KR100265573B1 - Super high aperture lcd and method for fabricating the same - Google Patents

Abstract

PURPOSE: A liquid crystal device having a super aperture rate and a method for manufacturing the same are to increase the capacity of a storage capacitor, as well as achieving a super aperture rate. CONSTITUTION: An insulating film(201) is formed on an insulating substrate(200), and a gate electrode(81a) is formed on the insulating film and is extended from a gate line. A gate insulating film(82) is formed on an insulating film(202) with the gate electrode formed thereon. A semiconductor layer(83) made of amorphous silicon is formed on the gate insulating film corresponding to the gate electrode, and an etch stopper(84) is stopper on the semiconductor layer corresponding to the gate electrode. A source electrode(86) and a drain electrode(87) are formed on the semiconductor layer and the gate insulating film to expose an upper surface of the etch stopper. An ohmic layer(85) is formed between the semiconductor layer and the source/drain electrodes. The first transparent electrode(90) is formed on the gate insulating film.

Description

Ultra high aperture liquid crystal display device and manufacturing method thereof

The present invention relates to a TFT-LCD (Thin Film Transistor-Liquid Crystal Display), which is one of the flat panel display devices. More specifically, it adopts a two-layer IT0 structure to obtain a high opening rate without reducing the storage capacity. The present invention relates to an aperture ratio liquid crystal display device.

In the TFT-LCD, the efficiency of the battery is gradually slowed down as the capacity is increased. There is a method of improving the transmittance of the liquid crystal panel as one method for solving such a decrease in battery efficiency.

As a method of improving the transmittance of a liquid crystal panel, there exist a method of largely improving the aperture ratio of a liquid crystal panel, the development of a high permeable polarizing plate, and use of a high permeability color filter. Among these methods, a method of improving the aperture ratio of a liquid crystal panel has been actively studied in recent years.

1 shows a planar structure of a conventional TFT-LED.

Referring to FIG. 1, the planar structure of a conventional liquid crystal display device is formed by crossing a gate line 10 and a data line 20 on a transparent insulating substrate 1 such as a glass substrate, and forming a gate line 10. The thin film transistor 30 to which the gate line 10 and the data line 20 are connected is arranged at a portion where the data line 20 crosses.

In addition, the pixel electrode 40 is connected to the thin film transistor 30 at regular intervals from the gate line 10 and the data line 20 in a space formed by the gate line 10 and the data line 20. The storage electrode 31b, which is a lower electrode of the storage capacitor 50, is arranged in parallel with the gate line 10.

FIG. 2 is a cross-sectional structural view taken along line 1A-1A 'of FIG. 1, showing a cross-sectional view of a thin film transistor in a liquid crystal display device. Referring to FIG. 2, the cross-sectional structure of the thin film transistor 30 is described. An insulating film 2 is formed on the insulating substrate 1, and a gate electrode 31 a extending from the gate line 10 is formed thereon. The gate insulating film 32 is formed on the insulating film 2 on which the gate electrode 31a is formed.

In addition, a semiconductor layer 33 made of amorphous silicon or the like is formed on the gate insulating layer 32 corresponding to the gate electrode 31a, and an etch stopper 34 is formed on the semiconductor layer 33 corresponding to the gate 31a. Source / drain electrodes 36 and 37 are formed to expose the top surface of the etch stopper 34, and impurities are doped between the source / drain electrodes 36 and 37 and the semiconductor layer 34. It has a structure in which an ohmic layer 35 made of or the like is formed.

FIG. 3 illustrates a cross-sectional structure along the line 1B-1B ′ of FIG. 1 and illustrates the cross-sectional structure of the storage capacitor 50.

Referring to FIG. 3, the storage capacitor 50 has an insulating film 2 formed on the insulating substrate 1, and a storage electrode 31b, which is a lower electrode made of the same material as the gate electrode 31a, is formed thereon. A gate insulating film 32 serving as a dielectric film of the storage capacitor is formed on the insulating film 2 including the storage electrode 31 b, and a pixel electrode serving as an upper electrode on the gate insulating film 32, which is a dielectric film. 40) has a formed structure.

