JP2011145378A - Photomask, color filter substrate, pixel electrode substrate, liquid crystal display device, method for producing color filter substrate, and method for producing pixel electrode substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color filter substrate or a pixel electrode substrate, both of them scarcely having fluctuation irrespective of a process condition, and methods for producing them, by optimizing a photomask for forming a fixed spacer for controlling a liquid crystal cell gap and a protrusion for controlling a liquid crystal alignment domain by one operation by using a positive photoresist on the color filter substrate or on the pixel electrode substrate for a liquid crystal display device; and to provide the high-quality liquid crystal display device. <P>SOLUTION: The photomask 20 is for forming the fixed spacer 5 and the protrusion 6 for controlling the domain by one operation by using the positive photoresist on the color filter substrate 11 or on the pixel electrode substrate in the liquid crystal display device, wherein a photomask pattern of the fixed spacer has a gray tone portion 9 including a total transmission slit on the periphery of a light-shielding portion 8, and a photomask pattern of the protrusion for controlling the domain has a gray tone portion 90 including a total transmission slit 80 interposed between a plurality of parallel band-shaped light-shielding portion 85. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device, and in particular, a color filter substrate having a fixed spacer for forming a liquid crystal cell, a pixel electrode substrate, a method for manufacturing the color filter substrate and the pixel electrode substrate, and the color filter substrate and the pixel. The present invention relates to a photomask used for manufacturing an electrode substrate.

  2. Description of the Related Art In recent years, flat display devices have been widely used, and in particular, LCDs (liquid crystal display devices) are multicolor types that perform color display using color filters, especially for display panels such as televisions, monitors, and portable terminals. Use is progressing. In order to make multicolor, a color filter substrate having a micro cell structure is generally used, and the color filter substrate plays an important role in determining the display quality of the liquid crystal display panel.

  An LCD (Liquid Crystal Display) has a cell structure in which liquid crystal is sealed between a pair of substrates having at least one light-transmitting substrate. A color filter is formed on the inner surface of the cell. As shown in FIG. 7, the general configuration of the color filter substrate on which the color filter is formed is a light-blocking black matrix pattern 2 (abbreviated as BM pattern) on one side of the transparent substrate 1 (the side that becomes the inner surface of the liquid crystal cell). The same applies hereinafter) and the repeated arrangement of the colored patterns 30, 31, and 32 for each color filter pixel that regularly fills the gap between the BM pattern 2 is formed by accurate alignment, and, for example, TN (twisted nematic) is formed by a liquid crystal display method. In the case of the type, the transparent electrode layer 4 is formed so as to cover the repeated arrangement of the BM pattern 2 and the colored patterns 30, 31, 32. In the past, the color filter substrate used to refer to the components described so far, but in recent years, especially as liquid crystal cells have become larger and narrower, they have been dispersed in the cell forming process for cell gap control. Instead of the bead spacers, a plurality of fixed spacers (abbreviated as PS portions; hereinafter the same) 5 selectively formed by a photosensitive resin, called photo spacers, post spacers, etc. are often regularly arranged.

  The PS section 5 has a function of keeping the liquid crystal cell gap constant by forming a pattern having the same shape in a regular arrangement selectively selected so as to overlap the BM pattern 2. For the purpose of ensuring a sufficient height for obtaining the cell gap, three colored patterns 30, 31, 32 of red (R), green (G), and blue (B) are overlaid on the BM pattern 2, It is also possible to compensate for the height of only the PS section (see Patent Document 1).

  Further, for the purpose of enlarging the viewing angle of the LCD by using vertical alignment division control for the liquid crystal alignment mode, for example, the PS portion 5 is formed on the color filter pixels as a band shape obtained by bending a planar shape in a zigzag manner, for example. A lower liquid crystal alignment domain regulating protrusion 6 is often formed. The entire structure including the PS portion 5 and the liquid crystal alignment domain regulating protrusion 6 is referred to as a color filter substrate (projection formation) 11.

As shown in the schematic diagram for explaining the cross-sectional structure of the LCD panel shown in FIG. 6, the pixel electrode on the opposite side constituting the liquid crystal cell structure together with the color filter substrate without providing the PS portion 5 on the color filter substrate side. It can be provided at a predetermined position on the substrate 12. Further, the liquid crystal alignment domain regulating protrusion 6 can be provided on the pixel electrode substrate 12. In this case, another domain regulating protrusion or slit of the transparent electrode layer 4 is provided at an appropriate position on the colored pixel of the opposing color filter substrate, and the alignment control function of both substrates is combined to provide a liquid crystal alignment domain. The regulation (see Patent Document 2) is usually performed. In the present invention, an example in which the various protrusions are provided on the color filter substrate side will be mainly described. However, the case where the protrusions are provided on the pixel electrode substrate side is substantially the same.

