JPH09269509A - Liquid crystal display element and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display element capable of improving the visual angle characteristic, etc., of a liquid crystal panel with a simple process and a process for producing the same. SOLUTION: This liquid crystal display element includes first and second sub-pixel electrodes 10, 12 and a first control capacitor electrode 20 which in formed below a protective insulating film 60 and is connected to a source electrode. A control capacitor C1 is formed by the second sub-pixel electrode 12 and the first control capacitor electrode 20 via the protective insulating film 60. The visual angle characteristic of the liquid crystal panel is improved by disposing the control capacitor C1 in such a manner. Further, the increase of process stages is prevented by forming the first control capacitor electrode 20 of a source electrode. The protective insulating film 60 is formed thinner than a gate insulating film 49 and, therefore, the area of the control capacitor electrode is minimized and the opening rate, etc., are improved.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to a liquid crystal display device. In particular, the present invention relates to a liquid crystal display element in which a pixel electrode is divided into a plurality. The present invention also relates to a method for manufacturing such a liquid crystal display element.

[0002]

2. Description of the Related Art In a liquid crystal display device, particularly in an active matrix type liquid crystal display device of 5 inches or more, a wide viewing angle technology of a liquid crystal panel is an essential technology for high performance display. Is coming. For example, as shown in Flat Panel Display 1994, "Beginning to be applied to mass-produced panels of wide-viewing-angle technology TFT essential for leap to large size" (December 10, 1993, Nikkei BP Publishing, P166), Various methods have been tried as wide viewing angle technology. Typical examples include (1) a method of controlling the liquid crystal alignment by devising a rubbing treatment or the like, and (2) a method of controlling the voltage applied to the liquid crystal molecules by using a control capacitor.

The above method (1) is a method of uniformizing the directions of the liquid crystal molecules aligned in the same direction in all directions.
However, this method has various problems such as complicated processes and poor reproducibility.

On the other hand, as the method (2), there are known conventional techniques such as Japanese Patent Laid-Open Nos. 4-348323, 5-107556, and 3-122621. However, in order to form a control capacitor (control electrode) and an additional capacitor in these conventional techniques, it is necessary to add a special electrode process, a dielectric film (insulating layer) forming process, etc., and the process becomes long. There was a problem.

Similarly, as the method (2), there are known conventional techniques such as JP-A-6-102537, JP-A-5-341318, JP-A-6-95144, and JP-A-5-289108. In these conventional techniques, a control capacitor is formed using a gate insulating film, a dielectric film on a light shielding layer, and the like. With these gate insulating films and dielectric films,
In order to prevent pixel defects and line defects due to pinhole formation, it is necessary to use two insulating films or increase the film thickness. Therefore, the capacitance per unit area of the control capacitor electrode becomes small. If the capacitance per unit area is small, it is necessary to increase the formation area of the control capacitor in order to obtain the required capacitance, which deteriorates the aperture ratio (light transmission characteristics) of the liquid crystal panel. Further, if the formation area of the control capacitor is large, defects and the like are likely to occur.

The present invention has been made in order to solve the technical problems described above, and an object of the present invention is to provide a liquid crystal display device capable of improving the visual characteristics of a liquid crystal panel by a simple process and a manufacturing method thereof. To provide.

[0007]

In order to solve the above problems, the present invention includes at least a thin film transistor, and a pixel electrode connected to the thin film transistor and driving a liquid crystal layer enclosed between a counter electrode and the pixel electrode. In a liquid crystal display device, a first to Nth (N is an integer of 2 or more) subpixel electrode formed by dividing the pixel electrode and a protective insulating film for protecting a source electrode of the thin film transistor. 1 to (K-1) (K is a positive number, and 1 <K ≦
N) control capacitor electrodes, and the first to Nth subpixel electrodes and the first to (K-1) th control capacitor electrodes are formed via the protective insulating film. 1-th (M-1) (M is a positive number and 2 <M≤N) control capacitors, and the first- (K-) th control capacitors are included.
At least a part of the control capacitor electrode of 1) is connected to the source electrode of the thin film transistor.

The present invention also provides the above-mentioned first to (K-1) th
At least a part of the control capacitor electrode of the (L-) is formed through a contact hole formed in the protective insulating film.
1) (L is a positive number and 2 <L ≦ N) and is connected to the sub-pixel electrode.

