KR100687490B1 - Method for fabricating Liquid crystal display device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device having a wide viewing angle, wherein an active layer of components of a thin film transistor is formed when a slit is formed to form a multi-domain in a pixel electrode to have a wide viewing angle characteristic. Alternatively, when the source and drain electrodes are formed, a fine division pattern for the slit is formed in advance, and then a slit pattern is formed using the back exposure, which is advantageous in forming a fine pattern rather than photolithography of the pixel electrode by the front exposure. A wide viewing angle liquid crystal display device having high brightness can be manufactured.

Description

Liquid crystal display device manufacturing method {Method for fabricating Liquid crystal display device}

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

2 is a plan view showing some pixels of an array substrate for a liquid crystal display device in which pixel electrodes are divided by slits;

3A through 3B and 4A through 4D are cross-sectional views illustrating a process sequence by cutting along III-III of FIG. 2, respectively.

<Description of Symbols for Main Parts of Drawings>

111 substrate 123 drain electrode

131: slit pattern 137: drain contact hole

139: transparent electrode layer 141: photoresist

      141a: exposed photoresist portion

      149a, 149b: unexposed photoresist portion

The present invention relates to a method for manufacturing an array substrate for a liquid crystal display device, and more particularly, to a wide viewing angle liquid crystal display device.

Recently, as the information society has progressed rapidly, a display field for processing and displaying a large amount of information has been developed.

Until recently, cathode ray tube (CRT) has become the mainstream of display devices and has been continuously developed. Recently, the necessity of flat panel display is required to meet the times of miniaturization, light weight and low power consumption. It has emerged. Accordingly, a thin film transistor-liquid crystal display device (hereinafter referred to as TFT-LCD) having excellent color reproducibility and thinness has been developed, and the size of the liquid crystal display device is gradually increasing in size. It is a trend.

As the liquid crystal display device becomes larger, the most important thing is the viewing angle characteristic of the liquid crystal display device.

In order to improve the viewing angle of the liquid crystal display, attempts have been made to manufacture a liquid crystal display having a wide viewing angle by attaching a separate compensation film or a diffusion plate to the liquid crystal panel.

Furthermore, the fabrication of liquid crystal display apparatuses in which the viewing angle is improved by the arrangement of liquid crystal molecules by modifying the operation mode of the liquid crystal has been studied.

In detail, the distribution of the common electrode and the pixel electrode is non-uniform to form a plurality of horizontal electric fields having different directions of electric fields. The set of liquid crystal molecules belonging to each of the horizontal electric field components is arranged by the first horizontal electric field, thereby forming a first domain in which the alignment directions are identically aligned. However, the set of liquid crystal molecules belonging to the second horizontal electric field in a direction different from the first horizontal electric field is aligned with the liquid crystal molecules belonging to the first domain by being constantly aligned in a direction different from the alignment direction of the molecules belonging to the first horizontal electric field. Form a second domain which is a set of liquid crystal molecules having different alignment directions.

Since a plurality of domains having different alignment directions can be formed, a liquid crystal display device having a greatly improved viewing angle can be manufactured.

Here, the configuration of the liquid crystal display device will be described.

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

As shown in the drawing, a general liquid crystal display 11 includes a color filter 7 including a black matrix 6, an upper substrate 5 on which a transparent common electrode 18 is formed, and a pixel region P. ) And a lower substrate 22 having an array wiring including a switching electrode T and a pixel electrode 17 formed on the pixel region, and a liquid crystal 14 between the upper substrate 5 and the lower substrate 22. ) Is filled.

The lower substrate 22 is also referred to as an array substrate, and the thin film transistor T, which is a switching element, is positioned in a matrix type, and the gate wiring 13 and the data wiring 15 passing through the plurality of thin film transistors cross each other. Is formed.

In this case, the pixel P area is an area defined by the gate wiring 13 and the data wiring 15 crossing each other. The transparent pixel electrode 17 is formed on the pixel region.

