KR19980026759A - LCD and manufacturing method thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transverse electric field liquid crystal display device and a method for manufacturing the same, wherein a pixel electrode and a counter electrode are formed of a transparent conductive film such as ITO, and have a pixel electrode and a counter electrode formed of metal. A large area through which the emitted light can pass and a protective insulating film are formed to obtain a liquid crystal display device having improved yield.

Description

LCD and its manufacturing method

The present invention relates to a liquid crystal display device and a manufacturing method thereof, and more particularly, to a transverse electric field type liquid crystal display device having a high aperture ratio and a manufacturing method thereof.

The transverse electric field liquid crystal display device having a wide viewing angle horizontally with respect to two substrates facing each other in which the direction of the electric field forms a liquid crystal display device is being actively used and developed, II-II of FIGS. 1 and 1. The transverse electric field liquid crystal display device will be described with reference to FIG.

The transverse electric field liquid crystal display device includes a liquid crystal layer filled between the first substrate 100 and the second substrate 110 and the first and second substrates facing each other. A plurality of gate bus wirings 101 and source bus wirings 131 are formed orthogonal to each other on the first substrate 100, and gate electrodes are formed at intersections of the gate bus wirings 101 and the source bus wirings 131. A thin film transistor, which is a switching element composed of a 101a, a semiconductor layer 105, a source electrode 132, and a drain electrode 133, is formed, and a pixel is formed in an area where the gate bus wiring and the source bus wiring cross each other. An electrode 134 and an opposite electrode 103 facing the pixel electrode are formed. The pixel electrode and the counter electrode have various shapes capable of forming a transverse electric field. The pixel electrode 134 of the liquid crystal display shown in FIG. 1 has a bar shape parallel to the source bus wiring 131. 103 has a shape in which the bar parallel to the pixel electrode is drawn from side to side in a bar parallel to the gate bus wiring. A portion parallel to the gate bus wiring of the counter electrode serves as a wiring for transmitting a signal applied to the counter electrode, and a portion parallel to the pixel electrode serves as an electrode to form a transverse electric field together with the pixel electrode. It may be formed in layers or in different layers. When formed in different layers, the wiring and the electrode are connected by contact holes. The color filter layer 111 is formed on the second substrate 110 opposite to the first substrate 100. The liquid crystal is filled between the first and second substrates.

2, the gate bus wiring, the gate electrode 101, and the counter electrode 103 are formed on the first substrate 100. The gate insulating film 104 covers the entire surface of the substrate on which the gate bus wiring, the gate electrode, and the counter electrode are formed. The semiconductor layer 105 and the impurity semiconductor layer 106 are sequentially formed on the gate insulating film 104 formed on the gate electrode 10. The source electrode 132 branching from the source bus wiring 131 formed on the gate insulating film and the drain electrode 133 integrally formed with the pixel electrode are formed to correspond to the impurity semiconductor layer 106 separated on both sides. have.

Since the pixel electrode and the counter electrode of the transverse electric field liquid crystal display device having the above structure are made of metal such as Cr or Al to block light from the light source, the transmittance of the liquid crystal display device is low and the aperture ratio is reduced. .

SUMMARY OF THE INVENTION An object of the present invention is to provide a transverse electric field type liquid crystal display device having improved aperture ratio and a method of manufacturing the same.

It is still another object of the present invention to provide a method of manufacturing a transverse electric field liquid crystal display device capable of obtaining a high opening liquid crystal display device with high yield and a transverse electric field liquid crystal display device manufactured by the method.

1 is a perspective view of a conventional transverse electric field liquid crystal display device.

FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1.

3 is a manufacturing process chart of a transverse electric field liquid crystal display device according to a first embodiment of the present invention.

4 is a manufacturing process chart of a transverse electric field liquid crystal display device according to a second embodiment of the present invention.

5 is a manufacturing process chart of a transverse electric field liquid crystal display device according to a third embodiment of the present invention.

