KR100251656B1 - Transverse electric field liquid crystal display device - Google Patents

Abstract

PURPOSE: An in plane switching mode LCD is provided to enable an electric current to flow regularly in case a power supply of a data electrode is suspended by forming a semiconductor layer between common wiring and a data electrode. CONSTITUTION: A gate insulation film(130) is formed on common wiring(119) and a-Si layer(131), n-plus layer(132) and a data electrode(120) are formed on the gate insulation film in order. Common wiring is made with depositing and etching Al, Ta, Mo, Cr through a sputtering method. The gate insulation film(130) is made with depositing an inorganic substance on a whole substrate through a CVD method. The a-Si layer(131) and the n-plus layer(132) are made with etching an amorphous silicon(a-Si) and n-plus a-Si and are formed in a whole area under a data electrode.

Description

Transverse electric field liquid crystal display device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transverse electric field liquid crystal display device, and more particularly to a transverse electric field liquid crystal display device in which a disconnection prevention layer is formed along a data electrode.

In the TFT LCD, which is widely used in portable televisions and notebook computers, a large area is strongly demanded. However, the above-described TFT LCDs have a problem in that the contrast ratio changes depending on the viewing angle. In order to solve this problem, various liquid crystal display devices such as a twisted nematic liquid crystal display device equipped with an optical compensation plate and a multi-domain liquid crystal display device have been proposed. It is difficult to solve the problem of lowering the contrast ratio and changing color depending on the viewing angle.

Another type of liquid crystal display device that is proposed to realize a wide viewing angle is a liquid crystal display device of the in plane switching mode (JAPAN DISPLAY 92 P547, Japanese Patent Laid-Open No. 7-36058, Japanese Patent Laid-Open No. 7-225538, It is proposed to ASIA DISPALY 95 P107.

FIG. 1A is a plan view of one pixel of a conventional transverse electric field type liquid crystal display device. The gate wiring 13 and the data wiring 10 arranged on a substrate to define a pixel region, and the gate wiring 13 described above. The common wiring 19 arranged in the pixel in parallel with each other, the thin film transistor arranged at the intersection of the gate wiring 13 and the data wiring 10, and the data wiring 10 in the pixel. The data electrode 20 and the common electrode 15. Further, the thin film transistor is formed on the substrate and connected to the gate wiring 13, the gate insulating film 30 (FIG. 1B) stacked on the gate electrode 12, and the gate insulating film. The semiconductor layer 17 is formed of the source electrode 11 and the drain electrode 16 formed on the semiconductor layer 17 and connected to the data wiring 10 and the data electrode 20, respectively. The common electrode 15 in the pixel is formed on the substrate and connected to the common wiring 19, and the data electrode 20 is formed on the gate insulating film and connected to the drain electrode 16 of the thin film transistor. A protective film (not shown) is stacked on the thin film transistor, the data electrode 20 and the gate insulating film, and a first alignment film (not shown) is coated thereon, and an orientation direction is determined.

Although not shown in the drawings, a light shielding layer is formed on the substrate corresponding to the substrate to prevent light leakage near the thin film transistor, the gate wiring, the data wiring, and the common wiring. A bi-orientation film is formed. In addition, a liquid crystal layer is formed between the two substrates.

In the transverse electric field type liquid crystal display device configured as described above, when a voltage is applied from an external driving circuit, a transverse electric field parallel to the substrate is generated between the data electrode 20 and the common electrode 15. Accordingly, the liquid crystal molecules oriented in the liquid crystal layer rotate along the transverse electric field, thereby controlling the amount of light passing through the liquid crystal layer.

FIG. 1B is a cross-sectional view taken along the line A-A 'of FIG. 1A. As shown in the drawing, the gate insulating film 30 is formed on the common wiring 19, and the data electrode 20 is formed thereon. However, as shown in FIG. 1C, when the gate taper is not good (when the taper angle is high or reverse tapering), the step coverage of the gate insulating film is not good, and particularly, in the case of dry etching, the step coverage is weak. Since the insulating layer is further damaged, the step coverage of the later-deposited data electrode 20 is worsened, and thus, there is a problem in that a break occurs at the stepped portion during wet etching, and thus the yield is decreased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the prior art, and an object of the present invention is to form a semiconductor layer between a common wiring and a data electrode so that the semiconductor layer plays a role of redundancy at the time of disconnection of the data electrode. It is to provide an electric field type liquid crystal display device.

In order to achieve the above object, a transverse electric field liquid crystal display device according to the present invention includes a gate wiring and a data wiring arranged on a substrate to define a pixel region, a common wiring arranged in a pixel in parallel with the gate wiring, and A thin film transistor disposed at the intersection of one gate wiring and a data wiring, a data electrode and a common electrode arranged substantially parallel to the data wiring in the pixel, and a first semiconductor layer formed between the data electrode and the common wiring. It consists of. The thin film transistor may include a gate electrode formed on the substrate and connected to the gate wiring, a gate insulating film stacked on the gate electrode, a second semiconductor layer formed on the gate insulating film, and a data wiring formed on the semiconductor layer. And a source electrode and a drain electrode respectively connected to the data electrode. The common electrode in the pixel is formed on the substrate and connected to the common wiring, and the data electrode is formed on the gate insulating film and connected to the drain electrode of the thin film transistor.

1A is a plan view of a conventional transverse electric field type liquid crystal display device.

