JP2003241221A - Liquid crystal display device and method of manufacturing the same - Google Patents

Abstract

(57) Abstract: An object of the present invention is to suppress an increase in line defect defects even when a thin film transistor receives a peeling charge before completion of an array portion. The method of manufacturing a liquid crystal display device includes a step of preparing an insulating transparent substrate, and a step of:
A step of arranging the short ring pattern 14 made of a conductor and the scanning signal supply wiring 2 connected to the short ring pattern at the connection portion 18;
A step of arranging a plurality of pixel electrodes 7 and switching elements 4 corresponding to the pixel electrodes on a matrix, a step of arranging a video signal supply wiring 5 connected to the switching elements, a short ring pattern and a scanning signal supply wiring Forming an opening pattern 17 that opens a connection portion connecting the first and second connection portions; and etching and removing the connection portion through the opening pattern to separate each scanning signal supply line from the short ring pattern. including.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active matrix type liquid crystal display device.

[0002]

2. Description of the Related Art A display device to which liquid crystal is applied has low power consumption, light weight, and features not found in conventional displays. In particular, an active matrix type liquid crystal display device using a thin film transistor (hereinafter, abbreviated as TFT) having a switching element for each pixel can display a clear image with less crosstalk, and is therefore a display for a notebook computer or car navigation system. It is used for etc. Furthermore, in recent years, it has been rapidly used as a large display monitor.

An example of a conventional active matrix type liquid crystal display device will be described below with reference to FIGS. As shown in the plan view of FIG. 5, this liquid crystal display device includes thin film transistors (TFTs) arranged in a matrix on a glass substrate 51. Further, the scanning signal supply wirings 52 extending left and right and the video supply wirings 55 extending vertically are arranged in a grid pattern, and thin film transistors are arranged in a matrix in the vicinity of intersections thereof. Further, pixel electrodes 57 connected to the drain electrodes 59 of the thin film transistors are arranged in a matrix. The scanning signal supply wiring 52 also serves as a gate electrode of a thin film transistor (TFT) and supplies a scanning signal to the gate electrode. The video signal supply wiring 55 also serves as a source electrode connected to the amorphous silicon semiconductor film 54 of the TFT, and supplies a video signal to the pixel electrode 57 via the drain electrode 59.

Next, the laminated structure of the liquid crystal display device will be described. First, the scanning signal supply wiring 52 is formed on the transparent glass substrate 51, and the first insulator layer 53 which also serves as the gate insulating film of the TFT is laminated thereon. An amorphous silicon semiconductor film 54 forming a channel region of a thin film transistor (TFT) is formed on the gate insulating film. On the other hand, a second insulating film 56, which also functions as a passivation insulating film 56 as a protective film, is formed to cover the first insulating film 53.
A contact hole 58 is opened in the second insulating film 56. The drain electrode 59 and the pixel electrode 57 are connected via the contact hole 58. Further, the mounting terminal 60 of the scanning signal supply wiring 52 has a contact hole 62 formed in the first insulator layer 53 and the second insulator layer 56.
It is connected to the scanning signal supply wiring 52 via. Further, the video signal supply wiring 61 is connected through a contact hole 66 formed in the second insulator layer 56. Further, the pixel electrode 57, the scanning signal supply wiring 52, and the video signal supply wiring are surrounded by a short ring pattern 64.

The method of manufacturing the liquid crystal display device generally comprises the following steps. (A) A step of patterning by selectively etching the scanning signal supply wiring 52. (B) A step of patterning by selectively etching the semiconductor layer. (C) A step of patterning by selectively etching the video signal supply wiring. (D) A step of selectively etching the first insulating layer 53 and the second insulating layer 56 to perform opening patterning. (E) A step of patterning by selectively etching the pixel electrode 57. Then, the array portion and the color filter portion are overlapped with each other to complete the liquid crystal display device.

The short ring pattern 64 is provided to prevent the switching elements from being damaged by static electricity after the array portion is completed and before the array portion and the color filter portion are bonded together. After the array portion is completed, the short ring pattern 64 is connected to the scanning signal supply wiring 52 and the video signal supply wiring 55 through the connecting portion 65 and the contact hole 66 as shown in the partial sectional view of FIG.

[0007]

However, in the structure and manufacturing method of the conventional liquid crystal display device as described above, the connection to the short ring pattern 64 is performed after the array portion is completed, that is, after the step (e). It is formed. For this reason, peeling charging or the like occurs in the middle of the array portion, that is, from the step (b) of selectively etching and patterning the semiconductor layer to the step (e) of depositing the thin film of the pixel electrode 57. In some cases, some scanning signal supply wirings 52
In some cases, the electrical characteristics of the switching element may change along the line, resulting in an increase in line defect defects.