The present invention also provides the above-mentioned first to (K-1) th
At least a part of the control capacitor electrode of
It is characterized in that it is connected to any one of the (K-1) th control capacitor electrodes.

Further, the present invention is a method of manufacturing a liquid crystal display device, which comprises at least a thin film transistor and a pixel electrode which is connected to the thin film transistor and drives a liquid crystal layer sealed between a counter electrode and A) The source electrode, the drain electrode, and the first to the first (K) of the thin film transistor
-1) forming a control capacitor electrode, and (B)
A step of forming a protective insulating film for protecting the thin film transistor or the control capacitor electrode above the source electrode and the control capacitor electrode;
(C) a step of forming first to Nth subpixel electrodes formed by dividing the pixel electrode, and the steps (A) to
As a result of (C), the first to Nth subpixel electrodes and the first to (K-1) th control capacitor electrodes are provided with the first to (M-1) th intervening via the protective insulating film. It is characterized by forming a control capacitor of.

The present invention also provides the first to the (K-1) th aspects.
At least a part of the control capacitor electrode is formed in the same step as the source electrode.

The present invention also provides the above-mentioned first to (K-1) th
At least a part of the control capacitor electrode is formed between the formation of the source electrode and the formation of the protective insulating film.

Further, according to the present invention, between the step (B) and the step (C), at least a part of the first to (K-1) th control capacitor electrodes and the first to Nth sub capacitors are provided. The method is characterized by including a step of forming a contact hole with at least a part of the pixel electrode.

[0014]

According to the present invention, the Nth subpixel electrode and the (K-
A (M-1) th control capacitor is formed between the 1) control capacitor electrode. By changing the area of the control capacitor, it is possible to change the voltage applied to the first to (N-1) th subpixel electrodes and the voltage applied to the Nth subpixel electrode. Accordingly, the visual characteristics of the liquid crystal layers in the Nth and the first to (N-1) th subpixel electrode regions can be made different. As a result, these regions having different visual characteristics complement each other, so that the visual characteristics of one pixel as a whole can be improved. Further, in the present invention, the first to (M-1) th control capacitors are formed by using the protective insulating film as a dielectric. When the protective insulating film is used as a dielectric, the protective insulating film can be made thinner than when the gate insulating film is used as a dielectric, so that the control capacitor capacity per unit area is increased. It becomes possible to do. As a result, the control capacitor area can be reduced. As a result, the aperture ratio can be improved.

At least a part of the first to (K-1) th control capacitor electrodes and at least a part of the (L-1) th subpixel electrode are connected to each other by forming a contact hole in a protective insulating film. It is also possible to do so. As a result, the visual characteristics of the liquid crystal layer on each subpixel electrode can be made different.

Further, at least a part of the first to (K-1) th control capacitor electrodes is the first to (K-1) th.
It is also possible to connect with any of the control capacitor electrodes. As a result, the control capacitors themselves can change the voltage on all the subpixel electrodes by changing the area of the control capacitors that are connected at the same time, and reduce the number of contact holes opened in the control capacitor electrodes. It leads to improvement of aperture ratio and reliability.

In this case, the first to (K-1) th control capacitor electrodes can be formed of the same material as the source electrode. In this case, it is possible to form the first to (K-1) th control capacitor electrodes and the source electrode in the same step. As a result, there is no need to add a new step for forming the control capacitor electrode, which leads to a reduction in manufacturing cost and an improvement in reliability.

It is also possible to form at least a part of the first to (K-1) th control capacitor electrodes with a transparent conductive material. This allows the control capacitor electrode itself to transmit light, and the presence of the protective insulating film on the control capacitor electrode allows the voltage applied to the liquid crystal layer on the control capacitor electrode to be connected. Can be made different from the applied voltage applied to the liquid crystal layer on the sub-pixel electrode. As a result, it is possible to improve the aperture ratio and the visual characteristics.

Further, in the present invention, it is desirable that the capacitance per unit area of the protective insulating film be larger than the capacitance per unit area of the gate insulating film provided above the gate electrode of the thin film transistor. This is easily established if the film thickness of the protective insulating film is smaller than that of the gate insulating film. As a result, the control capacitor electrode can be made smaller, and the aperture ratio can be improved.