The pixel electrode 17 uses a transparent conductive metal having a relatively high light transmittance, such as indium-tin-oxide (ITO).

In such a configuration, the multi-domain is induced by dividing the pixel electrode 17 formed on the array substrate 11. This will be described below with reference to FIG. 2.

2 is a plan view showing some pixels of an array substrate for a wide viewing angle liquid crystal display device.

As shown in the drawing, the substrate includes a gate wiring 113, a data wiring 117, a pixel electrode 141, and a thin film transistor T.

The thin film transistor T includes a gate electrode 125 protruding in one direction with a predetermined area from the gate wiring 113, an active layer 133 formed in an island shape on the gate electrode 125, and the data. A source electrode 121 protruding from the active layer 133 on the wiring 117 is formed of a drain electrode 123 spaced apart from the predetermined distance.

In this case, the gate wiring 113 and the data wiring 117 are formed to cross each other, the thin film transistor T is formed at an intersection point of the gate wiring 113 and the data wiring 117, and the gate wiring is formed. Reference numeral 113 and the data wiring 117 intersect to define the pixel region P. FIG.

The pixel electrode 135 in contact with the drain electrode 123 is formed in the pixel region P. At this time, the pixel electrode 145 has a slit having a cross-sectional shape in which a diagonal pattern is crossed for a multi-domain configuration. 127).

The slit 127 divides the pixel region P into four domains A, B, C, and D, and an arrangement of liquid crystal molecules (not shown) located in each domain affects the slit 127. The alignment direction of the liquid crystal molecules is configured differently by the horizontal electric field components thus received.

Therefore, the liquid crystal display including the multi-domains A, B, C, and D has a wide viewing angle characteristic.

In this case, the slit 127 is formed by depositing and patterning the pixel electrode 145 by a front exposure method. A mask for the divided pixel electrode 145 pattern is used during front exposure. When the slit patterning, a pattern defect may occur in which the pixel electrode 145 may be partially connected.

This is a problem that occurs during close exposure. When the mask pattern is fine to 5 μm or less, a problem occurs that the pattern is not partially exposed by the diffraction characteristic of the light source emitted on the mask pattern.

However, in consideration of this, when a large pattern is formed, the display quality of the liquid crystal panel is deteriorated.

In addition, there is a method of forming ribs on the black matrix portion of the upper color filter by patterning an insulating material instead of the slit 127, but this method has a complexity in the process of adding a process.

Accordingly, an object of the present invention is to manufacture a wide viewing angle liquid crystal display device having a high aperture ratio in order to solve the above problems.

