JPH10133230A - Manufacturing method of liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to connect first short-circuit ring wirings without complicating production stages by laminating and forming the first short-circuit ring wirings and insulating films, forming semiconductor films on these insulating films and connecting second shorting ring wirings after the insulating films are etched away. SOLUTION: Scanning signal wirings 2 are formed on a substrate 1 (a) and the first insulating films 3 are formed on these scanning signal wirings 2 (b). Metallic foil 4 consisting of SUS, etc., is then stuck onto the first insulating films 3 (c). Second insulating films 5, the first semiconductor films 6 and the second semiconductor films 7 are thereafter successively laminated and formed (d). The second insulating films 5 and the first insulating films 3 are etched away with the semiconductor films 6, 7 as a mask (e). Image signal wirings 8 are then formed from the second semiconductor film 7 parts to the scanning signal wiring 2 parts (f). The patterning of the insulating films is made possible even if resist films are not specifically formed. The easy connection of the first shorting ring wirings and the second shorting ring wirings is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of manufacturing a liquid crystal display device, and more particularly to a method of manufacturing an active matrix type liquid crystal display device using a panel in which a thin film transistor is formed in each pixel (hereinafter referred to as a TFT array panel).

[0002]

2. Description of the Related Art An active matrix type liquid crystal display has a higher contrast than a simple matrix type.
Because of its excellent multi-gradation display characteristics, it is an indispensable technology for color liquid crystal display devices. In particular, an active matrix type liquid crystal display device using a thin film transistor as a switching element can obtain image quality equivalent to that of a CRT.

Hereinafter, a conventional liquid crystal display device and a method of manufacturing the same will be described with reference to the drawings.

FIG. 2 is an equivalent circuit diagram of a TFT array panel in a liquid crystal display device manufactured by a conventional method, and FIG.
A plan view of one pixel of a TFT array panel in a liquid crystal display device manufactured by a conventional method, and FIG. 4 is a cross-sectional view taken along line AA ′ of FIG.

In the active matrix type liquid crystal display device, the thin film transistor 12 is switched by the scanning signal supplied from the scanning signal line 11, and the signal voltage of the image signal line 13 is applied to the pixel electrode 14 connected to the drain electrode 13b. By doing so, an image is displayed by applying a voltage to a liquid crystal material (not shown) sealed between the pixel electrode 14 and a counter electrode (not shown).

As shown in FIGS. 3 and 4, this conventional liquid crystal display device has an image signal wiring 13 and a scanning signal wiring 1.
Are provided so as to intersect with each other with an insulating film 15 interposed therebetween.
4, a gate electrode 11a for supplying an image signal to the pixel electrode 14, an insulating film 15, a semiconductor film 16, and a source electrode 13.
a and a drain electrode 13b, and an additional capacitor 1 for holding this image signal voltage.
7 are provided in a matrix. That is, the supply of the image signal to the pixel electrode 14 is controlled by the thin film transistor 12.

Here, the pixel electrode 14, the drain electrode 13b of the thin film transistor 12, and the additional capacitance electrode 18
Are contact holes 15a formed in the insulating film 15,
15b.

In such a liquid crystal display device, strong static electricity is charged to the TFT array panel during an assembling process or the like, and the gate electrode 11 and the source electrode 13 of the thin film transistor 12 or the scanning signal wiring 11 and the image signal wiring 13
And a high voltage due to static electricity was applied between them, causing dielectric breakdown of the insulating film 15.

Therefore, in the conventional liquid crystal display device, FIG.
As shown in FIG. 3, a first short-circuit ring 19 to which the scanning signal line 11 is connected and a second short-circuit ring 20 to which the image signal line 13 is connected are provided outside the display area X. The short-circuit wire 19 and the second short-circuit wire 20 are connected, and the gate electrode 11a and the source electrode 13 of the thin film transistor 12 are connected.
a and between the scanning signal wiring 11 and the image signal wiring 13 are kept at the same potential. The first short-circuit ring wiring 19 and the second short-circuit ring wiring 20 are, as shown in FIG.
The connection is made via a contact hole 15c formed in the insulating film 15.