Further, in the present invention, the above-mentioned first to (K-1) th
The control capacitor electrode may be used as a part of the black matrix serving as the light shielding layer. When the control capacitor electrode is made of the material of the light shielding layer, it is made a part of the black matrix to prevent light leakage and contrast. Even when the control capacitor electrode is formed of a transparent transparent conductive film, the electric field of the liquid crystal layer on the transparent conductive film can be changed to prevent light leakage and improve the contrast.

Further, in the present invention, the above-mentioned first to (K-1) th
The control capacitor electrode may be formed so as to be separated from the control capacitor electrode and the wiring electrode formed in the same layer and to cover a part of the gap between the subpixel electrodes. By doing so, it is possible to improve the aperture ratio and prevent production defects and the like due to adhesion of dust.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION

1. First Embodiment FIG. 1 is a diagram showing a planar configuration of the first embodiment.
FIG. 2 is a diagram showing a cross section taken along the line AB of FIG. 1.

As shown in FIGS. 1 and 2, this liquid crystal display device includes a thin film transistor (hereinafter referred to as TFT) 56.
And a pixel electrode divided into the first and second subpixel electrodes 10 and 12, and the pixel electrode drives the liquid crystal layer 76 enclosed between the counter electrode 66 and the pixel electrode. TFT56
Is at least the gate electrode 51, the source electrode 53, the drain electrode 55, the intrinsic silicon film 70, and the n-type silicon film 7.
Including 2, 73. If necessary, it also includes an etching stopper layer 74. The first subpixel electrode 10 is connected to the source electrode 53 via the contact hole 54. A liquid crystal panel is constructed by arranging a plurality of these scanning lines 50 and signal lines 52 so as to intersect in a matrix and arranging TFTs at the intersecting positions.

As shown in FIG. 2, the first control capacitor electrode 20 is provided below the protective insulating film 60 which serves as a protective film for the source electrode 53 and the like. In this embodiment, the first control capacitor electrode 20 is formed on the extension of the source electrode 53. Therefore, the first control capacitor electrode 2
There is no need to add a new step for forming 0, and as a result, the complexity of the manufacturing process can be prevented and the manufacturing cost can be reduced. However, it is also possible to form the control capacitor electrode 20 formed on the extension by a material different from that of the source electrode 53 and further connect to the source electrode 53.

A control capacitor (control capacitance) C1 is formed by using the protective insulating film 60 as a dielectric, the second subpixel electrode 12 as an upper electrode, and the first control capacitor 20 as a lower electrode. On the other hand, the liquid crystal capacitor CLC having the liquid crystal layer 76 as a dielectric is formed by the first subpixel electrode 10 and the counter electrode 66.
1 is formed, and the second subpixel electrode 12 and the counter electrode 66 form a liquid crystal capacitor CLC2.

FIG. 3 shows an equivalent circuit diagram of this embodiment. T
The liquid crystal capacitor CLC1 is connected to the terminal E which is the source electrode of the FT 56. Further, a control capacitor C1 and a liquid crystal capacitor CLC2 are connected in series to the terminal E. If the voltage of the terminal E when the scanning line 50 is selected and the TFT 56 is turned on is VE, this VE is set in the CLC 1.
Is applied as it is. On the other hand, the voltage at the terminal F is C1,
Since the capacity is divided by CLC2, VF is set in CLC2.
= VE × C1 / (C1 + CLC2) is applied. In this way, the voltage VE applied to CLC1 and CL
By changing the VF applied to C2, the CLC
1, it is possible to make the light transmittance of the liquid crystal in the region of CLC2 different. As a result, the visual characteristics of these liquid crystal layers can be made different, and the visual characteristics of one pixel (or the entire liquid crystal panel) can be improved by interpolating these different visual characteristics.