In order to achieve the above object, the present invention includes the steps of providing a substrate having a pixel region; Depositing and patterning a conductive metal on the substrate to form a gate wiring, a gate electrode extending from the gate wiring, and a bar pattern crossing the pixel region; Forming a first insulating layer by depositing an insulating material on an entire surface of the substrate having a pattern crossing the gate wiring and the pixel region; Forming an island type active layer on the first insulating layer; A conductive metal is deposited and patterned on the entire surface of the substrate on which the active layer is formed, and a source electrode and a drain electrode spaced apart from each other are disposed on one side of the gate electrode, and a data wiring connected to the source electrode and intersecting the gate wiring. Forming; Depositing and patterning an insulating material on the entire surface of the substrate on which the data wiring is formed to form a second insulating layer including a drain contact hole exposing the drain electrode; Depositing a transparent conductive metal on the second insulating layer; Depositing a photoresist on the transparent conductive metal layer; Exposing the photoresist to the backside exposure method using the gate electrode, the source electrode, the drain electrode and the bar pattern as a mask; Front exposing the drain contact hole portion; And removing the photoresist of the unexposed portion and removing the transparent electrode under the exposed portion to form slits in the pixel electrode contacting the drain electrode through the drain contact hole and the transparent electrode on the pixel region. A method of manufacturing an array substrate for a display device is provided.
The insulating material is one selected from a silicon nitride film (SiN _X ) and a silicon oxide film (SiO ₂ ).
The conductive metal is selected from the group of conductive metals including chromium, molybdenum and tungsten.
The slit may be formed in the pixel electrode to correspond to the bar pattern.
In another aspect, the present invention includes the steps of: providing a substrate having a pixel region; Depositing and patterning a conductive metal on the substrate to form a gate wiring and a gate electrode extending from the gate wiring; Depositing an insulating material on an entire surface of the substrate on which the gate wiring and the gate electrode are formed to form a first insulating layer; The semiconductor layer and the impurity semiconductor layer are stacked on the first insulating layer and simultaneously patterned, thereby forming a pixel region in an island-type active layer (and ohmic contact layer) on the gate electrode and a pixel region between the gate wiring and the gate wiring. Forming a bar pattern across the gap; Depositing and patterning a conductive line metal on the entire surface of the substrate on which the active pattern is formed and the active pattern crossing the pixel region, and connecting the source electrode and the drain electrode spaced apart from the source electrode on one side of the gate electrode; Forming a data line crossing the gate line; Depositing and patterning an insulating material on the entire surface of the substrate on which the data wiring is formed to form a second insulating layer including a drain contact hole exposing the drain electrode; Depositing a transparent conductive metal on the second insulating layer; Depositing a photoresist on the transparent conductive metal layer; Exposing the photoresist to the backside exposure method using the gate electrode, the source electrode, the drain electrode, and the bar pattern as a mask; Front exposing the drain contact hole portion; And removing the photoresist of the unexposed portion and removing the transparent electrode under the exposed portion to form slits in the pixel electrode contacting the drain electrode through the drain contact hole and the transparent electrode on the pixel region. A method of manufacturing an array substrate for a display device is provided.
The insulating material is one selected from a silicon nitride film (SiN _X ) and a silicon oxide film (SiO ₂ ).
The conductive metal is selected from the group of conductive metals including chromium, molybdenum and tungsten.
The slit may be formed in the pixel area corresponding to the bar pattern.
In another aspect, the present invention provides a method comprising the steps of: providing a substrate; Forming a switching element on the substrate; Forming first and second signal wires connected to the switching element and crossing each other to define a pixel area; Forming a bar pattern having a shape crossing the pixel area; Depositing a transparent conductive metal on the switching element and the bar pattern; Depositing a photoresist on the transparent conductive metal; Back exposing the photoresist using the switching element and the bar pattern as a mask, and exposing a portion of the switching element to the entire surface to remove the unexposed photoresist to partially expose the transparent conductive metal; And removing the exposed transparent conductive metal to form a pixel electrode in contact with the switching element and having a slit corresponding to the bar pattern.
The switching element is a thin film transistor having a gate electrode, a source electrode, a drain electrode, and an active layer, and the bar pattern is made of the same material as the gate electrode.
The switching element is a thin film transistor having a gate electrode, a source electrode, a drain electrode, and an active layer, and the bar pattern is made of the same material as the active layer.

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Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

In the present invention, the exposure method for the pixel electrode pattern uses the back exposure method instead of the front exposure method.

This will be described with reference to FIGS. 3A to 3B and 4A to 4D, respectively.

3A through 3B and 4A through 4D are cross-sectional views taken along the line III-III of FIG. 3.

As shown in FIG. 3A, one of aluminum (Al), tungsten (W), molybdenum (Mo), tungsten (W), and an alloy of molybdenum and tungsten is selected, deposited, and patterned on a substrate, thereby forming gate wiring and Referring to 113 of FIG. 2, a gate electrode 125 protruding from a predetermined area of the gate line and a pattern 131 having a diagonal pattern intersecting the pixel area on the pixel area P cross each other. Shape).

The pattern having a shape that crosses the pixel region P may be formed of the same material on the same layer as the gate wiring 113 (see FIG. 2) as described above. Alternatively, as illustrated in FIG. 3B, the pattern A pattern 131 having the same material as that of the active layer 133 formed on the gate electrode 125 and crossing the pixel area may be formed on the same layer.