  FIG. 2 shows a general example in the case where the various protrusions are formed by a photographic method. An example of forming a color filter substrate (projection part formation) 11 as a whole structure by adding a new projection part to a conventional color filter substrate (projection part non-formation) 10 having a limited function for color display It is. The photomask 20 corresponds to a new pattern of projections formed on the color filter substrate (projection not formed) 10 by the light shielding unit 8 formed on one side of the transparent substrate 21. The resist-type irradiation light 40 irradiated from the opposite side passes through a portion without the light-shielding portion 8 and selectively exposes the positive photoresist 7 applied on the color filter substrate (projection portion not formed) 10. To give development solubility. Thereafter, the light shielding part pattern is baked and fixed on the color filter 10 through development, washing, and baking processes.

  Further, as an example of forming the liquid crystal alignment domain regulating protrusions 6 that become the protrusions in parallel with the PS portion 5, as described in Patent Document 3, the above-mentioned 2 different in height using a positive photoresist of the same material The types of protrusions can be simultaneously formed by selectively performing two exposure steps.

  Further, among the two types of protrusions having different heights, the colored PS 30, 31, and 32 are formed as BM patterns in the higher PS portion 5 in order to ensure a sufficient height, as in the above-mentioned Patent Document 1. The height of the upper surface position of the PS part can be increased without increasing the height of the PS part itself by overlapping the upper part of the PS part, and for controlling the PS part 5 and the liquid crystal alignment domain. The protrusions 6 can also be formed simultaneously in exactly the same process (see Patent Document 4).

  Many proposals have been made to form the protrusion including the PS portion 5 with the positive photoresist by the above-mentioned various methods, but there are many problems, and at present, the negative photoresist is used to form the PS portion. There are many cases. The reason why the positive type photoresist is not always realized despite the advantage that it can be processed at a low material cost is that the control of the height shown in the PS sections 51 and 52 is explained as shown in FIG. This is because of the above-mentioned difficulty and the quality abnormality due to the depression of the upper surface shown in the PS portion 53. That is, in the small PS portions 51 and 52 having a planar size of less than 30 μm, variations in exposure amount and exposure gap with respect to a thickly applied photoresist film are sensitive to development thickness, that is, variations in PS portion height d. The function of the PS section giving a certain height that is particularly important for cell gap control is impaired. In addition, in the large PS portion 53 having a planar size of 30 μm or more, a dent e is generated on the upper surface of the PS portion, which causes a problem that in the liquid crystal cell manufacturing process, quality abnormality is caused when applying an alignment film.

  Further, in Patent Document 3, the purpose of using the above-described two exposure steps is to provide an intermediate between an area that gives a sufficient exposure to the positive photoresist and is removed by development, and an area that is completely shielded from light and stored after development. Is to make the height of the projections at an intermediate level. Based on the same concept, a method is also known in which an intermediate density pattern is selectively formed on the photomask itself, and the above-mentioned two types of protrusions having different heights are collectively formed by one exposure and development. As a method of forming an intermediate density pattern on a photomask, an average of the entire fine pattern area is semi-translucent by a collection of fine patterns of light shielding films such as dot (halftone dot) arrangement and line and space. There are two types of gray-tone masks: a general gray-tone mask type that corresponds to the part, and a half-tone mask type that forms a uniform semi-transparent part by directly forming a film having semi-transparent film characteristics and patterning means. (Patent Document 5).

Further, in FIG. 7, in the method of raising the portion corresponding to the base of the PS portion 5 by overlapping two or more of the colored patterns 30, 31, 32 on the BM pattern 2, and consequently forming the PS portion high, Since the thickness of the dedicated layer formed in the process as the PS portion 5 does not necessarily need to be particularly thick, the problems in the case of using the above positive photoresist can be largely avoided. However, when the colored patterns 30, 31, 32 are stacked to partially bulge the BM pattern 2, both the accuracy of application of the material forming each colored pattern and the accuracy of alignment of the overlapping are controlled with extremely high accuracy. This is particularly important and often involves difficulties in stabilizing the production process.