In the conventional liquid crystal display device as shown in FIGS. 1 to 3, the pixel electrode 14 is formed by separating the pixel line 14 from the data line 20, which is a signal line, at a predetermined distance and a distance of about several μm. As described above, when the pixel electrode 40 and the data line 20 overlap each other, parasitic capacitance exists between the pixel electrode 40 and the data line 20 to generate vertical crosstalk. .

The crosstalk generated when the pixel electrode 40 overlaps with the data line 20 causes a flicker phenomenon, resulting in a deterioration in image quality.

A method for improving the aperture ratio by overlapping the pixel electrode 40 and the data line 20 without generating cross talk, and is formed between the pixel electrode 40 and the lower electrode 31b, which are the upper electrodes of the storage capacitor 50. A method of using a dielectric film having a low dielectric constant as the gate insulating film 32 has been proposed.

In the method of using the dielectric film having the low dielectric constant described above, since the pixel electrode 40 can be oriented by overlapping with the data line 20, an ultra-high spherical ratio of 80% or more can be obtained. However, the above method has a problem of lowering the capacity of the storage capacitor because a material having a low dielectric constant is used as the dielectric film in order to obtain an ultra-high opening ratio.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, by using a two-layer structure ITO having the IT0 connected to the pixel electrode and the storage capacitor signal electrode as the storage capacitor lower electrode, and using a material having a low dielectric constant as the dielectric film, An object of the present invention is to provide a liquid crystal display device and a method of manufacturing the same, which can increase the capacitance of the capacitor and at the same time obtain an ultra-high opening ratio.

1 is a plan view of a conventional TFT-LCD.

FIG. 2 is a cross-sectional structural view of the TFT-LCD taken along the line AA 'of FIG.

3 is a cross-sectional structural view of the TFT-LCD taken along the line 1B-1B 'of FIG.

4 is a planar structure diagram of an ultra-high opening ratio liquid crystal display device having a two-layer IT0 structure according to an embodiment of the present invention;

5 is a cross-sectional structural view of the liquid crystal display device taken along the line 4A-4A 'of FIG.

6 is a cross-sectional structural view of the liquid crystal display device taken along the line 4B-4B 'of FIG.

* Explanation of symbols for the main parts of the drawings

200: insulating substrate 201: insulating film

60: gate line 70: data line

80 thin film transistor 90 IT0 electrode (lower electrode)

91: dielectric film of low dielectric constant 92: ITO electrode (pixel electrode and upper electrode)

100: storage capacitor 81a: gate electrode

In order to achieve the above object, the high aperture ratio display device of the present invention includes a transparent insulating substrate; A gate line and a data line formed to cross the insulating substrate; A thin film transistor formed at a portion where the gate line and the data line cross each other; A first transparent electrode formed at a predetermined distance from the data line and the gate line in a space formed by the gate line and the data line; A signal lower electrode of the storage capacitor in contact with the first transparent electrode through a first contact and arranged in parallel with the gate line; And a second transparent electrode formed on the first transparent electrode, overlapping the data line and the gate line, and contacting the thin film transistor through a second contact.

In the ultra-high opening liquid crystal display device according to the embodiment of the present invention, the first transparent electrode is composed of both the second transparent electrode and the IT0 film, the first transparent electrode is the lower electrode of the storage capacitor, the second transparent electrode is the storage capacitor At the same time as the upper electrode of the pixel electrode, the storage electrode and the gate line is made of the same material.

Further, a liquid crystal display device having a storage capacitor of the present invention, comprising: a transparent insulating substrate; A gate electrode formed on the transparent insulating substrate; A gate insulating film formed on the insulating substrate including the gate electrode; A semiconductor layer formed on the gate insulating film corresponding to the gate electrode; An etch stopper formed on the semiconductor layer corresponding to the gate electrode; A source / drain formed over the semiconductor layer and the gate insulating layer to expose an upper surface of the etch stopper; A transparent electrode formed at a predetermined distance from the source / drain electrode; An insulating film having a contact formed over the entire substrate; And a pixel electrode formed on the insulating layer which is simultaneously in contact with one of the source / drain electrodes through the contact and overlaps with the contact.