In the present invention, the structure of FIG. 3A will be described as an example.

Following the process in FIG. 3A, the process will be described continuously with reference to the structure except for the slits in the structure of FIG. 3B.

As shown in FIG. 3A, an insulating material such as silicon nitride (SiN _X ) or silicon oxide (SiO ₂ ) is deposited on the gate electrode 125 to form a first insulating layer 128.

Next, an impurity semiconductor material is deposited and patterned on the first insulating layer 128 continuously with a pure semiconductor material such as amorphous silicon or polysilicon to form an island-type active layer 133 on the gate electrode. do.

Next, as shown in FIG. 4A, the above-described conductive metal is deposited and patterned on the active layer 133 to form the active layer in the data line 117 of FIG. 2 and the data line 117 of FIG. 1. A source electrode 121 connected to the upper portion and a drain electrode 123 spaced apart from each other are formed.

Next, the above-described insulating material is deposited on the drain electrode 123 to form and pattern the passivation layer 136 to form a drain contact hole 137 exposing a portion of the drain electrode 123.

As shown in FIG. 4B, a transparent conductive material such as indium tin oxide and indium zinc oxide is deposited on the entire surface of the substrate 111 on which the drain contact hole 137 is formed. To form.

Next, a negative photoresist 141 is applied to the substrate 111 on which the transparent conductive metal layer 139 is deposited.

The negative photoresist 141 has a characteristic that photoresist in a portion not exposed by a light source is removed by a developer.

The substrate 111 on which the negative photoresist 141 is deposited is exposed by using a back exposure method. At this time, the remaining photoresist portion 141a is light (except for the portion patterned with the metal material or the active layer). 145).

Next, the entire surface of the substrate 111 to which the photoresist is partially exposed, except for the portion 147 corresponding to the drain contact hole 137 on the top of the drain electrode 123, is blocked in the front exposure method. The photoresist 141 of the portion 147 corresponding to the drain contact hole is exposed.

Next, as shown in FIG. 4C, when the negative photoresist is developed with a developer, the photoresist of the unexposed portions 149a and 149b is removed to expose the transparent electrodes 139a and 139b.

The exposed transparent electrode is removed through a predetermined etching method and then the photoresist 141a on the patterned transparent electrode is removed.

As shown in FIG. 4D, the pixel electrode 145 is formed to contact the drain electrode 123 through the drain contact hole 137.

In the center of the pixel electrode 145, a slit 127 using a pattern that crosses the pixel area as a mask is formed on the same layer as the gate wiring or the active layer.

The slit 127 divides the pixel electrode 145 into four domains. The slit 127 also divides the pixel electrode 145 into side surfaces of the gate wiring (113 in FIG. 2) and the data wiring during back exposure. This 0.5 micrometer overlaps and is patterned, and since the width | variety of the said slit 127 can be minimized to 3 micrometers, opening ratio can be ensured in the said single pixel area.

At this time, the shape of the slit can be variously modified.

Accordingly, the wide viewing angle liquid crystal display device according to the present invention performs back exposure using the gate wiring or the pattern formed on the same layer as the active layer as a mask when forming the slit for dividing the pixel electrode. Since the slit of 3 μm or less can be formed, the aperture ratio of the pixel region can be secured.

In addition, there is an effect that can reduce the pattern defect of the slit.