Japanese Patent No. 3651874 JP 2008-310358 A JP 2001-201750 A Japanese Patent No. 3255107 JP 2007-248988 A

  The present invention is proposed in view of the above problems, and the problem to be solved by the present invention is to provide a liquid crystal cell gap by using a positive photoresist on a color filter substrate or a pixel electrode substrate for a liquid crystal display device. A photomask for forming a fixed spacer for control and a liquid crystal alignment domain regulating protrusion lower than the fixed spacer at the same time is optimized, and a color filter substrate with little variation due to process conditions and its manufacturing method, or a pixel electrode substrate and its A manufacturing method is provided, and a high-quality liquid crystal display device is provided.

  As a means for solving the above problems, the invention described in claim 1 is a color filter substrate having a color filter in a liquid crystal display device, or a pixel having a switching element and a pixel electrode for active driving of the liquid crystal display device. A photomask for forming a fixed spacer for controlling a liquid crystal cell gap and a protrusion for regulating a liquid crystal alignment domain at once using a positive photoresist on an electrode substrate, wherein the photomask pattern of the fixed spacer is shielded from light And an isolated pattern having a gray tone part including a total transmission slit around the part, and the photomask pattern of the domain regulating projection part includes a total transmission slit sandwiched between a plurality of parallel strip-shaped light shielding parts A photomass comprising a strip pattern having a gray tone portion It is.

  According to a second aspect of the present invention, the planar shape of the fixed spacer is a convex simple polygon, or a circular shape such as a circle or an ellipse, and the size of the largest circle that can be stored within the contour of the fixed spacer. The width of the total transmission slit of the gray tone portion around the light shielding portion for the fixed spacer is 5 to 7 μm, and the gray around the light shielding portion and the light shielding portion is formed. 2. The photomask according to claim 1, wherein the total size including the tone portion is 30 μm or more.

  According to a third aspect of the present invention, since the planar shape of the domain regulating protrusion is formed in a strip shape having a width of 7 to 12 μm, the plurality of parallel strip-shaped light shielding portions are formed as two light shielding portions and sandwiched therebetween. 3. The photomask according to claim 1, wherein a width of the total transmission slit is 1.5 to 3.5 μm, and a width of a gray tone portion including the total transmission slit is 8 to 13 μm. is there.

  According to a fourth aspect of the present invention, the photomask according to any one of the first to third aspects is used, and the fixing spacer and the domain regulating protrusion are selectively provided on the color filter substrate. And a color filter substrate.

  According to a fifth aspect of the present invention, the height of the fixed spacer from the outermost surface of the color filter pixel central portion is set to 2.0 to 3.8 μm, and the height of the domain regulating protrusion is set to 0.8. The color filter substrate according to claim 4, wherein the color filter substrate is 8 to 1.4 μm.

  According to a sixth aspect of the present invention, the photomask according to any one of the first to third aspects is used, and the fixing spacer and the domain regulating protrusion are selectively provided on the pixel electrode substrate. A pixel electrode substrate.

  According to a seventh aspect of the present invention, the height of the fixed spacer from the outermost surface of the central portion of the pixel electrode is 2.0 to 3.8 μm, and the height of the domain regulating protrusion is 0.8. The pixel electrode substrate according to claim 6, wherein the pixel electrode substrate has a thickness of ˜1.4 μm.

  The invention according to claim 8 is a liquid crystal display device comprising the color filter substrate or pixel electrode substrate according to any one of claims 4 to 7.

  According to a ninth aspect of the present invention, a collective pattern is formed by a proximity exposure method using the photomask according to any one of the first to third aspects, and the fixed spacer and the domain regulating protrusion are arranged on a color filter substrate. A color filter substrate manufacturing method characterized by being selectively provided on the top.

  According to a tenth aspect of the present invention, the photomask according to any one of the first to third aspects is used, a collective pattern is formed by a proximity exposure method, and the fixed spacer and the domain restricting protrusion are provided on the pixel electrode substrate. A method of manufacturing a pixel electrode substrate, which is selectively provided on the top.

  A positive photoresist is used for the color filter substrate for the liquid crystal display device, and the fixed spacer for controlling the cell gap and the protrusion for regulating the liquid crystal alignment domain are integrated so that the difference in height between the two can be realized stably. It has been difficult to form easily. Furthermore, when the planar size of the spacer is small, fluctuations in the exposure gap and the exposure amount greatly affect the finished height of the spacer, and when the planar size of the spacer is large, the flat portion of the spacer upper surface is recessed. For this reason, there has been a difficulty in effectively using the positive photoresist as a spacer, for example, quality abnormalities occur when an alignment film is applied in the liquid crystal cell manufacturing process. However, by using an inexpensive photomask having a gray tone portion of the present invention, a high-quality fixed spacer and a liquid crystal alignment domain regulating protrusion whose height is lowered by a certain amount are colored with a positive photoresist. It can be easily formed collectively on the filter substrate or the pixel electrode substrate.