In the ultra-high opening liquid crystal display device according to the embodiment of the present invention, the insulating film is a photosensitive protective film having a low dielectric constant having a dielectric constant of 2.5 to 3.6, and has a thickness of 1-3 μm.

In addition, the present invention is a liquid crystal display device having a data line and a gate line arranged to cross each other on an insulating substrate, and a storage capacitor arranged in parallel with the gate line, the lower electrode of the storage capacitor formed on the insulating substrate Phosphorus storage electrodes; A first insulating layer formed on a substrate including the storage electrode having a contact; and an upper electrode of the storage capacitor contacted with the storage electrode through the contact and formed at a predetermined distance from the data line on the first insulating layer. and; A second insulating film formed over the entire substrate; And a pixel electrode formed on the second insulating layer to overlap the storage electrode and the data line.

In addition, a data line and a gate line arranged to cross each other on the insulating substrate of the present invention, a thin film transistor in which the intersection portion of the data line and the gate line is arranged, and a storage capacitor arranged in parallel with the gate line A liquid crystal display device comprising: forming a gate line, a gate electrode of a thin film transistor, and a signal electrode of a storage capacitor on the insulating substrate; Forming a first insulating film over the entire substrate; Forming a semiconductor layer, an etch stopper, and an ohmic layer of a thin film transistor on a first insulating film corresponding to the gate electrode; Etching a first insulating layer on the signal electrode of the storage capacitor to form a first contact; Forming a lower electrode of the storage capacitor in contact with the signal electrode through a first contact so as not to overlap the gate line and the data line; Forming a data line at the same time as forming a source / drain electrode on the ohmic layer and the first insulating layer so that the top surface of the etch stopper is exposed; Forming a second insulating film over the entire substrate; Etching a second insulating layer on any one of the source / drain electrodes to form a second contact; And forming a pixel electrode in contact with the source / drain electrodes on the second insulating layer through the second contact and overlapping the data line and the gate line. do.

EXAMPLE

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

4 is a cross-sectional view of the ultra-high magnification liquid crystal display device according to the exemplary embodiment of the present invention.

Referring to FIG. 4, the planar structure of the ultra-high-throughput liquid crystal display device according to an embodiment of the present invention is formed by crossing the gate line 60 and the data line 70 on a transparent insulating substrate 200 such as a glass substrate. The thin film transistor 80 to which the gate line 60 and the data line 70 are connected is arranged.

In addition, the first transparent electrode 90 is arranged in a space formed by the gate line 60 and the data line 70 at a predetermined distance from the data line 70. An upper portion of the first transparent electrode 90 overlaps the data line 70 so that the second transparent electrode 92 is in contact with the thin film transistor 80 through the contact C2.

The storage electrode 81b, which is a signal electrode of the storage capacitor 100, is in contact with the first transparent electrode 90 through the contact C1 to have a planar structure arranged in parallel with the gate line 60.

Here, the first transparent electrode 90 has a size of about 50-60% of the size of the second transparent electrode 92.

FIG. 5 is a cross-sectional view taken along line 4A-4A 'of FIG. 4, showing a cross-sectional view of a thin film transistor in a liquid crystal display device. Referring to FIG. 5, a cross-sectional structure of the thin film transistor 80 is formed. An insulating film 201 is formed on the insulating substrate 200, and a gate electrode 81 a extending from the gate line 60 is formed thereon. The gate insulating film 82 is formed on the insulating film 202 on which the gate 81a is formed.

In addition, a semiconductor chip 83 made of amorphous silicon or the like is formed on the gate insulating film 82 corresponding to the gate electrode 81a, and an etch stopper is formed on the semiconductor layer 83 corresponding to the gate electrode 81a. 84) is formed.