[0010]

However, in this conventional method for manufacturing a liquid crystal display device, although the first short-circuit ring wiring 19 and the second short-circuit ring wiring 20 are connected via the contact hole 15c, Immediately before forming the second short-circuit ring wiring 20 on the first short-circuit ring wiring 19, the contact hole 15c must be formed in the insulating film 15 by photolithography using a resist film. Is complicated.

The present invention has been made in view of such problems of the prior art, and provides a method of manufacturing a liquid crystal display device which can connect the first short-circuit ring wiring without complicating the manufacturing process. The purpose is to do.

[0012]

According to a first aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, wherein a plurality of image signal wirings and a plurality of scanning signal wirings intersect via an insulating film. A pixel electrode and a switching element for supplying an image signal to the pixel electrode are formed in a matrix at an intersection of the image signal wiring and the scanning signal wiring, and the pixel electrode is opposed to the pixel electrode. In a method of manufacturing a liquid crystal display device in which a liquid crystal material is sealed between a provided counter electrode, a first short-circuit ring wire to which the plurality of scan signal wires are connected and the insulating film are stacked and formed. A semiconductor film of the switching element was formed on the insulating film so that a part of the insulating film was exposed, and after the insulating film was removed by etching using the semiconductor film as a mask, the semiconductor film was connected to the plurality of image signal lines. No. The short-circuit ring line formed by connecting the first short-circuit ring line.

According to a second aspect of the present invention, in the method of manufacturing a liquid crystal display device, the second short-circuit ring wiring to which the plurality of image signal wirings are connected and the insulating film are laminated. Forming a semiconductor film of the switching element on the insulating film so that the portion is exposed, etching the insulating film using the semiconductor film as a mask, and then removing the first short circuit connected to the plurality of scanning signal lines. The ring wiring is formed by connecting to the second short-circuit ring wiring.

[0014]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the method of manufacturing a liquid crystal display device according to the present invention, a liquid crystal display device having a structure as shown in FIG. 2 is finally manufactured.

FIG. 1 is a process chart showing one embodiment of the liquid crystal display device according to the present invention. First, a scanning signal line 2 is formed on a substrate 1 as shown in FIG. The scanning signal wiring 2 is made of chromium (Cr), tantalum (Ta), aluminum (Al), titanium (Ti), or the like.
It is formed to a thickness of about 500 to 3000 ° by a vacuum evaporation method, an electron beam evaporation method, a sputtering method, or the like. The scanning signal wiring 2 is the same as a gate electrode (not shown) of a thin film transistor forming a switching element.
It is patterned simultaneously with the gate electrode.

Next, as shown in FIG. 1B, a first insulating film 3 is formed on the scanning signal wiring 2. The first insulating film 3 is made of, for example, a silicon dioxide (SiO ₂ ) film or the like.
It is formed to a thickness of about 0 °. The first insulating film 3 forms a part of the gate insulating film of the thin film transistor.

Next, a metal foil 4 made of SUS or the like is attached on the first insulating film 3, and a second insulating film 5, a first semiconductor film 6, and a second semiconductor film 7 are sequentially formed. I do.

The second insulating film 5 is made of, for example, a silicon nitride film and has a thickness of 500 to 3 by a plasma CVD method or the like.
It is formed to a thickness of about 000 mm. This second insulating film 5
Also constitute a part of the gate insulating film of the thin film transistor.

The first semiconductor film 6 is formed of an amorphous silicon film or the like, and has a thickness of 10 by a plasma CVD method or the like.
It is formed at about 00-3000 °. This first semiconductor film 6 functions as a channel of the thin film transistor.

The second semiconductor film 7 is made of an amorphous silicon film or the like containing a high concentration of n-type semiconductor impurities, and is formed to a thickness of about 500 ° by a plasma CVD method or the like. This second semiconductor film 7 functions as an ohmic contact layer of the thin film transistor.

Next, as shown in FIG. 1E, the second insulating film 5 and the first insulating film 3 are formed using the semiconductor films 6 and 7 as a mask.
Is removed by etching. This etching is, for example, 7:
1 with a buffered hydrofluoric acid solution or the like. In the buffered hydrofluoric acid solution, the first semiconductor film 6 and the second semiconductor film 7 made of silicon are not etched, but the first insulating film 3 made of silicon dioxide is etched. Therefore, the semiconductor film 6,
The first insulating film 3 can be etched using the mask 7 as a mask.