The feature of this embodiment is that the control capacitor C1 is formed by using the protective insulating film 60 as a dielectric.
On the other hand, as a conventional example of JP-A-6-102537, a plan configuration is shown in FIG. Also, in FIG.
FIG. At this time, in the conventional example, the control capacitor C41 is formed by using the gate insulating film 49 as a dielectric. Generally, the gate insulating film basically needs to be thick in order to prevent pixel defects due to the formation of pinholes. As the thickness of the insulating film increases, the capacitance per unit area decreases, so the area of the control capacitor electrode 420 (the second subpixel electrode 12
It becomes necessary to increase the (overlapping area) with, and this deteriorates the aperture ratio and the like. On the other hand, in this embodiment, the protective insulating film 60 is used as a dielectric. Therefore, the capacitance per unit area can be increased, and the area of the control capacitor electrode 20 can be reduced. This is because the purpose of the protective insulating film is to prevent entry of moisture or the like from the liquid crystal layer, and it is not necessary to make it thick so as to prevent pinholes unlike the gate insulating film.

Next, FIGS. 6A to 6E are sectional views showing steps for explaining the manufacturing process of this embodiment.
First, a glass substrate (for example, a non-alkali substrate or a non-alkali substrate with a base insulating film) 68 is sputtered and photoetched to, for example, 500 to 200.
Cr (Chromium) with a thickness of about 0 Å, Ta
A gate electrode 51 made of (tantalum), Al (aluminum), Mo (molybdenum), Ti (titanium), or an alloy thereof is formed (FIG. 6A).

Next, the gate insulating film 49 made of the silicon nitride film SiNx, the intrinsic silicon film 70, and the n-type silicon film 71 are formed by, for example, the plasma CVD method or the thermal CVD method.
Are continuously formed, and 70, 71 are formed by photoetching.
Are made into islands (FIG. 6 (B)). In this case, the gate insulating film 49, the intrinsic silicon film 70, the n-type silicon film 71
The thickness of each is, for example, 2000-4000 angstroms, 500-3000 angstroms, 200-
It will be about 500 angstroms. The gate insulating film 49 is formed under the silicon nitride film SiNx, for example, 500 to
A silicon oxide film SiOx having a thickness of about 1500 angstrom may be provided, or Ta or Al or an alloy thereof may be used as a heat or anodic oxide film of Ta.
You may make it the structure provided with 500-2000 angstroms of Ox and AlOx. When providing these oxide films, the silicon nitride film may have a thickness of 1000 to 4000 angstroms.

Next, for example, Cr, Ta, Al, Mo, T
i or 1000 to 2000 made of these alloys
A source electrode 53, a drain electrode 55, and a control capacitor electrode 20 each having a thickness of about angstrom are formed by sputtering and photoetching, and an n-type silicon film 72,
73 is separated to separate the source and drain. (FIG. 6
(C)). As described above, in this embodiment, the source electrode 53 and the like and the control capacitor electrode 20 are made of the same material. Therefore, it is not necessary to add a new manufacturing process for producing the control capacitor, and the cost can be reduced. In addition, an etch stopper (E
A method of providing S) may be adopted.

Next, a protective insulating film 60 to be a protective film for the source electrode 53 and the like is formed (FIG. 6D). The protective insulating film 60 has a thickness of, for example, about 500 to 3000 angstroms, and preferably 1000 to about 1000 to increase the moisture adsorption effect.
The film is formed of a silicon nitride film SiNx having a thickness of 3000 angstroms, preferably 1000 to 2000 angstroms, or a sputtered film of Al, Ta, or an alloy thereof, or an anodic oxide film of Al, Ta, or an alloy thereof for cost reduction. . Since the protective insulating film 60 can be made thinner than the gate insulating film 46 in this way, the capacitance per unit area of the control capacitor C1 (see FIG. 2) can be increased, and thus the aperture ratio can be increased. Can be improved.

Next, a contact hole 54 is opened, for example, between the control capacitor electrode 20 and the source electrode 53 or an extension of the control capacitor electrode 20, and, for example, IT is used.
About 500 to 2000 angstroms made of O (indium oxide film) or the like, preferably 5 for cost reduction.
First and second subpixel electrodes 10 and 12 having a thickness of about 00 angstrom are formed by sputtering and photoetching (FIG. 6E). Then, as shown in FIG. 2, an alignment film 62 is formed. Then, the TFT side substrate thus formed, the glass substrate 69, and the counter electrode 6
6. The liquid crystal layer 76 is sealed with the counter substrate composed of the alignment film 64 and the like, and the liquid crystal panel is completed.

