KR20020053575A - Liquid crystal display device and method for manufacturing the same - Google Patents

Abstract

PURPOSE: A liquid crystal display and a method of fabricating the liquid crystal display are provided to form a pixel electrode and a common electrode using the same mask on the same plane so as to reduce the number of processing steps and prevent generation of image sticking. CONSTITUTION: A gate electrode(22) and a common line(30) are formed on a glass substrate(20) using a gate mask. A gate insulating layer and a passivation layer(26) are formed on the glass substrate using an active mask. Source/drain electrodes(28) are formed on the gate insulating layer and passivation layer using a source/drain mask. The first contact hole(32) is formed to expose the drain electrode, and the second contact hole(36) is formed to expose the common line. A pixel electrode is connected to the source and drain electrode through the first contact hole, and a common electrode is connected with the common line through the second contact hole. The pixel electrode and the common electrode are patterned using the same mask.

Description

Liquid crystal display and its manufacturing method {LIQUID CRYSTAL DISPLAY DEVICE AND METHOD FOR MANUFACTURING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a method of manufacturing the same, and more particularly, to a liquid crystal display device having a FFS (Fringe Field Switch) mode having a good effect of removing an afterimage while being manufactured by a 5-mask process. .

Currently, liquid crystal display devices, which are designed as flat panel displays and enable low power consumption and light weight, are applied to various products.

Such a liquid crystal device (LCD) is a screen display device using a difference in the transmittance of light generated by a change in the alignment direction of the liquid crystal, the display mode of the LCD is polarized type, absorption type depending on the nature of using the light , Scattering, etc.

The TN (Twisted Nematic) type, which is known as a polarization modulation LCD, is manufactured by applying the mask process shown in FIG. 1A in the manufacturing process. The pattern of the gate electrode is formed by laminating a gate metal on a glass substrate. A gate mask process for forming a gate electrode by etching by applying a gate mask having a gate mask, and forming an insulating layer on the gate electrode, then forming a layer film for forming an active layer, and then applying an active mask to form an active layer An active mask process for forming, S / D for forming a source / drain metal layer by forming a source / drain metal layer on the structure on which the active layer is formed, and then patterning the source / drain metal layer using a source / drain (S / D) mask. Masking process, passivation layer is formed on the whole structure including source / drain metal and through hole in the protection layer Through hole forming mask process for forming via holes and pixel ITO mask process for laminating pixel indium tin oxide (ITO) films for forming pixel electrodes and patterning the pixel ITO film using a pixel ITO mask do.

In recent years, the FFS mode LCD has been proposed in consideration of the fact that the demand for a wider viewing angle and a larger size is gradually increased. The LCD of the FFS mode serves as a storage and a common electrode. On top of the lower electrode (i.e., the first ITO electrode), the second ITO electrode (i.e. pixel electrode) causes a potential difference in the liquid crystal so that the negative liquid crystal rotates so that the light propagates through the polarizing plate It is configured to perform image reproduction by passing through, and in that respect, the liquid crystal display device of the FFS mode provides an excellent viewing angle compared with the TFT-LCD of IPS mode or TN mode.

That is, the mask process shown in FIG. 1B applied to the manufacturing process of the FFS mode liquid crystal display device includes a common electrode ITO mask process for masking the common electrode ITO layer for forming the common electrode, and a gate for forming the gate electrode. Gate mask process for patterning metal layer, active mask process patterning active layer forming film for formation of active layer, S / D mask process used for patterning source / drain metal layer to form source / drain (S / D) electrode And a through hole forming mask process for forming through holes penetrating through the protective layer formed on the source / drain electrodes, and a pixel ITO mask process for forming a pixel electrode (second ITO electrode) as an upper layer.

However, the FFS mode LCD is advantageous in that a wide viewing angle can be secured and can be enlarged, but the mask process is more complicated than the TN-LCD manufacturing process shown in FIG. 1A.

