KR20030032242A - Method for manufacturing liquid crystal display device - Google Patents

Abstract

PURPOSE: A method for manufacturing a liquid crystal display device is provided to improve an aperture ratio by forming common lines without any mask, thereby improving the picture quality. CONSTITUTION: A conductor is deposited on a substrate(100), and then is selectively removed to form gates(120). An ITO and an insulating film are formed on the substrate in order. An amorphous silicon is deposited on the insulating film, and is selectively removed to form an active layer(160). An etching blocking layer(180) is formed on the active layer to prevent etching of the active layer. The insulating film and the transparent layer are selectively removed to form contact holes and common lines(130b). Source and drain electrodes(200a,200b), and pixel electrodes(220), and a passivation film(240) are formed on the substrate in order.

Description

Manufacturing method of liquid crystal display device {METHOD FOR MANUFACTURING LIQUID CRYSTAL DISPLAY DEVICE}

The present invention relates to a method of manufacturing a liquid crystal display device, and more particularly, to a method of manufacturing a liquid crystal display device which can improve aperture ratio by forming a transparent common electrode without using a gate metal and without a separate mask process.

In general, a liquid crystal display (LCD) has a large screen, high aperture ratio, high definition, thin weight, low power consumption, and so on, and replaces a conventional cathode ray tube (CRT). The range of applications of such devices is also expanding.

In manufacturing such a liquid crystal display device, as shown in FIG. 1, the gate 12, the gate insulating layer 14, the active layer 16, the etch stop layer 18, and the source / drain ( 20a, 20b, the pixel electrode 22, and the protective film 24 are also formed sequentially. At this time, each layer is formed by repeating a deposition process, a mask process, and an etching process.

In this structure, in consideration of storage capacitance, as shown in FIG. 2A, a structure in which the gate 12 is formed large and overlaps the upper pixel electrode 22 is possible. In addition, as shown in FIG. 2B, a structure in which a separate common line 13 is formed using the gate 12 metal is possible.

However, the liquid crystal display according to the prior art has the following problems.

In the prior art, since the gate line, the data line, and the thin film transistor portion occupy a certain area of the pixel opening portion, the reduction of the aperture ratio is inevitable. In addition, increasing the line width of the gate line and increasing the formation of the common line to increase the storage capacitance is another factor of decreasing the aperture ratio.

In other words, the margin of storage capacitance is traded off with the aperture ratio, so it is not easy to secure the aperture ratio, thereby improving image quality.

Accordingly, the present invention has been made to solve the problems of the prior art, an object of the present invention is to provide a liquid crystal display device which can secure the aperture ratio by forming a common line without using a gate metal and without adding a separate mask. To provide a manufacturing method.

1 is a cross-sectional view illustrating a method of manufacturing a liquid crystal display device according to the prior art.

2A and 2B are plan views illustrating a method of manufacturing a liquid crystal display device according to the related art.

3A to 3F are cross-sectional views of processes for explaining a method of manufacturing a liquid crystal display device according to the present invention.

Explanation of symbols on the main parts of the drawings

100: substrate 120: gate

130: transparent layer 130b: common line

140: insulating film 150: contact hole

160: active layer 180: etch stop layer

190: photoresist 200a, 200b: source / drain

220: pixel electrode 240: protective film

According to an aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, the method comprising: sequentially forming a transparent layer and an insulating film on an entire surface of a substrate including the gate after forming a gate on the substrate; Forming an etch stop layer on the active layer after forming an active layer on the insulating layer over the gate; Selectively removing the insulating layer and the transparent layer to form a contact hole and a common line; And sequentially forming a source / drain, a pixel electrode, and a protective film on the substrate.

Hereinafter, a method of manufacturing a liquid crystal display according to the present invention will be described in detail with reference to the accompanying drawings.

3A to 3D are cross-sectional views illustrating processes for manufacturing a liquid crystal display device according to the present invention.

In the method of manufacturing a liquid crystal display according to the present invention, as shown in FIG. 3A, a conductor having excellent electrical conductivity is first deposited on a substrate 100 formed of an insulating transparent body such as glass, and then selectively removed to form a gate. Form 120.

