JPH01123217A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To enlarge a picture element area and to improve an image grade by forming black stripes between the picture element electrodes of an active element side substrate and on at least either of the upper or lower side of the active element. CONSTITUTION:This device is made into the structure having the black stripes between the picture element electrodes 10 of the active element side substrate 19 and on at least either of the upper or lower side of the active element. The positional accuracy of the picture element electrodes 10 and the black stripes is, therefore, determined solely by the accuracy of the film formation and patterning of the active element side substrate. The problem of the registration accuracy of the picture element electrodes 10 and the black stripes in sticking of a color stripe side substrate 20 and the active element side substrate 19 is solved. The width of the black stripes is thereby narrowed and the picture element area is correspondingly enlarged; therefore, the image grade is improved by the increased brightness.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention is directed to an active element such as an amorphous silicon (a-3T) semiconductor thin film transistor (hereinafter abbreviated as a-3iTFT), an MIM element, or an a-3i diode. The present invention relates to an active matrix liquid crystal display device equipped as a switching element.

<Prior Art> In recent years, a-3i has come to be used as a material for TPT, which is a switching element in liquid crystal display devices. The structure of a liquid crystal surface device equipped with such a switching element is as shown in FIG. T F T (
! ! ! l substrate 202, color filter 210. A transparent electrode 209 and a color filter side substrate 203 having an alignment film 208 face each other, and a liquid crystal layer 211 exists between each alignment film 207 and alignment film 208 . A polarizing plate 212 is arranged on the outer surface of each of the TFT side substrate 202 and the color filter side substrate 203. A bank light source 201 is disposed on the back side of this liquid crystal display device, that is, at a position below the TFT side group Fi, 202 in the figure, and transmits transmitted light of the backlight to red, green, and blue color filters 201.
You will be looking through 0.

However, a portion of the backlight light from the back surface is transmitted through the gaps between the red, green, and blue picture elements of the color filter, reducing the contrast ratio of the liquid crystal display element. For this reason, as shown in FIG. 10, a so-called blank drive 214 made of a metal film such as Cr is formed in the gaps between the red, green, and blue picture elements 213 of the color filter 210 on the color filter side substrate 203, and Prevents light from passing through.

<Problems to be Solved by the Invention> When a black stripe is provided on the color filter side as described above, the following problems occur. In other words, when bonding a panel (electrode substrate) on which a color filter is formed and a panel on which an active element such as TPT is formed, the alignment accuracy between the two is usually about ~10 μm, so the line width of the black stripe is It becomes necessary to make the alignment accuracy bone wider than the gap between picture elements on the panel side where active elements are formed. Therefore, the picture element area is reduced by that amount, and the transmittance, that is, the brightness of the panel is reduced.

Means for Solving Problems> The present invention provides a liquid crystal display between an active element side substrate in which pairs of picture element electrodes and active elements are arranged in a matrix, and a color filter side substrate in which color filters are arranged. The liquid crystal display device has a black stripe between the picture element electrodes on the active element side substrate and at least on one side above or below the active element.

Effect> The liquid crystal display device according to the present invention has a structure in which black stripes cover between the picture element electrodes of the active element side substrate, and the black stripes are Becomes irrelevant.

<Example> FIG. 1 shows a cross-sectional structure of an active matrix color liquid crystal display device using a-3iTPT as an active element. In the figure, 1 is a glass substrate.

2 is an insulating film, 3 is a black stripe, 4 is an insulating film, 5
is a gate electrode, 6 is a gate insulating film, and 7 is a non-doped a-
3t semiconductor layer, 8 is a phosphorus-doped a-3t semiconductor layer, 9
1 is a source and drain electrode, 10 is a picture element electrode, 11 is a protective insulating film, and 12 is an alignment film.

13 is a liquid crystal layer, 14 is a glass substrate, 15 is a color filter, 16 is a transparent electrode, and 17 is an alignment film.

A blank drive 3 is patterned and formed on an etching stopper insulating film 2 made of SiNx on a glass substrate 1. This black stripe 3 is
It is composed of an a-3t semiconductor film, a metal film, or a resin film with a large light absorption coefficient. On this bra/ta stripe 3 and the etching stopper insulating film 2, Ta, O,
An etching stopper insulating film 4 is formed.

