KR100876402B1 - LCD and its manufacturing method - Google Patents

Abstract

The present invention relates to a method of manufacturing a liquid crystal display device, the present invention comprising the steps of preparing a substrate; Forming a gate electrode on the substrate; Forming a first gate insulating film having a thickness of 3000 상 에 on the gate electrode; Forming a second gate insulating film having a thickness of 1000 상 에 on the first gate insulating film, and forming an active layer on the second insulating film; Forming a source electrode and a drain electrode on the active layer; Forming a protective film on the source electrode and the drain electrode; Forming a pixel electrode connected to the drain electrode on the passivation layer; Is achieved by.

Description

Liquid crystal display and its manufacturing method {LIQUID CRYSTAL DISPLAY AND FABRICATION METHOD THEREOF}

1 is a schematic view of a general liquid crystal display device.

2a to 2e is a process flowchart showing a method of manufacturing a conventional thin film transistor.

3 to 3E are process flowcharts showing a method of manufacturing a thin film transistor of the present invention.

4 is a schematic diagram schematically showing components of a CVD deposition apparatus.

*** Explanation of symbols for main parts of drawing ***

101: substrate 103a: first gate insulating film

103b: second gate insulating film 103: gate insulating film

104a: semiconductor layer 104b: ohmic contact layer

104: active layer 105a: source electrode

105b: drain electrode 106: color filter

107: liquid crystal 108: protective film

109: pixel electrode 111: contact hole

The present invention relates to a liquid crystal display device, and more particularly, to a method of manufacturing a liquid crystal display device that can shorten the process time of the liquid crystal display device.

The active matrix driving type liquid crystal display device displays a natural moving image using a thin film transistor as a switching element. Such a liquid crystal display device can be miniaturized compared to a CRT and commercialized as a monitor such as a portable television or a laptop (Lap-Top) type personal computer.

In general, as shown in FIG. 1, the liquid crystal display as described above is arranged such that the lower substrate 10 including the switching element 19 and the upper substrate 20 including the color filter 6 face each other. The liquid crystal layer 30 into which the liquid crystal 7 is injected is formed between the lower substrate 10 and the upper substrate 12.

The thin film transistor 19 disposed at each pixel on the lower substrate 10 to apply and block a signal voltage to the liquid crystal is formed on a glass substrate or a plastic substrate, and has a gate electrode 2 to which a scan signal is applied. An active layer 4 composed of a semiconductor layer 4a for transmitting a data signal in response to a signal, an n + doped ohmic contact layer 4b on both sides of the semiconductor layer 4a, and the active layer A gate insulating film 3 that electrically isolates the gate electrode 2 from the gate electrode 2, a source electrode 5a formed on the active layer 4 to apply a data signal, and a data signal to the pixel electrode. Phosphorus is composed of a drain electrode 5b and a protective film 8 that protects the source electrode 5a and the drain electrode 5b. The drain electrode 5b is connected to the pixel electrode 9 through the contact hole 11.

In addition, in the pixel region of each pixel except for the region where the thin film transistor 19 is formed, ITO applies a signal voltage applied through the thin film transistor 19 to the liquid crystal cell, and transparent ITO to transmit the backlight light incident from the backlight. A pixel electrode 9 formed of a material is formed.

When a gate signal having a high level is applied to the gate electrode 2a of the thin film transistor configured as described above, a channel through which electrons can move is formed in the active layer 5 so that the source electrode 5a may be formed. The data signal is transmitted to the drain electrode 5b via the active layer 5.

On the other hand, when a gate signal having a low level is applied to the gate electrode 2a, the channel formed in the active layer 5 is cut off and the transmission of the data signal to the drain electrode 5b is stopped.

Hereinafter, a manufacturing method of a thin film transistor configured as described above with reference to the drawings in detail.

2A to 2D illustrate a method of manufacturing a thin film transistor.
As shown in FIG. 2A, a metal material is first deposited on the lower substrate 10 by a sputtering method, and then a photoresist is applied thereon, followed by the photo-etching method. After exposure and development, the metal material is patterned to form the gate electrode 2 of the thin film transistor.

