact hole is opened, and ITO 1014 to be a material of a pixel electrode is formed over the entire surface. At this time, a protective film for the source line 1004 may be formed if necessary. Next, as shown in FIG. 10C, patterns of a red color resist 1006, a green color resist 1007, and a blue color resist 1008 are sequentially formed. As such a color resist, for example, a pigment-dispersed resist formed by dispersing a pigment in the resist can be used. Thereafter, as shown in FIG. 10D, the ITO 1014 is etched using the formed color resists 1006 to 1008 as a mask to form a pixel electrode 1012. Subsequent steps are the same as in the first embodiment. This makes it possible to form the pixel electrode and the color filter on the thin film transistor side substrate.

  According to this embodiment, the pixel electrodes made of ITO are arranged below the color resists 1006 to 1008. For example, even if the color resists 1006 to 1008 have high resistance, the resistance in the vertical direction is small because the thickness of the color resist is small. For this reason, a reduction in the liquid crystal applied effective voltage due to the high resistance is effectively prevented. Further, in this embodiment, since the etching of the pixel electrode is performed using the color resists 1006 to 1008 as a mask, the step of forming a resist for patterning the pixel electrode can be omitted. As a result, the number of steps can be reduced, and the yield can be improved.

  In this case, it is desirable that the color resists 1006 to 1008 serving as color filters have conductivity. When the color resist serving as the color filter is made conductive, the problem of voltage division caused by the interposition of the color resist between the pixel electrode and the liquid crystal element is prevented, and electrons are trapped in the color resist to cause an afterimage and the like. Is also prevented.

Further, as in the first embodiment, the ratio of the solid components such as the coloring matter and the conductive substance contained in the color resist is desirably 30% or less, and the specific resistance of the conductive color resist is 1 × 10 ⁷ Ω. Cm or less, more preferably 1 × 10 ⁶ Ω · cm or less. When the conductive fine particles are dispersed, the shape thereof is desirably dish-like or rod-like, and the surface of the conductive fine particles is preferably subjected to a hydrophobic treatment with a coupling agent or the like.

  Further, when the pixel electrode 1012 is formed of a non-light-transmitting conductive layer such as a metal, a reflection type active matrix type liquid crystal display device can be configured as in the fifth embodiment.

7. Seventh Embodiment The seventh embodiment shows an example in which a black matrix is built in a thin film transistor side substrate in the sixth embodiment, and FIGS. 11A to 11E show the steps. A sectional view is shown. In the seventh embodiment, unlike the sixth embodiment, in FIG. 11D, a black matrix 1110 is selectively formed on the color resists 1106 to 1108 by using the LPD method. Since the method of forming the black matrix 1110 by the LPD method and the effect of using this method are as already described in the second embodiment, the description is omitted.

8. Eighth Embodiment An eighth embodiment is an embodiment in which an insulating film serving as a protective film is formed using a resist for patterning a pixel electrode by using the LPD method, and FIGS. E) shows a sectional view of the process. First, after a thin film transistor 1202 and an insulating film 1205 are formed in FIG. 12A, as shown in FIG. 12B, a contact hole is opened, and an ITO 1214 serving as a material for a pixel electrode is formed over the entire surface. At this time, if necessary, a protective film for the source line 1204 may be formed. Next, as shown in FIG. 12C, a resist pattern 1206 for patterning pixel electrodes is formed. Thereafter, as shown in FIG. 12D, the ITO 1214 is etched using the formed color resist 1206 as a mask to form a pixel electrode 1212. Next, using the resist pattern 1206 over the pixel electrode 1212 as a mask, an insulating film 1220 is selectively formed by the LPD method. The insulating film 1220 serves as a protective film for the source line 1204. The method of forming the insulating film 1220 by the LPD method and the effect of using this method are almost the same as those described in the second embodiment, and are different in that the insulating film 1220 does not need to contain a dye.

