KR101234212B1 - Liquid crystal display device and method of fabricating the same - Google Patents

Abstract

The liquid crystal display of the present invention and a method of manufacturing the same are to improve the reliability of the device without the addition of a mask process by forming an etch stopper and a pixel electrode at the same time, the first substrate divided into a pixel portion and a pad portion Providing; Forming a gate electrode on the pixel portion of the first substrate; Forming a gate insulating layer and an active pattern on the gate electrode; Forming an etch stopper made of an insulating film on the active pattern in one mask process, and forming a pixel electrode made of a conductive film in the pixel region; Forming a source electrode and a drain electrode on the pixel portion of the first substrate; And bonding the first substrate and the second substrate to each other.

Etch stopper, pixel electrode, diffraction exposure

Description

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

1 is an exploded perspective view schematically showing a general liquid crystal display device.

2A to 2E are sectional views sequentially showing a manufacturing process of an array substrate in the liquid crystal display device shown in Fig.

3 is a plan view illustrating a portion of an array substrate of a liquid crystal display according to an exemplary embodiment of the present invention.

4A to 4D are cross-sectional views sequentially illustrating a manufacturing process of the array substrate illustrated in FIG. 3.

5A to 5E are cross-sectional views illustrating a process of simultaneously forming an etch stopper and a pixel electrode in FIG. 4C.

DESCRIPTION OF REFERENCE NUMERALS

110: array substrate 116: gate line

116P: Gate Pad Wiring 117: Data Line

117P: Data pad wiring 118: Pixel electrode

121: gate electrode 122: source electrode

123: drain electrode 126P: gate pad electrode

127P: Data pad electrode 150: Etch stopper

The present invention relates to a liquid crystal display device and a manufacturing method thereof, and more particularly, to a liquid crystal display device and a method for manufacturing the same by reducing the number of masks to simplify the manufacturing process and improve the yield.

Recently, interest in information display has increased, and a demand for using portable information media has increased, and a light-weight flat panel display (FPD) that replaces a cathode ray tube (CRT) And research and commercialization are being carried out. Particularly, among such flat panel display devices, a liquid crystal display (LCD) is an apparatus for displaying an image using the optical anisotropy of a liquid crystal, and is excellent in resolution, color display and picture quality and is actively applied to a notebook or a desktop monitor have.

The liquid crystal display comprises a color filter substrate as a first substrate, an array substrate as a second substrate, and a liquid crystal layer formed between the color filter substrate and the array substrate.

In this case, a thin film transistor (TFT) is generally used as a switching element of the liquid crystal display, and an amorphous silicon thin film is used as a channel layer of the thin film transistor.

Since the manufacturing process of the liquid crystal display device basically requires a plurality of mask processes (ie, photolithography process) for fabricating an array substrate including a thin film transistor, a method of reducing the number of mask processes in terms of productivity is required. It is required.

Hereinafter, the structure of a typical liquid crystal display device will be described in detail with reference to FIG.

1 is an exploded perspective view schematically showing a general liquid crystal display device.

As shown in the figure, the liquid crystal display comprises a color filter substrate 5, an array substrate 10, and a liquid crystal layer (not shown) formed between the color filter substrate 5 and the array substrate 10 30).

The color filter substrate 5 distinguishes between the color filter C including the sub-color filter (red, green, blue) 7 that implements color and the sub-color filter 7, and the liquid crystal layer ( It consists of a black matrix (6) for blocking the light passing through 30, and a transparent common electrode (8) for applying a voltage to the liquid crystal layer (30).

In addition, the array substrate 10 includes a plurality of gate lines 16, data lines 17, and gate lines 16 arranged vertically and horizontally on the substrate 10 to define a plurality of pixel regions P. A thin film transistor (TFT) T, which is a switching element formed at an intersection region of the data line 17, and a pixel electrode 18 formed on the pixel region P are included.

The color filter substrate 5 and the array substrate 10 configured as described above are joined to face each other by a sealant (not shown) formed at the outside of the image display area to form a liquid crystal display panel. Is made through a bonding key (not shown) formed in the color filter substrate 5 or the array substrate 10.

2A to 2E are cross-sectional views sequentially showing the steps of manufacturing an array substrate in the liquid crystal display device shown in Fig.

As shown in FIG. 2A, a gate electrode 21 made of a conductive metal material is formed on the substrate 10 by using a photolithography process (first mask process).