  According to the second aspect of the present invention, a large planar size spacer particularly suitable for the fixed spacer constituting the color filter substrate or the pixel electrode substrate of the present invention can be realized stably and with high quality. The structure of the photomask can be defined.

  According to the third aspect of the present invention, in order to stably and with high quality, a protrusion pattern having a shape particularly suitable for the domain regulating protrusions constituting the color filter substrate or the pixel electrode substrate of the present invention. The structure of the photomask can be defined.

According to the invention described in claim 4 or 6, a color filter substrate or a pixel electrode substrate having a high-quality fixed spacer and a domain regulating protrusion can be obtained at a low material cost. The color filter substrate or the pixel electrode substrate is compatible with the liquid crystal cell formation process without any abnormality, and can contribute to the production of a high quality liquid crystal cell.

  Further, according to the invention described in claim 5 or 7, the height particularly suitable for the fixed spacer and the domain regulating protrusion constituting the color filter substrate or the pixel electrode substrate of the present invention is stably and high quality. Therefore, the obtained color filter substrate or pixel electrode substrate can be adapted to the liquid crystal cell formation process without any abnormality, and can further contribute to the production of a high-quality liquid crystal cell.

  According to the invention described in claim 8, a liquid crystal display device including a color filter substrate or a pixel electrode substrate with stable quality can be provided with high quality.

  According to the invention described in claim 9 or 10, it is possible to obtain a color filter substrate or a pixel electrode substrate having a high-quality fixed spacer and a domain regulating protrusion uniformly with a low material cost and a stable process. Therefore, productivity can be improved by high yield, and it is possible to easily cope with changes in specifications of the color filter substrate and the pixel electrode substrate without greatly changing the manufacturing process conditions.

It is a cross-sectional conceptual diagram for demonstrating the relationship between the PS part corresponding to the photomask of this invention, and the protrusion part for domain control. It is a cross-sectional conceptual diagram for demonstrating the general method of forming PS part in a color filter substrate. It is a cross-sectional conceptual diagram for demonstrating the condition where the cross-sectional shape of the conventional PS part produces a malfunction. It is a conceptual cross-sectional view for explaining a situation where a PS portion and a domain regulating protrusion are formed in an optimal cross-sectional shape on the color filter substrate of the present invention. It is a plane conceptual diagram for demonstrating an example of the photomask pattern for forming one PS part with the photomask of this invention. It is a conceptual cross-sectional view for explaining an example of the liquid crystal display device of the present invention. It is a conceptual cross-sectional view for explaining a general configuration of a color filter substrate. It is a cross-sectional conceptual diagram for demonstrating the height of PS part formed on a color filter substrate. It is a plane conceptual diagram for demonstrating an example of the photomask pattern for forming the domain regulation protrusion part with the photomask of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 2 is a cross-sectional conceptual diagram illustrating a general configuration of the color filter substrate in FIG. 7, and shows a general method for forming a new PS portion 5 on a conventional color filter substrate having no PS portion. This will be described with reference to a conceptual diagram. After forming the BM pattern 2 and the colored patterns 30, 31, 32 on the transparent substrate 1 by repeating different three colors such as red, green, and blue, the color filter substrate on which the transparent electrode layer 4 is formed (PS portion not formed) ) A positive type photoresist 7 is formed on 10 by coating. The positive photoresist 7 is a material for making the PS portion 5 and may be selected in consideration of shape quality including its height accuracy and elastic characteristics. For example, a commercially available novolac resin-based positive photoresist is applied at a dry height of about 3 to 4 μm, but is not limited thereto. The application method is preferably a method with high use efficiency of a photoresist such as a die coating method, but is not particularly limited as long as it can be applied uniformly.

  In FIG. 2, the positive type photo resist 7 is applied and dried to face the color filter substrate 10, the pattern surface of the photo mask 20 is brought close to the opposing surface while being aligned, and exposure for resist exposure from the back side of the photo mask is performed. Exposure is performed with light 40. In the exposure step, g-rays (436 nm), h-rays (405 nm), i-rays from an ultra-high pressure mercury lamp that is easy to obtain high-intensity and parallel light by a collective exposure machine for proximity exposure generally used for manufacturing color filters. With a line (365 nm) as the main wavelength, exposure is performed according to the photoresist sensitivity with an exposure gap of about 100 to 150 μm. Thereafter, through a process of development, washing, and baking, a protruding pattern corresponding to the light-shielding portion 8 of the photomask is formed as a PS portion 5 with a photoresist.