Next, as shown in FIG. 2B, an insulating material is entirely deposited on the lower substrate 10 on which the gate electrode 2 is formed to form a first gate insulating film 3a having a thickness of 2000 μs. After the transfer, a second gate insulating film 3b having a thickness of 2000 상 에 is formed on the first gate insulating film 3a. At this time, the reason why the gate insulating film is divided into the first and second gate insulating films without depositing 4000 Å continuously as described above is to suppress the growth of foreign matter during the growth of the gate insulating film as a single layer (4000 Å). Subsequently, a semiconductor layer 4a made of amorphous silicon (Si) and an ohmic contact layer 4b made of n + amorphous silicon doped with phosphorus (P) are successively deposited on the second gate insulating layer 3b. Patterning is performed to form the active layer 4 of the thin film transistor.

Next, as shown in FIG. 2C, a metal material is entirely deposited on the active layer 4 and the gate insulating film 3 and then patterned. In this case, the patterned metal material layer becomes the source electrode 5a and the drain electrode 5b of the thin film transistor.

Next, as shown in FIG. 2D, the protective film 8 is entirely formed on the gate insulating film 3 including the exposed semiconductor layer 4a and the source and drain electrodes 5b and the like, and then the protective film on the A contact hole 11 is formed in the portion 8 to expose a portion of the drain electrode 5b.

Next, as shown in FIG. 2E, an ITO material is entirely deposited on the protective film 8 by sputtering, and then patterned to form the pixel electrode 9. The pixel electrode 9 is electrically connected to the drain electrode 5b of the thin film transistor through the contact hole 11.

In order to deposit the first and second gate insulating layers and active layers, nine chemical vapor deposition (CVD) devices are currently used. In this case, three and second gate insulating layers and Five deposition apparatuses are allocated to deposit the active layer, and one apparatus for simultaneously depositing the first and second gate insulating layers and the active layer is allocated.

However, although the number of deposition equipment for depositing the second gate insulating film and the active layer is larger than the number of equipment allocated for depositing the first gate insulating film as described above, in the process line, the second gate is more than the time for depositing the first gate insulating film. The time required for depositing the insulating film and the active layer is about five times longer. Accordingly, after depositing the first gate insulating film, the time required to wait for the deposition of the second gate insulating film and the active layer is long, resulting in a problem of lowering productivity.

Accordingly, the present invention has been made to solve the above problems of the prior art, an object of the present invention is to reduce the waiting time to wait for the deposition of the gate insulating film and active layer liquid crystal display that can increase the production efficiency The present invention provides a method for manufacturing a device.

Other objects and features of the present invention will be described in detail in the configuration and claims of the following invention.

Method of manufacturing a liquid crystal display device for achieving the above object comprises the steps of preparing a substrate; Forming a gate electrode on the substrate; Forming a first gate insulating film having a thickness of 3000 상 에 on the gate electrode; Forming a second gate insulating film having a thickness of 1000 상 에 on the first gate insulating film, and forming an active layer on the second insulating film; Forming a source electrode and a drain electrode on the active layer; Forming a protective film on the source electrode and the drain electrode; Forming a pixel electrode connected to the drain electrode on the passivation layer; It is made, including.

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

3A to 3E are process flowcharts illustrating a method of manufacturing a liquid crystal display device according to the present invention.

First, as shown in FIG. 3A, a glass or plastic substrate 101 is prepared, a metal material is deposited on the substrate 101, and then patterned by photolithography using a photoresist to form a gate electrode of a thin film transistor. 102 is formed.

Next, as shown in FIG. 3B, an insulating material such as SiN or SiO is deposited on the upper surface of the gate electrode 102 and the substrate 101 by using a chemical vapor deposition (CVD) device to form a first gate having a thickness of about 3000 μs. An insulating film 103a is deposited.