Next, as illustrated in FIG. 2B, the first insulating film 15A, the amorphous silicon thin film, and the n + amorphous silicon thin film are sequentially deposited on the entire surface of the substrate 10 on which the gate electrode 21 is formed, and then a photolithography process The active pattern 24 made of the amorphous silicon thin film is formed on the gate electrode 21 by selectively patterning the amorphous silicon thin film and the n + amorphous silicon thin film using the (second mask process).

In this case, the n + amorphous silicon thin film pattern 25 patterned in the same shape as the active pattern 24 remains on the active pattern 24.

Subsequently, as illustrated in FIG. 2C, the conductive metal material is deposited on the entire surface of the substrate 10, and then the source electrode 22 and the upper portion of the active pattern 24 are formed using a photolithography process (third mask process). The drain electrode 23 is formed. In this case, a predetermined region of the n + amorphous silicon thin film pattern formed on the active pattern 24 is removed, thereby making an ohmic contact between the active pattern 24, the source electrode 22, and the drain electrode 23. Will form a layer 25 '.

Next, as shown in FIG. 2D, after depositing the second insulating film 15B on the entire surface of the substrate 10 on which the source electrode 22 and the drain electrode 23 are formed, a photolithography process (fourth mask process) A portion of the second insulating layer 15B is removed to form a contact hole 40 exposing a portion of the drain electrode 23.

Finally, as shown in FIG. 2E, a transparent conductive metal material is deposited on the entire surface of the substrate 10 and then patterned using a photolithography process (fifth mask process) to form a drain electrode through the contact hole 40. A pixel electrode 18 electrically connected to 23 is formed.

As described above, fabrication of an array substrate including a thin film transistor requires a total of five photolithography processes to pattern a gate electrode, an active pattern, a source electrode and a drain electrode, a contact hole, a pixel electrode, and the like.

The photolithography process is a series of processes for transferring a pattern drawn on a mask onto a substrate on which a thin film is deposited to form a desired pattern. The photolithography process includes a plurality of processes such as photoresist coating, exposure, and development. As a result, many photolithography processes have many problems, such as lowering the production yield and increasing the probability of defects in the formed thin film transistors.

In particular, a mask designed to form a pattern is very expensive, and as the number of masks applied to the process increases, the manufacturing cost of the liquid crystal display device increases in proportion.

In addition, the above-described thin film transistor is a back channel etch type in which an etch stopper is not formed, and a back channel of the thin film transistor may be damaged during the etching of the n + amorphous silicon thin film on the upper channel. This is a problem in the reliability of the device. In order to solve this problem, an etch stopper type thin film transistor in which an etch stopper is formed on an upper channel has a disadvantage in that another mask process is added to form the etch stopper.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a method of manufacturing a liquid crystal display device capable of forming an etch stopper without the addition of a mask process.

In addition, another object of the present invention is to provide a liquid crystal display device and a method for manufacturing the same which improve the reliability of the device by forming the etch stopper as described above.

Other objects and features of the present invention will be described in the following description of the invention and claims.

In order to achieve the above object, the liquid crystal display of the present invention comprises a first substrate divided into a pixel portion and a pad portion; A gate electrode formed on the pixel portion of the first substrate; An active pattern formed on the gate electrode through a gate insulating film; An etch stopper formed of an insulating film on the active pattern; A pixel electrode formed on the pixel portion of the first substrate via the pixel portion insulating film; A gate pad electrode and a data pad electrode formed on a pad portion of the first substrate via a pad insulating film; A source electrode and a drain electrode formed on the pixel portion of the first substrate on which the pixel electrode is formed; And a second substrate joined to face the first substrate, wherein the pixel portion insulating film and the pad portion insulating film are formed of the insulating film constituting the etch stopper.

In addition, the manufacturing method of the liquid crystal display device of the present invention comprises the steps of providing a first substrate divided into a pixel portion and a pad portion; Forming a gate electrode on the pixel portion of the first substrate; Forming a gate insulating layer and an active pattern on the gate electrode; Forming an etch stopper made of an insulating film on the active pattern in one mask process, and forming a pixel electrode made of a conductive film in the pixel region; Forming a source electrode and a drain electrode on the pixel portion of the first substrate; And bonding the first substrate and the second substrate to each other.

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

3 is a plan view illustrating a portion of an array substrate of a liquid crystal display according to an exemplary embodiment of the present invention, and shows one pixel including a gate pad part and a data pad part.

