JP2003307729A - Method for manufacturing liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device used as both of transmission and reflection type and a reflection type liquid crystal display device having a reflection plate having satisfactory reflection characteristics. <P>SOLUTION: The method for manufacturing the liquid crystal display device which is provided with a first substrate 10 or 180 and a counter substrate opposed to the first substrate sandwiching a liquid crystal layer, wherein light reflection plates 69 and 186 having ruggedness are provided on a first region A and a second region B on the surface on the liquid crystal layer side of the first substrate, comprises a stage for forming a photosensitive resin layer 68 on the first substrate so as to cover the first region and the second region, a stage for forming the ruggedness of the photosensitive resin layer on the upper surface of the first substrate by exposing the photosensitive resin layer so that the amounts of exposure in the first region and the second region are different from each other and a stage for forming the light reflection plate on the photosensitive resin layer so that the ruggedness is reflected. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a transflective liquid crystal display device and a reflective liquid crystal display device.

[0002]

2. Description of the Related Art In recent years, office automation equipment such as personal computers
(Office Automation) As devices are becoming more portable, cost reduction of display devices has become an important issue. The display device is provided with a pair of substrates each having electrodes formed on both sides of a display medium having electro-optical characteristics,
The display is configured by applying a voltage between the electrodes. As a display medium of such a display device,
Liquid crystals, electroluminescence, plasma, electrochromic, etc. are used, and in particular, liquid crystal display devices using liquid crystals (Liquid Crystal Dis).
play, LCDs) are most practical because they are thin and have low power consumption. Liquid crystal display devices are currently widely used in office automation equipment such as word processors and personal computers, portable information equipment such as electronic notebooks, and camera body type VTRs equipped with a liquid crystal monitor.

Regarding a display mode and a driving method of a liquid crystal display device, STN (Super Twisted Nematic)
The simple matrix method including the mode belongs to the category that can realize the lowest cost. However, in the future, with the progress of multimedia information, it is required that the display has high resolution, high contrast, multi-gradation (multi-color, full-color) and wide viewing angle. It seems that it is difficult to deal with. Therefore, an active matrix method has been proposed in which a switching element (active element) is provided in each pixel to increase the number of scan electrodes that can be driven. With this method, high resolution, high contrast, multi-gradation and wide viewing angle of a display are being achieved. In the active matrix type liquid crystal display device, pixel electrodes provided in a matrix and scanning lines passing near the pixel electrodes are electrically connected via an active element. 2 active elements
There is a non-linear element with three terminals and a non-linear element with three terminals. A typical active element currently adopted is a thin film transistor (Thin Film Transistor) with three terminals.
istor, TFT).

The liquid crystal display device has a transmission type and a reflection type. Liquid crystal display is CRT (CRT) or EL
Unlike (electroluminescence), since it does not emit light by itself, it is generally a transmissive type in which a device called a backlight, which is composed of a fluorescent tube, is installed in the back for illumination. However, since the backlight normally consumes 50% or more of the total power consumption of a liquid crystal display, a reflective plate is installed instead of the backlight and the ambient light is used for display, so the reflective type is used outdoors or at all times. This is advantageous from the viewpoint of low power consumption for portable information devices, which are often used in the future.

The display mode used in the reflection type liquid crystal display device uses a polarizing plate such as a TN (twisted nematic) mode and a STN mode which are widely used in the transmission type at present, and does not use a polarizing plate. Therefore, a phase transition type guest-host mode capable of realizing bright display has been actively developed in recent years.

The reflection type liquid crystal display device has a drawback that visibility is extremely deteriorated when ambient light is dark. On the other hand, the transmissive liquid crystal display device, on the contrary, has a problem that visibility is deteriorated when the ambient light is extremely bright-for example, in fine weather. Therefore, by using a substrate having a reflective electrode made of a material having a light reflecting function and a transparent electrode made of a material having a light transmitting function on the insulating substrate,
When the ambient light is dark, a transmissive liquid crystal display device that uses a backlight to display the light transmitted through the transparent electrode is used, and when ambient light is bright, it is formed of a film having a relatively high light reflectance. It becomes possible to display as a reflection type liquid crystal display device which displays by utilizing the light reflected by the reflection electrode. As a result, a single panel can be used as a transflective liquid crystal display device that uses a backlight when ambient light is dark and uses ambient light without ambient light when ambient light is bright. become.

This is low power consumption because the backlight is not used when the ambient light is brighter than the conventional transmissive liquid crystal display, and the backlight is used when the ambient light is dark by using the backlight. It is possible to overcome the drawback that a sufficient display cannot be obtained when the ambient light is dark as in the case of a liquid crystal display device.

In the reflective liquid crystal display device and the transflective liquid crystal display device as described above, in order to perform bright display by utilizing ambient light, the incident light from all angles is perpendicular to the display screen. It is necessary to increase the intensity of light scattered in the direction. In order to manufacture a reflection plate having optimum reflection characteristics, it is necessary to uniformly form uneven portions on the reflection plate with good reproducibility.

There is a method of forming the reflection plate by applying a photosensitive resin layer to an insulating substrate to form a pattern and then performing heat treatment to round off the pattern portion so that the pattern portion is rounded. The conventional manufacturing process of the transflective dual type substrate (element side substrate) of the transflective dual type liquid crystal display device will be described below with reference to FIGS.

FIG. 1 is a plan view of one pixel of a transflective type substrate 10. FIG. 2 is a sectional view taken along the line AA ′ of FIG. The transmissive / reflective type substrate 10 is a source bus line 1
2, the gate bus line 14, the pixel electrodes 27 and 29 formed in the region surrounded by the source bus line 12 and the gate bus line 14, and the amorphous silicon transistor (TF) provided corresponding to each pixel electrode.
T) 16 is included. A plurality of pixel electrodes are arranged in a matrix on the substrate to form a display portion of the liquid crystal display device. The pixel electrode includes a light transmission area 18 (corresponding to the electrode 27) and a light reflection area 19 (corresponding to the electrode 29) other than the light transmission area 18. The light reflection region 19 partially overlaps the gate bus line 14 (region A).

As shown in FIG. 2, the TFT 16 portion includes the gate electrode 14a (Ta film) on the glass substrate 20, the insulating layer 2
1 (SiNx film), semiconductor layer 22 (a-Si film), n-type semiconductor layer 23 (n-type a-Si film), source electrode 24 / drain electrode 25 (ITO film), and two layers 26 of Ta. Contains. Pixel electrode 27 in the light transmitting region
Is formed of a film such as ITO formed simultaneously with the source electrode 24 and the drain electrode 25 (note that the Ta film does not exist on the transmissive pixel electrode 27). A photosensitive resin layer 28 having an uneven portion is formed on the upper portion of the substrate, and the pixel electrode 2 of the light reflection region 19 formed of the Al / Mo film is formed on a part of the upper surface of the photosensitive resin layer 28.
9 is provided.