At this time, the CVD (Chmical Vapor Deposition) equipment is used, as shown in Figure 4, A, B, C, D four deposition chamber 123, the substrate is waiting to enter the deposition chamber 123 Loader unit 121 and a heater unit 125 for raising the temperature in the deposition chamber 123. Three CVD units are used to deposit the first gate insulating layer 103a having a thickness of 3000 Å. The equipment is being used. Hereinafter, three CVD apparatuses for depositing the first gate insulating layer 103a are referred to as first deposition apparatus.

Next, as shown in FIG. 3C, after the cleaning process for removing the foreign matter on the first gate insulating film 103a formed in the first deposition equipment, the substrate on which the first gate insulating film 103a is formed is again replaced. After loading with other CVD equipment, the second gate insulating film is deposited on the upper surface of the first gate insulating film 103a with the same material as that of the first gate insulating film 103a to about 1000 Å thick, and then the second gate insulating film ( 103b) Successively deposit an amorphous silicon layer and an n + amorphous silicon layer having a thickness of 2000 에 on the entire upper surface. At this time, the number of allocated CVD equipment is five, hereinafter, five CVD equipment for depositing the second gate insulating film 103b and the active layer 104 is referred to as a second deposition equipment.

The conditions for forming the active layer including the gate insulating layer, the amorphous silicon layer, and the n + amorphous silicon layer are as follows.
Conventionally, the thickness of the first gate insulating film deposited in the first deposition equipment is about 2000 kPa, and the thicknesses of the second gate insulating film and the active layer deposited in the second deposition equipment are 2000 kPa, respectively. Since the time required for the deposition of the second gate insulating film and the active layer (2000Å + 2000Å) in the second deposition equipment is about 4 to 5 times longer than the time required for the deposition of (2000Å), the flow of logistics It did not go smoothly.
However, according to the present invention, the thickness of the first gate insulating film deposited in the first deposition equipment is deposited to be about 1000 mm thicker than that of the conventional film, and the second gate insulating film deposited in the second deposition equipment is deposited to be about 1000 mm thinner than that of the conventional deposition. After that, the waiting time for waiting for depositing the second gate insulating film and the active layer can be reduced.

That is, the first gate insulating film is deposited to have a thickness of 3000 μs to increase the time required to deposit the first gate insulating film in the first deposition equipment, and the second gate insulating film is deposited to have a thickness of 1000 μs to reduce the time required for the second deposition equipment. By reducing, the flow of logistics can be smoothly progressed.

As described above, the second gate insulating layer 103b and the active layer 104 are deposited, and then an amorphous silicon layer and an n + amorphous silicon layer are patterned on the second gate insulating layer 103b corresponding to the gate electrode 102. The active layer 104 is formed. The active layer 104 includes a semiconductor layer 104a made of patterned amorphous silicon (Si) and an ohmic contact layer 104b made of n + amorphous silicon doped with phosphorus (P).

Thereafter, a metal material is entirely deposited on the active layer 104, and then patterned by photolithography using a photoresist to expose a predetermined portion of the center portion of the semiconductor layer 104a to expose the source electrode 105a of the thin film transistor. And the drain electrode 105b.

Next, as shown in FIG. 3D, the passivation layer 108 is deposited on the entire upper surface of the source electrode 105a and the drain electrode 105b including the exposed semiconductor layer 104a, and then the passivation layer 108 is formed. The contact hole 111 is formed so that a portion of the drain electrode 105b is exposed at the ()) portion.

3E, an ITO material is deposited on the upper surface of the passivation layer 108 by sputtering, and then patterned to form a pixel electrode 109. The pixel electrode 109 is electrically connected to the drain electrode 105b of the thin film transistor through the contact hole 111.