  Here, the situation of the shape defect of the PS portion described above will be described in more detail with reference to FIG. 3. In the PS portions 51 and 52 having a planar size of less than 30 μm, the exposure amount and the proximity to the thickly applied photoresist film are determined. Variations in the exposure gap of the exposure method sensitively affect the development thickness, more precisely, the height of the PS portion after baking, resulting in variations d. For this reason, the function which gives the constant height especially important for cell gap control is impaired. Further, in the PS portion 53 having a planar size of 30 μm or more, a dent e is generated on the upper surface of the PS portion, resulting in poor alignment in the liquid crystal cell manufacturing process and causing a quality abnormality.

  All of the above phenomena have been found to involve the bulge of the pattern edge due to baking. For example, when confirmed with an example of a regular octagonal shading pattern, a tendency that the bulge of the peripheral edge due to baking is particularly large is observed. Rather, fluctuations in exposure conditions tend to greatly affect the final height variation. On the other hand, in the case of a PS portion having a planar size of 30 μm or more, a dent on the upper surface of the PS portion is generated. Based on the above knowledge, we considered that it is possible to provide a common improvement measure for each of the above-mentioned plane sizes by providing a region for reducing fluctuations in exposure conditions and thermal deformation at the edge of the photomask pattern. Its effectiveness was confirmed. As a result of intensive studies, the inventors have found a design guideline for a photomask that is particularly convenient for forming a PS portion having a planar size of 30 μm or more without a recess in the upper surface.

  As shown in FIG. 7, the present invention relates to the formation of the PS portion 5 described above and the formation of the domain restricting protrusions 6 at the same time, both of which are photomasks. A gray tone portion is provided in the pattern to control the cross-sectional shape. In general, as compared with the PS portion, the domain control protrusions are mostly in the shape of a strip pattern rather than the isolated pattern, and the minimum line width corresponding to the width of the strip pattern is small, and the height of the cross-sectional shape is high. Use a lower one. Therefore, the specific measures for providing the gray tone portion in the photomask pattern are different between the PS portion and the domain control protrusion. On the other hand, the domain regulating protrusion 6 is most important to obtain morphological characteristics because the domain regulation of the liquid crystal alignment is based on the initial alignment of the liquid crystal by the fine inclined surface of each substrate surface. If there is no adverse chemical effect, the other characteristics need not be particularly limited, and the resist material used for this can be the same as that used for forming the PS portion.

  FIG. 1 is a conceptual cross-sectional view for explaining the relationship between the photomask of the present invention and the corresponding PS portion and domain regulating protrusion. The photomask of the present invention is positively applied to a color filter substrate 11 having a color filter in a liquid crystal display device or a pixel electrode substrate 12 (FIG. 6 described later) having a switching element and a pixel electrode for active driving of the liquid crystal display device. A photomask 20 for collectively forming a fixed spacer (PS portion 5) for controlling a liquid crystal cell gap and a projection portion 6 for regulating a liquid crystal alignment domain lower than the fixed spacer by using a type photoresist 7; The spacer photomask pattern is composed of an isolated pattern having a gray tone portion 9 including a total transmission slit around the light shielding portion 8, and other gray tone to be described later is used as the photomask pattern of the domain regulating projection portion. It is characterized by comprising a belt-like pattern having a portion 90.

  As in the case shown in FIG. 2, the transparent substrate 21 of the photomask emits light having a wavelength in a region that utilizes at least the photosensitivity of the photoresist 7 to be used among the resist exposure light 40 from the exposure machine. Examples thereof include fused silica glass and non-alkali glass. Further, in the production of the photomask 20, the light shielding portion 8 is formed by patterning a metal chromium film, which has been mainly formed by a sputtering method, or a thin film of a low reflection film in which chromium oxide is laminated on metal chromium by a photo etching method. In general, the etching means may be wet or dry. Further, the gray tone portion 9 can be formed of the same material as the light shielding portion 8 and by a device on the pattern such as a slit in the same process as the formation of the light shielding portion. The gray tone portion 90 which is a photomask pattern for the domain regulating protrusion can be formed simultaneously by a combination of the above-described thin film forming method and photoetching method.

