KR20010058190A - Thin film transistor liquid crystal display - Google Patents

Abstract

PURPOSE: A TFT(thin film transistor) LCD(liquid crystal display) is to design a gate line to have functions of two gate lines, thereby increasing an aperture rate and resolution of the LCD and also operating the LCD at a high speed. CONSTITUTION: A gate line(12) and an auxiliary capacitance electrode line(14) are alternately aligned in parallel on a transparent insulating substrate. The first dot type data line(18) is aligned at a prospective data line region without contacting with the gate line and the auxiliary capacitance electrode line. A gate insulating film is formed on an entire surface of the transparent insulating substrate to cover the gate line, the auxiliary capacitance electrode line and the first dot type data line. A contact hole(15) is formed at the gate insulating film to expose both end of the first dot type data line. A pixel electrode is aligned at each pixel region defined by the gate line, the first dot type data line and the auxiliary capacitance electrode to be overlapped with the auxiliary capacitance electrode line. A connecting line(19) is formed at the gate insulating film between the first dot type data lines of an inner portion of the contact hole to connect the first dot type data lines.

Description

Thin Film Transistor Liquid Crystal Display {THIN FILM TRANSISTOR LIQUID CRYSTAL DISPLAY}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film transistor liquid crystal display device, and more particularly, to a thin film transistor liquid crystal display device capable of improving aperture ratio and high-speed operation characteristics according to a decrease in the number of gate lines.

It has been developed in place of the liquid crystal display element CRT (Cathod-ray tube) used in display devices such as televisions and graphic displays. Particularly, thin film transistor liquid crystal display (TFT-LCD) has high speed response characteristics and suitable for high pixel number, so that it is possible to realize high quality, large size, and color screen comparable to CRT. Can be.

Such a TFT-LCD generally has a TFT array substrate provided with a TFT and a pixel electrode, and a color filter substrate on which a color filter and a counter electrode are formed to face each other at predetermined intervals, and a liquid crystal is enclosed in a space therebetween. Form.

1 is a plan view showing a TFT array substrate of a conventional TFT-LCD. As shown, several gate lines 2 are arranged in a row direction on the glass substrate 1, and the storage capacitor electrode lines between the gate lines 2 to obtain the storage capacitance in each pixel. (4) is arranged in parallel with the gate line (2). Further, several data lines 8 are arranged in the column direction so as to be orthogonal to the gate line 2 and the storage capacitor electrode line 4. At this time, although not shown, a gate insulating film is interposed between the gate line 2 and the data line 8 and the storage capacitor electrode line 4 and the data line 8 for electrical insulation therebetween.

Subsequently, in each pixel region defined by the gate line 2 and the data line 8, a pixel electrode 6 made of an ITO metal film is disposed, and the gate line 2 and the data line 4 are disposed. At the intersections of the TFTs 10, which are switching elements, are arranged. Here, the TFT 10 is a gate electrode which is a part of the gate line 2, a channel layer 3 formed on the gate electrode 3, and a data line 8 which are drawn out from the data line 8, and thus one side of the channel layer 3. A source electrode 8a disposed to overlap the upper surface, and a drain electrode 8b disposed to overlap the other upper surface of the channel layer 3 and in contact with the pixel electrode 6.

Although not shown, an ohmic contact layer is formed on the channel layer 3 to improve contact characteristics with the source and drain electrodes 8a and 8b, and an etch stopper is formed on the ohmic contact layer. do.

However, the conventional TFT-LCD having the TFT array substrate having the above structure cannot adequately respond to the demands of the large screen, and there is a problem that the aperture ratio is reduced by the gate line. In other words, the resolution of the TFT-LCD is determined by the number of gate lines and the number of data lines. Since a larger number of gate lines cannot be arranged for the same substrate area with a conventional structure, an improvement in resolution can be obtained. And at the same time, the aperture ratio is reduced by the gate line made of the opaque metal film.

In addition, when driving the TFT-LCD, the time of one frame is determined according to the number of gate lines. However, since the number of gate lines cannot be reduced by the existing structure, there is a limit to high-speed operation.

Accordingly, an object of the present invention is to provide a TFT-LCD which can achieve an improvement in aperture ratio and resolution, and can be operated at high speed by designing one gate line to function as two gate lines.

1 is a plan view illustrating a thin film transistor array substrate of a thin film transistor liquid crystal display device according to the related art.

2 is a plan view illustrating a thin film transistor array substrate of a thin film transistor liquid crystal display according to an exemplary embodiment of the present invention.

3A to 3C are plan views illustrating a method of manufacturing a thin film transistor array substrate of a thin film transistor liquid crystal display according to an exemplary embodiment of the present invention.

