KR0179267B1 - Manufacturing method of liquid crystal display device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a method of manufacturing a liquid crystal display device in which a stress is reduced to improve the reliability of the liquid crystal display device.

The method of manufacturing the liquid crystal display device of the present invention comprises the steps of forming a gate line having a gate electrode and a pad on a substrate, and then sequentially forming a gate insulating film, a semiconductor layer, and a high concentration n-type semiconductor layer on the entire surface of the substrate including the gate line. Depositing, selectively removing the gate insulating film, the semiconductor layer, and the high concentration n-type semiconductor layer of the pad portion, and forming data lines, source / drain electrodes, and pad electrodes on each portion of the high concentration n-type semiconductor layer. Patterning the high concentration n-type semiconductor layer and the semiconductor layer to have a wider width than the source / drain electrode, and forming a passivation layer on an entire surface of the substrate on which the data line and the source / drain electrode are formed, and forming the pad electrode. And forming a contact hole to expose the drain electrode and the drain hole through the contact hole. De comprises the step of forming a transparent electrode that is connected to the electrode and a drain electrode.

Description

Manufacturing Method of Liquid Crystal Display

1 (a) to 1 (b) are explanatory diagrams of stress characteristics when chromium is generally deposited on a glass substrate.

2A to 2B are explanatory diagrams of stress characteristics when amorphous silicon is generally deposited on a glass substrate.

3 is an explanatory diagram of a thin film transistor and a pixel electrode array of a general liquid crystal display.

4 is a layout view of a thin film transistor of a general liquid crystal display.

5A to 5E are process cross-sectional views of a conventional liquid crystal display device.

6 (a) to 6 (f) are process cross-sectional views of the liquid crystal display device of the present invention.

* Explanation of symbols for main parts of the drawings

1 glass substrate 4 gate electrode

5 pad 6 gate insulating film

7: amorphous silicon layer 8: high concentration n-type amorphous silicon layer

9a: pad electrode 9b: data line

9c: source / drain electrode 10: protective film

11: transparent electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device and a method of manufacturing the same, which are suitable for minimizing the stress of a substrate and improving the reliability of the liquid crystal display device.

In general, a liquid crystal display device includes a lower substrate on which a thin film transistor and a pixel electrode are arranged, an upper substrate on which a color filter and a common electrode are formed to display color, and a liquid crystal filled between the two substrates. do.

Here, a glass or quartz is used a lot as a board | substrate.

While quartz substrates are easy to process at high temperatures, they are difficult to make large areas into displays and are expensive.

On the other hand, glass substrates are relatively inexpensive, but cannot be subjected to a high temperature process and have a disadvantage in that reliability is lowered because they are affected by stress a lot.

In other words, when the chromium (Cr) film is deposited on the glass substrate, the stress when the amorphous silicon is deposited is different.

1 is an explanatory diagram of stress characteristics when chromium is deposited on a glass substrate, and FIG. 2 is an explanatory diagram of stress characteristics when amorphous silicon is deposited on a glass substrate.

As shown in FIG. 1 (a), when the chromium film 2 is deposited on the glass substrate 1, the glass substrate 1 is bent upward as shown in FIG. do.

When the amorphous silicon 3 is deposited on the glass substrate 1 as shown in FIG. 2A, the glass substrate 1 is bent downward as shown in FIG. 2B.

Therefore, when the data line is formed of chromium in the liquid crystal display, the glass substrate is bent due to tension as shown in FIG. 1 while the glass substrate has a property of returning to its original shape, so that the weak part of the data line is open. It happens.

Hereinafter, a conventional liquid crystal display will be described with reference to the accompanying drawings.

3 is an explanatory view of a thin film transistor and a pixel electrode array of a general liquid crystal display device, and FIG. 4 is a layout view of a thin film transistor of a general liquid crystal display device, and FIGS. 5A to 5E are conventional liquid crystal display devices. Process cross section of

In general, as shown in FIG. 3, a lower display panel includes an active display area in which a thin film transistor and a pixel electrode are arranged, and a gate line pad for applying a driving signal to the thin film transistor gate electrode of the active display area. The gate pad portion is divided into a data line pad portion for applying a data signal to a source electrode of the thin film transistor.