According to this embodiment, the control capacitor electrode 2
0 can be a part of the black matrix serving as the light shielding layer. FIG. 7 shows the relationship between the control capacitor electrode of this embodiment and the black matrix. Figure 7
In (A), for example, the black matrix 17 provided on the counter substrate and the control capacitor electrode 20 prevent light leakage and improve the contrast. According to the present embodiment, the capacitance of the control capacitor per unit area can be increased as described above, so that the second subpixel electrode 1
2 and the control capacitor electrode 20 can be reduced in overlap. Therefore, even in this case, the aperture ratio and the like can be improved according to this embodiment. As shown in FIG. 7B, the black matrix 18 may be provided so as to completely cover the control capacitor electrode 20, or the black matrix may be provided on the TFT substrate side.

According to this embodiment, the capacity of the control capacitor per unit area can be increased and the area of the control capacitor electrode 20 can be reduced. FIG. 8 shows the relationship between the signal line and the control capacitor electrode of this embodiment. In this embodiment, the area of the control capacitor electrode 20 connected to the second subpixel electrode 12 can be reduced. With this configuration, it is possible to increase the distance shown in C of FIG. 8, that is, the distance between the control capacitor electrode 20 and the signal line 52. The control capacitor electrode 20 is the source electrode 5
3 is formed by extension and is made of the same material as the signal line 52. Therefore, in the present embodiment, the distance between the electrode and the wiring is wider than that of the conventional example in which the gate electrode is used as the control capacitor electrode as in JP-A-5-289108. The manufacturing defects that caused it can be significantly reduced. That is, according to the present embodiment, the area of the control capacitor electrode 20 can be reduced, so that the distance C can be increased, and manufacturing defects caused by adhesion of dust and the like can be reduced.
On the other hand, when the gate metal is used for the control capacitor electrode as shown in FIG. 4, the distance D between the control capacitor electrode and the scanning line 50 is extremely short, so that the above manufacturing defect becomes a problem.

2. Second Embodiment FIG. 9 is a diagram showing a planar configuration of the second embodiment, and FIG. 10 is a diagram showing an AB cross section of FIG. 9.

The difference from the first embodiment is that the control capacitor electrode 20 is made of, for example, an ITO film of 500 to 500 as a transparent electrode.
It is in the point of using 2000 angstrom. Therefore, this embodiment has an advantage that the aperture ratio is increased as compared with the first embodiment.

Further, in this embodiment, the liquid crystal layer 76 and the protective insulating film layer 60 are formed between the counter electrode 66 and the control capacitor electrode 20. Therefore, CLC3 and C2 using the liquid crystal layer 76 and the protective insulating film layer 60 as a dielectric are formed on the control capacitor electrode 20. As a result, the equivalent circuit of the second embodiment is as shown in FIG. In the present embodiment, even if CLC2 = CLC3 is set, it is possible to set C1 ≠ C2.
When the voltage of the terminal E when the TFT 56 is turned on is VE, it is possible to make the voltage VF of the terminal F different from the voltage VF of the terminal G and the voltage VG of the terminal G. As a result, CLC1 and CLC
The light transmittances of the liquid crystal layers in the LC2 and CLC3 regions can be made different, and the visual characteristics of these liquid crystal layers can be made different. By interpolating these different visual characteristics with each other, the visual characteristics of one pixel (or the entire liquid crystal panel) can be further improved as compared with the first embodiment. Further, even if the light transmittance is lowered due to the presence of the transmissive electrode, in this embodiment, the control capacitor electrode can be made small similarly to the first embodiment, and the light transmittance of one pixel as a whole can be improved. You can As described above, in this embodiment, similarly to the first embodiment, the capacity of the control capacitor is reduced, the aperture ratio is improved, the light transmittance of the entire one pixel is improved, and the viewing angle characteristics can be further improved. Become.

Also in this embodiment, for example, the control capacitor electrode 20 or a part thereof is brought as a part of the black matrix, and it is used as an electrode for preventing light leakage to improve the contrast. It is also possible.

3. Third Embodiment FIG. 12 shows a planar configuration of a third embodiment, and FIG. 13 is a view showing a cross section taken along the line AB of FIG.