In the actual array substrate, N gate lines and M data lines intersect and MxN pixels exist, but for simplicity, only one pixel is shown in the drawing.

As shown in the figure, a gate line 116 and a data line 117 are formed on the array substrate 110 to be arranged vertically and horizontally on the substrate 110 to define a pixel area. A thin film transistor, which is a switching element, is formed in an intersection area of the gate line 116 and the data line 117, and is connected to the thin film transistor in the pixel area to form a liquid crystal together with a common electrode of a color filter substrate (not shown). A pixel electrode 118 for driving (not shown) is formed.

In this case, a gate pad electrode 126P and a data pad electrode 127P electrically connected to the gate line 116 and the data line 117 are formed in the edge region of the array substrate 110. The scan signal and the data signal applied from the driving circuit unit (not shown) are transferred to the gate line 116 and the data line 117, respectively.

That is, the gate line 116 and the data line 117 extend toward the driving circuit unit to form the gate pad wiring 116P and the data pad wiring 117P, respectively, and the gate pad wiring 116P and the data pad wiring ( The 117P receives scan and data signals from the driving circuit unit through the gate pad electrode 126P and the data pad electrode 127P electrically connected to the wirings 116P and 117P, respectively.

The thin film transistor includes a gate electrode 121 connected to the gate line 116, a source electrode 122 connected to the data line 117, and a drain electrode 123 connected to the pixel electrode 118. In addition, the thin film transistor may include a first insulating film (not shown), a second insulating film (not shown), and the gate electrode 121 for insulating between the gate electrode 121, the source electrode 122, and the drain electrode 123. And an active pattern (not shown) for forming a conductive channel between the source electrode 122 and the drain electrode 123 by the gate voltage supplied to the source electrode 122.

A part of the source electrode 122 is connected to the data line 117 to form a part of the data line 117, and a part of the drain electrode 123 extends toward the pixel area so that the lower pixel electrode 118 is formed. ) Is electrically connected.

In this case, an etch stopper 150 formed of the same insulating material as the second insulating layer is formed on the active pattern, and the etch stopper 150 uses the same mask as the pixel electrode 118 by using diffraction exposure. It is formed through the process.

That is, after forming the active pattern, an insulating material for forming the second insulating film is deposited and a transparent conductive material is deposited without patterning. In addition, the etch stopper region is formed to be thinner than the pixel electrode region by using diffraction exposure, and then the conductive material of the etch stopper region is selectively removed to thereby remove the pixel electrode 118 and the etch stopper 150. ) At the same time. Subsequently, the pixel electrode 118 and the etch stopper 150 may be formed through one mask process by removing the transparent conductive material remaining on the etch stopper 150 through a photoresist ashing process. This will be described in detail through the following manufacturing process of the liquid crystal display.

4A through 4D are cross-sectional views sequentially illustrating a manufacturing process of the array substrate illustrated in FIG. 3, in which a process of manufacturing an array substrate of a pixel portion is performed on the left side, and an array substrate of a gate pad portion and a data pad portion is sequentially manufactured on the right side. The process is shown.

As shown in FIG. 4A, the gate electrode 121 is formed in the pixel portion of the substrate 110 made of a transparent insulating material such as glass, and the gate pad wiring 116P is formed in the gate pad portion.

In this case, the gate electrode 121 and the gate pad wiring 116P are formed by depositing a first conductive layer on the entire surface of the substrate 110 and patterning the same through a photolithography process (first mask process).

The first conductive layer may include aluminum (Al), aluminum alloy (Al alloy), tungsten (W), copper (Cu), chromium (Cr), molybdenum (Mo), or the like. The same low resistance opaque conductive material can be used. In addition, the gate electrode 121 and the gate pad wiring 116P may be formed in a multilayer structure in which two or more low resistance conductive materials are stacked.

Next, as shown in FIG. 4B, the first insulating film and the amorphous silicon thin film are sequentially deposited on the entire surface of the substrate 110 on which the gate electrode 121 and the gate pad wiring 116P are formed, and then a photolithography process ( By selectively patterning the first insulating film and the amorphous silicon thin film using a second mask process), the gate insulating film 115A made of the first insulating film and the active pattern 124 made of an amorphous silicon thin film are formed on the gate electrode 121. Form.

