JP2003131258A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device capable of preventing a gate line and a common line from being short-circuited at the crossing part of the gate line and the common line in the periphery of a screen due to conductive foreign matters and static electricity during the manufacturing process. SOLUTION: The liquid crystal display device is provided with gate lines 1 and in-screen common lines 2 formed of a 1st conductive film for forming the gate lines and screen end common lines 5a for forming auxiliary capacitance which are formed of a 2nd conductive film for forming pixel electrodes and are crossing the gate lines 1. Then, at the crossing parts of the gate lines 1 and the screen end common lines 5a, a two-layer structured interlayer insulating film consisting of a gate insulating film 10 and a protective insulating film 11 is formed between the gate lines 1 and the screen end common lines 5a. This two-layer structured insulating film prevents the gate lines 1 and the screen end common lines 5a from being short-circuited by conductive foreign matters and static electricity in the interlayer insulating film during the manufacturing process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device having a common line for forming an auxiliary capacitance, the common line intersecting a gate line at a peripheral portion of a screen.

[0002]

2. Description of the Related Art Generally, in a conventional liquid crystal display device, a gate line formed of a first conductive film for forming a gate line and a source line are formed at an intersection of a gate line and a common line for forming an auxiliary capacitance. And a common line composed of a second conductive film for use with the gate insulating layer are arranged via the gate insulating layer so that insulation between both lines is maintained.

FIG. 5 is a diagram showing a layout on a glass substrate in the vicinity of an intersection of a gate line and a common line for forming an auxiliary capacitance in such a conventional liquid crystal display device. Also,
FIG. 6 is a cross-sectional view of the liquid crystal display device shown in FIG. As shown in FIGS. 5 and 6, in this conventional liquid crystal display device, a gate line 1, an in-screen common line 2, a semiconductor layer 3, a source line 4, a screen end common line 5b, a pixel electrode are provided on a glass substrate 9. 7, conductive film 8, gate insulating film 10, protective insulating film 1
1 etc. are provided. The screen common line 5b and the conductive film 8 are connected in the contact hole 6.

In this conventional liquid crystal display device, the gate line 1 formed of the first conductive film and the screen end common line 5b formed of the second conductive film for forming the source line are insulated from each other. Crossing while keeping. Specifically, gate line 1
The gate line 1 and the screen end common line 5b are insulated by the gate insulating film 10 at the intersection of the screen end common line 5b.

[0005]

However, in the conventional liquid crystal display device shown in FIGS. 5 and 6, for example, an interlayer insulating film at the intersection of the gate line 1 and the screen end common line 5b for forming the auxiliary capacitance is formed. The insulating property of the gate insulating film 10 is
It is easily reduced by conductive foreign matter generated during the formation of the gate insulating film or static electricity generated during the manufacturing process of the liquid crystal display device, and the gate line 1 and the screen end common line 5b (and thus the screen common line 2) are easily short-circuited. There is such a problem.

The present invention has been made in order to solve the above-mentioned conventional problems. In the case where a conductive foreign substance is generated during the formation of the interlayer insulating film or static electricity is generated during the manufacturing process of the liquid crystal display device. However, it is an object or a problem to be solved to provide a liquid crystal display device capable of maintaining excellent insulation properties of an interlayer insulating film at an intersection of a gate line and a common line for forming an auxiliary capacitance.

[0007]

A liquid crystal display device according to the present invention, which has been made to solve the above problems, includes (i) a gate line formed of a first conductive film (first conductive type conductive film). And (ii) a second conductive film (a conductive film of the second conductivity type) having a conductivity type different from that of the first conductive film, and intersecting the gate line (in a separated state) for forming the auxiliary capacitance. And (iii) two or more layers including at least a gate insulating film and a protective insulating film between the gate line and the common line at the intersection of the gate line and the common line (of course, 2 It may be a layer).

According to this liquid crystal display device, the gate line and the common line are insulated from each other at their intersections by the two or more interlayer insulating films including the gate insulating film and the protective insulating film. The insulation between wires is very high. Therefore, even if a conductive foreign substance is generated during the formation of the interlayer insulating film or static electricity is generated during the manufacturing process of the liquid crystal display device,
The insulating property of the interlayer insulating film at the intersection of the gate line and the common line can be maintained well.

In the above liquid crystal display device, it is preferable that the second conductive film is a conductive film for forming a pixel electrode. Further, it is more preferable that the semiconductor layer is provided between the gate line and the common line (or between the gate insulating film and the protective insulating film) at the intersection of the gate line and the common line.