The difference from the first and second embodiments is that the control capacitor electrode 20 is newly provided with a third subpixel electrode 15 and a control capacitor C4 is formed. As a result, the equivalent circuit of this embodiment is as shown in FIG. At this time, the values of the control capacitors C1 and C4 are changed by changing the overlap area between the control capacitor electrode and the subpixel electrode,
Terminal E voltage VE, terminal F voltage VF, and terminal I voltage V
I can be different. As a result, CLC1 and CL
The light transmittances of the liquid crystal layers in the regions C2 and CLC5 can be made different, and the viewing angle characteristics of these liquid crystal layers can be made different. By interpolating these different visual characteristics with each other, the viewing angle characteristics of one pixel or the entire liquid crystal panel can be further improved as compared with the first and second embodiments.

In FIGS. 12, 13, and 14, three pixel electrodes are provided.
An example of division is shown, but division into four or more is also possible. That is, according to this embodiment, the pixel electrode is divided into first to Nth (N is an integer of 2 or more) subpixel electrodes,
First to (K−1) th (K is an integer, 1 <K ≦ N) control capacitor electrodes can be provided. Then, the first to the (M-1) th control capacitors are formed between the first to the (K-1) th control capacitor electrodes and the first to the Nth subpixel electrodes via a protective insulating film. You can Then, by changing the area of the first to (M-1) th control capacitors or the area of the first to Nth subpixels,
It is possible to improve the viewing angle characteristics by changing the voltage applied to the liquid crystal layer on each of the first to Nth subpixel electrodes.

Further, in this embodiment, the area of the control capacitor electrode can be made small as in the first embodiment, so that even if the pixel is divided into a large number, the aperture ratio is not so deteriorated as compared with the prior art. Therefore, according to this embodiment, it is possible to further improve the visual characteristics by dividing the pixel electrode into a large number without deteriorating the aperture ratio so much.

In the third embodiment, of course, the control capacitor electrode 20 may be a part of the black matrix as shown in FIGS. 7A and 7B, or C of FIG.
It is possible to separate the distance C from the signal line 52 by reducing the area of the control capacitor 20 as shown in FIG.

4. Fourth Embodiment FIG. 15 is a diagram showing a planar configuration of a fourth embodiment, and FIG. 16 is a diagram showing an AB cross section of FIG.

The difference from the first, second, and third embodiments is that the second control capacitor electrode 22 and the third subpixel electrode 14 are provided on the first subpixel electrode 10. Is provided and the control capacitor C3 is formed. In addition, a contact hole 55 is formed on the second control capacitor electrode 22.
Is provided to establish electrical connection with the first subpixel electrode 10. As a result, the equivalent circuit of the fourth embodiment becomes as shown in FIG. When the voltage of the terminal voltage E is VE, for example, this VE, the voltage VF of the terminal F, and the voltage VH of the terminal H
Can be different. As a result, CLC1 and CLC
2. The light transmittances of the liquid crystal layers in the CLC 4 region can be made different, and the visual characteristics of these liquid crystal layers can be made different. By complementing these different visual characteristics with each other, the visual characteristics of one pixel (or the entire liquid crystal panel) can be further improved as compared with the first embodiment.

Of course, it is sufficiently possible to provide the contact hole 55 between the third subpixel electrode 14 and the second control capacitor electrode 22 in this embodiment. in this case,
The control capacitor C3 is provided between the first subpixel electrode 10 and the control capacitor electrode 22. Furthermore, it is possible to form the second control capacitor electrode 22 below the subpixel electrodes 14 and 10 without using the contact hole 55.

Here, FIGS. 15, 16 and 17 show an example in which the pixel electrode is divided into three, but it is also possible to divide into four or more. That is, according to the present embodiment, it is possible to further form the control capacitor electrode 23 and the subpixel electrode 16 on the subpixel electrode 14 to form the control capacitor and the contact hole.

Further, in this embodiment, since the area of the control capacitor electrode can be made small, even if the pixel electrode is divided into multiple layers as described above, the aperture ratio is not so deteriorated as compared with the prior art. Therefore, according to the present embodiment, it is possible to further improve the visual characteristics by dividing the pixel electrode into a large number without significantly deteriorating the aperture ratio and the like.