  FIG. 4 is a conceptual cross-sectional view for explaining a situation where the PS portion and the domain regulating protrusion are formed in the optimum cross-sectional shape on the color filter substrate of the present invention. As the PS portion and the domain restricting protrusion, a protrusion is formed at a predetermined position on the color filter substrate 11. For convenience, various sizes of the PS portions 51 and 53, the domain restricting protrusions 62 and 64 are provided. As shown above, they are displayed adjacently on the same drawing. The PS portion is disposed on the BM pattern, and the domain regulating protrusion is disposed on the colored pattern.

  Since it is necessary for the PS portion to exhibit a function as a fixed spacer for constituting the liquid crystal cell, it is desirable that the PS portion has a uniform height, shape, and elastic characteristics. On the other hand, unlike the PS portion, the domain restricting protrusion is desired to have a uniform convex shape that is lower than the PS portion (the difference is represented by m and n in FIG. 4). In general, it is not preferable that the planar size of the PS portion constituting a large liquid crystal cell is too small from the viewpoint of function and production yield. Actually, the size of the fixed spacer defined later is desirably 20 μm or more, and more desirably 30 to 50 μm. For example, when a trapezoidal projection having a regular octagonal horizontal cross section is formed as a PS portion, the plane size of one PS portion is regarded as the diameter between the two opposite sides of the lower bottom portion as a difference diameter. When this is done, this planar size is 30 μm or more, which is an effective method for forming the PS portion of the present invention.

  In the photomask 20 of the present invention, the patterns corresponding to the PS portions 5, 51, 53 on the color filter substrate 11 cover the patterns of the light shielding portions 8, 81, 83 as shown in FIGS. Gray tone portions 9, 91 and 93 are formed. The structure will be described with reference to FIG. For example, the regular octagonal light shielding portion 8 is covered so as to be surrounded by a gray tone portion 9 including a total transmission slit. In order for the photomask pattern to exert its effect on the formation of the PS portion, it is better to limit the sizes of the light shielding portion and the gray tone portion. As a result of the experimental study, the photomask pattern for forming the PS portion so that the plane size is 30 μm to 50 μm and the upper surface is not dented is the total transmission slit of the gray tone portion provided around the light shielding portion. It has been found that it is optimal to set the width c to 5 to 7 μm and the overall size a of the light-shielding portion and the gray tone portion to 30 μm or more.

  Note that, assuming that the light-shielding line width w of the gray tone portion is as thin as 1 to 2 μm, the light-shielding portion size b is between the light shielding portion and the overall size a of the gray tone portion and the light shielding portion size b in the photomask pattern. In addition, the planar size p of the PS portion formed of photoresist is located. That is, when expressed by a mathematical formula, there is a relationship of a ≧ p ≧ b.

The planar shape of the PS portion provided as the fixed spacer is not limited to the regular octagon or the general circle described above, and can be used as long as it is a convex simple polygon or a circle such as a circle or an ellipse. . Here, the convex shape means that the inner angles of all the vertices of the polygon are less than 180 degrees. A simple polygon means a region surrounded by a closed multi-sided continuous chain that does not intersect each other.
In the above generalized shape, the planar size p of the PS portion can be defined by the diameter of the largest circle that can be accommodated in the outline of the PS portion.

In order to improve the shape caused by the bulge of the end portion of the projection pattern formed of the photoresist, it can be specifically expressed as follows.
In the photomask of the present invention, the planar shape of the fixed spacer is a convex simple polygon or a circle such as a circle or an ellipse, and the size is represented by the diameter of the largest circle that can be stored in the contour of the fixed spacer. The width of the total transmission slit of the gray tone portion provided around the light shielding portion for the fixed spacer is 5 to 7 μm, and the periphery of the light shielding portion and the light shielding portion. 2. The photomask according to claim 1, wherein the total size including the gray tone portion is 30 μm or more.

  The relationship between the planar size of the PS portion, the light-shielding portion of the photomask pattern, and the gray tone portion is different with respect to the domain restricting projection portion having a large difference in pattern shape, planar size, and height. A device for forming the photomask pattern of the domain regulating projection on the same transparent substrate as the photomask pattern of the PS portion and using it in the same photolithography process as the pattern formation of the PS portion will be described with reference to FIG. To do.

FIG. 9 is a schematic plan view for explaining an example of a photomask pattern for forming a domain regulating protrusion using the photomask of the present invention.
This is an example in which a plurality of parallel strip-shaped light shielding portions are formed of a light shielding film 85 divided into two as a photomask pattern of the domain regulating projection portion, including a total transmission slit 80 having a width B sandwiched between the light shielding portions. The gray tone portion 90 is formed, and the entire width A is used as a strip pattern.