Therefore, an object of the present invention is to suppress an increase in line defect defects even when peeling electrification is performed until the array portion is completed.

[0009]

A method of manufacturing a liquid crystal display device according to the present invention comprises a step of preparing an insulating transparent substrate, a short ring pattern made of a conductor on the insulating transparent substrate, Arranging a short ring pattern and a scanning signal supply wiring connected at a connection portion, and arranging a plurality of pixel electrodes and switching elements corresponding to the pixel electrodes on a matrix on the insulating transparent substrate. A step of arranging a video signal supply wiring connected to the switching element, a step of forming an opening pattern for opening the connection portion connecting the short ring pattern and the scanning signal supply wiring, and the opening pattern A step of etching and removing the connection part through the via to separate the respective scanning signal supply wirings from the short ring pattern. Characterized in that it comprises a.

The liquid crystal display device according to the present invention includes an insulating transparent substrate, a short ring pattern made of a conductor formed on the insulating transparent substrate, and the short ring pattern on the insulating transparent substrate. Inside surrounded by
A plurality of pixel electrodes arranged in a matrix, a plurality of switching elements corresponding to the pixel electrodes, a plurality of scanning signal supply wirings for supplying a scanning signal to the plurality of switching elements, and a drain electrode for the plurality of pixel electrodes. And a plurality of video signal supply wirings for supplying a video signal via
Each of the scan signal supply wirings may be separated from the short ring pattern by an opening pattern between the scan signal supply wiring and the short ring pattern.

As described above, in this method of manufacturing a liquid crystal display device, the scanning signal supply wirings 2 are all connected in the same layer as the short ring pattern 14 until the array portion is completed. As a result, even if peeling electrification occurs during the process, the short ring pattern 14
Can be protected by. That is, even when peeling electrification occurs, all the scanning signal supply wirings 2 are connected to the short ring pattern 14, so that only some of the scanning signal supply wirings 2 are changed in the electrical characteristics of the switching element. Therefore, it is possible to suppress an increase in line defect defects in the liquid crystal display device.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A liquid crystal display device according to an embodiment of the present invention will be described with reference to the accompanying drawings. The substantially same members are designated by the same reference numerals.

(Embodiment 1) A liquid crystal display device according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 to 4. This liquid crystal display device is an active matrix liquid crystal display device, and as shown in the plan view of FIG. 1, a scanning signal supply wiring 2 extending left and right on a glass substrate 1,
The image supply wirings 5 extending vertically are arranged in a grid pattern,
Thin film transistors (TFTs) are arranged in a matrix near the intersections. Further, pixel electrodes 7 connected to the drain electrodes 9 of the thin film transistors are arranged in a matrix. The scanning signal supply wiring 2 also serves as a gate electrode of a thin film transistor (TFT) and supplies a scanning signal to the gate electrode. The video signal supply wiring 5 also serves as a source electrode connected to the amorphous silicon semiconductor film 4 of the TFT, and supplies a video signal to the pixel electrode 7 via the drain electrode 9.

Further, this liquid crystal display device has a pixel electrode 7,
A short ring pattern 14 is provided which surrounds the scanning signal supply wiring 2 and the video signal supply wiring 5 and which suppresses the destruction of the switching element due to static electricity. The short ring pattern 14 and the operation signal supply wiring 2 are
As shown in the partial cross-sectional view of FIG. 2, they are separated by the opening pattern 17. In the process up to the completion of the array portion, the short ring pattern 14 is connected to the scanning signal supply wiring 2 in the same layer as the connecting portion 18 as shown in the partial sectional view of FIG. Further, the short ring pattern 14 is connected to the mounting terminal 11 of the video signal supply wiring via the connection portion 15 and the contact hole 16. Then, in order to operate as a liquid crystal display device, in the partial cross-sectional view of FIG. 4, an etching process is performed through the opening pattern 17 opened above the connection portion 18, and each scanning signal supply wiring 2 is short-circuited. It is separated from the ring pattern 14 (FIG. 2).