Source / drain electrodes 86 and 87 are formed on the semiconductor layer 83 and the gate insulating layer 83 so that the top surface of the etch stopper 84 is exposed, and the semiconductor layer 83 and the source / drain electrodes ( An ohmic layer 85 made of a doped amorphous silicon layer or the like is formed between 86 and 87, and a source electrode 86 extends from the data line 70.

In addition, a first dielectric electrode 90 is formed on the gate insulating layer 82 to serve as a lower electrode of the storage capacitor 100 at a predetermined distance from the drain electrode 87, and has a low dielectric constant having a contact C2. An insulating film 91 is formed on the entire surface of the substrate, and a second transparent electrode 92 is formed on the insulating film 91 to be in contact with the drain electrode 87 through the contact C2.

Here, a photosensitive protective film having a dielectric constant of 2.5 to 3.6 is formed with an insulating film 91 having a dielectric constant having a thickness of 1-3 탆.

FIG. 6 illustrates a cross-sectional structure along the line 4B-4B 'of FIG. 4, and illustrates the cross-sectional structure of the storage capacitor 100.

Referring to FIG. 6, an insulating film 201 is formed on the insulating substrate 200, and a signal electrode 81b made of the same material as the gate electrode material is formed thereon, and the signal electrode 81b is formed. A gate insulating film 82 having a high dielectric constant having a contact C1 is formed on the insulating film 201, and a first transparent electrode 91 serving as a lower electrode is formed on the gate insulating film 82. It has a structure formed with a predetermined distance from the gate line 60.

An insulating film 91 having a low dielectric constant is formed on the gate insulating film 82 including the first transparent electrode 91, and a second electrode simultaneously acting as a pixel electrode and an upper electrode of the storage capacitor on the insulating film 91 having a low dielectric constant. It has a structure in which the transparent electrode 92 is formed.

In the liquid crystal display of the present invention having the structure as described above, the first transparent electrode 90 serving as the lower electrode of the storage capacitor 35 is not overlapped with the data line 70 to prevent crosstalk and The storage capacitor is formed with the two transparent electrodes 92 so as not to reduce the storage capacity of the storage capacitor.

In addition, the second transparent electrode 92 serving as the pixel electrode is formed to overlap with the data line to improve the aperture ratio and to be generated when the insulating film serving as the dielectric film below the material having a low dielectric constant is used. Crosstalk can be prevented.

That is, the liquid crystal display device of the present invention uses the transparent electrode IT0 electrode in a two-layer structure, so that the first transparent electrode 90 and the low dielectric constant dielectric film 91 and the second transparent electrode connected to the storage preferred electrode 81b. By forming the storage capacitor 100 as the electrode 92, it is possible to obtain a high opening rate without reducing the accumulation capacity.

The manufacturing method of the liquid crystal display device having the structure as described above is as follows.

First, a gate metal material is deposited and patterned on a transparent insulating substrate 200 having an insulating film 201 formed thereon to form a gate line 60, a gate 81a of the thin film transistor 80, and a storage capacitor 100. The storage electrode 8lb, which is a signal electrode, is formed. Subsequently, a gate insulating film 82 made of a material having a high dielectric constant is formed on the entire surface of the substrate.

Subsequently, a semiconductor layer 83 made of an amorphous silicon film or the like, an etch stopper 84, and an ohmic layer 85 made of a doped amorphous silicon film are formed by a conventional method. Subsequently, the gate insulating layer 82 is etched to expose the upper surface of the signal electrode 81b of the storage capacitor 100 to form the first contact C1. After depositing the IT0 film on the front surface of the substrate through the first contact C1 and patterning, the lower electrode made of the first transparent electrode 90 which is in contact with the signal electrode 81b through the first contact C1. Form.

Next, a metal for source / drain electrodes is deposited and patterned to form a data line 70, a source electrode electrode 86 extending from the data line, and a predetermined distance from the lower electrode 90 of the storage capacitor 100. The drain electrode 87 is formed.