6 is a manufacturing process chart of a transverse electric field liquid crystal display device according to a fourth embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

131, 231: source bus wiring 132, 232: source electrode

133 and 233 drain electrodes 134 and 234 pixel electrodes

103, 203: counter electrode 233: counter electrode wiring

A scanning line, a signal line, a switching element formed at an intersection of the scanning line and the signal line, a pixel electrode connected to the switching element, and an opposing electrode facing the pixel electrode are formed. In a liquid crystal display device comprising a first substrate, a second substrate facing the first substrate, and a liquid crystal layer filled between the first substrate and the second substrate, the pixel electrode is made of indium tin oxide (ITO) or the like. It is characterized by consisting of a transparent conductive film. Alternatively, both the pixel electrode and the counter electrode are formed of a transparent conductive film. Alternatively, a protective insulating film is formed over the entire surface of the substrate including the switching device so that the pixel electrode is connected to the drain electrode, which is an output terminal of the switching device, through the contact hole.

In the liquid crystal display device, when the pixel electrode or the counter electrode is formed of a transparent conductive film such as ITO, light from the light source passes through the pixel electrode or the counter electrode and has a counter electrode and a pixel electrode made of a metal such as Al or Cr. Unlike the liquid crystal display device, it can have a high aperture ratio. The shape and position of the pixel electrode and the counter electrode are different for each liquid crystal display device, but the larger the area, the greater the improvement of the aperture ratio. In addition, when the protective insulating layer covers the switching element and the gate insulating layer formed on the substrate and the pixel electrode is formed on the protective insulating layer, the liquid crystal display device can be obtained with improved yield.

Hereinafter, a method of manufacturing a substrate on which a pixel electrode and a counter electrode of a transverse electric field liquid crystal display device according to an embodiment of the present invention are formed will be described with reference to FIGS. 3, 4, 6, and 6.

Example 1

A first metal layer of Al, Cr, or the like is deposited on the substrate 200, and then patterned to form a gate electrode 201a and an opposite electrode 203 branching from the gate bus wiring and the gate bus wiring. (FIG. 3A)

Subsequently, the gate insulating film 204 made of silicon nitride or the like, the semiconductor layer 205 of amorphous silicon, and the impurity semiconductor layer 206 of n + amorphous silicon are successively deposited by plasma CVD and then patterned to form an impurity semiconductor layer and a semiconductor layer. Is formed in an island shape and the gate insulating film on the gate bus wiring portion (the gate bus wiring pad portion) connected to the external driving circuit is removed. (Figure 3B)

The second metal layer is deposited on the entire surface of the substrate by a sputtering method and then patterned to form a source bus wiring 231 and a source electrode 232 and a drain electrode 233 branching from the source bus wiring. Then, a predetermined portion of the impurity semiconductor layer is etched and removed. (Figure 3C)

Subsequently, a transparent conductive film such as indium tin oxide (ITO) is deposited over the entire surface of the substrate and then patterned to form a pixel electrode 234 electrically connected to the drain electrode 233. (Figure 3D)

Since the pixel electrode is formed of a transparent conductive film such as ITO, light from the light source passes through the pixel electrode, and the aperture ratio is improved.

Example 2

After depositing and patterning a first metal layer of Al, Cr, etc. on the substrate 200, the gate electrode 201a branching from the gate bus wiring and the gate bus wiring and the counter electrode 203 formed in a subsequent process are electrically Opposite electrode wiring (which also functions as a storage line to form an accumulating capacity) is formed. (FIG. 4A)

Subsequently, the gate insulating film 204 such as silicon nitride, the semiconductor layer 205 of amorphous silicon, and the impurity semiconductor layer 206 of n + amorphous silicon are successively deposited by plasma CVD and then patterned to form the impurity semiconductor layer and the semiconductor layer. A gate insulating film 204 formed in an island shape and connected to an external driving circuit (a gate bus wiring pad part) and a gate insulating film 204 on the counter electrode wiring electrically connected to a counter electrode formed in a subsequent process. Remove (Fig. 4B)

The second metal layer is deposited on the entire surface of the substrate by a sputtering method and then patterned to form a source bus wiring 231 and a source electrode 232 and a drain electrode 233 branching from the source bus wiring. Then, a predetermined portion of the impurity semiconductor layer is etched and removed. (Figure 3C)

Subsequently, a transparent conductive film such as indium tin oxide (ITO) is deposited over the entire surface of the substrate, and then patterned to form a pixel electrode 234 electrically connected to the drain electrode 233, while the counter electrode wiring 223 is formed. And a counter electrode 203 connected to the electrode. (Figure 4D)

Since the pixel electrode and the counter electrode are made of a transparent conductive film such as ITO, light from the light source passes through the pixel electrode and the counter electrode, so that the aperture ratio is improved.