4C, a second insulating film (not shown) and a second conductive film (not shown) are sequentially deposited on the entire surface of the substrate 110, and then one photolithography process is performed using diffraction exposure. (3 mask process) to form an etch stopper 150 made of the second insulating film on the gate electrode 121 of the pixel portion and at the same time to form a pixel electrode 118 made of the second conductive film in the pixel region of the pixel portion. do.

Hereinafter, the third mask process will be described in detail with reference to the drawings.

5A through 5E are cross-sectional views illustrating in detail the process of simultaneously forming the etch stopper and the pixel electrode in FIG. 4C, and sequentially illustrate the third mask process of the present embodiment.

As shown in FIG. 5A, the second insulating layer 115 and the second conductive layer 130 are sequentially formed on the entire surface of the substrate 110 on which the active pattern 124 is formed.

In this case, the second insulating film 115 for forming an etch stopper includes a transparent inorganic insulating material such as a silicon oxide film or a silicon nitride film, and for high opening ratio, benzocyclobutene (BCB) or acrylic resin (resin). It may also include a transparent organic insulating material such as.

In addition, the second conductive layer 130 is a transparent conductive material having excellent transmittance such as indium tin oxide (ITO) or indium zinc oxide (IZO) to form a pixel electrode. It includes.

Next, as shown in FIG. 5B, a photosensitive film 170 made of a photosensitive material such as a photoresist is formed on the entire surface of the substrate 110 and then formed on the photosensitive film 170 through the diffraction mask 180 of the present embodiment. Selectively irradiates light.

In this case, the diffraction mask 180 used in the present embodiment is applied with a transmission region I and a slit pattern that transmit all of the irradiated light so that only a part of the light is transmitted and a portion of the slit region II and all of the irradiated light are blocked. The blocking region III is provided to block the light, and only the light passing through the mask 180 is irradiated to the photosensitive film 170.

Subsequently, after developing the photosensitive film 170 exposed through the diffraction mask 180, as shown in FIG. 5C, light is blocked or partially blocked through the blocking region III and the slit region II. The photoresist patterns 170A to 170D having a predetermined thickness remain in the exposed region, and the photoresist layer is completely removed in the transmission region I through which all the light is transmitted, thereby exposing the surface of the second conductive layer 130.

In this case, the first photoresist pattern 170A formed through the slit region II is thinner than the second photoresist pattern 170B to the fourth photoresist pattern 170D formed in the blocking region III. In addition, the photoresist film 170 is completely removed in the region where all the light is transmitted through the transmission region I. This is because a positive photoresist is used, and the present invention is not limited thereto, and a negative photoresist may be used. It's okay.

Next, when the second conductive film 130 and the second insulating film 115 formed thereon are selectively removed using the photosensitive film patterns 170A to 170D formed as above as a mask, the active pattern 124 may be removed. The etch stopper 150 is patterned on a predetermined region (ie, specifically, the channel region of the active pattern 124) and the pixel electrode 118 is patterned on the pixel region.

In this case, the conductive film pattern 118 ′ patterned in the same form as the etch stopper 150 remains on the etch stopper 150 formed of the transparent second insulating film, and the pixel is disposed below the pixel electrode 118. The pixel portion insulating film 115B patterned in the same manner as the electrode 118 is formed.

In addition, a gate pad electrode 126P for electrically connecting to an external driving circuit unit (not shown) is formed on the gate pad wiring 116P of the gate pad unit, and the driving circuit unit is arranged on the array substrate 110 of the data pad unit. And a data pad electrode 127P for electrically connecting with each other. At this time, pad portion insulating films 115B 'and 115B "patterned in the same shape as the gate pad electrode 126P and the data pad electrode 127P remain below the gate pad electrode 126P and the data pad electrode 127P, respectively. Will be.

In this case, the above-described transparent region I is also applied to a predetermined region of the gate pad portion so that the gate pad electrode 126P and the gate pad portion insulating film 115B 'are patterned to expose a portion of the gate pad wiring 116P. .

Subsequently, when the ashing process of removing a portion of the photoresist patterns 170A to 170D is performed, as illustrated in FIG. 5D, the etch stopper 150 is formed, that is, the slit region II to which diffraction exposure is applied. The first photoresist layer pattern 170A is completely removed to expose the surface of the conductive layer pattern 118 ′.

