KR20130039573A - Liquid crystal display device and method of fabricating the same - Google Patents

Abstract

PURPOSE: A liquid crystal display device and a manufacturing method are provided to reduce a data load between a data line and a common electrode or the data line and a pixel electrode by an RGB color filter. CONSTITUTION: A first insulating layer(170a) is formed with a PECVD(Plasma-Enhanced Chemical Vapor Deposition) method or a CVD(Chemical Vapor Deposition) method on a gate insulating layer(120) which includes a TFT(Thin Film Transistor) and a DL(Data Line). RGB color filters(160R,160G) are formed by using third to fifth masks. A light blocking column spacer(210) is formed with a light blocking material. A process, which forms a black matrix on an upper substrate(300), is omitted by forming the light blocking column spacer.

Description

TECHNICAL FIELD [0001] The present invention relates to a liquid crystal display device and a method of manufacturing the same,

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device capable of reducing the number of masks and a method of manufacturing the same.

(PDP), Electro Luminescent Display (ELD), Vacuum Fluorescent (VFD), and the like have been developed in recent years in response to the demand for display devices. Display) have been studied, and some of them have already been used as display devices in various devices.

Among them, liquid crystal display devices are mostly used in place of CRT (Cathode Ray Tube) for the purpose of portable image display devices because of their excellent image quality, light weight, thinness and low power consumption, But also various kinds of monitors such as a television and a computer monitor receiving and displaying a broadcast signal in addition to the use of the same mobile type.

Such a liquid crystal display device displays an image by adjusting the light transmittance of a liquid crystal having dielectric anisotropy using an electric field. The liquid crystal display device includes a color filter substrate on which a color filter is formed, a thin film transistor substrate on which a thin film transistor is formed, And a liquid crystal layer formed on the substrate.

The color filter substrate is formed with R, G, and B color filters for color implementation, a black matrix for preventing light leakage, and a column spacer for maintaining a cell gap between the thin film transistor substrate and the color filter substrate. A plurality of pixel electrodes, to which data signals are individually supplied, are formed in a matrix form on the thin film transistor substrate. In the thin film transistor substrate, a thin film transistor for driving a plurality of pixel electrodes individually, a gate wiring for controlling the thin film transistor, and a data wiring for supplying a data signal to the thin film transistor are formed.

A typical driving mode most commonly used in a liquid crystal display device is a TN (Twisted Nematic) mode in which a liquid crystal director is arranged so as to be twisted by 90 ° and then a voltage is applied to control the liquid crystal director, An in-plane switching mode in which liquid crystal is driven by a horizontal electric field between an electrode and a common electrode, and the like. In the transverse electric field mode, the pixel electrode and the common electrode are alternately formed in the opening of the thin film transistor substrate so that the liquid crystal is aligned by the transverse electric field generated between the pixel electrode and the common electrode.

However, since the transverse electric field mode liquid crystal display device has a wide viewing angle but low aperture ratio and transmittance, a fringe field switching (FFS) mode liquid crystal display device has been proposed in order to solve the above problems. A fringe field-effect mode liquid crystal display device has a structure in which a common electrode in the form of a tubular electrode is formed in a pixel region and a plurality of pixel electrodes are formed in a slit shape on a common electrode, The liquid crystal molecules are operated by a fringe electric field formed between the pixel electrode and the common electrode.

Hereinafter, a method of manufacturing a general fringe field-mode liquid crystal display device will be described with reference to the accompanying drawings.

1 is a cross-sectional view of a general fringe field mode thin film transistor substrate.