This transmission / reflection dual type substrate 10 is shown in FIG.
To (f) are formed. It should be noted that FIGS. 3A to 3F correspond to the portions where the TFT 16 of FIG. 2 is omitted. First, as shown in FIG. 3A, a positive type photosensitive resin layer 28 is formed on the substrate 20 on which the gate bus lines 14, the insulating layer 21, and the pixel electrodes 27 are formed.
(Acrylic resin made by Japan Synthetic Rubber) is applied to a thickness of 3.7 μm. Below the portion in the region A of the photosensitive resin layer 28, there is a pattern having a relatively high surface reflection such as the gate bus line 14, and the region B of the photosensitive resin layer 28 is present.
Under the portion of, the insulating film 21, the transparent electrode (pixel electrode 27) and other layers having relatively low surface reflection are formed, and there is no pattern having relatively high surface reflection.

An exposure 44 is uniformly performed on such a substrate with a low illuminance using a photomask (light-shielding mask) 40 having a light-shielding portion 42 shown in FIG. 4 (FIG. 3B). In the photomask 40, the light shielding part 42 has a round shape with a diameter of 12 μm, and the center interval of the light shielding part 42 is 14 μm. However, since the interference of the reflected light becomes a problem when the light-shielding portions 42 are arranged so that the center interval of the light-shielding portions 42 is 14 μm,
The light-shielding portions 42 are randomly arranged so that the minimum center distance is around 14 μm. For the exposure intensity, the reflection characteristics are evaluated while changing the exposure conditions on the base glass,
It is set to 50 mJ based on the result of obtaining the exposure intensity with which good reflection characteristics are obtained.

Next, using a photomask 50 having exposed portions 28b and 27b, which are opened in the contact hole portion 28a and the portion corresponding to the transmission electrode 27 in the transmission region 18, as shown in FIG. ) As shown in (), uniformly expose with high illuminance. The exposure intensity is 260 mJ.

Next, as shown in FIG. 3D, development is performed with a developing solution. As a result, the resin in the high-illuminance exposed portions (exposed portions 28b and 27b) described above is completely removed, and the resin in the low-illuminance exposed portion is somewhat thinned with respect to the initial film thickness.

Next, as shown in FIG. 3 (e), 100 ° C.
By heating for 11 minutes at 220 ° C. and then for 60 minutes at 220 ° C., the resin in the region exposed to low illuminance is deformed due to the heat sagging phenomenon, and a gentle uneven shape is obtained.

Next, a Mo thin film having a thickness of 100 nm is formed as the reflective electrode 29 by a sputtering method, and an A1 thin film is formed thereon by a sputtering method to have a thickness of 100 nm and patterned. Specifically, a photoresist is applied on the substrate, the photoresist portion above the transparent electrode portion 27a is exposed, and then the development, etching, and peeling steps are performed to pattern the Al / Mo electrode, The reflective pixel electrode 29 as shown in FIG. 3F is completed.

The conventional reflective liquid crystal display device will be briefly described below. Regarding the formation of the element side substrate of the reflection type liquid crystal display device, the controlled plate is formed on the surface of the substrate made of glass or the like so as to have the optimum reflection characteristics, and the thin film such as silver is formed on it to form the reflection plate. There is a way to do it. In Japanese Patent Laid-Open No. 6-75238, a plurality of convex portions are formed by applying a photosensitive resin on a substrate, exposing and developing the photosensitive resin through a light-shielding mask in which circular light-shielding portions are arranged, and then performing heat treatment. Is formed. An insulator protection film is formed on the protrusion along the shape of the protrusion, and a reflector made of a metal thin film is formed on the insulator protection film. Further, the problem of double reflection due to the influence of the glass thickness, which is a problem when the reflector is formed on the outside, is solved by forming the reflector inside and also serving as a pixel electrode.

[0019]

The reflective plate of the conventional transflective liquid crystal display device formed by the above steps has the following problems.

A region A where a wiring pattern having a relatively strong surface reflection such as a bus line or an auxiliary capacitor exists below the photosensitive resin layer 28, and a surface reflection such as an insulating film or a transparent electrode below the photosensitive resin layer 28. In the region B where is relatively weak, even if the uneven shape is formed with the same exposure intensity, there is a difference in the uneven step shape.
For example, according to the process of FIG. 3 above, in the region A, the thickness a of the photosensitive resin layer 28 of the convex portion is 2.7 μm, and the thickness b of the concave portion is 1.0 μm, while in the region B, The thickness a ′ of the photosensitive resin layer 28 of the convex portion is 2.9 μm, and the thickness b ′ of the concave portion is 1.9 μm (FIG. 3 (e)). The reason why the unevenness in the area A is large is that the unevenness in the area B is caused by the increase in the exposure amount due to the surface reflection in the pattern existing under the photosensitive resin layer in the area A. It may be larger than that.

That is, when the photosensitive resin is applied to the insulating substrate to form a pattern, the surface reflection of the insulating film, the transparent electrode, and the like when the underlying surface of the photosensitive resin has a relatively high surface reflection. When the height was relatively low, the concavo-convex shape formed thereon was different, and the reflection characteristics as designed could not be realized. Even if the uneven shape is patterned with the same exposure intensity,
When the base of the photosensitive resin has a relatively high surface reflection, the amount of exposure increases due to the surface reflection, so that the unevenness has a larger step than when the base has a relatively low surface reflection.

On the substrate on which the three-terminal nonlinear resistance element is formed, many conductive thin film layers such as bus lines and auxiliary capacitors, insulator layers, semiconductor layers, etc. are formed and are not flat. There is a step in each layer. For this reason, the photosensitive resin for forming the uneven portion is also affected by the step in the lower layer and cannot maintain a uniform film thickness. When the photosensitive resin is applied on the area A like the area B, the film thickness of the photosensitive resin on the bus line, the auxiliary capacitor, and the like is changed to the other portion (area B) due to the step on the substrate surface. It becomes thinner than the film thickness of the photosensitive resin. When forming a concavo-convex portion with a positive-type photosensitive resin, if a light-shielding means having circular light-shielding portions with the same diameter is used, in regions where the film thickness of the photosensitive resin is different, circular shapes with different sizes (diameters) are used. A convex portion will be formed. Further, even when the light shielding means having circular light transmitting portions having the same diameter is used, circular recesses having different sizes (diameters) are formed in regions where the film thickness of the photosensitive resin is different. Similarly, when forming the concave-convex portion with the negative photosensitive resin, different circular concave portions or convex portions are formed. Further, when the photosensitive resin is applied to the insulating substrate to form a pattern, if the region A is exposed so that the reflection efficiency is good, the region B is not sufficiently exposed because the exposure amount is insufficient and the uneven shape is not sufficiently formed. The reflection characteristics cannot be obtained. On the other hand, when applying a photosensitive resin to the insulating substrate to form a pattern, the area B
When the exposure is performed so that the reflection efficiency becomes good, a sharp uneven shape is formed in the region A due to the excessive exposure amount, and good reflection characteristics cannot be obtained.

As described above, even in the same pixel, the concavo-convex shape varies from region to region, and it is difficult to uniformly form controlled concavities and convexities within the pixel in order to obtain optimum reflection characteristics.

The above description relates to the transflective liquid crystal display device, but in the reflective liquid crystal display device, the display portion does not have the transmissive region 18 and all are reflective regions. Have a similar problem with. The concavo-convex portion of the reflection plate of the reflective liquid crystal display device is formed by randomly arranging circular ones, and the diameter φ thereof is 1 μm to 3 μm.
0 μm, and the spacing between them is also 1 μm
It is extremely small as m to 30 μm. For this reason, high-definition photolithography is required, and it is difficult to form a reflection plate having uniform unevenness.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a transflective liquid crystal display device and a reflective liquid crystal display device having a reflection plate having good reflection characteristics. , And their manufacturing method.