In this case, the second photoresist pattern 170B to the fourth photoresist pattern 170D may include the fifth photoresist pattern 170B 'to the seventh photoresist pattern 170D' having the same thickness as that of the first photoresist pattern 170A. Therefore, only the predetermined area corresponding to the blocking area III remains.

Thereafter, the remaining fifth photoresist pattern 170B 'to seventh photoresist pattern 170D' is used as a mask to completely remove the conductive layer pattern 118 'on the etch stopper 150.

After removing the remaining fifth photoresist pattern 170B 'through the seventh photoresist pattern 170D', as shown in FIG. 5E, the second insulating layer is formed on the gate electrode 121 of the pixel portion. The etch stopper 150 is formed, and the pixel electrode 118 made of the transparent second conductive material is formed in the pixel region of the pixel portion.

In this case, a gate pad electrode 126P made of the transparent second conductive material is formed on the gate pad wiring 116P of the gate pad part, and data made of the transparent second conductive material is formed on the array substrate 110 of the data pad part. The pad electrode 127P is formed.

Thereafter, as illustrated in FIG. 4D, the n + amorphous silicon thin film and the third conductive film are sequentially deposited on the entire surface of the substrate 110, and then the n + amorphous silicon thin film and the first thin film are formed through a photolithography process (fourth mask process). By selectively patterning the three conductive films, the source electrode 122 and the drain electrode 123 electrically connected to a predetermined region of the active pattern 124 are formed in the pixel portion. The source electrode 122 and the drain electrode 123 form an ohmic contact with a predetermined region of the active pattern 124 through an ohmic contact layer 125 formed of the n + amorphous silicon thin film. In addition, the drain electrode 123 is electrically connected with the pixel electrode 118 below and the ohmic contact layer 125 therebetween.

At this time, the formation of the etch stopper 150 prevents the back channel of the active pattern 124 from being damaged when the n + amorphous silicon thin film is etched, thereby improving the reliability of the device. That is, the thin film transistor of the present embodiment may include an etch stopper 150 to prevent damage to the back channel of the thin film transistor element generated when the n + amorphous silicon thin film is etched. By using the diffraction exposure is formed at the same time as the pixel electrode 118 has the advantage that no additional mask process is required.

As such, when the source electrode 122 and the drain electrode 123 are formed in the pixel portion through the fourth mask process, the connection electrodes 116 are respectively connected to the gate pad portion and the data pad portion with the third conductive layer through the same mask process. 'P) and the data pad wiring 117P are formed.

The connection electrode 116 ′ P electrically connects the lower gate pad wiring 116P and the gate pad electrode 126P, and the data pad wiring 117P has a lower data pad electrode 127P. And electrically connect the data signal input through the data pad electrode 127P to a corresponding data line (not shown).

Here, reference numerals 125 'and 125 "denote the gate pad portion n + amorphous silicon thin film pattern and the data pad portion n + amorphous silicon thin film pattern, respectively.

Many details are set forth in the foregoing description but should be construed as illustrative of preferred embodiments rather than to limit the scope of the invention. Therefore, the invention should not be construed as limited to the embodiments described, but should be determined by equivalents to the appended claims and the claims.

As described above, the liquid crystal display device and the method of manufacturing the same according to the present invention provide an effect of reducing the number of masks used for manufacturing the thin film transistor by simultaneously patterning the etch stopper and the pixel electrode, thereby reducing the manufacturing process and cost.

In addition, the liquid crystal display of the present invention provides an effect of improving the reliability of the device by forming the etch stopper.

Claims (20)