Furthermore, this embodiment is based on the above-mentioned FIGS.
The second control capacitor electrode 22 and the second sub-pixel electrode 12 are connected via the contact hole 55 because they are independent of the means for dividing by the second control capacitor electrode 22 and the third sub-pixel electrode. It is also possible to provide the control capacitor C3 between the pixel electrode 14 and the pixel electrode 14. At this time, since the voltage on the second subpixel electrode is different from the voltage on the third subpixel electrode, the viewing angle characteristics between the subpixels can be made different.

Further, in this embodiment, it is also possible to connect the control capacitor electrodes to each other. FIG. 19 is a diagram showing another planar structure of this embodiment. In this configuration, the control capacitor electrodes 22 and 24 are connected to each other and connected to the first subpixel electrode 10 via the contact hole 55 to reduce the contact hole, and further improve the viewing angle characteristic as compared with the first embodiment. While performing the above, it is possible to improve the aperture ratio and prevent manufacturing defects.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the gist of the present invention.

For example, the structure of the thin film transistor is not limited to that described in the above embodiment, but is amorphous.
Various reverse stagger structures in a silicon thin film transistor, a positive stagger structure, a planar in a polycrystalline silicon thin film transistor, a positive stagger structure, and the like can be adopted.

The manufacturing process of the liquid crystal display element is not limited to the one described in the above embodiment, and various methods such as using anodic oxidation can be adopted.

A structure in which a color filter, a black matrix and the like are formed on the TFT substrate is also included in the scope of the present invention.

[0055]

According to the present invention, the manufacturing process can be facilitated and the aperture ratio can be improved while improving the viewing angle characteristics. Thereby, a high-performance and low-cost liquid crystal display device can be provided. Further, it is possible to prevent the occurrence of manufacturing defects due to the adhesion of dust and the like, and it is possible to improve reliability and yield.

[Brief description of drawings]

FIG. 1 is a diagram showing a planar configuration of a first embodiment.

FIG. 2 is a diagram showing a cross section taken along the line AB of FIG.

FIG. 3 is an equivalent circuit diagram of the first embodiment.

FIG. 4 is a diagram showing a planar configuration of a conventional example.

5 is a diagram showing a cross section taken along the line AB of FIG.

6A to 6E are process cross-sectional views for explaining the manufacturing process of the first example.

FIG. 7 is a diagram showing a relationship between a control capacitor electrode and a black matrix of the first embodiment.

FIG. 8 is a diagram showing a relationship between a signal line and a control capacitor electrode of the first embodiment.

FIG. 9 is a diagram showing a planar configuration of a second embodiment.

10 is a diagram showing a cross section taken along the line AB of FIG. 9;

FIG. 11 is an equivalent circuit diagram of the second embodiment.

FIG. 12 is a diagram showing a planar configuration of a third embodiment.

13 is a diagram showing a cross section taken along the line AB of FIG.

FIG. 14 is an equivalent circuit diagram of the third embodiment.

FIG. 15 is a diagram showing a planar configuration of a fourth embodiment.

16 is a diagram showing an AB cross section of FIG. 15;

FIG. 17 is an equivalent circuit diagram of the fourth embodiment.

FIG. 18 is a diagram showing another planar configuration of the fourth embodiment.

[Explanation of symbols]

10 1st subpixel electrode 12 2nd subpixel electrode 15 3rd subpixel electrode in 3rd Example 14 3rd subpixel electrode in 4th Example 16 4th in 4th Example Sub-pixel electrode 20 First control capacitor electrode 22 Second control capacitor electrode 23 Third control capacitor electrode 24 Third control capacitor electrode 420 in another example of the fourth embodiment 420 Control capacitor electrode 49 in the conventional example Insulating film 50 Scan line 51 Gate electrode 52 Signal line 53 Source electrode 54 Contact hole between first subpixel electrode 10 and source electrode 53 Between first subpixel electrode 10 and second control capacitor electrode 22 Contact hole between 56 TFT 57 Drain electrode 60 Protective insulating film 62, 64 Alignment film 66 Counter electrode 68, 69 Glass substrate 70 Intrinsic silicon film 71, 72, 73 N-type silicon film 76 Liquid crystal layer