A gate electrode 5 made of Ta is formed on the portion of the etching stopper insulating film 4 that covers the black stripe 3, and a gate insulating film 6 made of SiNx is formed on the gate electrode 5 and the etching stopper insulating film 4. It is formed. On the upper part of the black stripe 3 of the gate insulating film 6, a non-doped 3t semiconductor layer 7 is formed.
A phosphorus-doped Mi3i semiconductor layer 8 is formed on this a-Si semiconductor layer 7.
Source and drain electrodes 9 made of Ti are formed on the 3t semiconductor layer 8. Gate electrode 5 above. Non-doped a-3t semiconductor N7. Phosphorus Dope Me 3i Semiconductor N
a-3iT by 8 and source and drain electrodes 9
FT18 is configured. A picture element electrode 10 made of ITO (transparent conductive film) is patterned and formed on a portion of the gate insulating film 6 other than above the black stripe 3. This picture element electrode 10 and a-S i T F T 1
The B pairs are formed in a matrix on the glass substrate 1.

A protective insulating film 11 made of SiNx is formed on the a-S i T F T 18 and the picture element electrode 10 . An alignment film 12 is formed on this protective insulating film 11 .

A color filter 15 is placed on the glass substrate 14 on the opposite side.
．． Transparent electrode 16 made of ITO. An alignment film 17 is formed. No black stripe is formed between the color filters 15 on the opposing sides.

The active element side substrate 19 and the color filter side substrate 20 having the above configuration face each other, and the liquid crystal layer 13 is present between the alignment film 12 of the active element side substrate 19 and the alignment film 17 of the color filter side substrate 20. .

FIG. 2 shows the planar structure of the active element side substrate 19.

In the figure, 3 is a black stripe, 10 is a picture element electrode, 18 is an a-3i TFT, 21 is a source pass line, 2
2 is a gate pass line.

A large number of pairs of a-3i TFT f8 and picture element electrodes 10 are arranged in a matrix, and black stripes 3 are patterned and formed to cover the areas between the picture element electrodes 10. This black stripe 3 is formed along the source pass line 21 and gate pass line 22 which are arranged in the vertical and horizontal directions between the picture element electrodes 10, and these pass lines 21 and 22 and the a-3iTF
The lower side of 718 is covered with black stripe 3.

The pattern of the a-3i semiconductor film, metal film, or resin film constituting the black stripe 3 overlaps with the edge of the picture element electrode 10 by about 1 to 2 μm from above to ensure alignment accuracy.

The film thickness of the a-3i semiconductor layer constituting the blank drive 3 is such that it absorbs more than 99% of the light from the backlight source,
Furthermore, it is sufficiently thinner than the step of TPTl 8, for example, in the range of 0.2 μm to 1.0 μm. Moreover, when the black stripe 3 is a metal film, the thickness of this metal film is 0.01 μm to 1.0 μm for the same reason. Furthermore, regarding the resin film, the film thickness ranges from 0.05 μm to 2.0 μm.
It is 0 μm.

In the structure of this liquid crystal display device, the active element side substrate 1
This structure has a blank drive 3 between the picture element electrodes 10 of 9 and below the a-SiTF 718, and the black stripe 3 has no relation to the bonding accuracy between the color filter side substrate 20 and the active element side substrate 19. .

Next, an embodiment using an MIM element as an active element will be described.

Figure 3 shows a cross-sectional structure, in which 23 is a glass substrate;
4 is an insulating film, and 25 is a black stripe.

26 is an insulating film, 27 is a Ta electrode, 28 is a Ta, 0° layer, 29 is a Ti electrode, 30 is a pixel electrode, 31 is an alignment film,
32 is a liquid crystal layer, 33 is a glass substrate, 34 is a color filter, 35 is a transparent electrode, and 36 is an alignment film.

A black stripe 25 is patterned and formed on an etching substrate insulating film 24 made of SiNx on a glass substrate 23. As shown in FIG. This black stripe 25 is an a-3i semiconductor film.

It is composed of a metal film or a resin film with a large light absorption coefficient. On this blank drive 25 and the etching stopper insulating film 2'4, a Sin film is formed.