Referring to FIG. 1, a general fringe field effect mode thin film transistor substrate fabrication method includes forming a gate wiring (not shown), a gate electrode 10a, a gate pad lower electrode 10b, and a common wiring (not shown) A step of forming a semiconductor layer 13 in which an active layer 13a and an ohmic contact layer 13b are sequentially stacked using a second mask and a step of forming a source and drain electrodes 14a, The first and second protective films 15a and 15b including a pixel contact hole, a gate contact hole, and a data contact hole are formed by using a fourth mask, a step of forming a data line DL, a data pad lower electrode 14b, ). ≪ / RTI >

The step of forming the pixel electrode 16 to be connected to the drain electrode 14b on the second protective film 15b using the fifth mask and the step of forming the gate pad lower electrode 10b and the data pad Forming a third protective film 15c for exposing the lower electrode 14c and forming a third protective film 15c on the common electrode 18a for generating a fringe electric field with the pixel electrode 16 sandwiching the third protective film 15c And a data pad upper electrode 18c connected to the gate pad upper electrode 18b and the data pad lower electrode 14c connected to the gate pad lower electrode 10b.

Although not shown, a typical liquid crystal display device is formed using a total of 12 masks, including the step of fabricating a color filter substrate including R, G, and B color filters, a black matrix, and a column spacer. Therefore, the process is complicated and the manufacturing cost is increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a liquid crystal display device and a method of manufacturing the same that can be manufactured using nine masks.

According to an aspect of the present invention, there is provided a liquid crystal display device including: a thin film transistor formed in a region intersecting a gate wiring and a data wiring intersecting each other vertically on a lower substrate; A first insulating layer formed on the entire surface of the lower substrate including the thin film transistor; A color filter formed on the first insulating film; A second insulating layer formed on the entire surface of the first insulating layer to cover the color filter; A common electrode formed on the second insulating film; A protective film covering the common electrode; A pixel electrode connected to the exposed thin film transistor by selectively removing the first and second insulating films and the protective film, and forming a fringe electric field with the common electrode across the protective film; And a light-shielding column spacer formed on the protective film so as to overlap with the thin film transistor.

The light-shielding column spacer is at least one material selected from carbon, titanium oxide, color pigment, and black resin.

The first and second insulating films and the color filter are positioned between the data line and the common electrode.

The color filter is also formed on a region corresponding to the thin film transistor.

According to another aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device including forming a gate wiring and a gate electrode on a lower substrate using a first mask; Forming a semiconductor layer, a source electrode, a drain electrode, and a data line using a second mask, and forming a first insulating layer on the entire surface of the lower substrate including a semiconductor layer, a source electrode, a drain electrode, and a data line; Forming a color filter on the first insulating film using a third, fourth, and fifth masks, and forming a second insulating film on the entire surface of the first insulating film including the color filter; Forming a common electrode on the second insulating film by using a sixth mask and forming a protective film over the entire surface of the second insulating film including the common electrode; Exposing the drain electrode by selectively removing the protective film and the first and second insulating films using a seventh mask; Forming a pixel electrode connected to the drain electrode on the protective film using an eighth mask; And forming a light-shielding column spacer on the protective film using a ninth mask.

The light-shielding column spacer is formed of at least one material selected from carbon, titanium oxide, color pigment, and black resin.

The first and second insulating films and the color filter are positioned between the data line and the common electrode.

The color filter is also formed on a region corresponding to the thin film transistor.

The liquid crystal display of the present invention and its manufacturing method as described above have the following effects.

First, a general liquid crystal display device covers a data line by using a PAC (Photo Acryl Compound) having a high unit cost and a low unit cost in order to reduce the data load between the data line and the common electrode or the pixel electrode. However, since the R, G, and B color filters formed on the thin film transistor substrate can reduce the data load between the data line and the common electrode or between the data line and the pixel electrode, the present invention eliminates the process of forming the PAC, The cost can be reduced.

Second, a general liquid crystal display device forms a planarization layer to prevent light leakage of a step portion where a black matrix and a color filter are overlapped. However, since it is not necessary to consider the cohesion margin of the color filter substrate and the thin film transistor substrate, Widen the width to prevent light leakage. Therefore, the step of forming the planarization layer can be eliminated.

Third, the step of forming a black matrix can be eliminated by using a light-shielding column spacer.

1 is a cross-sectional view of a general fringe field mode thin film transistor substrate.
2 is a sectional view of a liquid crystal display device of the present invention.
3A to 3H are process sectional views showing a method of manufacturing a liquid crystal display device of the present invention.