[0026]

A method of manufacturing a liquid crystal display device according to the present invention comprises a first substrate and a liquid crystal layer sandwiched between the first substrate and the first substrate.
A method of manufacturing a liquid crystal display device, comprising: a counter substrate facing the first substrate; and a first region having a lower reflectance than the first region on the liquid crystal layer side surface of the first substrate. Two
And forming a photosensitive resin layer in the region, and using a light shielding mask having a plurality of circular patterns and the diameter of the circular pattern in the first region is smaller than the diameter of the circular pattern in the second region. And exposing the photosensitive resin layer to form irregularities due to the photosensitive resin layer in the first region and the second region, and the irregularities are reflected on the liquid crystal layer side of the photosensitive resin layer. Forming a light reflection plate as described above.

The circular pattern is a light shielding part.

The exposure is performed in the first area and the second area.
The same illuminance is applied to the area.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION The basic concept of the present invention will be described below.

In the present invention, in order to form a transflective liquid crystal display device and a reflective liquid crystal display device having a reflection plate having good reflection characteristics, in the exposure process of the photosensitive resin layer, Change the exposure dose for different areas. More specifically, the exposure amount of a region (region A) where the thickness of the photosensitive resin layer is relatively small due to the presence of a region where the base of the photosensitive resin has a relatively high surface reflection or a wiring,
The amount of exposure is set to be lower than the exposure amount of a region (region B) where the thickness of the photosensitive resin layer is relatively large due to the absence of a region where the base has a relatively low surface reflection or wiring.

Regarding the adjustment of the exposure amount, a method of controlling the intensity of the light to be exposed (exposure intensity) by using a photomask (light-shielding mask) having a uniform pattern and a photomask in which the patterns of different regions are different from each other are used. There is a method of performing exposure.

(First Embodiment) The first embodiment of the present invention will be described below.
As an embodiment of the present invention, a transflective dual-mode liquid crystal display device including a transflective dual-mode substrate and a method for manufacturing the same will be described.

The plan view of one pixel of the transmission / reflection dual-use substrate in this embodiment is basically the same as the configuration shown in FIG. 1, and the description thereof will be omitted. FIG. 6 shows a sectional structure of the transflective type substrate 60 according to the present invention taken along the line AA ′ in FIG. Reflection plate 69 in transmissive / reflective type substrate 60
Have unevenness of substantially the same size, and have uniform and good reflection characteristics. In the specification of the present application, the "unevenness of substantially the same size" possessed by the reflection plate means that the reflection plate exhibits a reflection characteristic that does not cause unevenness in display quality within one pixel. Refers to unevenness. The other parts of the transflective type substrate 60 are basically the same as the corresponding parts shown in FIG.

A method of manufacturing a transflective type liquid crystal display device will be described below with reference to FIGS. 7 (a) to 7 (g).
In this embodiment, a desired unevenness is formed on the surface of the photosensitive resin layer by controlling the exposure amount for exposing the photosensitive resin layer using a photomask having a uniform pattern. It should be noted that FIGS. 7A to 7G correspond to the portions of FIG. 6 where the TFT 16 is omitted.

First, as shown in FIG. 7A, the positive photosensitive resin layer 6 is formed on the substrate 20 on which the gate bus lines 14, the insulating layer 21 and the pixel electrodes 27 are formed.
8 (Japanese synthetic rubber acrylic resin) is applied to a thickness of about 3.7 μm. A pattern having a relatively high surface reflection such as the gate bus line 14 exists below the portion of the photosensitive resin layer 68 in the region A, and an insulating layer is formed below the portion of the photosensitive resin layer 68 in the region B. Only the layer having a relatively low surface reflection such as the film 21 and the transparent electrode (pixel electrode 27) is formed, and there is no pattern having a relatively high surface reflection. Therefore, the thickness of the photosensitive resin layer 68 in the region A is smaller than that in the region B.

A first photomask 80 having a light-shielding portion 82 in which all regions A are shielded from light and other regions (regions B) are irregularly arranged as shown in FIG. And uniformly perform exposure 44 with low illuminance (FIG. 7).
(B)). In the photomask 80, the light shielding portion 82 has a round shape with a diameter D of 12 μm, and the center distance E of the light shielding portion 82 is 14 μm. However, if the light-shielding portions 82 are arranged so that the center distance between them is 14 μm, interference of reflected light becomes a problem.
Those randomly arranged so as to be around 4 μm are used. The exposure intensity is set to about 50 mJ.

Next, as shown in FIG. 9, the second photomask 90 in which the area A has the light-shielding portions 82 arranged irregularly and the other area (area B) is entirely shielded from light. Then, as shown in FIG. 7C, the exposure 44 is uniformly performed with low illuminance. The size and arrangement of the light shielding portion 82 are the same as those in the exposure process using the first photomask 80 described above. In this step, if the exposure intensity is 50 mJ as in the case of the first photomask 80, the unevenness of the uneven shape in the region A of the photosensitive resin layer becomes larger than that in the region B. Because, under the area A of the photosensitive resin layer 68, the wiring pattern (gate bus line 1
4) is present, and the photosensitive resin layer 6 is thereby added.
This is because the film thickness of the area A of 8 is thinner than that of the other area (area B).

In order to set the optimum exposure intensity for the area A, the transmission / reflection dual-type substrate is exposed using the conventional photomask 40 shown in FIG. 4, and the exposure intensity and the areas A and B are exposed. The relationship between the unevenness of the unevenness was investigated. The result is shown in FIG. In FIG. 10, in order to consider not only the relative shape of the unevenness but also the height uniformity from the same surface as the variation in the size of the unevenness that governs the reflection characteristics, a value obtained by adding the base film to the resin film thickness. Is set on the vertical axis. That is, in the area A, the film thickness of the gate bus line is 0.3 μm so that the uniformity of the height from the same surface as the area B can be compared. As can be seen from FIG. 10, the thickness a of the photosensitive resin layer on the convex portion of the region A and the thickness a ′ of the photosensitive resin layer on the convex portion of the region B (see FIG. 3E) are
It is almost constant regardless of the exposure intensity. On the other hand, the thickness of the photosensitive resin layer in the recess is as follows when the exposure intensity is 35 mJ (thickness b):
The exposure intensities of 50 mJ (thickness b ') are almost equal. Based on the above result, in the present embodiment, the exposure intensity when the second photomask 90 for the region A is exposed in the step shown in FIG. 7C is set to about 35 mJ.

Next, as shown in FIG. 5, a photomask 50 (third photomask) having exposure portions 28b and 27b in which a portion corresponding to the transmission electrode 27a of the contact hole portion 28a and the transmission region 18 is opened is formed. Using FIG.
As shown in (d), the exposure is performed uniformly with high illuminance. The exposure intensity is 260 mJ.

Next, as shown in FIG. 7E, development is performed with a developing solution. As a result, the resin in the high-illuminance exposed portions (exposed portions 28b and 27b) described above is completely removed, and the resin in the low-illuminance exposed portion is somewhat thinned with respect to the initial film thickness.