An etching stopper insulating film 26 is formed.

On the part of the etching stopper insulating film 26 that covers the black stripe 25, an electrode 27 made of Ta is provided.
Ta, O, layer 2 which is a Ta oxide layer on this electrode 27
8 and an electrode 29 made of Ti.
An M element 37 is formed. blanks drive 25
A picture element electrode 30 made of ITO is formed in a pattern on the insulating film 26 covering the area between the two. MIM
An alignment film 31 is formed on the element 37 and the picture element electrode 30. MIM element 37 which is an active element and picture element electrode 30
The pairs are formed in a matrix on the glass substrate 23.

A color filter 34.1 is provided on the glass substrate 33 on the opposite side.
Transparent electrode 35 made of TO. An alignment film 36 is formed. No black stripe is formed between the color filters 34 on the opposing sides.

The active element side substrate 38 and the color filter side substrate 39 having the above-described configuration face each other, and the liquid crystal layer 37 is present between the alignment film 31 of the active element side substrate 38 and the alignment film 36 of the color filter side substrate 39. .

FIG. 4 shows a cross-sectional structure of an active matrix color liquid crystal display device using an a-3i diode as an active element. In the figure, 40 is a glass substrate, 41 is an insulating film,
42 is black stripe.

43 is an insulating film, 44 is a picture element electrode, and 45 is a boron conductor a.
-3i semiconductor layer, 46 is a non-doped a-3i semiconductor layer,
47 is a phosphorus-doped Si semiconductor layer.

48 is a light shield layer, 49 is an insulating film, 50 is a Cr electrode,
51 is an alignment film, 52 is a liquid crystal layer, 53 is a glass substrate, 54
55 is a color filter, and 55 is a transparent electrode.

56 is an alignment film.

A blank drive 42 is patterned and formed on an etching stopper insulating film 41 made of SiNx on a glass substrate 40 . This blank drive 42 is an a-3i semiconductor film.

It is composed of a metal film or a resin film with a large light absorption coefficient. On the black stripe 42 and the etching stopper insulating film 41, an etching stopper insulating film 43 made of SiO□ is formed.

On the etching stopper insulating film 43, a picture element electrode 44 made of ITO is formed in a pattern.

This picture element electrode 44 is continuously formed on a part of the upper part of the black stripe 42 of the insulating film 43 and a part covering between the black stripes 42.

A boron-doped Mi3i semiconductor layer 45. Non-doped a-3i semiconductor layer 46. Phosphorus doped me 3t semiconductor layer 47. Optical shield layer 48 made of Cr. Insulating film 49
Also, an a-3i diode 57 is formed by the electrode 5o. This active element a
Pairs of Si diodes 57 and picture element electrodes 44 are formed in a matrix on the glass substrate 40. An alignment film 51 is formed on the a-3i diode 57 and the picture element electrode 44.

On the opposite glass substrate 53, a color filter 54, an I
Transparent electrode 55 made of TO. An alignment film 56 is formed. No black stripe is formed between the color filters 54 on the opposing sides.

The active element side substrate 58 and the color filter side substrate 59 configured as described above face each other, and the alignment film 5 of the active element side substrate 58
1 and the alignment film 56 of the color filter side substrate 59 .

The embodiment described below is an example in which a black mask is placed above an active element. , FIG. 5 shows a cross-sectional structure of an active matrix color liquid crystal display device using a-3i TFTs as active elements. In the figure, 60 is a glass substrate, 61 is a gate electrode,
62 is a gate insulating layer, 63 is a non-doped Mi3i semiconductor layer, 64 is a phosphorus-doped Mi3i semiconductor layer, 65 is a source and drain electrode, 66 is a picture element electrode, 67 is an insulating film, 6
8 is a black stripe, 69 is an alignment film, 70 is a liquid crystal layer, 71 is a glass substrate, 72 is a color filter, 73 is a transparent electrode, and 74 is an alignment film.