That is, in the current FFS mode LCD, the common electrode and the pixel electrode are formed on different layers, and thus, a separate mask is required for the common electrode and the pixel electrode. This is due to the addition of a mask for forming the common ITO according to the structure of the FFS mode LCD which forms the role of the common ITO electrode in the color filter in the LCD in the TN mode LCD. Compared to LCD in TN mode, it is disadvantageous in terms of manufacturing productivity.

2A and 2B, in the FFS mode LCD, an insulating layer and a protective layer 16 exist between the common ITO electrode 10 and the pixel ITO electrode 12, and are common to the common ITO electrode 10. As the wiring 18 is spoken, the insulating layer and the protective layer 16 are present, which increases the likelihood of causing residual DC components, and thus becomes quite disadvantageous in terms of afterimage.

That is, according to the FFS mode LCD device, the common electrode 10 and the pixel electrode 12 show the same polarity for one frame in the pixel, and thus, the same direction of the field in the same frame period is always used. field). Therefore, a mismatch of fields occurs every frame period, which increases the likelihood of causing residual DC components, which causes afterimages.

Accordingly, the present invention has been made in view of the above-described prior art, and in the structure of the FFS mode, the pixel ITO and the common ITO are formed by the same mask, so that the number of processes is reduced and the ITO and the common ITO are formed on the same layer, thereby remaining DC. It is an object of the present invention to provide a liquid crystal display device and a method of manufacturing the same, which prevents generation of components and afterimage.

In order to achieve the above object, according to the first preferred embodiment of the present invention, in the FFS mode liquid crystal display device, a gate electrode and common wiring formed by using a gate mask on a glass substrate, and the gate electrode and common wiring, A gate insulating layer and a protective layer formed on the formed glass substrate using an active mask, a source / drain electrode formed on the gate insulating layer and a protective layer using a source / drain mask, and a source using a through hole mask And a pixel electrode connected to the source / drain electrode through the first through hole, the first through hole formed for the drain electrode, and the second through hole formed for the common wiring, and the same mask as the pixel electrode. A liquid crystal display device comprising a common electrode patterned and connected to the common wiring through the second through hole is provided. Ball.

Preferably, the pixel electrode and the common electrode are formed on the same layer.

Further, according to the second embodiment of the present invention, in the liquid crystal display of the FFS mode, a glass electrode having a gate electrode and common wiring formed using a gate mask on the glass substrate, and the glass on which the gate electrode and the common wiring are formed A gate insulating layer and a protective layer formed on the substrate using an active mask, a source / drain electrode formed using a source / drain mask on the gate insulating layer and the protective layer, and a through hole formed using a through hole mask. A liquid crystal display device comprising a common electrode whose ITO portion is connected to the common wiring, and a pixel electrode whose slit is formed at the time of forming the source / drain electrode and whose ITO portion is formed of the source / drain electrode. do.

Preferably, the common electrode and the pixel electrode are formed on different layers from each other without an interface between the insulating layer and the protective layer interposed therebetween.

According to an embodiment according to the first embodiment of the present invention, in the method for manufacturing a liquid crystal display device in FFS mode, a gate electrode and a common wiring are formed on a glass substrate using a gate mask, and the gate electrode and A gate insulating layer and a protective layer are formed on the glass substrate on which the common wiring is formed by using an active mask. A source / drain electrode is formed on the gate insulating layer and the protective layer by using a source / drain mask. Using to form a first through hole formed for the source / drain electrode, and to form a second through hole formed for the common wiring, connected to the source / drain electrode through the first through hole A common pixel connected to the common wiring through the second through hole by the same mask as the pixel electrode There is provided a method of manufacturing a liquid crystal display device which comprises a process of forming an electrode.

Preferably, the common electrode and the pixel electrode are formed on the same layer so that the interface between the insulating layer and the protective layer is not interposed.

In addition, according to the second embodiment of the present invention, in the method for manufacturing a liquid crystal display device in FFS mode, a gate electrode and a common wiring are formed on a glass substrate using a gate mask, and the gate electrode and A gate insulating layer and a protective layer are formed on the glass substrate on which the common wiring is formed by using an active mask. A source / drain electrode is formed on the gate insulating layer and the protective layer by using a source / drain mask. An ITO (Indium Tin Oxide) portion is formed through the through hole formed by using a common electrode, the slit is formed at the time of forming the source / drain electrode and the ITO portion is formed There is provided a method of manufacturing a liquid crystal display device comprising a process of forming a pixel electrode formed of a / drain electrode.