Claims (11)

Providing a substrate having a pixel region; Depositing and patterning a conductive metal on the substrate to form a gate wiring, a gate electrode extending from the gate wiring, and a bar pattern crossing the pixel region; Forming a first insulating layer by depositing an insulating material on an entire surface of the substrate having a pattern crossing the gate wiring and the pixel region; Forming an island type active layer on the first insulating layer; A conductive metal is deposited and patterned on the entire surface of the substrate on which the active layer is formed, and a source electrode and a drain electrode spaced apart from each other are disposed on one side of the gate electrode, and a data wiring connected to the source electrode and intersecting the gate wiring. Forming; Depositing and patterning an insulating material on the entire surface of the substrate on which the data wiring is formed to form a second insulating layer including a drain contact hole exposing the drain electrode; Depositing a transparent conductive metal on the second insulating layer; Depositing a photoresist on the transparent conductive metal layer; Exposing the photoresist to the backside exposure method using the gate electrode, the source electrode, the drain electrode and the bar pattern as a mask; Front exposing the drain contact hole portion; Removing the photoresist of the unexposed portion and removing the transparent electrode under the exposed portion to form slits in the pixel electrode contacting the drain electrode through the drain contact hole and the transparent electrode on the pixel region; Array substrate manufacturing method for a liquid crystal display device comprising a. The method of claim 1, And wherein the insulating material is one selected from a silicon nitride film (SiN _X ) and a silicon oxide film (SiO ₂ ). The method of claim 1, And the conductive metal is one selected from the group of conductive metals including chromium, molybdenum and tungsten. The method of claim 1, The slit is formed in the pixel electrode corresponding to the bar pattern. Providing a substrate having a pixel region; Depositing and patterning a conductive metal on the substrate to form a gate wiring and a gate electrode extending from the gate wiring; Depositing an insulating material on an entire surface of the substrate on which the gate wiring and the gate electrode are formed to form a first insulating layer; The semiconductor layer and the impurity semiconductor layer are stacked on the first insulating layer and simultaneously patterned, thereby forming a pixel region in an island-type active layer (and ohmic contact layer) on the gate electrode and a pixel region between the gate wiring and the gate wiring. Forming a bar pattern across the gap; Depositing and patterning a conductive line metal on the entire surface of the substrate on which the active pattern is formed and the active pattern crossing the pixel region, and connecting the source electrode and the drain electrode spaced apart from the source electrode on one side of the gate electrode; Forming a data line crossing the gate line; Depositing and patterning an insulating material on the entire surface of the substrate on which the data wiring is formed to form a second insulating layer including a drain contact hole exposing the drain electrode; Depositing a transparent conductive metal on the second insulating layer; Depositing a photoresist on the transparent conductive metal layer; Exposing the photoresist to the backside exposure method using the gate electrode, the source electrode, the drain electrode, and the bar pattern as a mask; Front exposing the drain contact hole portion; Removing the photoresist of the unexposed portion and removing the transparent electrode under the exposed portion to form slits in the pixel electrode contacting the drain electrode through the drain contact hole and the transparent electrode on the pixel region; Array substrate manufacturing method for a liquid crystal display device comprising a. The method of claim 5, wherein And wherein the insulating material is one selected from a silicon nitride film (SiN _X ) and a silicon oxide film (SiO ₂ ). The method of claim 5, wherein And the conductive metal is one selected from the group of conductive metals including chromium, molybdenum and tungsten. The method of claim 5, wherein And said slit is formed in said pixel region corresponding to said bar pattern. Providing a substrate; Forming a switching element on the substrate; Forming first and second signal wires connected to the switching element and crossing each other to define a pixel area; Forming a bar pattern having a shape crossing the pixel area; Depositing a transparent conductive metal on the switching element and the bar pattern; Depositing a photoresist on the transparent conductive metal; Back exposing the photoresist using the switching element and the bar pattern as a mask, and exposing a portion of the switching element to the entire surface to remove the unexposed photoresist to partially expose the transparent conductive metal; Removing the exposed transparent conductive metal to form a pixel electrode in contact with the switching element and having a slit corresponding to the bar pattern Array substrate manufacturing method for a liquid crystal display device comprising a. The method of claim 9, The switching element is a thin film transistor having a gate electrode, a source electrode, a drain electrode, and an active layer, and the bar pattern is made of the same material as the gate electrode. The method of claim 9, The switching element is a thin film transistor having a gate electrode, a source electrode, a drain electrode, and an active layer, and the bar pattern is made of the same material as the active layer.

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