A gate electrode 61 made of Ta, S
Gate insulating layer 62 made of iNx. non-doped a-3i
Semiconductor layer 63. A TPT 75 constituted by a phosphorous-doped Mi3i semiconductor layer 64 and a source and drain electrode 65 made of Ti, and a patterned picture element electrode 66 made of ITO are formed. This a-3iTFT
Pairs of the pixel electrodes 75 and 66 are formed in a matrix on the glass substrate 60. These picture element electrodes 66 and a
The -3i TFT 75 is covered with an insulating film 67 made of SiNx, and the upper insulating film 67 between the TPT 75 portion and the picture element electrodes 66 is covered with an a-3i semiconductor film, a metal film, or a light absorption coefficient film. A black stripe 68 made of a large resin film is formed in a pattern.

An alignment film 69 is formed covering the blank stripe 8 and the insulating film 67.

A color filter 72 is placed on the opposing glass substrate 71.
, a transparent electrode 73 made of ITO. An alignment film 74 is formed. No black stripe is formed between the color filters 72 on the opposing sides.

The active element side substrate 76 and the color filter side substrate 77 configured as described above face each other, and the liquid crystal layer 70 is present between the alignment film 69 of the active element side substrate 76 and the alignment film 74 of the color filter side substrate 77. .

FIG. 6 shows the planar structure of the active element side substrate 76.

In the figure, 66 is a picture element electrode, 68 is a black stripe, 75 is an a-3i TFT, 7B is a source pass line,
79 is a gate pass line.

A large number of a-S i T F T 75 and picture element electrodes 66
pairs are arranged in a matrix, and black stripes 68 are patterned to cover between the many picture element electrodes 660. This black stripe 6
8 is formed along a source pass line 78 and a gate pass line 79 which are arranged in the vertical and horizontal directions between the picture element electrodes 66, and these pass lines 78 and 79 and the a-3i TFT 75 are formed on an insulating layer. 67 (FIG. 5) is covered by a black stripe 68. Therefore, when this active element side substrate 76 is viewed from above, only the black stripe 68 and the picture element electrode 66 are visible.

The pattern of the a-3i semiconductor film, metal film, or resin film constituting the black stripe 68 is the pattern of the pixel electrode 6
6 end and 1~2μ from the top to ensure alignment accuracy
They overlap by about m.

The thickness of the a-3i semiconductor layer constituting the black stripe 68 is such that it absorbs 99% or more of the light from the bank light source and is sufficiently thinner than the cell thickness of the liquid crystal layer 70, for example, from 0.2 μm to 2.0 μm. The thickness ranges from . Further, when the black stripe 68 is a metal film, the thickness of this metal film is 0.01 μm to 2.0 μm for the same reason.
becomes. Furthermore, for the resin film, the film thickness is 0.05μ
It is 6.0 μm from m.

In the structure of this liquid crystal display device, the active element side substrate 7
This structure has a black stripe 68 between the 6 picture element electrodes 66 and above the a-3i TFT 75, and the black stripe 68 has no relation to the bonding accuracy between the color filter side substrate 77 and the active element side substrate 76. .

Next, an embodiment using an MIM element as an active element will be described.

FIG. 7 shows a cross-sectional structure, in which 80 is a glass substrate;
1 is a Ta electrode, 82 is a Ta, O, layer, 83 is a picture element electrode, 84 is a Ti electrode, 85 is an insulating film, 86 is a black stripe, 87 is an alignment film, 88 is a liquid crystal, 89 is a glass substrate, 90 91 is a color filter, 91 is a transparent electrode, and 92 is an alignment film.

On the glass substrate 80, there is an electrode 81 made of Ta, and an oxide film of Ta on this electrode 81, T a , 0°N8.
2 and an electrode 84 made of Ti.
3 and a picture element electrode 83 are formed. Pairs of the MIM 93, which is an active element, and the picture element electrode 83 are formed in a matrix on the glass substrate 80.

Furthermore, an insulating film 85 made of SiNx is formed to cover the MTM 93 and the picture element electrodes 83 on the active element side substrate 94, and the upper part of the MIM 93 of this insulating film 85 and between the picture element electrodes 83 are formed. On top of the upper part, a-3i
A black stripe 86 is formed of a semiconductor layer, a metal film, or a resin film with a large light absorption coefficient. An alignment film 8 covers this black stripe 86 and the insulating film 85.
7 is formed.