Providing a first substrate divided into a pixel portion and a pad portion; Forming a gate electrode on the pixel portion of the first substrate; Forming a gate insulating layer and an active pattern on the gate electrode; Forming an etch stopper made of an insulating film on the active pattern in one mask process, and forming a pixel electrode made of a conductive film in the pixel region; Forming a source electrode and a drain electrode on the pixel portion of the first substrate; And And attaching the first substrate and the second substrate to each other. The method of claim 1, wherein the forming of the etch stopper and the pixel electrode is performed. Forming an insulating film and a conductive film on the first substrate; Applying a diffraction mask to form a first photoresist pattern having a first thickness in a first region of the active pattern and forming a second photoresist pattern having a second thickness in a pixel electrode region; By selectively removing the insulating film and the conductive film using the first photoresist pattern and the second photoresist pattern as masks, an etch stopper made of the insulating film is formed on the first region of the active pattern, and the conductive film is formed in the pixel electrode region. Forming a pixel electrode made of; Removing the first photoresist pattern and simultaneously removing the thickness of the second photoresist pattern by the thickness of the first photoresist pattern to form a third photoresist pattern having a third thickness; And And removing the conductive film remaining on the etch stopper using the third photoresist pattern as a mask. The method of claim 2, wherein the forming of the first photoresist pattern and the second photoresist pattern Forming a photoresist film on the conductive film; Irradiating light on the photosensitive film through a diffraction mask having a first transmission region for transmitting all the light, a second transmission region for selectively transmitting the light, and a blocking region for blocking the light; And Developing a photoresist film irradiated with light through the mask to form a photoresist pattern on the conductive layer, a first photoresist pattern having a first thickness is formed on the first region of the active pattern, and a second thickness in the pixel electrode region. Forming a second photosensitive film pattern having a liquid crystal display device comprising a. 4. The liquid crystal display of claim 3, wherein in the case of using a positive type photoresist, the blocking region of the diffraction mask is applied to the pixel electrode region and the second transmission region is applied to the first region of the active pattern. Manufacturing method. The diffraction mask of claim 3, wherein a diffraction pattern is formed in a second transmission region selectively transmitting light to form a first photoresist pattern having a first thickness thinner than the second thickness on the first region of the active pattern. Method of manufacturing a liquid crystal display device characterized in that. 3. The pixel portion insulating film having the same shape as the pixel electrode is formed under the pixel electrode by selectively removing the insulating film and the conductive film using the first photoresist pattern and the second photoresist pattern as masks. Method of manufacturing a liquid crystal display device. 3. The method of claim 2, further comprising forming a gate pad line on a pad portion of the first substrate using a first conductive material constituting the gate electrode. 4. 8. The method of claim 7, further comprising forming a pad insulating film on a pad portion of the first substrate using the insulating film constituting the etch stopper. 8. The method of claim 7, further comprising forming a gate pad electrode and a data pad electrode on a pad portion of the first substrate by using a conductive film constituting the pixel electrode. . 10. The method of claim 9, wherein a connection electrode for electrically connecting the gate pad wiring and the gate pad electrode is formed using a second conductive material constituting the source electrode and the drain electrode, and electrically connected to the data pad electrode. A method of manufacturing a liquid crystal display device, further comprising the step of forming a data pad wiring line. The method of claim 2, wherein the first region of the active pattern is a channel region. The method of claim 1, wherein the forming of the source electrode and the drain electrode is performed. Forming an n + amorphous silicon thin film on the first substrate; Forming a conductive film on the first substrate on which the n + amorphous silicon thin film is formed; And Selectively patterning the n + amorphous silicon thin film and the conductive film to form a source electrode and a drain electrode electrically connected to the source region and the drain region of the active pattern through the n + amorphous silicon thin film at a pixel portion of the first substrate Method of manufacturing a liquid crystal display device comprising the step. A first substrate including a pixel portion and a pad portion; A gate electrode formed on the pixel portion of the first substrate; An active pattern formed on the gate electrode through a gate insulating film; An etch stopper formed of an insulating film on the active pattern; A pixel electrode formed on the pixel portion of the first substrate via the pixel portion insulating film; A gate pad electrode and a data pad electrode formed on a pad portion of the first substrate via a pad insulating film; A source electrode and a drain electrode formed on the pixel portion of the first substrate on which the pixel electrode is formed; And And a second substrate bonded to the first substrate, wherein the pixel portion insulating film and the pad portion insulating film are formed of the insulating film constituting the etch stopper. The liquid crystal display of claim 13, wherein the etch stopper is formed on a channel region of an active pattern. The liquid crystal display of claim 13, further comprising a gate pad line formed on a pad of the first substrate using a conductive material constituting the gate electrode. delete delete The method of claim 15, further comprising: a connection electrode formed on the pad portion of the first substrate, the connection electrode electrically connecting the gate pad wiring and the gate pad electrode, and the data pad wiring electrically connected to the data pad electrode. A liquid crystal display device. 19. The liquid crystal display device according to claim 18, wherein the source electrode, the drain electrode, the connection electrode, and the data pad wiring are made of substantially the same conductive material. 15. The method of claim 13, further comprising an ohmic contact layer formed between the active pattern, the source electrode, and the drain electrode to ohmic-contact the source region, the drain region, the source electrode, and the drain electrode of the active pattern. A liquid crystal display device.

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