Next, an image signal wiring 8 is formed from the second semiconductor film 7 to the scanning signal wiring 2. This image signal wiring 8 is made of chromium (Cr), titanium (Ti),
It is made of aluminum (Al), molybdenum (Mo), or the like, and is formed to a thickness of about 2000 mm by a vacuum evaporation method, an electron beam evaporation method, a sputtering method, or the like. The image signal wiring 8 forms a part of the source / drain electrode of the thin film transistor. Note that a transparent electrode such as ITO (indium tin oxide) may be interposed below the source / drain electrodes. Such a transparent electrode,
Used as a pixel electrode (not shown).

In the liquid crystal display device of the first aspect, an inverted staggered switching element in which a gate electrode is located below a source / drain electrode is used.
A staggered switching element in which the drain electrode is located above the gate electrode may be used. This is the liquid crystal display device according to the second aspect.

[0024]

As described above, according to the method of manufacturing a liquid crystal display device according to the first aspect, the first short-circuit ring wiring to which a plurality of scanning signal wirings are connected and the insulating film are laminated. ,
A semiconductor film of the switching element was formed on the insulating film so that a part of the insulating film was exposed, and after the insulating film was removed by etching using the semiconductor film as a mask, the semiconductor film was connected to a plurality of image signal lines. Since the second short-circuit ring is formed by connecting to the first short-circuit ring, the insulating film can be patterned without forming a resist film,
Thus, the first short-circuit ring to which the scanning signal wiring is connected and the second short-circuit ring to which the image signal wiring is connected can be connected very easily.

In the method of manufacturing a liquid crystal display device according to a second aspect of the present invention, the insulating film is formed by laminating a second short-circuit ring wire to which a plurality of image signal wires are connected, and a part of the insulating film. Forming a semiconductor film of the switching element on the insulating film such that the first short-circuit ring wiring connected to the plurality of scanning signal wirings after etching the insulating film using the semiconductor film as a mask; Is connected to the second short-circuit ring wiring, the same effects as those of the method for manufacturing a liquid crystal display device according to claim 1 can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing steps of a method for manufacturing a liquid crystal display device according to the present invention.

FIG. 2 is a diagram illustrating a configuration of a conventional liquid crystal display device.

FIG. 3 is a plan view of one pixel portion of a conventional liquid crystal display device.

FIG. 4 is a sectional view taken along line A-A ′ of FIG. 3;

FIG. 5 is a cross-sectional view illustrating a connection portion between a first short-circuit ring and a second short-circuit ring in a conventional liquid crystal display device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Scan signal wiring, 3 ... First insulating film, 4 ... Metal mask, 5 ... Second insulating film, 6 ... Semiconductor film, 7 ..Omic contact layers, 8 ... Image signal wiring

Claims (2)

[Claims] A plurality of image signal wirings and a plurality of scanning signal wirings are formed to intersect with an insulating film interposed therebetween, and a pixel electrode is formed at an intersection between the image signal wirings and the scanning signal wirings, and an image is formed on the pixel electrode. A switching element for supplying a signal is formed in a matrix, and a liquid crystal display device is encapsulated with a liquid crystal material between the pixel electrode and a counter electrode provided to face the pixel electrode. A first short-circuit ring wiring to which a scanning signal wiring is connected and the insulating film are stacked and formed, and a semiconductor film of the switching element is formed on the insulating film so that a part of the insulating film is exposed; After the insulating film is removed by etching using the semiconductor film as a mask, a second short-circuit ring connected to the plurality of image signal lines is connected to the first short-circuit ring to form. Liquid crystal display Production method. A plurality of image signal lines and a plurality of scanning signal lines intersecting each other with an insulating film interposed therebetween, and a pixel electrode at an intersection between the image signal line and the scanning signal line; A switching element for supplying a signal is formed in a matrix, and a liquid crystal display device is encapsulated with a liquid crystal material between the pixel electrode and a counter electrode provided to face the pixel electrode. A second short-circuit ring wiring to which the image signal wiring is connected and the insulating film are laminated and formed, and a semiconductor film of the switching element is formed on the insulating film so that a part of the insulating film is exposed, After the insulating film is removed by etching using the semiconductor film as a mask, a first short-circuit ring connected to the plurality of scanning signal lines is connected to the second short-circuit ring to form. Liquid crystal display Production method.