As described above, the thin film transistor and the pixel electrode of the formed active display region are shown in FIG. 4.

That is, the thin film transistor is connected to the pixel electrode (ITO Pixel) so that the drain electrode is connected to the pixel electrode with the gate line as the gate electrode and the data line as the source electrode at the portion where the gate line and the data line intersect. Is formed.

Here, amorphous silicon is used as an active region of the thin film transistor, and is formed between the gate electrode and the source / drain electrode, and is formed wider than the width of the data line under the data line.

In the conventional manufacturing method of the liquid crystal display device having such a structure, as shown in FIG. 5 (a), a metal such as aluminum (Al) is deposited on the glass substrate 1 and selectively etched to form a gate electrode 4 and a pad. A gate line having (5) is formed.

As shown in FIG. 5B, a gate insulating film 6 (silicon nitride film), an amorphous silicon layer 7, and a high concentration n-type amorphous silicon layer 8 are sequentially placed on the entire surface of the glass substrate 1 including the gate line. Deposit.

As shown in FIG. 5 (c), the amorphous silicon layer 7 and the highly concentrated n-type amorphous silicon layer 8 are selectively removed to remain only in the active region and the data line forming region of the thin film transistor, and the gate of the pad 5 portion is removed. The insulating film 6 is selectively removed.

As shown in FIG. 5 (d), a chromium (Cr) film 9 is deposited on the entire surface, and the high concentration n-type amorphous silicon layer 8 of the pad and data line forming region and the amorphous silicon layer 7 of the active region are formed. And the source / drain electrodes of the data line and the thin film transistor are selectively removed so as to remain only on both sides of the high concentration n-type amorphous silicon layer 8.

The exposed high concentration n-type amorphous silicon layer 8 is removed using the chromium film of the source / drain electrode as a mask.

Although not shown in the drawing, the data line and the source electrode are integrally formed.

As shown in FIG. 5E, the protective film 10 is formed on the entire surface of the substrate on which the chromium film 9 is formed, and the protective film 10 on the pad 5 and the drain electrode chromium film 9 is selectively removed. To form contact holes.

A transparent conductive film is deposited on the entire surface, and selectively etched to remain only in the pad region and the pixel region to form the transparent electrode 11.

Here, the transparent electrode 11 of the pixel region is electrically connected to the chromium film 9 of the drain electrode.

However, such a conventional liquid crystal display device has the following problems.

When the chromium film is deposited, the chromium film is deposited while the amorphous silicon layer and the high concentration n-type amorphous silicon layer are left only in the active region and the data line forming region, and the remaining portions are removed, and thus the glass substrate is bent under tension. Since the data line is opened due to the property to be restored to its original state, the reliability of the liquid crystal display is degraded.

The present invention has been made to solve the above problems, and the object of the present invention is to prevent the opening of a data line by minimizing the tension during chromium film deposition.

According to an aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, the method including: forming a gate line including a gate electrode and a pad on a substrate; Depositing a semiconductor semiconductor layer in sequence, selectively removing a gate insulating film, a semiconductor layer, and a high concentration n-type semiconductor layer of the pad portion, a data line, a source / drain electrode at each portion of the high concentration n-type semiconductor layer, and Forming a pad electrode, patterning the high concentration n-type semiconductor layer and the semiconductor layer to have a wider width than the source / drain electrode, and forming a passivation layer on an entire surface of the substrate on which the data line and the source / drain electrode are formed And forming a contact hole so that the pad electrode and the drain electrode are exposed. Through a contact hole characterized by comprising a step of forming a transparent electrode connected with the pad electrode and the drain electrode.

The manufacturing method of the liquid crystal display device according to the present invention as described above will be described with reference to the accompanying drawings.