Preferably, the common electrode and the pixel electrode are formed on different layers from each other without an interface between the insulating layer and the protective layer interposed therebetween.

According to a preferred embodiment of the liquid crystal display and the manufacturing method according to the present invention described above, when the pixel electrode and the common electrode of the FFS mode LCD are formed on the same layer by a single mask, the interface between the insulating layer and the protective layer is interposed. After the residual DC component generated in the substrate is excluded, no afterimage is generated, and the entire mask process of the FFS mode LCD is shortened by the single mask process.

In another preferred embodiment of the present invention, the pixel electrode and the common electrode are formed in different layers while the ITO portion of the pixel electrode is formed of a source / drain, but in this case, the interface between the insulating layer and the protective layer is not interposed. Since residual DC components are excluded, no afterimage occurs.

1A and 1B illustrate a mask process of a twisted nematic (TN) mode and an FFS mode of a conventional liquid crystal display;

FIG. 2 is a view for explaining the cross-sectional structure and operation of the FFS mode LCD manufactured by the mask process described in FIG. 1B;

3 is a view for explaining a mask process applied to the manufacturing method of the liquid crystal display device according to the present invention;

4 and 5 are a plan view and a cross-sectional view of a liquid crystal display according to a first embodiment of the present invention;

FIG. 6 is a diagram illustrating slit intervals and slit widths of the pixel electrode and the common electrode illustrated in FIGS. 4 and 5;

7 is a plan view of a liquid crystal display according to a second exemplary embodiment of the present invention.

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

20: glass substrate, 22: gate electrode,

24: gate wiring, 28: source / drain,

30: common wiring, 32: first through hole,

36: common electrode, 38: common wiring,

40: pixel electrode, 42: common electrode.

Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail.

3 is a view illustrating a mask process for manufacturing an FFS mode LCD according to the liquid crystal display device and a manufacturing method according to the present invention, Figure 4 is a liquid crystal display according to the present invention including the mask process shown in FIG. 5 is a cross-sectional view of the liquid crystal display device according to the present invention shown in FIG.

First, according to the present invention, after a gate metal layer is stacked on a glass substrate (ie, an array substrate) 20, the gate metal layer is patterned using a gate mask (gate mask process of FIG. 3) to form a gate electrode 22. In addition, the common wiring and the light blocking plate 30 are formed.

An insulator and a protective layer 26 are formed on the entire surface including the gate electrode 22 by using an active mask (active mask process of FIG. 3), and then source / drain electrodes 28 are formed. The source / drain electrodes 28 are formed by stacking source / drain forming films in the S / D mask process of FIG. 3 and patterning them using an S / D mask.

Then, the first through hole 32 for the source / drain electrode 28 is formed, and the second through hole 36 connected to the common wiring 30 is formed. And the second through hole 32 is formed using a through hole mask having a shape corresponding to the first and second through holes 32 in the through hole mask process of FIG. 3.

Next, in the pixel / common ITO mask process of FIG. 3, the pixel / common electrode ITO layer for forming the pixel electrode 40 and the common electrode 42 is stacked on the pixel / common electrode ITO layer. Patterning is done using a common ITO mask.

That is, according to the present invention, the common ITO electrode and the pixel ITO electrode are formed using the same mask.

In addition, according to the present invention, two through holes 32 and 36 are formed. The through holes 32 are formed to contact the pixel ITO 40 with the S / D electrode 28. A hole 36 is formed to contact the common ITO 42 to the common wiring 30.

Preferably, referring to Figure 6 in the FFS mode LCD manufactured according to the present invention, the interval 50 of the slit (Slit) of the pixel / common ITO (40, 42) is set to about ~ 5㎛ compared to the conventional 4㎛ In addition, the width 52 of the slit is set to a conventional 4 ~ 5㎛ to enable the formation at the level of the current photo and etching process.