Next, as shown in FIG. 7 (f), 100 ° C.
By heating for 11 minutes at 220 ° C. and then for 60 minutes at 220 ° C., the resin in the region exposed to low illuminance is deformed due to the heat sagging phenomenon, and a gentle uneven shape is obtained.

Next, a Mo thin film having a thickness of 100 nm is formed as the reflective electrode 69 by a sputtering method, and an A1 thin film is formed thereon by a sputtering method to have a thickness of 100 nm and patterned. Specifically, a photoresist is applied on the substrate, the photoresist portion above the transmissive electrode 27a is exposed, and then development, etching,
By patterning the Al / Mo electrode by performing the peeling process, the reflective pixel electrode 6 as shown in FIG.
Complete 9. The reflective pixel electrode 69 has substantially the same uneven shape as the photosensitive resin layer 68.

Through the above steps, the reflection plate having a smooth and high-density reflection unevenness is formed, and in both the region A and the region B where the reflection plate is formed, an uneven shape having a uniform step is formed. can get. That is, the concavo-convex shape (the step (ab = 2.7 μm-1.0 μm) in the region A) of the conventional reflector is 1.7 μm, and B is
Step in area (a'-b '= 2.9 μm-1.9 μm)
Is 1.0 μm, the unevenness of the reflector according to the present invention has a step (ab = 2.7−1.6 =) in both area A and area B.
1.1 and a'-b '= 3.0-1.9 = 1.1) have the same size of 1.1 μm. As a result, the reflector according to the present invention has a uniform and good reflectance as compared with the conventional reflector.

The transflective dual-use type substrate formed as described above and the color filter substrate having the counter electrode are bonded together, and liquid crystal is injected between the substrates to form a transflective dual-use liquid crystal display panel.

In the above description, the light-shielding portion of the photomask has a circular shape, but instead of the circular shape, a square shape,
It may have other geometric shapes such as a rectangle. Further, in the present embodiment, after the photosensitive resin layer is developed, the exposure is performed so that the concave portions are present. However, as shown in FIG. 20, which will be described later, after the photosensitive resin layer is developed, only the convex portions are present. Also, since the shape of the convex portion is adjusted, the uneven shape having substantially the same size can be realized by setting the optimum exposure amount. The same applies to the following embodiments.

(Second Embodiment) The second embodiment of the present invention will be described below.
As another embodiment, another manufacturing method of the transflective liquid crystal display device will be described. In the first embodiment described above, two photomasks (80 and 90) are used to form the unevenness on the photosensitive resin layer, and the regions A and B of the photosensitive resin layer are formed in two steps. It is exposed. In this embodiment, in order to form the unevenness, one exposure process is performed using one photomask having different patterns in the portions corresponding to the regions A and B. In this photomask, the ratio of the exposed area to the shielded area in the area A is set smaller than the ratio of the exposed area to the shielded area in the area B. With reference to FIGS. 11A to 11F, a method of manufacturing a transflective liquid crystal display device having a diagonal size of 2 inches according to this embodiment will be described.

First, as shown in FIG. 11A, a positive type photosensitive resin layer 68 (Japan) is formed on a substrate 20 having a gate bus line 14, an insulating layer 21 and a pixel electrode 27 formed on the upper surface thereof. Synthetic rubber acrylic resin) is applied to a thickness of about 3.7 μm.

12 is uniformly exposed at low illuminance (exposure intensity, about 50 mJ) (FIG. 11B). The photomask 120 is irregular. Pattern of the area A having the circular light shielding portion 122a arranged in the area, the pattern of the area A and the light shielding portion 1
22a has a pattern of a region B having a light shielding portion 122b having different diameters and center intervals. Light-shielding parts 122a and 12
By adjusting the size and center interval of 2b, the exposure amount for the region A of the photosensitive resin layer 68 can be made smaller than the exposure amount for the region B. (Shading section 12
A discussion of the optimal values for the size and center spacing of 2a and 122b will be described in detail later. ) In this embodiment, the circular light shielding portion 122 a in the region A of the photomask 120 is used.
Has a diameter of 10 μm and a center-to-center spacing of 12 μm.
The round light-shielding portion 122b has a diameter of 12 μm and a center interval of 1
It is 4 μm. However, the center interval of the light shielding part should be 12μ evenly.
When m and 14 μm are set, interference of reflected light becomes a problem. Therefore, it is preferable to randomly set the center intervals of the light-shielding portions so that the minimum intervals are about 12 μm and 14 μm, respectively. The exposure condition is 50 m as in the first embodiment.
The exposure intensity is set to J.

Next, using a photomask 50 having exposure portions 28b and 27b in which the contact hole portion 28a and the portion of the transmission region 18 corresponding to the transmission electrode 27a are opened, as shown in FIG. ) As shown in (), uniformly expose with high illuminance. The exposure intensity is 260 mJ.

Next, as shown in FIG. 11D, development is performed with a developing solution. As a result, the resin in the high-illuminance exposed portions (exposed portions 28b and 27b) described above is completely removed,
The resin in the low-illuminance exposed area is slightly reduced with respect to the initial film thickness.

Next, as shown in FIG. 11 (e), 100
By carrying out heat treatment at 11 ° C. for 11 minutes and then heat treatment at 220 ° C. for 60 minutes, the resin in the region exposed to low illuminance is deformed due to the heat sagging phenomenon, and a smooth uneven shape is obtained.

Next, a Mo thin film is formed as the reflective electrode 69 to a thickness of 100 nm by the sputtering method, and an A1 thin film is formed thereon to a thickness of 100 nm by the sputtering method, and patterning is performed. Specifically, a photoresist is applied on the substrate, the photoresist portion above the transmissive electrode 27a is exposed, and then development, etching,
By patterning the Al / Mo electrode by performing a peeling process, a reflective pixel electrode 69 as shown in FIG. 11F is completed. The transflective dual-use substrate thus formed and a color filter substrate having a counter electrode are bonded together, and liquid crystal is injected between the substrates to produce a transflective dual-use liquid crystal display panel.

The optimum values of the sizes and the center intervals of the light shielding portions 122a and 122b of the photomask 120 used in this embodiment will be considered below.

First, in order to carry out this consideration, a plurality of transflective dual-use substrates are formed by using a plurality of photomasks (see the photomask 40 shown in FIG. 4) having different sizes of light-shielding portions and center intervals. To do. Specifically, a positive type photosensitive resin layer is applied on a glass substrate to a thickness of about 3.7 μm, and then a photomask having a light-shielding portion having a constant size and center interval is used. And uniformly expose it with low illuminance (exposure intensity, about 50 mJ). After development, heat treatment is performed at 100 ° C. for 11 minutes, and further heat treatment is performed at 220 ° C. for 60 minutes. Then, Al (thickness 100n
A reflector made of m) / Mo (thickness 100 nm) is formed. The reflection substrate and the glass substrate were attached to each other with methyl salicylate in between, and a Y value representing reflection intensity was measured using Minolta CM-2002 with a standard white plate as a reference. The result is shown in FIG.