A second contact C2 is formed by spin coating a dielectric film 91 made of a photosensitive protective film having a low dielectric constant of 2.5 to 3.6 on the entire surface of the substrate and patterning the drain electrode 87 to expose the drain electrode 87. After depositing an IOD film on the entire surface of the substrate, a pixel electrode 92 made of a second transparent electrode is formed to contact the drain electrode 87 through the second contact C2. In this case, the pixel electrode 92 is formed to overlap the data line 70 and the gate line 60, and forms the storage lower electrode 90 and the storage capacitor 100.

According to the present invention as described above, the lower electrode of the storage capacitor is formed so that the ITO film does not overlap with the data line, and the IT0 area is maintained at about 50-60% of the pixel electrode so as not to reduce the storage capacity of the capacitor. In addition, it is possible to prevent the occurrence of crosstalk.

In addition, the ITO film is formed to overlap with the data line as the pixel electrode to improve the aperture ratio, and crosstalk can be prevented by using an insulating film having a low dielectric constant as the dielectric film.

Accordingly, it is possible to provide a liquid crystal display device having an ultra-high opening ratio of high quality.

Claims (33)

A liquid crystal display device having a storage capacitor, comprising: a transparent insulating substrate; A gate line and a data line formed to cross the insulating substrate; A thin film transistor formed at a portion where the gate line and the data line cross each other; A first transparent electrode formed at a predetermined distance from the data line and the gate line in a space formed by the gate line and the data line; A signal electrode of the storage capacitor in contact with the first transparent electrode through a first contact and arranged in parallel with the gate line; And a second transparent electrode formed on the first transparent electrode and overlapping the data line and the gate line and contacting the thin film transistor through a second contact. The ultra-high aperture liquid crystal display device according to claim 1, wherein the first transparent electrode is made of the same material as the second transparent electrode. The ultra-high aperture liquid crystal display device according to claim 2, wherein the first transparent electrode and the second transparent electrode are made of an ITO film. The ultra-high opening liquid crystal display device of claim 1, wherein the first transparent electrode serves as a lower electrode of the storage capacitor. The liquid crystal display of claim 1, wherein the second transparent electrode functions as an upper electrode and a pixel electrode of the storage capacitor. The liquid crystal display of claim 1, wherein the insulating substrate is a glass substrate having an insulating film formed on an upper surface thereof. The liquid crystal display of claim 1, wherein the storage signal electrode and the gate line are made of the same material. A liquid crystal display device having a storage capacitor, comprising: a transparent insulating substrate; A gate electrode formed on the transparent insulating substrate; A gate insulating film formed on the insulating substrate including the gate electrode; A semiconductor layer formed on the gate insulating film corresponding to the gate electrode; An etch stopper formed on the semiconductor layer corresponding to the gate electrode; A source / drain formed over the semiconductor layer and the gate insulating layer to expose an upper surface of the etch stopper; A transparent electrode formed at a predetermined distance from the source / drain electrode; An insulating film having a contact formed over the entire substrate; And a pixel electrode formed on the insulating film which is simultaneously in contact with one of the source / drain electrodes through the contact and overlaps with the contact. 10. The liquid crystal display of claim 8, wherein the transparent electrode and the pixel electrode are made of the same material. 10. The liquid crystal display device according to claim 9, wherein the transparent electrode and the pixel electrode are made of an ITO film. The liquid crystal display of claim 8, wherein the transparent electrode serves as a lower electrode of the storage capacitor. 10. The liquid crystal display of claim 8, wherein the insulating film is a material having a low dielectric constant having a dielectric constant of 2.5 to 3.6. 13. The super-opening liquid crystal display device according to claim 12, wherein the insulating film is a photosensitive protective film. The super-aperture liquid crystal display device according to claim 12, wherein the photosensitive protective film which is the insulating film has a thickness of 1 to 3 mu m. 10. The liquid crystal display of claim 8, wherein the insulating substrate is a glass substrate having an insulating film formed on an upper surface thereof. 