Example 3

In the first and second embodiments, the drain electrode and the pixel electrode made of ITO are directly connected. However, in the present embodiment, a protective insulating film 240 made of silicon nitride or the like is performed by performing the same process as shown in FIGS. 3A, B and C. FIG. Is deposited by plasma CVD and patterned to form a contact hole for connecting the drain electrode and the pixel electrode. (FIG. 5D) Next, a transparent conductive film such as ITO is deposited and patterned to form the pixel electrode 234. FIG. . (Fig. 5E)

Since the pixel electrode is made of a transparent conductive film such as ITO, the aperture ratio is improved, and the pixel electrode is formed on the protective insulating film to improve the yield.

Example 4

When the counter electrode wiring and the counter electrode are connected through the contact holes as in Example 2, the process shown in FIGS. 4A, B, and C is performed, and the protective insulating film 240 made of silicon nitride or the like is deposited by plasma CVD. A contact hole connecting the drain electrode 233 and the pixel electrode and a contact hole connecting the opposite electrode wiring 223 and the opposite electrode are formed. (D) Next, a transparent conductive film such as ITO is deposited and then patterned to form the pixel electrode 234 and the counter electrode 203. (Figure 6E)

The pixel electrode and the counter electrode are formed of a transparent conductive film such as ITO to improve the aperture ratio, and the pixel electrode is formed on the protective insulating film to improve the yield.

According to the present invention, the pixel electrode and the counter electrode of the transverse electric field liquid crystal display device are formed of a transparent conductive film such as ITO to improve the aperture ratio. In addition, since the protective insulating layer covers the switching element and the gate insulating layer and the pixel electrode is formed on the protective insulating layer, a liquid crystal display device can be obtained with high yield.

Claims (5)

A first substrate and a first substrate formed with a scanning line, a signal line, a switching element formed at an intersection of the scanning line and the signal line, a pixel electrode connected to the switching element, and an opposing electrode facing the pixel electrode; The liquid crystal display device comprising a second substrate and a liquid crystal layer filled between the first substrate and the second substrate, wherein the pixel electrode is a transparent conductive film. The liquid crystal display of claim 1, wherein the switching element is covered with a protective insulating film so that the pixel electrode is electrically connected to the switching element through a contact hole. A first substrate and a first substrate formed with a scanning line, a signal line, a switching element formed at an intersection of the scanning line and the signal line, a pixel electrode connected to the switching element, and an opposing electrode facing the pixel electrode; A liquid crystal display device comprising a second substrate and a liquid crystal layer filled between the first substrate and the second substrate, wherein the pixel electrode and the counter electrode are transparent conductive films. Depositing and patterning a first metal layer on the substrate to form a gate electrode and an opposite electrode; Forming a gate insulating film on a substrate on which the gate electrode and the counter electrode are formed; Depositing a semiconductor layer and an impurity semiconductor layer sequentially on the gate insulating film and then performing predetermined patterning; Depositing and patterning a second metal layer on the impurity semiconductor layer to form a source electrode and a drain electrode; Depositing and patterning a protective film to form a contact hole on the drain electrode; And depositing and patterning a transparent conductive film to form a pixel electrode electrically connected to the contact hole. Depositing and patterning a first metal layer on the substrate to form a gate electrode and an opposite electrode wiring; Forming a gate insulating film on the substrate on which the gate electrode and the counter electrode wiring are formed; Depositing a semiconductor layer and an impurity semiconductor layer sequentially on the gate insulating film and then performing predetermined patterning; Depositing and patterning a second metal layer on the impurity semiconductor layer to form a source electrode and a drain electrode; Depositing and patterning a passivation layer to expose a portion of the drain electrode and a portion of the counter electrode wiring; And depositing and patterning a transparent conductive film to form a pixel electrode electrically connected to the drain electrode and a counter electrode electrically connected to the counter electrode wiring.