In FIG. 13, a curve (8-2P) is a reflective substrate formed using a photomask having a pattern in which the diameter of the round light-shielding portion is 8 μm and the center interval is 10 μm, and the curve (10-2P) is The diameter of the round light shield is 10 μm
And a reflective substrate formed by using a photomask having a pattern with a center interval of 12 μm, a curve (12-2
In P), the diameter of the round light-shielding part is 12 μm and the center interval is 1
The relationship between the exposure intensity and the Y value of the reflection plate in the case of a reflection substrate formed using a photomask having a pattern of 4 μm is shown. However, when the light-shielding portions are arranged so that the center distances thereof are 14 μm, 12 μm, and 10 μm, respectively, interference of reflected light poses a problem.
Those randomly arranged such that the minimum values were around 14 μm, 12 μm, and 10 μm were used.

According to FIG. 13, the diameter of the light shielding part is 12 μm.
It can be seen that the exposure intensity at which the Y value becomes maximum increases with decreasing from 10 μm to 8 μm. From this, when the photosensitive resin layer is exposed using the photomask 120 shown in FIG. 12, by making the diameter of the light shielding portion 122a in the region A smaller than the diameter of the light shielding portion 122b in the region B, the light shielding portion is formed. It can be seen that better reflection characteristics can be obtained as compared with the case where exposure is performed with a photomask having the same diameter on the entire surface.

The display panel formed according to this embodiment can obtain a higher Y value than the display panel according to the prior art (note that the layer thickness of the liquid crystal layer influences the reflection characteristics in the measurement of the Y value. The polarizing plate is measured without being attached to the panel so that it is not given). More specifically, FIG.
Photomask 40 shown in (The light-shielding portion has a uniform diameter of 12 μm.
m and the center interval is 14 μm), the Y value is 5.28 in the panel according to the related art. On the other hand, according to the method of the second embodiment, the diameter of the light shielding portion 122a in the region A is 8 μm, the center interval is 10 μm, and the region B is
The light-shielding portion 122b has a diameter of 12 μm and a center interval of 14 μm.
The Y value of the panel formed using the photomask 120 having m is 5.31. Further, similarly, according to the method of the second embodiment, the diameter of the light shielding portion 122a in the region A is 10 μm.
m, the center interval is 12 μm, the diameter of the light-shielding portion 122b in the region B is 12 μm, and the Y value of the panel formed using the photomask 120 with the center interval of 14 μm is 5.73, which is about the same as that of the conventional panel. A 9% improvement in reflection properties is observed. In this way, the regions A and B of the photomask are
It is possible to improve the reflection characteristics of the reflection plate by changing the diameter or center interval of the light shielding part.

The present embodiment has the following advantages over the first embodiment. In the first embodiment, in the exposure step for forming unevenness on the photosensitive resin layer,
The process is performed twice using two photomasks.
According to the embodiment of the present invention, by using the photomasks having two types of patterns, it is possible to form the desired unevenness in one exposure process with one photomask. Therefore, it is possible to avoid a decrease in production efficiency due to an increase in the number of masks and the number of steps by changing the exposure amount.

In consideration of the wiring pattern formed on the substrate and the like, it is possible to form uniform unevenness on the entire surface of the photosensitive resin layer on which the reflective pixel electrode (reflection plate) is formed. If necessary, two or more types of patterns (sizes and intervals of light shielding portions) of the light shielding portions of the photomask used for exposing the photosensitive resin layer may be used.

(Third Embodiment) As a third embodiment of the present invention, a further manufacturing method of a transflective liquid crystal display device will be described. In this embodiment, the pattern of the photomask used for forming the unevenness on the photosensitive resin layer is the second pattern.
Different from that of the second embodiment, the manufacturing method is similar to that of the second embodiment. Hereinafter, the pattern of this photomask will be mainly described.

As shown in FIG. 14, the two types of patterns of the region A and the region B of the photomask 140 used in this embodiment have light-shielding portions 142a and 142 arranged irregularly.
The diameters of b are the same, but the center intervals of the light shielding parts are different. In order to form a uniform uneven shape on the photosensitive resin layer, the center distance between the light shielding portions 142a in the region A of the photomask 140 is set smaller than the center distance between the light shielding portions 142b in the region B.

In order to evaluate the optimum exposure intensity in a mask pattern in which the distance between the light-shielding portions is changed and the diameter of the light-shielding portions is constant, the light-shielding portion has a round shape with a diameter of 8 μm and the center distance of the light-shielding portions is 10 μm. The pattern (8-2
P), and a pattern (8 having a circular shape with a diameter of the light-shielding portion of 8 μm and arranged so that the center interval of the light-shielding portion 17 is 11 μm.
-3P) was used to prepare a reflection plate by changing the exposure intensity, and the relationship between the exposure intensity and the Y value was investigated. The result is shown in FIG. When creating the reflector, the center intervals of the light-shielding parts should be 10μ and 11μ, respectively.
Since the interference of the reflected light becomes a problem when it is arranged so as to be m, the center intervals of the light shielding parts are randomly arranged so that the minimum distance is around 10 μm or 11 μm.

According to FIG. 15, the distance between the light shielding parts is 11 μm.
It can be seen that the exposure intensity at which the Y value is maximized increases with decreasing from 10 μm to 10. From this, the interval between the light shielding portions 142a in the region A is set to be equal to that in the region B
By making the exposed area of the photosensitive resin layer in the region A smaller than the exposed area of the photosensitive resin layer in the region B, the light having the same intensity with respect to the regions A and B can be obtained. Even if it is irradiated with, it is expected to form irregularities having a uniform shape. As a result, it is possible to obtain a reflective electrode exhibiting better reflective characteristics than in the case of performing exposure with a photomask in which the intervals of the light-shielding portions are the same.

When unevenness is formed on the photosensitive resin layer using the photomask 140 according to the present embodiment, the specific dimensions of the photomask patterns 142a and 142b are the coating thickness of the photosensitive resin and the photosensitive resin. It may be set appropriately in consideration of the surface reflection characteristics and the film thickness of the wiring pattern below.

(Fourth Embodiment) As a fourth embodiment of the present invention, still another method of manufacturing a transflective liquid crystal display device will be described. In this embodiment, the pattern of the photomask used for forming the unevenness on the photosensitive resin layer is the second pattern.
Different from that of the second embodiment, the manufacturing method is similar to that of the second embodiment. Hereinafter, the pattern of this photomask will be mainly described.

As shown in FIG. 16, in the photomask 160 according to the present embodiment, the diameter of the light transmitting portion 162a in the region A is smaller than the diameter of the light transmitting portion 162b in the region B, and thus the light transmitting portion 16 is formed.
The minimum distance of 2a (the minimum distance between the side of one transparent portion and the side of the adjacent transparent portion) and the minimum distance of the transparent portion 162b are set to be the same. The light transmitting portions 162a and the light transmitting portions 162b are arranged irregularly.

In order to evaluate the optimum exposure intensity with such a photomask, a pattern (8- having a circular shape with a diameter of the light transmitting portion of 8 μm and a center interval of the light transmitting portions of 12 μm at the minimum) is used. 4N) and a photomask having a pattern (6-4N) which is a circular shape having a diameter of the light transmitting portion of 6 μm and is arranged such that the center interval of the light transmitting portion is at least 10 μm. The dependence of the exposure intensity and the Y value on the prepared reflector was examined. The result is shown in FIG.
In the production of the reflection plate, if the light-transmitting portions are arranged such that the center distances thereof are 10 μm and 12 μm, the interference of the reflected light becomes a problem. And those randomly arranged so as to be around 12 μm were used.