  In the conventional example, when an insulating film serving as a protective film for a source line is formed, a step of removing the insulating film above the pixel electrode is required in order to prevent a decrease in the effective voltage applied to the liquid crystal. On the other hand, the LPD method has a feature that the insulating film 1220 can be selectively formed in a region where the resist pattern 1206 is not provided. In this embodiment, the insulating film 1220 is formed using the feature of the LPD method. Therefore, the step of removing the insulating film above the pixel electrode becomes unnecessary, whereby the number of steps can be reduced and the yield can be improved. In addition, by using the LPD method, an insulating film can be formed at a low temperature of about room temperature; therefore, an inexpensive glass substrate can be used as the substrate. In addition, by using the LPD method, an insulating film can be formed using a silicon oxide film generally used in manufacturing a thin film transistor. Therefore, there are advantages such as easy selection of chemicals and the like used in the manufacturing process. Further, even when the insulating film 1220 and the other insulating films forming the thin film transistor have a multilayer structure, they are formed of the same material, and thus have an advantage such that the adverse effect of distortion caused by stress or the like can be reduced. Further, in this embodiment, by using the LPD method, the insulating film 1220 is formed in a self-aligned manner with respect to the resist pattern 1206, so that the aperture ratio can be improved.

  It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention.

  For example, the conductive colored layer only needs to have at least the conductive function and the function of the colored layer, and is not limited to those described in the first embodiment and the like.

  Further, for example, the LPD method used in the present invention is not limited to the method described in the above embodiment, and at least a saturated aqueous solution of a compound containing at least one substance constituting an insulating substance is brought into a supersaturated state to precipitate the insulating substance. Any film forming method may be used.

  Further, the manufacturing method of the active matrix type liquid crystal display device and the like of the present invention is not limited to the manufacturing method described in the above embodiment.

  Further, the structure of the thin film transistor is not limited to that described in the above embodiment, but may be a reverse type or positive type in an amorphous silicon thin film transistor, a planar type or a positive type in a poly (polycrystalline) silicon thin film transistor. Various structures can be adopted.

  According to the present invention, since it is not necessary to form a color filter on the opposing substrate, the manufacturing cost of the opposing substrate can be reduced, and the margin for bonding accuracy between the thin film transistor-side substrate and the opposing substrate can be greatly reduced. Further, since the step of forming the pixel electrode material and the step of patterning the pixel electrode material can be omitted, the cost can be reduced and the yield can be improved. In addition, it is possible to prevent a problem of a decrease in image quality due to a decrease in the effective voltage applied to the liquid crystal, and to increase an aperture ratio.

  Further, according to the present invention, an insulating film serving as a black matrix can be formed at a low temperature, so that an inexpensive glass substrate can be employed, thereby reducing product cost and preventing a situation in which device characteristics of a thin film transistor are degraded due to a heating temperature. it can. Further, the step of etching the insulating film can be omitted, and the cost of the product can be reduced. Further, the black matrix can be formed with high accuracy, and the aperture ratio can be improved. In addition, since problems such as glare and cracks can be solved, display characteristics and reliability can be improved.

  Further, according to the present invention, it is possible to realize a reflection type liquid crystal display device which is simple in process and inexpensive, and has excellent display characteristics such as an aperture ratio.

  Further, according to the present invention, since a reduction in the effective voltage applied to the liquid crystal can be effectively prevented, display characteristics can be improved. Further, since the patterning of the pixel electrode is performed using the color resist as a mask, the number of steps can be reduced, the yield can be improved, and the manufacturing cost can be reduced.

  Further, according to the present invention, the step of removing the insulating film above the pixel electrode can be omitted, and the yield can be improved. Further, adoption of an inexpensive glass substrate, prevention of deterioration of device characteristics of the thin film transistor, and the like can be achieved.