In general, a liquid crystal display device has a thin film transistor substrate in which a thin film transistor (TFT) and a pixel electrode are formed in a pixel region defined by a gate wiring and a data wiring, and a color filter substrate on which a color filter is formed, A liquid crystal layer having dielectric anisotropy is formed therebetween. However, when the color filter substrate and the thin film transistor substrate are bonded together, light leakage may occur due to mis-alignment. And, because of this, the aperture ratio remarkably drops.

Therefore, in order to prevent the above-described problems, a liquid crystal display (COT) structure in which a color filter and a thin film transistor are simultaneously formed on one substrate is introduced and studied.

The liquid crystal display of the present invention has a COT structure in which a color filter and a thin film transistor are simultaneously formed on a substrate as described above, and a color filter and a thin film transistor are simultaneously formed on a substrate using a total of nine masks, The manufacturing cost can be reduced.

Hereinafter, a liquid crystal display device according to the present invention will be described with reference to the accompanying drawings.

2 is a cross-sectional view of a liquid crystal display device of the present invention.

2, the liquid crystal display of the present invention includes a lower substrate 100, an upper substrate 300, and a liquid crystal layer between the lower substrate 100 and the upper substrate 300. Specifically, the lower substrate 100 includes a thin film transistor, first and second insulating films 170a and 170b formed to cover the thin film transistor, and first, second, and third insulating films 170a and 170b, B color filters 160R and 160G, a common electrode 180 formed on the second insulating film 170b and the common electrode 180 with the protective film 190 interposed therebetween, And the pixel electrode 200a. A light shielding column spacer 210 is formed on the same layer as the pixel electrode 200a to prevent light leakage of the thin film transistor and maintain the cell gap between the lower substrate 100 and the upper substrate 300. [

Specifically, on the lower substrate 100, a plurality of pixel regions are defined by the gate interconnection GL and the data interconnection DL perpendicularly intersecting each other, and a plurality of pixel regions are defined in the intersection region where the gate interconnection GL and the data interconnection DL cross each other. A transistor is formed. A gate pad lower electrode 110b connected to the gate line GL and a data pad lower electrode 130c connected to the data line DL are formed and connected to the common line and the common line And includes a common pad.

The thin film transistor includes a gate electrode 110a, a source electrode 140a and a drain electrode 140b and a semiconductor layer 130 including an active layer 130a and an ohmic contact layer 130b sequentially stacked. The gate electrode 110a may protrude from the gate line GL to be supplied with a scan signal from the gate line GL and may be defined as a partial region of the gate line GL.

The active layer 130a overlaps the gate electrode 110a with the gate insulating film 120 formed of an inorganic insulating material such as silicon oxide (SiOx), silicon nitride (SiNx) or the like interposed therebetween. The ohmic contact layer 130b formed on the active layer 130a serves to reduce electrical contact resistance between the source and drain electrodes 140a and 140b and the active layer 130a. Then, the ohmic contact layer 130b corresponding to the spaced interval of the source and drain electrodes 140a and 140b is removed to form a channel.

The source electrode 140a is connected to the data line DL to receive the pixel signal of the data line DL and the drain electrode 140b is formed to face the source electrode 140a with the channel therebetween. The first and second insulating films 170a and 170b are formed on the entire surface of the gate insulating film 120 including the thin film transistor and the data line DL as an inorganic insulating material or an organic insulating material.

R, G and B color filters 160R and 160G (not shown) are formed on the first insulating layer 170a. More specifically, R, G and B color filters 160R and 160G The data load between the data line DL and the common electrode 180 can be reduced by the R, G, and B color filters 160R and 160G (not shown).

The second insulating film 170b is formed so as to cover the R, G, and B color filters 160R and 160G (not shown). That is, the second insulating film 170b is connected to the first insulating film 170a in at least one region, and the second insulating film 170b is connected to the R, G, and B color filters 160R and 160G (not shown) And is connected to the first insulating film 170a in all regions except for the formed region.

Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), Indium Tin Zinc Oxide (ITZO), and the like are formed on the second insulating layer 170b. And a protective layer 190 is formed on the entire surface of the second insulating layer 170b including the common electrode 180. The protective layer 190 is formed on the entire surface of the second insulating layer 170b.

The drain contact 140 exposing the drain electrode 140b, the gate pad lower electrode 110b and the data pad lower electrode 130c is formed by selectively removing the protective film 190 and the first and second insulating films 170a and 170b. A gate contact hole 190b and a data contact hole 190c are formed on the passivation layer 190. A transparent conductive material is deposited on the passivation layer 190 and patterned to form the drain contact hole 190a and the gate contact hole 190b, The gate pad upper electrode 200b and the data pad 200b which are connected to the drain electrode 140b, the gate pad lower electrode 110b and the data pad lower electrode 130c through the data contact hole 190c, An upper electrode 200c is formed.

At this time, the pixel electrode 200a is formed in a plurality of slit shapes to form a fringe electric field with the common electrode 180 in the form of a tubular electrode with the protective film 190 therebetween. The liquid crystal molecules are rotated by the dielectric anisotropy by the fringe field, and the light transmittance through the pixel region is changed according to the degree of rotation of the liquid crystal molecules, thereby realizing an image.

Although the pixel electrode 200a is formed on the upper layer than the common electrode 180 in the drawing, the pixel electrode 200a may be formed on the common electrode 180. FIG. In this case, the pixel electrode 200a in the form of a tubular electrode is formed which selectively removes the first and second insulating films 170a and 170b and is electrically connected to the exposed drain electrode 140b, A protective layer 190 is formed on the entire surface of the second insulating layer 170b and a slit-shaped common electrode 180 is formed on the protective layer 190. The gate pad upper electrode 200b and the data pad upper electrode 200c are formed simultaneously with the common electrode 180.

The light shielding column spacer 210 formed on the protective film 190 prevents light leakage of the thin film transistor and maintains the cell gap between the lower substrate 100 and the upper substrate 300. Specifically, the light-shielding column spacer 210 may be formed of an organic material including carbon, carbon dioxide, titanium oxide (TiOx), a color pigment, or the like, which absorbs light, or an organic material of black type, And the black matrix may not be formed on the upper substrate 300.

In a typical liquid crystal display device in which a color filter is formed on an upper substrate, a black matrix is formed on the upper substrate, and a color filter is formed so as to overlap with the black matrix. Light leakage occurs in a step where the black matrix and the color filter overlap . The width of the data lines of the thin film transistor substrate can be increased to prevent the light leakage, but there is a limitation in increasing the width of the data lines because the margin of adhesion between the color filter substrate and the thin film transistor substrate must be considered.

Therefore, a general liquid crystal display device has to further form a planarization layer on the entire surface of the upper substrate including the data color filter to prevent light leakage, which complicates the process and increases the manufacturing cost.

However, since the color filter is formed on the lower substrate 100 in the liquid crystal display device of the present invention, there is no need to consider the adhesion margin when the color filter substrate and the thin film transistor substrate are attached. Therefore, the light shielding can be prevented by widening the width of the data line DL, so that the process of forming the planarization layer in addition to the lower substrate 100 can be eliminated. In the region corresponding to the data line DL, It is not necessary to form a spacer. Specifically, the width of a data line of a general liquid crystal display device is about 3.5 m, but the present invention can form a data line DL having a width of about 6 m, so that the thickness of the data line DL can be made thin .

Hereinafter, a manufacturing method of a liquid crystal display device according to the present invention will be described in detail with reference to the accompanying drawings.

3A to 3H are process cross-sectional views illustrating a method of manufacturing a liquid crystal display device of the present invention.