(Explanation of symbols for the main parts of the drawing)

11: glass substrate 12: gate line

13a: first channel layer 13b: second channel layer

14: auxiliary capacitance electrode line 15: contact hole

16 pixel electrode 18 first data line

19: connection line 19a: first source electrode

19b: first drain electrode 20: first thin film transistor

22: second data line 22a: bend

23a: second source electrode 23b: second drain electrode

30: second thin film transistor

TFT-LCD of the present invention for achieving the above object, a transparent insulating substrate; Gate lines and storage capacitor electrode lines alternately arranged in parallel on each other on the transparent insulating substrate; A dot-shaped first data line arranged in a data line plan region without contact with the gate line and the storage capacitor electrode line; A gate insulating film formed on an entire surface of the transparent insulating substrate so as to cover the gate line, the storage capacitor electrode line, and the dot-shaped first data line; A contact hole formed in the gate insulating film to expose both ends of the dot-type first data line; A pixel electrode disposed to overlap the storage capacitor electrode line in each pixel region defined by the gate line, the dot first data line, the storage capacitor electrode line, and the dot first data line; A connection line formed on a portion of the gate insulating layer between the dot-shaped first data lines and the contact hole to connect the dot-shaped first data lines; A second data line arranged on a portion of the gate insulating layer on the dot-type first data line and bent to be in contact with the connection line at a portion where the connection line is disposed; A first gate electrode, which is a gate line portion to the right of the connection line, a gate insulating film covering the gate electrode, a first channel layer formed on the gate insulating film portion above the first gate electrode, and drawn from the connection line; A first thin film transistor including a first source electrode disposed to overlap the upper surface of one side of the channel layer, and a first drain electrode disposed to contact the lower pixel electrode while overlapping the other upper surface of the first channel layer; And a second gate electrode which is a gate line portion on the left side of the gate line, a gate insulating film covering the second gate electrode, a second channel layer formed on the gate insulating film portion on the second gate electrode, and the second data line. A second source electrode withdrawn from the bent portion of the second channel layer and overlapping with the upper surface of one side of the second channel layer, and a second drain disposed to contact the upper pixel electrode while overlapping with the other upper surface of the second channel layer. It comprises a second thin film transistor composed of an electrode.

According to the present invention, since one gate line is designed to function as two gate lines, the number of the gate lines can be reduced by half as compared with the conventional one, and thus an improvement in aperture ratio and resolution can be obtained. In addition, high-speed operation characteristics can be obtained.

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

2 is a plan view illustrating a TFT array substrate of a TFT-LCD according to an embodiment of the present invention.

As shown, the gate line 12 and the storage capacitor electrode line 14 are alternately arranged on the transparent insulating substrate, for example, the glass substrate 11, in parallel with each other in the row direction. Here, the storage capacitor electrode line 14 has an opening at a portion overlapping with the pixel electrode. A dot-shaped first data line 18 is arranged in a region where a data line is to be formed, wherein the dot-type first data line 18 is connected to the gate line 12 and the storage capacitor electrode line 14. Without contact, it is arranged only between the gate line 12 and the storage capacitor electrode line 14. A gate insulating film (not shown) is coated on the entire surface of the glass substrate 11 to cover the gate line 12, the storage capacitor electrode line 14, and the dot-shaped first data line 18. A contact hole 15 is formed in the gate insulating film so as to expose both ends of the dot-shaped first data line 18.

Subsequently, in each pixel area defined by the gate line 12, the dot-type first data line 18, the storage capacitor electrode line 14, and the dot-type first data line 18, ITO is used. The pixel electrode 16 made of a transparent metal film such as a metal film is disposed to overlap the storage capacitor electrode line 14.

A connection line 19 for electrically contacting the dot first data lines 18 is disposed on the gate insulating layer between the dot first data lines 18. Here, the connection line 19 is formed between the adjacent dot-shaped first data lines 18 through contact holes 15 formed to expose both ends of the dot-shaped first data line 18. Contact. A second data line 22 is arranged to be orthogonal to the gate line 12 and the storage capacitor electrode line 14 on the gate insulating layer on the dot-type first data line 18. In this case, the second data line 22 has a bent portion 22a which is bypassed so as not to contact the connection line 19 at a portion where the connection line 19 is disposed.

Subsequently, a first thin film transistor 20 and a second thin film transistor 30 are disposed on the left and right sides of the connection line 19, respectively. The first thin film transistor 20 may include, for example, a first gate electrode disposed on the right side of the connection line 19 and a portion of the gate line 12, a gate insulating layer covering the first gate electrode; And a first channel layer 13a formed on the gate insulating layer on the first gate electrode, and the first channel layer 13a drawn from the connection line 19 and overlapping with an upper surface of one side of the first channel layer 13a. One source electrode 19a and a first drain electrode 19b disposed to contact the lower pixel electrode 16 while overlapping the other upper surface of the first channel layer 13a. In addition, the second thin film transistor 30 may be disposed on, for example, a left side of the connection line 19, and may include a second gate electrode that is a portion of the gate line 12, and a gate that covers the second gate electrode. The second channel layer 13b is extracted from the insulating layer, the second channel layer 13b formed on the gate insulating layer on the second gate electrode, and the bent portion 22a of the second data line 22. A second source electrode 23a disposed to overlap with an upper surface of one side, and a second drain electrode disposed to contact the upper pixel electrode 16 while overlapping with an upper surface of the other side of the second channel layer 13b. (22b).

The TFT-LCD of the present invention having the TFT array substrate having the above structure can reduce the number of gate lines and the number of data lines by half, as compared with the prior art. This means that one gate line has two gates. This is because it is designed to function as a line, and a structure in which two data lines are stacked.