7 is a plan view of a liquid crystal display according to another exemplary embodiment of the present invention. Unlike the above-described exemplary embodiment, the pixel ITO portion is formed of the S / D electrode 28. A slit of 40 is formed and the ITO is connected to the common wiring 38 by connecting to the through hole 36.

In this case, only the protective layer is present between the electrodes, and as in the conventional method, there is no interface between the insulator and the protective layer, which is advantageous in the afterimage.

In addition, although the pixel electrode 40 and the common electrode 42 are formed in different layers, the entire mask process is shortened and pixel defects are reduced.

As described above, according to the liquid crystal display device according to the present invention, when the liquid crystal display device is in the FFS mode, not only the mask process can be reduced but also the pixel electrode is formed by forming the pixel ITO and the common ITO by the same mask. Induction and residual image generation of residual DC, which are caused when a gate insulating layer and a protective layer are present between the electrodes, are not generated.

Claims (8)

In the liquid crystal display device of the FFS (Fringe Field Switch) mode, A gate electrode and a common wiring formed using a gate mask on a glass substrate, A gate insulating layer and a protection layer formed on the glass substrate on which the gate electrode and the common wiring are formed by using an active mask; A source / drain electrode formed on the gate insulating layer and the protective layer using a source / drain mask; A first through hole formed for the source / drain electrode and a second through hole formed for the common wiring by using a through hole mask, And a pixel electrode connected to the source / drain electrode through the first through hole and a common electrode patterned by the same mask as the pixel electrode and connected to the common wiring through the second through hole. Display. The liquid crystal display of claim 1, wherein the pixel electrode and the common electrode are formed on the same layer. In the FFS mode liquid crystal display device, A gate electrode and a common wiring formed using a gate mask on a glass substrate, A gate insulating layer and a protective layer formed on the glass substrate on which the gate electrode and the common wiring are formed by using an active mask; A source / drain electrode formed on the gate insulating layer and the protective layer using a source / drain mask; A common electrode in which its indium tin oxide (ITO) portion is connected to the common wiring through a through hole formed using a through hole mask, And a slit (slit) is formed at the time of forming the source / drain electrode and the ITO portion is formed of a pixel electrode formed of the source / drain electrode. 4. The liquid crystal display device according to claim 3, wherein the common electrode and the pixel electrode are formed on different layers with no interface between the insulating layer and the protective layer interposed therebetween. In the method for manufacturing a liquid crystal display device of the FFS mode, Forming a gate electrode and a common wiring using a gate mask on a glass substrate, Forming a gate insulating layer and a protective layer on the glass substrate on which the gate electrode and the common wiring are formed by using an active mask; A source / drain electrode is formed on the gate insulating layer and the protective layer by using a source / drain mask; A through hole mask is used to form a first through hole formed in the source / drain electrode, and a second through hole formed in the common wiring is formed. Forming a pixel electrode connected to the source / drain electrode through the first through hole and forming a common electrode connected to the common wiring through the second through hole by the same mask as the pixel electrode; Method of manufacturing a liquid crystal display device, characterized in that made. The method of claim 5, wherein the common electrode and the pixel electrode are formed on the same layer so that the interface between the insulating layer and the protective layer is not interposed. In the method for manufacturing a liquid crystal display device of the FFS mode, Forming a gate electrode and a common wiring by using a gate mask on the glass substrate, Forming a gate insulating layer and a protective layer on the glass substrate on which the gate electrode and the common wiring are formed by using an active mask; A source / drain electrode is formed on the gate insulating layer and the protective layer by using a source / drain mask; Through holes formed using through hole masks, the ITO (Indium Tin Oxide) part forms a common electrode connected to the common wiring, And forming a pixel electrode whose slit is formed at the time of forming the source / drain electrode and whose ITO portion is formed of the source / drain electrode. The method of claim 7, wherein the common electrode and the pixel electrode are formed on different layers without interposing an interface between the insulating layer and the protective layer.