First, as shown in FIG. 3A, on the lower substrate 100, Al / Cr, Al / Mo, Al (Nd) / Al, Al (Nd) / Cr, Mo / Al Mo / Cu alloy / Al / Cu alloy / Mo alloy / Cu alloy / Al alloy / Al / Mo alloy / Mo alloy / Mo / Al / Nd / Al, Al alloy, Mo alloy, Mo alloy / Al alloy, Mo / Al alloy, etc., or a structure in which two or more layers of Al, Al alloy / Mo alloy, Mo alloy / A gate metal layer is formed with a single layer. Then, the gate electrode 110a, the gate wiring GL, the gate pad lower electrode 110b, and the common wiring (not shown) are formed by patterning the gate electrode using the first mask. Specifically, after a metal layer is formed by a deposition method such as a sputtering method, a metal layer is patterned to form a gate electrode 110a, a gate wiring GL, a gate pad lower electrode 110b, and a common wiring (not shown) .

A gate insulating film 120 is formed of an inorganic insulating material on the entire surface of the substrate 100 including the gate electrode 110a, the gate wiring GL, the gate pad lower electrode 110b and the common wiring (not shown) do. A semiconductor layer 130 having a structure in which an active layer 130a and an ohmic contact layer 130b are sequentially stacked on a gate insulating film 120 using a halftone mask or a second mask as a diffraction exposure mask, And source and drain electrodes 140a and 140b spaced apart from the data line DL by a predetermined distance are formed. Then, the ohmic contact layer 130b exposed in the spaced interval between the source and drain electrodes 140a and 140b is removed to form a channel. As a result, a thin film transistor (TFT) including the gate electrode 110a, the semiconductor layer 130, and the source and drain electrodes 140a and 140b is formed.

Although the data pad lower electrode 130c is formed simultaneously with the data line DL in the drawing, the data pad lower electrode 130c may be formed simultaneously with the gate line GL. In this case, And a structure for connecting the lower electrode 130c and the data line DL.

Referring to FIG. 3C, a first insulating layer 170a is formed on the gate insulating layer 120 including the thin film transistor (TFT) and the data line DL by PECVD or CVD. Then, R, G, and B color filters 160R and 160G (not shown) are formed by using third, fourth, and fifth masks. At this time, since the R, G, and B color filters 160R and 160G (not shown) can reduce the data load between the data line and the common electrode, the liquid crystal display of the present invention eliminates the process of forming the PAC, And manufacturing cost can be reduced.

A second insulating layer 170b is formed on the entire surface of the first insulating layer 170a including the R, G, and B color filters. In this case, the first and second insulating films 170a and 170b may be formed of an inorganic insulating material such as a gate insulating film, or an organic insulating material such as photo-acryl.

The R, G, and B color filters 160R and 160G (not shown) are formed by a deposition process, aligning a shadow mask having an opening in the deposition process, and positioning an organic source under the shadow mask , And the organic material is deposited through the opening of the shadow mask. In order to connect the pixel electrode to be described later and the drain electrode 140b of the thin film transistor, the color filter formed to cover the thin film transistor is formed so as to expose the first insulating film 170a corresponding to the drain electrode 140b .

Then, as shown in FIG. 3D, on the second insulating film 170b, a conductive film such as tin oxide (TO), indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide A transparent conductive material such as Indium Tin Zinc Oxide (ITZO), or the like, is deposited on the transparent electrode 180, and the transparent electrode 180 is formed by patterning the transparent conductive material using a sixth mask.

3E, a protective film 190 is formed on the entire surface of the second insulating film 170b including the common electrode 180 and the protective film 190 and the first and second insulating films 170a and 170b are formed using a seventh mask. A gate contact hole 190b and a data contact hole 190b which selectively expose the drain electrode 140b, the gate pad lower electrode 110b and the data pad lower electrode 130c, 190c.

A transparent conductive material is deposited on the entire surface of the passivation layer 190 including the drain contact hole 190a, the gate contact hole 190b and the data contact hole 190c, And a pixel electrode 200a which is electrically connected to the drain electrode 140b is formed by patterning. At this time, the pixel electrode 200a is formed in a plurality of slit shapes to form a fringe electric field with the common electrode 180 with the protective film 190 therebetween.

At the same time, the gate pad upper electrode 200b connected to the gate pad lower electrode 110b exposed through the gate contact hole 190b and the data pad lower electrode 130c exposed through the data contact hole 190c Thereby forming a data pad upper electrode 200c.