The method of making an array substrate for a liquid crystal display device having such a structure comprises the following steps. (A) A step of preparing the insulating transparent substrate 1. (B) Short ring pattern 14 made of a conductor and the short ring pattern 14 on the insulating transparent substrate
And a step of arranging the scanning signal supply wiring 2 connected by the connection portion 18. In this case, by patterning, the connecting portion 18 connected to the short ring pattern 14 is simultaneously formed. (C) a plurality of pixel electrodes 7 on the insulating transparent substrate 1,
A step of arranging the switching elements 4 corresponding to the pixel electrodes 7 on a matrix. In the process of forming the switching element 4, the first insulating film 3 is patterned as a gate insulating film, and after the switching element 4 is formed, the second insulating film 6 is formed as a protective layer. (D) A step of arranging the video signal supply wiring 5 connected to the switching element 4. (E) Opening pattern 17 for opening a connecting portion 18 for connecting the short ring pattern 14 and the scanning signal supply wiring 2
Forming step. For this opening, the first insulator layer 3 and the second insulator layer 6 are selectively etched at the same time,
The opening pattern 17 is patterned. As described above, the steps (a) to (e) are performed in the above order. As shown in the partial cross-sectional view of FIG. 4, the scanning signal supply wiring 2 is connected between the short ring pattern 14 and the connecting portion 18 between these steps, so that even if static electricity is generated during the step, the short ring pattern is formed. The electrical characteristics of the switching element are not changed only along a part of the scanning signal supply wiring, and line defect defects in the liquid crystal display device can be suppressed.

Then, in order to function as a liquid crystal display device, each scanning signal supply wiring 2 is separated from the short ring pattern 14 by the following step (f). (F) The connecting portion 18 is removed by etching through the opening pattern 17, and each scanning signal supply wiring 2 is removed.
Separating the short ring pattern 14 from the short ring pattern 14. In this process, each scan signal supply wiring is connected to the short ring pattern 1
4 and can be made to function as a liquid crystal display device. After that, the array portion and the color filter portion are overlapped with each other to complete the liquid crystal display device.

This liquid crystal display device is different from the conventional liquid crystal display device of FIG. 5 in the following points. That is, in the configuration and the manufacturing method of the conventional liquid crystal display device, the scanning signal supply wirings are arranged independently for each line in the steps from the step of selectively etching and patterning the semiconductor layer to the step of depositing the thin film of the pixel electrode. Therefore, the electrical characteristics of the switching elements change along some of the scanning signal supply wirings due to peeling charging, and as a result, line defect defects in the liquid crystal display device increase.

On the other hand, in this liquid crystal display device, the scanning signal supply wiring 2 is entirely connected in the same layer as the short ring pattern 14 throughout the process of forming the array portion of the thin film transistor. Therefore, even if peeling charging occurs, the short ring pattern 14 protects the switching element, and the electrical characteristics of the switching element do not change only along a part of the scanning signal supply wiring 2, and line defects in the liquid crystal display device. It is possible to suppress defects. After completing the array part, to operate as a liquid crystal display device,
As shown in the cross-sectional view of FIG. 2, each scanning signal supply wiring and short ring pattern 14 are formed by etching through the opening pattern 17 in which the first insulator layer 3 and the second insulator layer 6 are simultaneously opened. It suffices to remove the connection portion 18 and separate the respective scanning signal supply wirings 2. Therefore, in the liquid crystal display device, the scanning signal supply wiring 2 is separated from the short ring pattern 14 by the opening pattern 17.

Next, the laminated structure of this liquid crystal display device will be described with reference to the partial sectional views of FIGS. First, a scanning signal supply wiring 2 is formed on a transparent glass substrate 1, and a thin film transistor (TFT) is formed on the scanning signal supply wiring 2.
The first insulator layer 3 also serving as the gate insulating film is laminated. An amorphous silicon semiconductor film 4 forming a channel region of a thin film transistor (TFT) is formed on the gate insulating film. On the other hand, a second insulating film 6 which covers the first insulating film 3 and also serves as a passivation insulating film 6 as a protective film is formed. The protective film 6 (second insulating film) may be, for example, SiN _x or Si.
O ₂ , acrylic resin, polyimide, polyamide, polycarbonate, or a laminated film thereof may be used. A contact hole 8 is opened in the second insulating film 6. The drain electrode 9 and the pixel electrode 7 are connected via the contact hole 8. The mounting terminal 10 of the scanning signal supply wiring 2 is connected to the scanning signal supply wiring 2 via a contact hole 12 formed in the first insulating layer 3 and the second insulating layer 6. Furthermore, the mounting terminal 11 of the video signal supply wiring is connected to the video signal supply wiring 5 through a contact hole 16 formed in the second insulator layer 6.