It can be seen from FIG. 17 that the exposure intensity at which the Y value becomes maximum increases as the diameter of the light transmitting portion decreases from 8 μm to 6 μm. From this, the area A
By making the diameter of the light-transmitting portion 162a of the light-transmitting portion 162a smaller than the diameter of the light-transmitting portion 162b of the region B, better reflection characteristics can be obtained as compared with the case where exposure is performed using a photomask having the same light-transmitting portion diameter. Can be expected to be. Therefore, by making the area of the photosensitive resin exposed to low illuminance smaller in the area A than in the area B, it is possible to form a reflective electrode having good reflection characteristics in the areas A and B with the same exposure intensity.

When irregularities are formed on the photosensitive resin layer using the photomask 160 according to the present embodiment, the specific dimensions of the photomask patterns 162a and 162b are determined by the coating thickness of the photosensitive resin and the photosensitive resin. It may be set appropriately in consideration of the surface reflection characteristics and the film thickness of the wiring pattern below.

In the above embodiment, the region 18 (region C) which is the transmissive electrode region is included in the region B (see FIG. 2).
Although the low-illuminance exposure is performed with the same mask pattern as the region B, the region C, which is the transmissive electrode region, has the same mask pattern as the region A because the region C removes all the photosensitive resin together with the contact hole portion. Illuminance exposure may be performed.

Further, in the above description, the unevenness of the reflecting plate is formed by one layer of photosensitive resin, but the unevenness may be formed by using a plurality of photosensitive resin layers. For example, it is possible to form a concavo-convex pattern after applying the first photosensitive resin and then apply the second photosensitive resin layer thereon to form the reflector.

It should be noted that irregularities similar to those of the surface of the photosensitive resin layer in the area (area B) where the base has a relatively low surface reflection may be formed on the surface of the photosensitive resin layer on the bus line (area A). Although ideal, if the pattern of the bus line is relatively thin, it may be difficult to form the desired unevenness on the surface of the photosensitive resin layer on the bus line. However, since only a part of the reflective layer is usually formed on the bus line, it does not significantly contribute to the reflection characteristic as compared with the reflective layer formed on the auxiliary capacitance forming portion having a large area. Therefore,
The reflection characteristics of the reflective electrode can be obtained only by forming an uneven shape different from the uneven shape formed in the region where the base has a relatively low surface reflection in a region where the surface has a relatively high surface reflection (for example, the auxiliary capacitance forming portion). Can be improved.

(Fifth Embodiment) The fifth embodiment of the present invention will be described below.
As an embodiment, a method of manufacturing a reflective liquid crystal display device will be described.

FIG. 18 is a plan view of one pixel of the element side substrate 180. 19 is a cross-sectional view taken along the line AA ′ of FIG. The element-side substrate 180 includes a source bus line 181, a gate bus line 182, a pixel electrode (reflection electrode) 186 that also serves as a reflector formed in a region surrounded by the source bus line 181 and the gate bus line 182, and each pixel. It includes a 3-terminal non-linear resistance element 185 provided corresponding to the electrode. Glass substrate 1 with multiple pixel electrodes
The display units 90 are arranged in a matrix on the screen 90 to form a display unit of the liquid crystal display device. Note that an auxiliary capacitance electrode and an auxiliary capacitance wiring 194 are provided over the glass substrate 190 so as to partially overlap with the reflective electrode 186.

As shown in FIG. 19, the three-terminal non-linear resistance element 185 includes a gate electrode 182a made of a conductive thin film on a glass substrate 190 and an insulator layer 189 formed on the gate electrode 182a and the auxiliary capacitance electrode 194. The semiconductor layer 187, the contact layers 187a and 187b, the source electrode 183, and the drain electrode 184.

An insulator protection layer 192 is formed on the three-terminal nonlinear resistance element 185, and the insulator protection layer 19 is formed.
2 is patterned so that the contact hole 198 is located above the leading electrode 184a of the drain electrode 184. A reflective electrode 186 made of aluminum or the like is further formed thereon so as to be electrically connected to the lead-out electrode 184a of the drain electrode 184 through a contact hole 198.

Further, in order to form a reflector having optimum reflection characteristics for increasing the intensity of light scattered in a direction perpendicular to the display screen with respect to incident light from all angles,
Insulator protective layer 192 at the portion where the reflective electrode 186 is formed
A photosensitive resin layer 191 composed of a plurality of concave and convex portions is formed in the lower part of the.

A method of manufacturing the above-mentioned reflective liquid crystal display device will be described below with reference to FIGS.

As shown in FIG. 20A, the substrate 19 on which the auxiliary capacitance electrode 194, the insulator layer 189, the drain electrode 184 and the terminal nonlinear resistance element 185 (not shown) are formed.
The positive photosensitive resin 191a is applied to the entire surface of 0. As the resist material which is the photosensitive resin 191a, for example, OF
PR-800 (manufactured by Tokyo Ohka) is preferably 500 rp
It is applied by spin coating at m to 3000 rpm. In this example, application was performed at 2000 rpm for 30 seconds.

A large number of metal thin film layers (auxiliary capacitance electrode 19) are formed on the substrate 190 on which the three-terminal nonlinear resistance element 185 is formed.
4, the drain electrode 184, etc.), the insulator layer 189, the semiconductor layer (not shown), etc. are stacked, so that they are not flat, and there is a step in each layer. As shown in FIG. 20A, the substrate 190 has a region A in which the thickness of the photosensitive resin 191a is relatively small and a region B in which the thickness of the photosensitive resin layer 191a is relatively large. The thickness of the photosensitive resin layer 191a in the region A is 2 μm, and the thickness of the photosensitive resin layer 191a in the region B is 3 μm.

Next, a photomask 2 as shown in FIG.
20 is used to perform exposure as shown in FIG. In the photomask 210, circular light shielding regions 212a and 212b indicated by diagonal lines are arranged irregularly. The light-shielding region 212a is arranged in the region A where the auxiliary capacitance electrode 194 is formed in the lower layer on the substrate 190, and
b is arranged in the region B where the other drain electrode is located. The diameter D1 of the light blocking area 212a is equal to that of the light blocking area 21.
It is formed larger than the diameter D2 of 2b. For example, the diameter D1 is 15 μm and the diameter D2 is 10 μm. By using the photomask 210, the area A
The ratio of the exposed area to the light-shielded area in
It is set to be smaller than the ratio of the exposed area to the light-shielded area.

When exposure is performed with the photomask 210, the region A where the auxiliary capacitance electrode 194 is formed in the lower layer is overexposed because the photosensitive resin 191a is thinner than the region B where the other drain electrodes are located. , FIG. 20
Exposure is performed up to the position indicated by the arrow in the photosensitive resin layer 191a in (b).

Next, as shown in FIG. 20C, the photosensitive resin 191a is developed to form a circular convex portion. 2.38% NMD-3 (manufactured by Tokyo Ohka Co., Ltd.) is used as a developer. As a result, the convex portion of the area A in which the auxiliary capacitance electrode 194 is formed in the lower layer becomes a circular convex portion having a smaller diameter than the light shielding area 212a of the photomask 210 used in the step of FIG. The circular convex portion has the same diameter as the convex portion formed in the region B where the drain electrode is located.