Claims (12)

[Claims] 1. A liquid crystal display device comprising at least a thin film transistor and a pixel electrode connected to the thin film transistor and driving a liquid crystal layer enclosed between a counter electrode and the thin film transistor, wherein the pixel electrode is divided and formed. The first to Nth (N is an integer of 2 or more) subpixel electrodes, and the first to (K-1) th (K is provided below) a protective insulating film for protecting the source electrode of the thin film transistor. A positive number, 2 <K ≦ N) control capacitor electrode, the first to Nth subpixel electrodes, and the first to (K−1) th subpixel electrodes.
The first to (M-1) th (M is a positive number, formed between the control capacitor electrode and the control capacitor electrode via the protective insulating film.
2 <M ≦ N), and at least a part of the first to (K−1) th control capacitor electrodes is connected to the source electrode of the thin film transistor. A liquid crystal display device characterized by the above. 2. The liquid crystal display element according to claim 1, wherein at least a part of the first to (K-1) th control capacitor electrodes is provided through a contact hole formed in the protective insulating film, (L-1) (L is a positive number and 1 <L
A liquid crystal display element characterized by being connected to a subpixel electrode of ≦ N). 3. The liquid crystal display device according to claim 1, wherein at least a part of the first to (K-1) th control capacitor electrodes is the first to (M-1) th control capacitors. A liquid crystal display device characterized by being connected to one of capacitors. 4. The liquid crystal display element according to claim 1, wherein at least a part of the first to (K−1) th control capacitor electrodes is made of the same material as the source electrode. A liquid crystal display device characterized by the following. 5. The liquid crystal display element according to claim 1, wherein at least a part of the first to (K-1) th control capacitor electrodes is made of a transparent conductive material. Liquid crystal display device characterized by. 6. The liquid crystal display element according to claim 1, wherein the capacitance per unit area of the protective insulating film is equal to the capacitance per unit area of the insulating film provided above the gate electrode of the thin film transistor. A liquid crystal display device characterized by being larger than the capacity. 7. The liquid crystal display element according to claim 1, wherein at least a part of the first to (K-1) th control capacitor electrodes is a part of a black matrix serving as a light shielding layer. A liquid crystal display device characterized by: 8. A method of manufacturing a liquid crystal display device comprising at least a thin film transistor and a pixel electrode connected to the thin film transistor and driving a liquid crystal layer enclosed between a counter electrode and the thin film transistor, comprising: (A) the thin film transistor. Forming a source electrode, a drain electrode, and first to (K-1) th control capacitor electrodes, and (B) protecting the thin film transistor or the control capacitor electrode above the source electrode and the control capacitor electrode. A step of forming a protective insulating film for achieving the above, and (C) forming first to Nth sub-pixel electrodes formed by dividing the pixel electrode, and the steps (A) to (C). ), The first to (M-1) th control is performed between the first to Nth subpixel electrodes and the first to (K-1) th control capacitor electrodes via the protective insulating film. A method of manufacturing a liquid crystal display device, which comprises forming a capacitor. 9. The method of manufacturing a liquid crystal display element according to claim 8, wherein at least a part of the first to (K-1) th control capacitor electrodes is formed in the same step as the source electrode. A method for manufacturing a characteristic liquid crystal display device. 10. The method for manufacturing a liquid crystal display element according to claim 8, wherein at least a part of the first to (K-1) th control capacitor electrodes is formed by forming the source electrode and the protective insulation. A method for manufacturing a liquid crystal display element, characterized in that it is formed between the formation of a film. 11. The method for manufacturing a liquid crystal display element according to claim 8, wherein the first to the third steps are between the step (B) and the step (C).
A liquid crystal comprising a step of forming a contact hole between at least a part of the (K-1) th control capacitor electrode or the source electrode and at least a part of the first to Nth subpixel electrodes. Display element manufacturing method. 12. The method for manufacturing a liquid crystal display element according to claim 8, wherein in the step (B), the capacitance per unit area of the protective insulating film is above the gate electrode of the thin film transistor. A method of manufacturing a liquid crystal display device, wherein the gate insulating film is formed so as to have a larger capacity per unit area.