As shown in FIG. 3E, the liquid crystal display of the present invention manufactured through the above process includes: a gate electrode 102 formed on a glass substrate or a plastic substrate and to which a scan signal is applied; An active layer (104) comprising a semiconductor layer (104a) for transmitting a data signal corresponding to the scan signal and an n + doped ohmic contact layer (104b) on both sides of the semiconductor layer (104a); A first gate insulating film 103a electrically insulating the active layer 104 and the gate electrode 102 and having a thickness of about 3000 GPa and a second gate insulating film having a thickness of about 1000 GPa on the first gate insulating film 103a. A gate insulating film 103 made of 103b; A source electrode 105a formed on the active layer 104 to apply a data signal; A drain electrode 5b for applying a data signal to the pixel electrode; The passivation layer 108 protects the source electrode 105a and the drain electrode 105b, and the drain electrode 105b is connected to the pixel electrode 109 through the contact hole 111.

In addition, the pixel region of each pixel except for the region where the thin film transistor (not shown) is formed is applied a signal voltage applied through the thin film transistor (not shown) to the liquid crystal cell, and the backlight light incident from the backlight (not shown) is applied. The pixel electrode 109 formed of a transparent ITO material is formed so as to be transparent.

When a gate signal having a high level is applied to the gate electrode 102 of the thin film transistor fabricated as described above, a channel through which electrons can move is formed in the active layer 104 so that the source electrode 105a is formed. Is transmitted to the drain electrode 105b via the active layer 104.

On the other hand, when a gate signal having a low level is applied to the gate electrode 102, the channel formed in the active layer 104 is cut off and the transmission of the data signal to the drain electrode 105b is stopped.

In addition, as described above, in the present invention, in forming the gate insulating film, the time required for the first deposition equipment and the second deposition equipment are corrected by correcting the deposition time for depositing the first gate insulating film and the second gate insulating film. The time difference can be reduced by about three times.

As described above, in the method of manufacturing the liquid crystal display device according to the present invention, the thickness of the first gate insulating film is deposited to be about 1000 mm thicker than that of the conventional film, and the second gate insulating film is deposited to be about 1000 mm thinner than the conventional film. By reducing the waiting time to wait for depositing the gate insulating film and the active layer, there is an effect that can increase the production efficiency.

Claims (10)

Preparing a substrate; Forming a gate electrode on the substrate; Forming a first gate insulating film having a thickness of 3000 상 에 on the gate electrode; Forming a second gate insulating film having a thickness of 1000 상 에 on the first gate insulating film, and forming an active layer on the second insulating film; Forming a source electrode and a drain electrode on the active layer; Forming a protective film on the source electrode and the drain electrode; And Forming a pixel electrode connected to the drain electrode on the passivation layer; Method of manufacturing a liquid crystal display device comprising a. The method of claim 1, further comprising cleaning the first gate insulating layer after depositing the first gate insulating layer. The method of claim 1, wherein the second gate insulating layer and the active layer are formed in the same deposition apparatus. The method of claim 1, wherein the active layer is formed by successively depositing amorphous silicon and n + doped amorphous silicon and then patterning the silicon. 8. The deposition apparatus of claim 1, wherein eight deposition apparatuses are used for depositing the first gate insulating layer, the second gate insulating layer / active layer, and the protective layer, and among them, the first gate insulating layer, the second gate insulating layer / active layer, and the protective layer. The equipment allocated to deposit the bay is 1, 3, and 2, respectively, one of the other two deposition equipments is the deposition of the first gate insulating film and the second gate insulating film, and the other one is the second gate insulating film / active A method of manufacturing a liquid crystal display device, characterized by using both a layer and a protective film for deposition. A gate electrode formed on the substrate; A first gate insulating layer formed over the gate electrode and the upper surface of the substrate and having a thickness of 3000 Å; A second gate insulating film formed on the first gate insulating film and having a thickness of 1000 占 퐉; An active layer formed on a second gate insulating layer corresponding to an upper portion of the second gate insulating layer; Source and drain electrodes formed on the active layer and spaced apart from each other; A protective film formed on the source electrode and the drain electrode and exposing the drain electrode; And A pixel electrode formed on the passivation layer and electrically connected to the exposed drain electrode; Liquid crystal display device comprising a. delete delete delete delete

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