Next, as shown in FIG. 20D, heat treatment is preferably carried out at 120 ° C. to 250 ° C. to remove the corners of the convex portions (photosensitive resin layer 191a) and thereby form a smooth photosensitive portion. Resin layer 191 is formed. In this embodiment, heat treatment is performed at 180 ° C. for 30 minutes.

Then, as shown in FIG.
A resist resin is preferably used as the insulator protective film 192 on the substrate on which the photosensitive resin layer 191 having the convex portions is formed.
It is applied by spin coating at 00 rpm to 3500 rpm. In this embodiment, a film thickness of 1 μm is obtained by applying 20 seconds at 2200 rpm. As a result, convex portions corresponding to the convex portions of the photosensitive resin layer 191 are formed on the insulating protective film 192, but the shape is smoother than that of the photosensitive resin layer 191. Further, a contact hole 198 (see FIG. 19) for connecting the drain electrode 184 and the reflective electrode 186 formed in the next step is formed by using the photolithography method.

Finally, as shown in FIG. 20 (f),
A metal thin film to be the reflective electrode 186 is vacuum-deposited on the insulator protection film 192 to a thickness of 2000 Å. As a result, the drain electrode 184 and the reflective electrode 186 are contact holes 1
Connected via 98. Furthermore, the reflective electrode 186 is completed by patterning the metal thin film for each pixel.
The metal thin film used aluminum in this embodiment, but silver,
It is also possible to use copper, nickel, chromium or the like.
The reflection type liquid crystal display device is obtained by bonding the element side substrate 180 formed as described above to a counter substrate by a known method and injecting liquid crystal therebetween.

Through the above steps, the light-shielding regions 212 having different diameters in the regions A and B where the film thickness of the photosensitive resin 191 is different.
By using the light-shielding means 210 having a and 212b, it is possible to form a uniform uneven shape in the same pixel, and it is possible to obtain a reflection plate which also has a reflection electrode and has optimum reflection characteristics.

Although the positive type photosensitive resin is used in this embodiment, the negative type photosensitive resin is used to form circular concave portions having the same diameter in both the regions A and B, so that the unevenness is uniform in the same pixel. A shape can be created, and the same effect as when using a voluminous type photosensitive resin can be obtained.

In this embodiment, two types of light blocking areas 212 are used.
The photomask 210 having a and 212b is used.
The light shielding means is not limited to this. For example, circular light-shielding regions having different diameters may be formed on the three-terminal nonlinear resistance element 185, and the light-shielding regions may have three or more types of circular shapes.

(Sixth Embodiment) The sixth embodiment of the present invention will be described below.
As another embodiment, another method of manufacturing a reflective liquid crystal display device will be described. In this embodiment, the photomask used in the exposure process for forming the photosensitive resin layer on the plurality of convex portions is different from that in the fifth embodiment, and the other processes are basically the same. .

FIG. 22 shows the plane of the photomask 220 used in this embodiment. The difference between the photomask 220 and the photomask 210 of the fifth embodiment is that the photomask 210 has a circular light-shielding region as a light-shielding portion, whereas the photomask 220 has a circular light-shielding portion as a light-transmitting portion. Transparent regions 222a and 222b are provided.

With reference to FIGS. 23A to 23F, a method of manufacturing the reflective liquid crystal display device of this embodiment will be described.

First, as shown in FIG. 23A, the positive type photosensitive material is formed on the entire surface of the substrate 190 on which the auxiliary capacitance electrode 194, the insulating layer 189, the drain electrode 184 and the terminal nonlinear resistance element 185 (not shown) are formed. The resin 191a is applied. As the resist material which is the photosensitive resin 191a, for example, OFPR-800 (manufactured by Tokyo Ohka Co., Ltd.) is preferable.
It is applied by spin coating at 00 rpm to 3000 rpm. In this example, application was performed at 2000 rpm for 30 seconds.

A large number of metal thin film layers (auxiliary capacitance electrode 19) are formed on the substrate 190 on which the three-terminal nonlinear resistance element 185 is formed.
4, the drain electrode 184, etc.), the insulator layer 189, the semiconductor layer (not shown), etc. are stacked, so that they are not flat, and there is a step in each layer. As shown in FIG. 23A, the substrate 190 has a region A in which the thickness of the photosensitive resin 191a is relatively small and a region B in which the thickness of the photosensitive resin layer 191a is relatively large. The thickness of the photosensitive resin layer 191a in the region A is 2 μm, and the thickness of the photosensitive resin layer 191a in the region B is 3 μm.

Next, a photomask 2 as shown in FIG.
20 is used to perform exposure as shown in FIG. The photomask 220 has circular light-transmitting regions 222a and 222b formed therein, and further has a light-transmitting region 222c for forming a contact hole 198 for electrically connecting the drain electrode 184 and the reflective electrode 186 (see FIG. 19).
Are formed. The light-transmitting region 222a is arranged in the region A where the auxiliary capacitance electrode 194 is formed in the lower layer on the substrate 190, and the light-transmitting region 222b is arranged in the region B where other drain electrodes are located. The diameter F1 of the transparent region 222a is smaller than the diameter F2 of the transparent region 222b. For example, the diameter F1 is 5 μm and the diameter F2 is 10 μm. By using the photomask 220, the ratio of the exposed area to the shielded area in the area A is set to be smaller than the ratio of the exposed area to the shielded area in the area B.

When exposure is performed with the photomask 220, the region A in which the auxiliary capacitance electrode 194 is formed in the lower layer is overexposed because the photosensitive resin 191a is thinner than the region B in which the other drain electrodes are located. , FIG. 23
Exposure is performed up to the position indicated by the arrow in the photosensitive resin 191a in (b).

Next, as shown in FIG. 23C, the photosensitive resin 191a is developed to form a circular convex portion. 2.38% NMD-3 (manufactured by Tokyo Ohka Co., Ltd.) is used as a developer. As a result, the convex portion of the area A in which the auxiliary capacitance electrode 194 is formed in the lower layer becomes a circular concave portion having a larger diameter than the light transmissive area 222a of the photomask 220 used in the step of FIG. The circular concave portion has the same diameter as the convex portion formed in the region B where the drain electrode is located.

Next, as shown in FIG. 23D, heat treatment is preferably carried out at 120 ° C. to 250 ° C. to remove the corners of the convex portions (photosensitive resin layer 191a) and to form a photosensitive film having a smooth convex portion. Resin layer 191 is formed. In this embodiment, heat treatment is performed at 180 ° C. for 30 minutes.

Then, as shown in FIG. 23 (e),
A resist resin is preferably used as the insulator protective film 192 on the substrate on which the photosensitive resin layer 191 having the convex portions is formed.
It is applied by spin coating at 00 rpm to 3500 rpm. In this embodiment, a film thickness of 1 μm is obtained by applying 20 seconds at 2200 rpm. As a result, convex portions corresponding to the convex portions of the photosensitive resin layer 191 are formed on the insulating protective film 192, but the shape is smoother than that of the photosensitive resin layer 191. Further, a contact hole 198 (see FIG. 19) for connecting the drain electrode 184 and the reflective electrode 186 formed in the next step is formed by using the photolithography method.

