KR20010103431A - method for fabricating liquid crystal display device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an array substrate for a liquid crystal display device. In particular, among the array substrates including gate wirings, data wirings, and pixel electrodes, the data wirings are formed by double wirings spaced apart from each other. Since disconnection of wiring and short circuit between wirings can be repaired on a pixel-by-pixel basis, a large-area liquid crystal display device can be repaired and the yield of the product can be improved.

Description

Method for fabricating an array substrate for a liquid crystal display device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an array substrate for a liquid crystal display device, and more particularly, to a structure and a manufacturing method of an array substrate for a liquid crystal display device including a plurality of gate wirings and data wirings in a matrix form and further including a repair wiring.

1 is a plan view schematically illustrating a general 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.

The pixel P area is an area where the gate line 13 and the data line 15 cross each other. The pixel electrode 17 formed on the pixel region P uses a transparent conductive metal having relatively high light transmittance, such as indium-tin-oxide (ITO).

In the liquid crystal display configured as described above, the thin film transistor T and the pixel electrode 17 connected to the thin film transistor are present in a matrix to display an image.

The gate wiring 13 transfers a pulse voltage driving a gate electrode, which is a first electrode of the thin film transistor T, and the data wiring 15 receives a source electrode, which is a second electrode of the thin film transistor T. It is a means for transmitting the driving signal voltage.

In this configuration, when a pulse is scanned on the gate wiring 13, a pulse is applied to the gate electrode of the thin film transistor T, and when a signal voltage is applied to all the data wirings 15, the thin film transistor T Signal is applied to the source electrode.

At this time, if a voltage capable of driving the liquid crystal is applied to an arbitrary source electrode by the signal of the gate electrode, and a voltage smaller than the liquid crystal driving voltage is applied to the rest, only the pixel to which the liquid crystal driving voltage is applied will operate.

By this operation principle, it is possible to drive all the pixel electrodes of the liquid crystal display by applying pulses to all the gate electrodes sequentially and applying the signal voltage to the corresponding source electrodes.

As described above, in order to independently drive millions of pixel electrodes, the gate wiring 13 and the data wiring are arranged in a matrix form on the entire display area, and the gate wiring 13 and the data wiring are thin films that are switching elements. Used to drive transistors.

In manufacturing a display device in which a switching device must be provided for each pixel to drive millions of pixels, it is important to form a fine pattern and simultaneously control the characteristics of the thin film device.

In forming such fine patterns, various dusts are the main cause of disconnection, short-circuit and poor thin film characteristics of the pattern.

As a result, these causes are a major factor in weakening the overall yield, quality and reliability of the liquid crystal display.

In addition, in the element arrangement, the causes of defects are very diverse.

For example, there are various causes such as dust in the film forming process, dust in a resist coating process, dust in the cleaning process, uneven drying in the cleaning process, and minute scratches on the glass substrate.

Due to these various causes, various defects may occur during the manufacturing process of the array substrate for the liquid crystal display device.

These defects may be caused by process deviations due to process deviations due to the deviation of the design standard, defects due to poor cleaning or dust at the membrane interface, and defects caused by changes in characteristics due to static electricity and destruction of the thin film transistor or liquid crystal cell. Etc. can be mentioned. These defects can be divided into dot defects, predecessors, or marking spots depending on their shape. Point defects are caused by defects such as thin film transistor elements or pixel electrodes. This is caused by destruction of a thin film transistor or the like.

These defects are becoming more important problems as the display area of the image device becomes larger, and a redundancy and repairable design has been introduced as a way to proactively cope with such defects.

The redundancy concept is, for example, in the case of a defect of a thin film transistor which is a kind of point defect, in order to replace a thin film transistor in which a defect occurs, a plurality of thin film transistors may be further disposed in one pixel to prevent occurrence of the point defect. When the gate wiring 13 or the data wiring, which is one type of defect, is disconnected, the defect can be prevented by connecting the preliminary wiring adjacent to both ends of the respective wirings and repairing the disconnection.