  The relationship between the planar size of the domain regulating projection, the light shielding portion of the photomask pattern, and the gray tone portion, the line width of the domain regulating projection formed in a strip shape, and the width A and width B of the photomask pattern In this process, the height of the PS portion is 3.5 μm and the planar size of the PS portion is 35 μm. As a result, in order to form the planar shape of the domain regulating protrusion into a strip shape having a width of 7 to 12 μm, the plurality of parallel strip-shaped light shielding portions are formed as two light shielding portions, and the width B of the total transmission slit sandwiched therebetween It was found that it is optimal to set the width A of the gray tone portion including the total transmission slit to 8 to 13 μm. A similar comparative experiment was performed using a photomask using a halftone film having a transmittance of 33%, and it was found that the same protrusion shape as described above was obtained. There was a tendency to be inferior when using.

  The height of the PS portion provided as the fixed spacer is suitably 2.0 to 3.8 μm in consideration of the cell gap of the liquid crystal display device. However, as shown in the conceptual cross-sectional view for explaining the height of the PS portion formed on the color filter substrate in FIG. 8, the colored patterns 31 and 32 are formed on the BM pattern 2 so as to swell, and the swell is formed. When the PS part 5 is formed in the part via the transparent electrode layer 4, the height f of the PS part can be set lower by the height g of the raised part. In other words, if the height h from the outermost surface of the color filter pixel central portion at the lowest position to the upper bottom of the PS portion is set to 2.0 to 3.8 μm, it is equivalent to the case where there is no bulging portion. Because of the above circumstances, it is possible to reduce the height of the photoresist protrusion of the PS portion to be actually formed due to the overlapping state of the colored patterns on the BM pattern.

Further, the film thickness of the domain regulating protrusion is determined by the design value of the gray tone portion as a photomask pattern, the coating thickness of the positive photoresist that determines the height of the PS portion, and the exposure conditions. It is necessary that the film thickness be appropriate for exhibiting a function that affects the tilt of the vertical alignment of the liquid crystal. According to the experiment for optimizing the design value of the gray tone portion described above,
Although a film thickness of about 0 to 1.3 μm can be obtained, when the coating thickness of the positive photoresist that determines the height of the PS portion is set to 2.0 to 3.8 μm, the height of the domain regulating protrusion is high. The thickness can be set to 0.8 to 1.4 μm, and the function of regulating the orientation domain can be normally obtained.

  The fixed spacer can be selectively provided on the color filter substrate by a photolithography method using the photomask of the present invention. In the exposure process, a proximity exposure system that maintains an exposure gap of 100 to 150 μm is suitable. As a result, an optimal color filter substrate constituting the liquid crystal display device can be provided.

  In the above description, the case where the PS portion and the domain regulating protrusion are formed mainly on the color filter substrate has been described. However, when the PS portion is formed on the pixel electrode substrate, the photomask of the present invention is similarly applied. The positive photoresist for forming the PS portion and the domain regulating protrusion can be processed and formed by photolithography.

  Similarly to the case of the color filter substrate, on the pixel electrode substrate, the height of the PS portion from the outermost surface of the pixel electrode central portion is set to 2.0 to 3.8 μm, and the height of the projection for restricting the domain is set. Is 0.8 to 1.4 μm in order to obtain the cell gap and orientation domain regulation functions normally.

  FIG. 6 is a conceptual cross-sectional view for explaining an example of the liquid crystal display device of the present invention. In the figure, a transparent substrate 41, an active driving switching element 13 (usually using TFTs), and a pixel electrode substrate 12 on which a PS portion 5 and a domain regulating projection 6 are formed on a pixel electrode 14 are used for liquid crystal alignment. An alignment film 15 is formed, and an alignment film 15 is formed and disposed on the surface of the color filter substrate (PS portion not formed) 10 on the opposite side. A liquid crystal 16 is sealed between the substrates to form a sealant 17. Close the cell structure. Although not shown, domain regulating means such as a domain regulating projection 6 can be appropriately provided on the liquid crystal side surface of the color filter substrate (PS portion not formed) 10. An optical layer such as a polarizing plate 18 is appropriately disposed outside both substrates, and a backlight 19 is provided outside the pixel electrode substrate side. Except for the process of forming the PS part 5 and the domain regulating protrusion 6 according to the present invention, the process can be performed in the same manner as the manufacturing process of a normal liquid crystal display device.