6 (a) to 6 (f) are cross-sectional views for explaining the manufacturing method of the liquid crystal display device of the present invention.

First, the structure of the liquid crystal display of the present invention is the same as FIG. 3 and FIG.

In the method of manufacturing the liquid crystal display of the present invention, as shown in FIG. 6 (a), a metal such as aluminum (Al) is deposited on the glass substrate 1, and selectively etched to form the gate electrode 4 and the pad 5. To form a gate line having a.

As shown in FIG. 6B, a gate insulating film 6 (silicon nitride film), an amorphous silicon layer 7, and a high concentration n-type amorphous silicon layer 8 are sequentially placed on the entire surface of the glass substrate 1 including the gate line. Deposit.

As shown in FIG. 6C, the gate insulating film 6 of the pad 5 portion, the amorphous silicon layer 7, and the high concentration n-type amorphous silicon layer 8 are sequentially deposited.

As shown in FIG. 6C, the gate insulating film 6, the amorphous silicon layer 7, and the high concentration n-type amorphous silicon layer 8 in the pad 5 are selectively removed.

As shown in FIG. 6 (d), a chromium (Cr) film is deposited on the entire surface, and selectively removed so as to remain only in the pad 5 region, the data line forming region, and the source / drain region. 9b), the source / drain electrodes 9c of the thin film transistor are formed.

As shown in FIG. 6E, the high concentration n-type amorphous silicon layer 8 and the amorphous silicon layer 7 are patterned using photolithography so as to remain wider than the source / drain electrodes of the thin film transistor. .

At this time, the high concentration n-type amorphous silicon layer 8 corresponding to the channel region of the thin film transistor in the active region is also removed.

Although not shown in the drawing, the data line and the source electrode are integrally formed, and the high concentration n-type amorphous silicon layer 8 and the amorphous silicon layer 7 below the data line are wider than the width of the data line.

As shown in FIG. 6 (f), the passivation layer 10 is formed on the entire surface of the substrate on which the data line 9b and the source / drain electrode 9c are formed, and the passivation layer 10 on the pad portion and the drain electrode is selectively etched. Thus, the transparent electrode 11 is formed.

A transparent conductive film is deposited on the entire surface, and selectively etched to remain only in the pad region and the pixel region to form a transparent electrode.

Here, the transparent electrode 11 of the pixel region is electrically connected to the drain electrode 9c.

As described above, the manufacturing method of the liquid crystal display device of the present invention has the following effects.

That is, in the method of manufacturing a liquid crystal display of the present invention, a chromium film is deposited in a state in which amorphous silicon is deposited on the entire glass substrate during chromium film deposition to form data lines and source / drain electrodes.

Therefore, because amorphous silicon is deposited on the glass substrate, the glass substrate is bent downwards, and since the chromium film is deposited in that state, a compensation effect occurs, so that even when the glass substrate is tensioned, data lines are much less open, so the reliability of the device is increased. Is improved.

Claims (3)

Forming a gate line having a gate electrode and a pad on the substrate, sequentially depositing a gate insulating film, a semiconductor layer, and a high concentration n-type semiconductor layer on the entire surface of the substrate including the gate line; Selectively removing the layer and the high concentration n-type semiconductor layer, forming a data line, a source / drain electrode and a pad electrode at each portion of the high concentration n-type semiconductor layer, the wider width than the source / drain electrode Patterning the high-concentration n-type semiconductor layer and the semiconductor layer to form a passivation layer, and forming a protective film on an entire surface of the substrate on which the data line and the source / drain electrodes are formed, and forming contact holes to expose the pad electrode and the drain electrode. A transparent electrode connected to the pad electrode and the drain electrode through the contact hole Method for manufacturing a liquid crystal display device, characterized by comprising the yirueojim sex. The method of claim 1, wherein the semiconductor layer and the high concentration n-type semiconductor layer are patterned to have a width wider than the data line below the data line. The method of claim 1, wherein the semiconductor layer and the high concentration n-type semiconductor layer are amorphous silicon.