10. The liquid crystal display device according to claim 8, wherein the gate insulating film is made of a dielectric film having a high dielectric constant. A liquid crystal display device comprising a data line and a gate line arranged to cross each other on an insulating substrate, and a storage capacitor arranged to be parallel to the gate line, the liquid crystal display device comprising: a storage signal electrode formed on the insulating substrate; A first insulating film formed on a substrate including the storage signal electrode having a contact; A lower electrode of the storage capacitor in contact with the storage signal electrode through the contact and formed at a predetermined distance from the data line on the first insulating layer; A second insulating film formed over the entire substrate; And a pixel electrode formed on the second insulating layer so as to overlap the storage signal electrode and the data line. 18. The liquid crystal display of claim 17, wherein the gate line and the storage signal electrode are made of the same material. 18. The liquid crystal display device according to claim 17, wherein the first insulating film is a dielectric film having a high dielectric constant. 18. The ultra-high aperture liquid crystal display device according to claim 17, wherein the second insulating film is a material having a low dielectric constant having a dielectric constant of 2.5 to 3.6. 21. The liquid crystal display device according to claim 20, wherein the second insulating film is a photosensitive protective film. 22. The liquid crystal display device according to claim 21, wherein the photosensitive protective film which is the insulating film has a thickness of 1 to 3 mu m. 18. The liquid crystal display of claim 17, wherein the insulating substrate is a glass substrate having an insulating film formed on an upper surface thereof. 18. The liquid crystal display of claim 17, wherein the storage lower electrode and the pixel electrode are made of the same material. 10. The liquid crystal display of claim 9, wherein the storage lower electrode and the pixel electrode are made of an IT0 film. A liquid crystal display device comprising: a data line and a gate line arranged to cross each other on an insulating substrate; a thin film transistor arranged at a portion where the data line and the gate line intersect; and a storage capacitor arranged to be parallel to the gate line. Forming a gate line, a gate electrode of a thin film transistor, and a signal electrode of a storage capacitor on the insulating substrate; Forming a first insulating film over the entire substrate; Forming a semiconductor layer, an etch stopper, and an ohmic layer of a thin film transistor on a first insulating film corresponding to the gate electrode; Forming a first contact by etching the first insulating layer on the signal electrode of the storage capacitor, and forming a lower electrode of the storage capacitor in contact with the signal electrode through the first contact so as not to overlap the gate line and the data line. Process of doing; Forming a data line at the same time as forming a source / drain electrode on the ohmic layer and the first insulating layer so that the top surface of the etch stopper is exposed; Forming a second insulating film over the entire substrate; Etching a second insulating layer on any one of the source / drain electrodes to form a second contact; And forming a pixel electrode in contact with the source / drain electrodes through the second contact and overlapping the data line and the gate line on the second insulating layer. (Correction) The method according to claim 26, wherein the first insulating film is a dielectric film having a high dielectric constant, and functions as a gate insulating film of a thin film transistor and a dielectric film of a storage capacitor. 27. The liquid crystal display of claim 26, wherein the second insulating film has a low dielectric constant having a dielectric constant of 2.5 to 3.6, and acts as a dielectric film between the lower electrode and the pixel electrode of the storage capacitor. Manufacturing method of display element. (Correction) The method according to claim 28, wherein the second insulating film is formed to a thickness of 1-3 mu m by spin coating a photosensitive protective film. (Correction) The method according to claim 26, wherein the insulating substrate is a glass substrate having an insulating film formed on an upper surface thereof. (Correction) The method of claim 26, wherein the lower electrode and the pixel electrode of the storage capacitor are made of the same material. (Correction) A method according to claim 31, wherein the lower electrode and the pixel electrode are made of an IT0 film. (Correction) The method of claim 26, wherein the lower electrode of the storage capacitor has a size of about 50-60% of the size of the pixel electrode.

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