FIG. 1B is a cross-sectional view taken along the line AA ′ of FIG. 1A.

FIG. 1C is a cross-sectional view along the line A-A 'in a state in which disconnection occurs in FIG.

2A is a plan view of a transverse electric field type liquid crystal display device according to the present invention;

FIG. 2B is a cross-sectional view taken along the line BB ′ of FIG. 2A.

-Explanation of symbols for the main parts of the drawing-

110: data wiring 111: source electrode

112: gate electrode 113: gate wiring

115: common electrode 116: drain electrode

117: semiconductor layer 119: common wiring

120: data electrode 130: gate insulating film

133: redundancy

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2A is a plan view of one pixel of a transverse electric field type liquid crystal display device according to the present invention, the gate wiring 113 and the data wiring 110 arranged on a substrate to define a pixel region, and the gate wiring described above. A common wiring 119 arranged in a pixel in parallel with 113, a thin film transistor arranged at an intersection of the gate wiring 113 and the data wiring 110, and a data wiring 110 substantially in the pixel. The data electrode 120 and the common electrode 115 arranged in parallel and the redundancy 133 formed between the data electrode and the common wiring are formed. In addition, the thin film transistor is formed on a substrate and connected to the gate wiring 113, a gate insulating film (not shown) stacked on the gate electrode 112, and a semiconductor layer formed on the gate insulating film. And a source electrode 111 and a drain electrode 116 formed on the semiconductor layer 117 and connected to the data wiring 110 and the data electrode 120, respectively. The common electrode 115 in the pixel is formed on the substrate and connected to the common wiring 119, and the data electrode 120 is formed on the gate insulating film and connected to the drain electrode 116 of the thin film transistor. A protective film (not shown) is stacked on the thin film transistor, the data electrode 120, and the gate insulating layer, and a first alignment layer (not shown) is coated thereon, and an orientation direction is determined.

Although not shown in the drawings, a light shielding layer is formed on the substrate corresponding to the substrate to prevent light leakage near the thin film transistor, the gate wiring, the data wiring and the common wiring. After the alignment layer is formed, the liquid crystal layer is formed between the two substrates to complete the transverse electric field type liquid crystal display device according to the present invention.

FIG. 2B is a cross-sectional view taken along line B-B 'of FIG. 1A, and as shown in the drawing, a gate insulating film 130 is formed on the common wiring 119, and the a-Si layer 131 and the n ⁺ layer ( 132 and the data electrode 120 are formed in order. The common wiring 119 is formed by stacking and etching Al, Ta, Mo, Cr, or Al alloy by a sputtering method, and the gate insulating layer 130 deposits an inorganic material such as SiNx on the entire substrate by CVD (Chemical Vapor). It is formed by laminating by the deposition method. In addition, the a-Si layer 131 and the n ⁺ layer 132 are formed by etching amorphous silicon (a-Si) and n ⁺ a-Si stacked by the CVD method. Here, the a-Si layer 131 and the n ⁺ layer 132 can be formed together when forming the semiconductor layer 117 as shown in FIG. 2A, and thus do not require a separate process. . In addition, the a-Si layer 131 and the n ⁺ layer 132 may be formed over the entire area under the data electrode 20. That is, each of the a-Si layer 131 and the n ⁺ layer 132 may be formed by being connected along the shape of the data electrode 120.

In the liquid crystal display having the above structure, when the stepped portion of the data electrode 20 is disconnected, current flows normally through the n ⁺ layer 132 and the a-Si layer 131.

In the transverse electric field type liquid crystal display device according to the present invention, by forming a semiconductor layer composed of an impurity amorphous silicon layer and an amorphous silicon layer between the data electrode and the common wiring, normal current flow is possible even when the data electrode is disconnected. Smooth operation can be performed.

Claims (8)

A first substrate and a second substrate, A gate wiring and a data wiring arranged vertically and horizontally on the first substrate; A switching element formed at an intersection point of the data line and the gate line; A common wiring formed in parallel with the gate wiring; At least one pair of first and second electrodes formed alternately in parallel with the data line to apply a transverse electric field; A disconnection prevention layer formed along the first electrode, and A transverse electric field liquid crystal display device comprising a liquid crystal layer formed between the first substrate and the second substrate. The transverse electric field liquid crystal display device according to claim 1, wherein the switching element is a thin film transistor. The transverse electric field liquid crystal display of claim 1, wherein the first electrode is a data electrode and the second electrode is a common electrode. The transverse electric field liquid crystal display device according to claim 1, wherein the disconnection prevention layer is formed between the first electrode and the common wiring. A first substrate and a second substrate, A gate wiring and a data wiring arranged vertically and horizontally on the first substrate; A switching element formed at an intersection point of the data line and the gate line; A common wiring formed in parallel with the gate wiring; At least one pair of first and second electrodes formed alternately in parallel with the data line to apply a transverse electric field; A semiconductor layer formed between the first electrode and the common wiring, and A transverse electric field liquid crystal display device comprising a liquid crystal layer formed between the first substrate and the second substrate. The transverse electric field liquid crystal display device according to claim 5, wherein the switching element is a thin film transistor. 6. The transverse electric field liquid crystal display device according to claim 5, wherein the semiconductor layer comprises an impurity amorphous silicon layer and an amorphous silicon layer. 6. The transverse electric field liquid crystal display device according to claim 5, wherein the first electrode is a data electrode and the second electrode is a common electrode.

Images