Therefore, since a larger number of pixels can be provided for the same substrate area, an improvement in resolution is obtained, and an improvement in aperture ratio is obtained by reducing the number of gate lines. In addition, since the number of pixels operated by one gate line is doubled, high-speed operation is possible up to twice as fast as in the prior art, and thus, charging is poor during operation of the TFT-LCD. It is possible to reduce the occurrence of defects and Mura.

3A to 3C are cross-sectional views illustrating a method of manufacturing a TFT array substrate of a TFT-LCD according to an embodiment of the present invention.

First, as shown in FIG. 3A, the gate line and the storage capacitor electrode line 14 are formed through the deposition and patterning process of the gate metal film on the glass substrate 11, and at the same time, the dot-shaped first data line. (18) is formed. Then, a gate insulating film is applied on the resultant, and then first and second channel layers 13a and 13b made of undoped amorphous silicon are formed. Here, the first channel layer 13a is formed, for example, on the gate line portion to the right of the dot-shaped first data line 18, and the second channel layer 13b is, for example, And the gate line portion on the left side of the dot series first data line 18. Although not shown, an etch stopper made of an ohmic contact layer made of a doped amorphous silicon layer and a silicon nitride film is formed on the channel layers 13a and 13b.

Next, as shown in FIG. 3B, each pixel region defined by the gate line 12, the dot-type first data line 18, and the storage capacitor electrode line 14, and the dot-type first data line 18. A pixel electrode 16 is formed on the substrate, and then an etching process is performed on the gate insulating layer to expose both ends of the dot-type first data line 18.

Next, as illustrated in FIG. 3C, a source / drain metal film is deposited on the resultant, a patterning process is performed on the metal film, and the dot-type second data line is formed through the contact hole 15. The connection line 19 which electrically contacts the fields 18 and the second data line 22 disposed above the dot-shaped first data line 18 are formed. In addition, at the same time, the first source electrode 19a and the other upper surface of the first channel layer 13a which are drawn out from the connection line 19 and overlap the upper surface of one side of the first channel layer 13a. A second source that overlaps the first drain electrode contacting the lower pixel electrode 160 and is drawn from the bent portion 922a of the second data line 22 and overlaps the upper surface of one side of the second channel layer 13b The first thin film transistor 20 and the second thin film are formed by forming the second drain electrode 22b which is in contact with the upper pixel electrode 16 while overlapping the other upper surface of the electrode 22a and the second channel layer 13b. The thin film transistor 30 is formed.

As described above, since the present invention reduces the number of gate lines by half as compared with the related art, an improvement in aperture ratio can be obtained, and a larger number of pixels can be provided for the same substrate area. Can get improvement.

In addition, since the time of one frame is shortened due to the decrease in the number of gate lines, high-speed operation is possible, and defects caused by a defective defect due to increased gate on time are also possible. It is possible to reduce, so that the screen quality of the TFT-LCD can be improved.

Meanwhile, although specific embodiments of the present invention have been described and illustrated, modifications and variations can be made by those skilled in the art. Accordingly, the following claims are to be understood as including all modifications and variations as long as they fall within the true spirit and scope of the present invention.

Claims (2)

Transparent insulating substrates; Gate lines and storage capacitor electrode lines alternately arranged in parallel on each other on the transparent insulating substrate; A dot-shaped first data line arranged in a data line plan region without contact with the gate line and the storage capacitor electrode line; A gate insulating film formed on an entire surface of the transparent insulating substrate so as to cover the gate line, the storage capacitor electrode line, and the dot-shaped first data line; A contact hole formed in the gate insulating film to expose both ends of the dot-type first data line; A pixel electrode arranged to overlap the storage capacitor electrode line in each pixel region defined by the gate line, the dot first data line, the storage capacitor electrode line, and the dot first data line; A connection line formed on a portion of the gate insulating layer between the dot-shaped first data lines and the contact hole to connect the dot-shaped first data lines; A second data line arranged on a portion of the gate insulating layer on the dot-type first data line and bent to be in contact with the connection line at a portion where the connection line is disposed; A first gate electrode, which is a gate line portion on the right side of the connection line, a gate insulating film covering the gate electrode, a first channel layer formed on the gate insulating film portion on the first gate electrode, and drawn from the connection line; A first thin film transistor including a first source electrode disposed to overlap the upper surface of one side of the channel layer, and a first drain electrode disposed to contact the lower pixel electrode while overlapping the other upper surface of the first channel layer; And A second gate electrode which is a gate line portion on the left side of the gate line, a gate insulating film covering the second gate electrode, a second channel layer formed on the gate insulating film portion on the second gate electrode, and a second data line A second source electrode that is drawn out from the bent portion and overlaps with an upper surface of one side of the second channel layer, and a second drain electrode disposed to contact the upper pixel electrode while overlapping with the other upper surface of the second channel layer A thin film transistor liquid crystal display comprising a second thin film transistor composed of. The method of claim 1, wherein the storage capacitor electrode line, The thin film transistor liquid crystal display device having an opening portion overlapping with the pixel electrode.