This concept of redundancy or repair design is more necessary in the case of predecessors than in the case of point defects. This is because in the case of point defects, there is an acceptable level according to the distribution, number, and type, but in the case of any one of the case defects, the product value is lost.

For example, assuming that one of the data and gate lines 13 is disconnected, the operation of all thin film transistors connected to the disconnected line will be impossible. Becomes a fatal flaw in

FIG. 2 is a cross-sectional view illustrating a part of an array substrate corresponding to one pixel in the configuration of FIG. 1.

As shown in the drawing, an active matrix array substrate is formed by crossing the gate line 13 and the data line 15, and the region defined by the crossing of the gate line 13 and the data line 15 is a pixel area. It is defined as (P).

The pixel electrode 17 formed of a transparent electrode is formed on the pixel area P.

One side of the pixel electrode 17 is formed to be connected to the thin film transistor T, and the other side of the pixel electrode 17 is positioned above the partial gate wiring 13 defining the pixel area P. Together, the storage capacitor (C) is configured.

As described above, the thin film transistor T includes a gate electrode 31, a source electrode 33, and a drain electrode 35, and includes a semiconductor layer 37 as an active channel.

If the gate wiring 13 is disconnected during the process of the array substrate configured as described above, repair is not possible because no repair wiring is formed to replace the disconnected gate wiring 13 as shown.

However, if the gate wiring 13 under the storage capacitor is opened, the repair using the storage capacitor electrode can be repaired to some extent, but a point defect occurs because the storage function for one pixel cannot be used.

In addition, even if a short occurs at the intersection of the gate wiring 13 and the data wiring 15, since no wiring is repaired since the repair is not possible, the liquid crystal display device is wasteful of cost. There is a problem that significantly lowers the yield.

Accordingly, an object of the present invention is to propose an array substrate for a liquid crystal display device and a method of manufacturing the same, in which the data wiring is composed of adjacent double lines to solve the above-mentioned problems and solves the disconnection of the wiring or the short circuit between the wirings. .

1 is a plan view schematically illustrating a general liquid crystal display device;

2 is a plan view showing a part of an array substrate for a liquid crystal display device;

3 is a plan view showing a part of an array substrate for a liquid crystal display device according to a first example of the present invention;

4A to 4F are process cross-sectional views cut along line IV-IV of FIG. 3 according to a process sequence;

5 is a plan view showing a part of an array substrate for a liquid crystal display according to a second example of the present invention;

6 is a plan view showing a short circuit repair method using the wiring structure of the first example;

7 is a plan view showing a short circuit repair method using the wiring structure of the second example.

<Description of the symbols for the main parts of the drawings>

113: gate wiring 115a: first data wiring

115b: second data line 119: data pad

117: gate pad 123: gate electrode

125 source electrode 127 drain electrode

131a: active line 131b: active channel

According to an exemplary embodiment of the present invention, an array substrate for a liquid crystal display device includes: a gate wiring extending in one direction on a substrate; First and second data lines connected to one pad and extending in parallel with each other while crossing the gate lines on a semiconductor line doped with impurities; A switching device connected to the gate wiring and the data wiring; The pixel electrode receives a liquid crystal driving signal from the switching device.

The first and second data lines may be connected to each other at a position crossing the gate line.

Example

According to the present invention, in order to repair the above-described wiring defect, the data wiring is configured as a double wiring, and even if the first data wiring of the double wiring is disconnected, the signal can flow by the remaining second data wiring.

3 is a partial cross-sectional view of an array substrate for a liquid crystal display according to a first example of the present invention.

The gate wiring 113 and the data wiring 115 are orthogonal to each other, and the thin film transistor T, which is a switching element, is positioned at orthogonal points of the gate wiring 113 and the data wiring 115.