FIG. 11 is a diagram illustrating an example of the structure of a conventional active matrix liquid crystal display device. FIGS. 2A to 2C are process cross-sectional views of a first embodiment in which a conductive colored layer also serves as a pixel electrode. 3A to 3D are process cross-sectional views of a second embodiment in which a black matrix is built in a thin film transistor side substrate in the first embodiment. 4A to 4D are process cross-sectional views of a third embodiment in which a conductive layer is interposed between a conductive coloring layer and a drain region. FIGS. 5A to 5C are process cross-sectional views in the case where a conductive layer is formed of the same material as the source line in the third embodiment. It is a top view showing the structure of the 3rd example. It is a top view showing the structure of the 3rd example when a conductive layer is formed in a peripheral part of a conductive coloring layer. FIGS. 8A to 8D are process cross-sectional views of a fourth embodiment in which a black matrix is built in a thin film transistor-side substrate in the third embodiment. FIGS. 9A to 9C are process cross-sectional views of a fifth embodiment in which a conductive colored layer is formed on a non-translucent pixel electrode to constitute a reflective liquid crystal display device. FIGS. 10A to 10E are process sectional views of a sixth embodiment in which a color resist is formed on a pixel electrode and the pixel electrode is patterned with the color resist. FIGS. 11A to 11E are process sectional views of a seventh embodiment in which a black matrix is incorporated in a thin film transistor-side substrate in the sixth embodiment. FIGS. 12A to 12E are process sectional views of an eighth embodiment in which an insulating film is formed by a LPD method using a resist for pixel electrode patterning. It is a figure which shows the relationship between a solid component ratio and pot life. FIGS. 14A to 14C are diagrams showing the relationship between the specific resistance and the difference between the effective values. FIGS. 15A and 15B are diagrams showing the relationship between the specific resistance and the difference between the effective values.

Explanation of reference numerals

201, 301, 401, 501, 801, 901, 1001, 1101, 1201. Thin film transistor side substrates 202, 302, 402, 502, 802, 902, 1002, 1102, 1202 ... Thin film transistors 206 to 208, 306 to 308, 406 to 408, 506 to 508, 806 to 808, 1006 to 1008, 1106 to 1108, color resists 906 to 908, conductive colored layers 1206, resist patterns 209, 309, 409, 509, 809, 909, 1009, 1109, 1209 Drain regions 310, 810, 1110 ... Black matrices 411, 512, 812 ... Conductive layers 1014, 1114, 1214 ... ITO
912, 1012, 1112, 1212 ... pixel electrodes 217, 317, 417, 517, 817, 917, 1017, 1117 ... counter substrates 218, 318, 418, 518, 818, 918, 1018, 1118 ... counter electrodes 219, 319, 419, 519, 819, 919, 1019, 1119 ... liquid crystal 220, 420, 520, 920, 1020, 1120, 1220 ... insulating films 221, 321, 421, 521, 821, 921, 1021, 1121 ... alignment films 222, 322 , 422, 522, 822, 922, 1022, 1122 ... orientation film

Claims (8)

A method of manufacturing a liquid crystal display device including a thin film transistor-side substrate having a thin film transistor, a counter substrate having a counter electrode, and a liquid crystal element sandwiched between the thin film transistor-side substrate and the counter substrate.
Forming a pixel electrode material, which is a material of a pixel electrode selectively driven by the thin film transistor, on the thin film transistor side substrate;
Forming a colored layer on the pixel electrode material;
Patterning the pixel electrode material using the coloring layer as a mask. In claim 1,
The method for manufacturing a liquid crystal display device, wherein the colored layer is formed of a color resist and forms a color filter for color display. In claim 1 or 2,
The method for manufacturing a liquid crystal display device, wherein the coloring layer includes a conductive material. In claim 3,
A method of manufacturing a liquid crystal display device, wherein a ratio of a solid component containing the coloring matter and the conductive material in the color layer in the color resist is 30% or less. In any one of claims 1 to 4,
The method for manufacturing a liquid crystal display device, wherein the coloring layer is made of a resist in which a pigment is dispersed. In any one of claims 1 to 4,
The method for manufacturing a liquid crystal display device, wherein the coloring layer includes a dyed polymer material. In any one of claims 1 to 4,
The method for manufacturing a liquid crystal display device, wherein the coloring layer is made of ink. In any one of claims 1 to 7,
The method for manufacturing a liquid crystal display device, wherein the pixel electrode is made of a non-translucent material.

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