Next, as shown in FIG. 3G, a light-shielding column spacer 210 is formed on the passivation layer 190 using a ninth mask to simultaneously serve as a spacer and a black matrix. Specifically, the light-shielding column spacer 210 may be formed of an organic material including carbon, carbon dioxide, titanium oxide (TiOx), a color pigment, or the like, which absorbs light, or an organic material of black type, And may be formed to have a single height or a height of double or more.

Therefore, since the light-shielding column spacer 210 is formed of a light-shielding material and does not need to form a black matrix separately, the number of masks can be reduced by eliminating the step of forming the black matrix on the upper substrate 300. The light-shielding column spacer 210 is formed to overlap with the thin film transistor, and is formed of a material having a strength capable of maintaining a cell gap between the lower substrate 100 and the upper substrate 300 facing the upper substrate 300. Finally, as shown in FIG. 3H, the lower substrate 100 and the upper substrate 300 are bonded together using the sealant 310, and then liquid crystal is injected to manufacture a liquid crystal display device.

In the method of manufacturing a liquid crystal display device according to the present invention as described above, the liquid crystal display device can be formed by a total of nine mask processes by eliminating the step of forming the PAC and the step of forming the black matrix, The manufacturing cost can be reduced and the process can be simplified.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Will be apparent to those of ordinary skill in the art.

DL: Data line GL: Gate line
100: lower substrate 110a: gate electrode
110b: gate pad lower electrode 120: gate insulating film
130: semiconductor layer 130a: active layer
130b: Ohmic contact layer 130c: Data pad lower electrode
140a: source electrode 140b: drain electrode
160R: R color filter 160G: G color filter
170a: first insulating film 170b: second insulating film
180: common electrode 190: protective film
190a: drain contact hole 190b: gate contact hole
190c: Data contact hole 200a: Pixel electrode
200b: gate pad upper electrode 200c: data pad upper electrode
210: shielding column spacer 300: upper substrate
310: Mr.

Claims (8)

A thin film transistor formed in a crossing region of a gate wiring and a data wiring vertically crossing on a lower substrate and a gate wiring and a data wiring;
A first insulating layer formed on the entire surface of the lower substrate including the thin film transistor;
A color filter formed on the first insulating film;
A second insulating layer formed on the entire surface of the first insulating layer to cover the color filter;
A common electrode formed on the second insulating film;
A protective film covering the common electrode;
A pixel electrode connected to the exposed thin film transistor by selectively removing the first and second insulating films and the protective film, and forming a fringe electric field with the common electrode across the protective film; And
And a light-shielding column spacer formed on the protective film so as to overlap with the thin film transistor. The method according to claim 1,
Wherein the light-shielding column spacer is at least one material selected from carbon, titanium oxide, color pigment, and black resin. The method according to claim 1,
And the first and second insulating films and the color filter are disposed between the data line and the common electrode. The method according to claim 1,
And the color filter is formed also on a region corresponding to the thin film transistor. Forming a gate wiring and a gate electrode on the lower substrate using a first mask;
Forming a semiconductor layer, a source, a drain electrode, and a data line using a second mask, and forming a first insulating layer on the entire surface of the lower substrate including the semiconductor layer, the source, the drain electrode, and the data line;
Forming a color filter on the first insulating film using a third, fourth, and fifth masks, and forming a second insulating film on the entire surface of the first insulating film including the color filter;
Forming a common electrode on the second insulating film by using a sixth mask and forming a protective film over the entire surface of the second insulating film including the common electrode;
Exposing the drain electrode by selectively removing the protective film and the first and second insulating films using a seventh mask;
Forming a pixel electrode connected to the drain electrode on the protective film using an eighth mask; And
And forming a light-shielding column spacer on the protective film using a ninth mask. 6. The method of claim 5,
Wherein the light-shielding column spacer is formed of at least one material selected from carbon, titanium oxide, color pigment, and black resin. 6. The method of claim 5,
Wherein the first and second insulating films and the color filter are disposed between the data line and the common electrode. 6. The method of claim 5,
Wherein the color filter is formed also on a region corresponding to the thin film transistor.

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