A gate pad 117 to receive a signal is formed at the end of the gate line 113, and a data pad 119 is formed at the end of the data line 115.

The data line 115 according to the present invention is patterned such that a portion starting from the data pad 119 branches into the first data line 115a and the second data line 115b and is spaced a predetermined distance apart.

The thin film transistor T is connected to the gate line 113 to receive a scan signal, and the source electrode 125 connected to the second data line 115b to receive a data signal. ) And drain electrodes 127 spaced apart from each other.

The spaced first data line 115a and the second data line 115b have a structure in which a signal is simultaneously applied to the data pad 115. It is a structure that can transmit data signals.

In detail, the distance between the first data line 115a and the second data line 115b is closely patterned to form a capacitance formed between the two lines or a coupling effect generated between the two lines. In this case, a channel is formed between the two wires so that a signal flowing to the portion not disconnected may flow to the source electrode 125 connected to the disconnected signal wire.

Hereinafter, a method of manufacturing an array substrate for a liquid crystal display device according to an exemplary embodiment of the present invention will be described with reference to the process cross-sectional views of FIGS. 4A to 4F.

4A through 4F are cross-sectional views illustrating a process sequence, taken along line IV-IV of FIG. 3.

First, as shown in FIG. 4A, a conductive metal such as aluminum (Al), tungsten (W), molybdenum (Mo), chromium (Cr), or the like is deposited and patterned on the substrate 111 to form a gate wiring 113. And a gate electrode 123 protruding in one direction from the gate wiring in a predetermined area.

A gate pad 117 of FIG. 3 is formed at an end of the gate wiring 113, and a data pad 119 of FIG. 3 is formed at one side not parallel to the gate pad.

Next, as shown in FIG. 4B, an inorganic insulating material such as silicon oxide film (SiO ₂ ), silicon nitride film (SiN _X ), and, in some cases, benzocyclobutene on the entire surface of the substrate 111 on which the gate wiring and the like are formed. Organic insulating materials such as (BCB) and acrylic resin (resin) are deposited or coated, and subsequently impurities are doped by doping impurities (n-type or p-type) on the surfaces of pure amorphous silicon and the pure amorphous silicon layer. An amorphous silicon layer is formed to form a gate insulating film 116 as a first insulating layer, an active layer 118 as a semiconductor layer, and an ohmic contact layer 120.

Next, as shown in FIG. 4C, the semiconductor layer protrudes and extends from the active line to the gate electrode 123 from the active line in the same direction as the data line formed later. The active channel 131b is formed and configured.

Next, as shown in FIG. 4D, one of the above-described conductive metals is deposited on the entire surface of the substrate 111 on which the active line 131a is formed to form a conductive metal layer (not shown).

The conductive metal layer is patterned to overlap the active line 131a formed in the one direction, branched into the first wiring and the second wiring in the vicinity of an end of the active line 131a, and spaced apart from each other by a predetermined distance. The first data line 115a and the second data line 115b are formed to overlap with both sides of the first and second data lines 115b.

At the same time, the source electrode 125 extending from the second data line 115b to the gate electrode 123 and overlapping the active channel 131b in plan view, is spaced apart from the active electrode 131b by a predetermined interval. And a drain electrode 127 formed to overlap a predetermined area.

In this case, the ohmic contact layer is removed from the active line exposed between the first data line 115a and the second data line 115b.

Simultaneously with the formation of the data line, the source / drain metal layer 133 is formed in an island form on the gate line defining the pixel area.

As shown in FIG. 4E, the protective layer 137, which is the second insulating layer, is formed on the front surface of the substrate on which the double data wiring and the like are formed, and then patterned. A first data pad contact hole (not shown), a second data pad contact hole (not shown) is formed on an upper end of the data line, and a drain contact hole 139 is formed on the drain electrode. In addition, a storage contact hole 141 is formed on the source / drain metal layer.

Although not shown, a gate pad contact hole (not shown) is formed on the gate pad.