The operation of this liquid crystal display device will be described. (1) First, a voltage is applied to the scanning signal supply wiring 2 to form a TFT channel in the amorphous silicon semiconductor film 4 of the thin film transistor (TFT). (2) Next, the video signal from the video signal supply wiring 5 is T
It passes through the channel of FT, flows into the drain electrode 9, and is transmitted to the pixel electrode 7. (3) Then, an electric field is generated between the pixel electrode 7 and a counter electrode (not shown) provided in the color filter portion facing the pixel electrode 7 in parallel. (4) By the generated electric field, the orientation of the liquid crystal injected between the pixel electrode 7 and the counter electrode is arbitrarily changed, and the light transmittance is adjusted to produce a desired image.

[0021]

According to the method of manufacturing a liquid crystal display device of the present invention, the scanning signal supply wiring surrounds the pixel electrode and the scanning signal supply wiring, the mounting terminal thereof, and the video signal supply wiring and the mounting terminal thereof. All are connected in the same layer as the short ring pattern arranged in. By this, even when peeling electrification or the like occurs until the completion of the array substrate, it is protected by the short ring pattern, and the electrical characteristics of the switching element may change only along a part of the scanning signal supply wiring. Therefore, it is possible to suppress line defect defects in the liquid crystal display device. Such a TFT
When a TFT liquid crystal display device using the above configuration is created,
The line defect defect due to static electricity along the scanning signal supply wiring direction could be reduced to 0.1% or less.

[Brief description of drawings]

FIG. 1 is a partial plan view showing a configuration of a TFT array portion of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional view taken along the line AA ′ of FIG.

3 is a partial cross-sectional view taken along the line BB ′ of FIG.

FIG. 4 A- of FIG. 1 until completion of the array substrate
It is a partial cross section figure along the A'line.

FIG. 5 is a partial plan view showing a configuration of a TFT array portion of a conventional liquid crystal display device.

6 is a partial cross-sectional view taken along the line CC ′ of FIG.

[Explanation of symbols]

1 glass substrate 2 Scan signal supply wiring (gate electrode) 3 First insulating film (gate insulating film) 4 Amorphous silicon semiconductor layer 5 Video signal supply wiring (source electrode) 6 Second insulating film 7 pixel electrode 8 contact holes 9 Drain electrode 10 mounting terminals 11 mounting terminals 12, 13 Contact hole 14 short ring pattern 15 Connection 16 contact holes 17 opening pattern 18 Connection 51 glass substrate 52 Scan signal supply wiring (gate electrode) 53 First insulating film (gate insulating film) 54 Amorphous silicon semiconductor layer 55 Video signal supply wiring (source electrode) 56 Second insulating film 57 pixel electrodes 58 contact holes 59 drain electrode 60 Scan signal mounting terminal 61 Video signal mounting terminal 62, 63 contact holes 64 short ring pattern 65 Connection 66 contact holes

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H092 GA31 GA32 GA34 GA38 GA44                       GA46 JA01 JA21 JB22 JB31                       JB79 MA17 MA18 MA19 MA20                       NA14                 5C094 AA42 AA43 BA03 BA43 CA19                       CA24 DA13 DB01 DB04 EA04                       EA10 EB02 ED03 FA01 GB10

Claims (2)

[Claims] 1. A step of preparing an insulative transparent substrate, and a short ring pattern made of a conductor and a scanning signal supply wiring connected to the short ring pattern at a connecting portion are arranged on the insulative transparent substrate. A step of arranging a plurality of pixel electrodes and switching elements corresponding to the pixel electrodes in a matrix on the insulating transparent substrate; and arranging a video signal supply wiring connected to the switching elements. A step of forming an opening pattern for opening the connection portion that connects the short ring pattern and the scanning signal supply wiring, and removing the connection portion by etching through the opening pattern, respectively. And a step of separating the scanning signal supply wiring from the short ring pattern. 2. An insulating transparent substrate, a short ring pattern made of a conductor formed on the insulating transparent substrate, and an inner side surrounded by the short ring pattern on the insulating transparent substrate, A plurality of pixel electrodes arranged in a matrix and a plurality of switching elements corresponding to the pixel electrodes, a plurality of scanning signal supply wirings for supplying a scanning signal to the plurality of switching elements, and a drain electrode for the plurality of pixel electrodes. A plurality of video signal supply wirings for supplying a video signal via the scanning signal supply wirings, and each of the scanning signal supply wirings is separated from the short ring pattern by an opening pattern between the scan signal supply wirings. Liquid crystal display device.