Subsequently, a transparent layer 130, for example, indium tin oxide (ITO) is deposited on the entire surface of the substrate 100 on which the gate 120 is formed, and then the insulating layer 140 is formed as an oxide on the entire surface of the transparent layer 130. To form.

Next, as shown in FIG. 3B, a semiconductor, for example, amorphous silicon is deposited on the insulating layer 140 corresponding to the gate 120, and then the amorphous silicon layer is selectively removed to form an active layer. To form 160. The active layer 160 is specifically formed of a double composite layer composed of at least a resistance layer and a channel layer. Subsequently, an etch stop layer 180 is formed on the top surface of the active layer 160 to prevent etching of the surface of the active layer 160 that may occur when forming the source / drain 200a and 200b to be described later.

3C and 3D, the oxide layer 140 and the transparent layer 130 are selectively removed by the first and second etching steps to form the contact hole 150 and the common line 130b.

Specifically, as shown in FIG. 3C, a photoresist is applied to a predetermined portion of the oxide film 140, that is, an upper surface of the oxide film 140 in a region where a common line 130b to be described later will be formed, and then the photoresist. Pattern to. The oxide layer 140 is selectively removed in the first etching step using the photoresist 190 patterned in a predetermined shape as a mask to form an insulating layer 140a of the thin film transistor forming region and an insulating layer of the common line 130b forming region, which will be described later. (140b).

The insulating layer 140a of the thin film transistor forming region serves as a gate insulating layer, and the other insulating layer 140b serves to insulate the common line 130b and the pixel electrode 220 which will be described later.

Next, the transparent layer 130 is selectively removed in the second etching step using the patterned insulating layer 140b as a mask to form the transparent layer 130a and the common line 130b on the thin film transistor forming region. In this case, when the width of the insulating layer 140b that serves as a mask required for forming the common line 130b is appropriately adjusted, the width of the common line 130b may also be adjusted. Then, the capacitance formed between the common line 130b and the pixel electrode 220 to be described later can be arbitrarily changed.

Meanwhile, as shown in FIG. 3D, the common line 130b formed of the contact hole 150 and the transparent layer is formed on the substrate 100 by the first photoresist process as shown in FIG. 3D. .

3E, a source / drain 200a and 200b and a pixel electrode 220 in contact with the source / drain 200a and 200b are formed on the active layer 160. . In the case of the pixel electrode 220, it is advantageous to form indium tin oxide (ITO), which is a transparent material, in view of the aperture ratio and the transmittance.

Subsequently, as illustrated in FIG. 3E, a passivation layer 240 is formed to apply the source / drain 200a and 200b and a portion of the pixel electrode 220.

Thereafter, a predetermined subsequent process is performed to complete the liquid crystal display device.

Various embodiments can be easily implemented as well as self-explanatory to those skilled in the art without departing from the principles and spirit of the present invention.

Accordingly, the claims appended hereto are not limited to those already described above, and the following claims are intended to cover all of the novel and patented matters inherent in the invention, and are also common in the art to which the invention pertains. Includes all features that are processed evenly by the knowledgeable.

As described above, the liquid crystal display according to the present invention has the following effects.

In the present invention, the transparent electrode without the opening ratio blocking is used as a common line, and the mask for forming the common line does not have a cost increase due to the addition of the mask by using a mask used for forming a conventional layer.

In addition, since the storage capacitance can be sufficiently secured without reducing the aperture ratio, it is possible to realize more improved image quality.

Claims (2)

After forming a gate on the substrate, sequentially forming a transparent layer and an insulating film on the entire surface of the substrate including the gate; Forming an etch stop layer on the active layer after forming an active layer on the insulating layer over the gate; Selectively removing the insulating layer and the transparent layer to form a contact hole and a common line; And And sequentially forming a source / drain, a pixel electrode, and a protective film on the substrate. The method of claim 1, Selectively removing the insulating layer and the transparent layer to form a contact hole and a common line, A first etching step of applying a photoresist on a portion of the insulating film, patterning the photoresist, and selectively removing the insulating film with the patterned photoresist mask; And And a second etching step of selectively removing the transparent layer using the selectively removed and remaining insulating film as a mask.