Next, a transparent conductive layer such as indium tin oxide (ITO) and indium zinc oxide (IZO) is deposited on the entire surface of the substrate on which the contact holes are formed to form a transparent electrode layer (not shown).

As shown in FIG. 4F, the transparent electrode layer is patterned, and one side of the transparent electrode layer is in electrical contact with the drain electrode 127 through the drain contact hole 139, and the other side of the transparent electrode layer is formed through the storage contact hole 141. The pixel electrode 143 which is in electrical contact with the storage electrode 133 which is a source / drain metal layer, and the first data pad contact hole and the second data pad contact hole are not simultaneously shown, and are simultaneously filled in the data wiring 115a. And a data pad terminal electrically connecting the data pad to the data pad, and a gate pad terminal filled in the gate pad contact hole and patterned in an island shape on the gate pad.

5 is a partial plan view of an array substrate for a liquid crystal display according to a second example of the present invention.

In the second example of the present invention, in the data wiring branched into the first data wiring 115a and the second data wiring 115b, even if any one of the two branched wirings is disconnected, the source electrode 125 is connected to the source electrode 125. A structure capable of smoothly supplying a data signal is a structure in which a portion of the first data line 115a adjacent to the source electrode extends to the source electrode 125 so that the data line has a ladder shape as a whole. .

Therefore, even if any one of the two wires is disconnected during the process, the data signal flows smoothly.

The first and second structures described above are structures in which a data signal can flow normally by one wire even if any one of the two branched wires is disconnected.

Hereinafter, when the data wiring and the gate wiring are shorted in the structures of the first and second examples, respective repair methods will be described with reference to FIGS. 6 and 7.

6 is a cross-sectional view showing a repairing method for a case where a short circuit occurs between wirings in the configuration according to the first example of the present invention.

In the configuration of FIG. 3, when any one of the branched first data lines 115a and the second data lines 115b and the gate line 113 are shorted, the short circuit as shown in FIG. The data wiring of the part A is cut | disconnected by making the cutting part B (C) the upper / lower of the said short-circuit point, respectively.

At this time, in order to completely block the flow of the signal between the cutting portion (B) (C), it cuts to the active line (131a) exposed between the two wiring (115a, 115b).

The cutting method generally requires the use of a laser beam since it is necessary to cut minute portions.

7 is a cross-sectional view showing a repairing method for a case where a short circuit occurs between wirings in the configuration according to the second example of the present invention.

As shown, when any one of the branched first data wiring 115a and the second data wiring 115b is shorted with the gate wiring 113 in the second example configuration, the The lower side F of the portion close to the short circuit portion D is cut off, and the portion G extending from the data line not shorted to the gate wiring 113 to the source electrode is also cut.

That is, the data wiring not shorted to the gate wiring 113 is completely independent from the data wiring shorted to the gate wiring 113.

The short-circuit repair method between the wirings according to the first example and the second example converts the predecessor into an acceptable one to manufacture as a product.

In this way, it is possible to prevent the disconnection of the wiring and the short circuit failure between the wirings by using the configuration of the array substrate for a liquid crystal display device according to the present invention.

Therefore, since the wiring structure of the array substrate for the liquid crystal display device according to the present invention does not have to make a repair wiring for repairing disconnection or short circuit of the wiring, firstly, there is no problem of lowering the aperture ratio of the liquid crystal panel. Since repairing by pixel unit is possible, it is advantageous to repair large area liquid crystal panel.

Claims (2)

On the substrate, A gate wiring extending in one direction; First and second data lines connected to one pad and extending in parallel with each other while crossing the gate lines on a semiconductor line doped with impurities; A switching device connected to the gate wiring and the data wiring; A pixel electrode receiving a liquid crystal driving signal from the switching element Array substrate for a liquid crystal display device comprising a. The method of claim 1, And the first and second data lines are connected to each other at a position crossing the gate line.