  As described above, a liquid crystal display device can be manufactured using the color filter substrate or the pixel electrode substrate of the present invention. A color filter substrate or a pixel electrode substrate having the same configuration as that of the present invention is manufactured in the same manner as in the case of a liquid crystal display device that is manufactured by a conventional method. In the present invention, a liquid crystal display device with stable quality is manufactured. High quality can be provided. For example, the quality of the color filter substrate or the pixel electrode substrate PS portion and the domain regulating protrusion has no height variation, and there is no dent on the upper surface of the PS portion when the planar size is large. In the process of manufacturing the display device, no quality abnormality is caused in alignment film application.

1, 21, 41 ... Transparent substrate 2 ... BM pattern 4 ... Transparent electrode layer 5 ... PS part (fixed spacer)
6... Domain restricting projection 7... Positive type photoresist 8... Shading portion 9... Gray tone portion 10 .. Color filter substrate (projection not formed)
11 ... Color filter substrate (projection formation)
DESCRIPTION OF SYMBOLS 12 ... Pixel electrode substrate 13 ... Switching element 14 for active drive ... Pixel electrode 15 ... Orientation film 16 ... Liquid crystal 17 ... Sealant 18 ... Polarizing plate 19 ... Backlight 20 ... Photomask 30, 31, 32 ... Colored pattern 40 ... Irradiation light 51, 52, 53 ... for resist exposure PS part (fixed spacer)
62, 64 ... Protrusion part 80 for domain regulation ... All transmission slits 81, 82, 83 ... Light shielding part 85 ... Light shielding film 90, 92, 94 in gray tone part Gray tone part ( (For domain control protrusion formation)
91, 93 ... Gray tone part (for PS part formation)

Claims (10)

  A fixed spacer for controlling a liquid crystal cell gap using a positive photoresist on a color filter substrate having a color filter in a liquid crystal display device or a pixel electrode substrate having a switching element for active driving of the liquid crystal display device and a pixel electrode. A photomask for forming liquid crystal alignment domain regulating protrusions at a time, and as the photomask pattern of the fixed spacer, an isolated pattern having a gray tone portion including a total transmission slit around the light shielding portion; In addition, the photomask pattern of the domain restricting protrusion includes a strip-shaped pattern having a gray tone portion including a total transmission slit sandwiched between a plurality of parallel strip-shaped light shielding portions.   The planar shape of the fixed spacer is a convex simple polygon or a circle such as a circle or an ellipse, and the size is expressed by the diameter of the largest circle that can be stored in the contour of the fixed spacer, and is formed to be 30 to 50 μm. Therefore, the width of the total transmission slit of the gray tone portion around the light shielding portion for the fixed spacer is 5 to 7 μm, and the total size including the light shielding portion and the gray tone portion around the light shielding portion is 30 μm or more. The photomask according to claim 1, wherein:   In order to form the planar shape of the domain regulating protrusion into a strip shape having a width of 7 to 12 μm, the plurality of parallel strip-shaped light shielding portions are formed as two light shielding portions, and the width of the total transmission slit sandwiched between them is 1.5. 3. The photomask according to claim 1, wherein the gray tone portion including the total transmission slit has a width of 8 to 13 μm.   A color filter substrate comprising the photomask according to claim 1, wherein the fixed spacer and the domain regulating protrusion are selectively provided on the color filter substrate.   The height of the fixed spacer from the color filter pixel center outermost surface is 2.0 to 3.8 μm, and the height of the domain regulating protrusion is 0.8 to 1.4 μm. The color filter substrate according to claim 4.   4. A pixel electrode substrate using the photomask according to claim 1, wherein the fixed spacer and the domain regulating protrusion are selectively provided on the pixel electrode substrate.   The height of the fixed spacer from the outermost surface of the central portion of the pixel electrode is 2.0 to 3.8 μm, and the height of the domain regulating protrusion is 0.8 to 1.4 μm. The pixel electrode substrate according to claim 6.   A liquid crystal display device comprising the color filter substrate or the pixel electrode substrate according to claim 4.   A collective pattern is formed by a proximity exposure method using the photomask according to claim 1, and the fixing spacer and the domain regulating protrusion are selectively provided on a color filter substrate. A method for manufacturing a color filter substrate.   A collective pattern is formed by a proximity exposure method using the photomask according to claim 1, and the fixed spacer and the domain regulating protrusion are selectively provided on the pixel electrode substrate. A method for manufacturing a pixel electrode substrate.