Finally, as shown in FIG. 23 (f),
A metal thin film to be the reflective electrode 186 is vacuum-deposited on the insulator protection film 192 to a thickness of 2000 Å. As a result, the drain electrode 184 and the reflective electrode 186 are contact holes 1
Connected via 98. Furthermore, the reflective electrode 186 is completed by patterning the metal thin film for each pixel.
The metal thin film used aluminum in this embodiment, but silver,
It is also possible to use copper, nickel, chromium or the like.
The reflection type liquid crystal display device is obtained by bonding the element side substrate 180 formed as described above to a counter substrate by a known method and injecting liquid crystal therebetween.

Through the above steps, the light transmissive regions 222 having different diameters in the regions A and B where the film thickness of the photosensitive resin 191 is different.
By using the light shielding means 220 having a and 222b, it is possible to form a uniform uneven shape in the same pixel, and to obtain a reflection plate that also has a reflection electrode and has optimum reflection characteristics.

In this embodiment, the positive type photosensitive resin is used. However, by using the negative type photosensitive resin, circular recesses having the same diameter are formed in both the regions A and B, and the unevenness is uniform in the same pixel. A shape can be created, and the same effect as when using a voluminous type photosensitive resin can be obtained.

In this embodiment, two kinds of light transmitting areas 222 are used.
The photomask 220 having a and 222b is used.
The translucent means is not limited to this. For example, circular light-transmitting regions having different diameters may be formed on the three-terminal nonlinear resistance element 185, and the light-transmitting regions may have three or more types of circular shapes.

Although the auxiliary capacitance pixel electrode 194 is provided in the fifth and sixth embodiments and the auxiliary capacitance pixel electrode is not shown in the first to fourth embodiments, the auxiliary capacitance pixel electrode is shown. Also for this, an auxiliary capacitance pixel electrode may be provided.
For example, as shown in FIG. 24 (corresponding to FIG. 1), the auxiliary capacitance pixel electrode 242 can be formed in the same portion as the gate bus line 14 in the same process at the central portion of the pixel electrode. In this case, the area in which the auxiliary capacitance pixel electrode 242 is formed is also the area A defined in the above description (the area where the base of the photosensitive resin has a relatively high surface reflection or the wiring, etc. This is a region where the thickness of the resin layer is relatively small).

[0105]

According to the present invention, even if the light reflection characteristic of the base film of the photosensitive resin for forming the unevenness of the reflection plate is non-uniform or there is a step on the surface of the base film, the transmission with good reflection characteristics is achieved. It is possible to obtain a reflection type liquid crystal display device and a reflection type liquid crystal display device.

Further, in the case of the transflective liquid crystal display device, since the translucent portion cannot be formed in a region having a relatively high surface reflection forming a bus line or the like, the base of the photosensitive resin in the reflective portion is the surface. The existence ratio of the region having relatively high reflection is high. Therefore, in a transflective liquid crystal display device, the characteristics of a reflective layer formed on a region having a relatively high surface reflectance forming a bus line and the like are better than those of a reflective crystal device in which all pixels are reflective portions. , Greatly affects the characteristics of the reflector. From this, in the transflective liquid crystal display device, the effect of improving the reflection characteristics of the reflector according to the present invention is more remarkable.

[Brief description of drawings]

FIG. 1 is a plan view of one pixel of a transflective type substrate.

FIG. 2 is a cross-sectional view taken along the line AA ′ of FIG.

3A to 3F are manufacturing process diagrams of a transflective type liquid crystal display device according to a conventional technique.

FIG. 4 is a plan view of a photomask used in the process of FIG.

5 is a plan view of a photomask used in the process of FIG.

FIG. 6 is a sectional view of a transflective type substrate according to the present invention (corresponding to the sectional view of FIG. 1).

7A to 7G are manufacturing process diagrams of the transflective liquid crystal display device according to the first embodiment of the present invention.

8 is a plan view of a photomask used in the process of FIG.

9 is a plan view of a photomask used in the process of FIG.

FIG. 10 is a diagram showing a relationship between the thickness of a photosensitive resin layer and exposure intensity.

11A to 11F are manufacturing process diagrams of a transflective dual-use liquid crystal display device according to a second embodiment of the present invention.

12 is a plan view of a photomask used in the step of FIG.

FIG. 13 is a diagram showing a relationship between a Y value representing a reflection intensity and an exposure intensity with respect to a photosensitive resin layer.

FIG. 14 is a plan view of a photomask used in a third embodiment of the present invention.

FIG. 15 is a diagram showing a relationship between a Y value representing a reflection intensity and an exposure intensity with respect to a photosensitive resin layer.

FIG. 16 is a plan view of a photomask used in the fourth embodiment according to the present invention.

FIG. 17 is a diagram showing a relationship between a Y value representing a reflection intensity and an exposure intensity with respect to a photosensitive resin layer.

FIG. 18 is a plan view of one pixel of an element side substrate of a reflective liquid crystal display device according to a fifth embodiment of the present invention.

FIG. 19 is a cross-sectional view taken along the line AA ′ of FIG.

20A to 20F are manufacturing process diagrams of the reflective liquid crystal display device according to the fifth embodiment.

21 is a plan view of a photomask used in the process of FIG.

FIG. 22 is a plan view of a photomask used in the sixth embodiment of the present invention.

23A to 23F are manufacturing process diagrams of a reflective liquid crystal display device according to a sixth embodiment.

FIG. 24 is a plan view corresponding to FIG. 1 when an auxiliary capacitance pixel electrode is provided.

[Explanation of symbols]

10 Transmissive / Reflective Liquid Crystal Display Element Side Substrate 12 Source Bus Line 14 Gate Bus Line 16 TFT 20 Glass Substrate 21 Insulation Layer 27 Pixel Electrode 27a Transmission Electrodes 28, 68, 191 Photosensitive Resin Layers 29, 69, 186 Reflector (Reflection pixel electrode) 40, 50, 80, 90, 120, 160, 220 Photomask 42, 82, 122a, 122b, 212a, 212b
Light-shielding part 44 exposure 162a, 162b, 222a, 222b, 222c
Translucent part 180 Element-side substrate of reflective liquid crystal display device

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yozo Narutaki             22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka             Inside the company (72) Inventor Shogo Fujioka             22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka             Inside the company F-term (reference) 2H042 AA06 AA15 AA26                 2H091 FA15Y FA16Y FA31Y FA34Y                       LA16 LA18 LA19

Claims (3)

[Claims] 1. A method of manufacturing a liquid crystal display device, comprising: a first substrate; and a counter substrate facing the first substrate with a liquid crystal layer sandwiched therebetween, the liquid crystal layer of the first substrate. A step of forming a photosensitive resin layer on the first region on the side surface and on a second region having a lower reflectance than the first region; and having a plurality of circular patterns and forming the circular pattern in the first region. The photosensitive resin layer is exposed by using a light-shielding mask having a diameter smaller than the diameter of the circular pattern in the second region, and unevenness due to the photosensitive resin layer is formed in the first region and the second region. A method of manufacturing a liquid crystal display device, comprising: a forming step; and a step of forming a light reflection plate on the liquid crystal layer side of the photosensitive resin layer so that the irregularities are reflected. 2. The method for manufacturing a liquid crystal display device according to claim 1, wherein the circular pattern is a light shielding portion. 3. The method for manufacturing a liquid crystal display device according to claim 1, wherein the exposure is performed on the first region and the second region with the same illuminance.