A color filter 90, an I
Transparent electrode 91 made of TO. An alignment film 92 is formed. No black stripe is formed between the color filters 90 on the opposing sides.

The active element side substrate 94 and the color filter side substrate 95 having the above-described configuration face each other, and the liquid crystal layer 88 is present between the alignment film 87 of the active element side substrate 94 and the alignment film 92 of the color filter side substrate 95. .

FIG. 8 shows a cross-sectional structure of an active matrix color liquid crystal display device using an a-3i diode as an active element. In the figure, 96 is a glass substrate, 97 is a picture element electrode, 98 is a light shield layer, 99 is a boron-doped a-St semiconductor layer, 100 is a non-doped Mi3i semiconductor layer, 101
is a phosphorus-doped 3T semiconductor layer, 102 is an insulating film, 10
3 is an electrode, 104 is an insulating film, 105 is a black stripe, 106 is an alignment film, 107 is a liquid crystal layer, 108 is a glass substrate, 109 is a color filter, 110 is a transparent electrode, 1
11 is an alignment film.

On a glass substrate 96, a picture element electrode 97 made of ITO,
A light shield N98 made of Cr is placed on the end of the picture element electrode 97. Boron-doped 3T semiconductor layer 99. Non-doped Mi 3i semiconductor layer 100° Phosphorus doped Mi 3i semiconductor layer 101. Insulating film 102 made of SiO□. A-3i diode 1 configured with an electrode 103 made of Cr
12 are formed. A pair of the a-3t diode 112 and the picture element electrode 97, which are active elements, are connected to the glass substrate 96.
It is formed in a matrix shape on top.

Further, an insulating film 104 made of SiNx is formed covering the a-3i diode 112 and the picture element electrode 97 on the active element side substrate 113, and the a-
A black stripe 105 made of an a-3i semiconductor film, a metal film, or a resin film with a large light absorption coefficient is formed above the portion covering the 3i diode 112. An alignment film 106 is formed to cover the black stripe 105 and the insulating film 104.

A color filter 109 is provided on the glass substrate 108 on the opposite side.
．． Transparent electrode 110 made of ITO. An alignment film 111 is formed. No black stripe is formed between the color filters 109 on the opposing sides.

The active element side substrate 113 and the color filter side substrate 114 configured as described above face each other, and the alignment film 106 of the active element side substrate 113 and the alignment film 11 of the color filter side substrate 114
1, a liquid crystal layer 107 exists between the two.

<Effects of the Invention> As explained above, in the present invention, by adopting a structure in which the active element side substrate has a black stripe,
The positional accuracy of the picture element electrode and black stripe is determined by the accuracy of film formation and patterning of the active element side substrate. The problem of alignment accuracy can be solved. Therefore, the width of the black stripe can be narrowed, and the area of the picture elements can be increased accordingly, so that the image quality can be improved by increasing the brightness. Furthermore, since the requirement for bonding accuracy between the active element side substrate and the color filter side substrate is relaxed, the yield of non-defective products due to bonding misalignment is improved.

[Brief explanation of the drawing]

1, 3, 4, 5, 7, and 8 are diagrams showing cross-sectional structures of embodiments of the present invention, and FIGS. 2 and 6 are planar structures of embodiments of the present invention. 9 is a diagram showing a cross-sectional structure of a conventional example, and FIG. 10 is a diagram showing a planar structure of a conventional example. 1.14,23,33,40.53゜60.71.80,89,96,108...Glass substrate 10.30,44,66.83.97...Picture element electrode 18.75...・a-8iTFT 19.38, 58, 76.94, 113... Active element side substrate 20.39, 59, 77.95, 114... Color filter side substrate 37.93... MIM element 57. 112...a-3i diode patent distributor
Sharp Corporation Representative Patent Attorney Nishi 1) Arata

Claims (1)

[Claims] An active matrix structure in which a liquid crystal layer exists between an active element side substrate in which pairs of picture element electrodes and active elements are arranged in a matrix, and a color filter side substrate in which picture element electrodes and color filters are arranged. A liquid crystal display device, wherein a black stripe is formed between the picture element electrodes of the active element side substrate and at least on one side above or below the active element.