In the above liquid crystal display device, a common line is formed by a two-layer wiring in which a first conductive film and a second conductive film are laminated between the adjacent intersections, and both conductive films are formed. It is preferable that they are electrically connected to each other in the contact holes. In addition, between the adjacent crossing portions, the common line is formed by a two-layer wiring in which a conductive film for forming a source line and a second conductive film are stacked, and both conductive films are mutually formed in the contact hole. It may be electrically connected.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the accompanying drawings. (Embodiment 1) FIG. 1 is a plan view (top view) of a TFT array substrate in the vicinity of an intersection of a gate line and a common line for forming an auxiliary capacitance of a liquid crystal display device according to Embodiment 1 of the present invention. Is. FIG. 2 is a cross-sectional view taken along the line AA ′ of the liquid crystal display device shown in FIG. 1, showing a cross section of an intersection of a gate line and a common line (screen end common line).

As shown in FIGS. 1 and 2, in this liquid crystal display device, a plurality of gate lines each formed of a first conductive film for forming a gate line and extending in parallel with each other are formed on a glass substrate 9. 1 and a plurality of in-screen common lines 2 are provided. Each in-screen common line 2 is connected to a screen-end common line 5a made of a second conductive film for forming pixel electrodes in the through-hole 6 at the screen end (right end in FIG. 1). . In other words, between adjacent intersections, a common line is formed by a two-layer wiring in which a conductive film for forming a gate line and a conductive film for forming a pixel electrode are stacked, and both conductive films are formed in the contact hole 6. Electrically connected to each other. Thus, all in-screen common lines 2 are one screen edge common line 5
connected to a. Thus, the in-screen common line 2 and the screen end common line 5a are integrated to form a common line for forming the auxiliary capacitance.

Here, the screen end common line 5a intersects with each gate line 1 while being separated in the vertical direction (direction perpendicular to the paper surface in FIG. 1). And in the vicinity of this intersection,
A gate insulating film 10, a semiconductor layer 3, and a protective insulating film 11 are provided between the gate line 1 and the screen edge common line 5a. That is, the gate line 1 and the screen edge common line 5a are strongly insulated from each other by the interlayer insulating film including the gate insulating film 10 and the protective insulating film 11 that sandwich the semiconductor layer 3 therebetween. In addition, in this liquid crystal display device, a plurality of source lines 4 extending above the gate lines 1 in a direction perpendicular to the gate lines 1 are provided.
And a pixel electrode 7 (transparent electrode).

A method of manufacturing the liquid crystal display device shown in FIGS. 1 and 2 will be described below. In the manufacturing process of this liquid crystal display device, first, the gate line 1 and the in-screen common line 2 each made of the first conductive film are formed on the glass substrate 9.
Then, a gate insulating film 10 is deposited on the glass substrate 9 so as to cover the gate line 1 and the in-screen common line 2. Next, the semiconductor layer 3 is deposited on the gate insulating film 10. Then, the semiconductor layer 3 is etched so that the semiconductor layer 3 remains only at the intersection of the gate line 1 and the screen end common line 5a.

Further, a protective insulating film 11 is deposited on the gate insulating film 10 so as to cover the semiconductor layer 3, and then a contact hole 6 is formed. Then, after depositing a conductive film for pixel electrode formation on the protective insulating film 11 or the in-screen common line 2 (portion exposed in the contact hole 6), etching is performed to form a screen-edge common line 5a. To do.
As a result, all the in-screen common lines 2 become the screen end common lines 5.
connected to a. After that, the source line 4 and the pixel electrode 7 are formed.

In the liquid crystal display device having the structure shown in FIGS. 1 and 2, the interlayer insulating film at the intersection of the gate line 1 and the screen end common line 5a is composed of the gate insulating film 10 and the protective insulating film 11. It has a two-layer structure. Further, the semiconductor layer 3 is sandwiched between the gate insulating film 10 and the protective insulating film 11. Therefore, even if a conductive foreign substance is mixed in during the deposition of the insulating film or static electricity is generated during the manufacturing process of the liquid crystal display device, the insulating property between the gate line 1 and the screen end common line 5a is maintained well. Thus, it is possible to realize a liquid crystal display device having excellent insulating properties.

(Second Embodiment) The second embodiment of the present invention will be described below with reference to FIGS. 3 and 4. However, the liquid crystal display device according to the second embodiment has many common points with the liquid crystal display device according to the first embodiment shown in FIGS. 1 and 2. Therefore, to avoid duplication of explanation,
The same members as those in the first embodiment are designated by the same reference numerals as those in the first embodiment, and the detailed description thereof will be omitted. Below, mainly the points different from the first embodiment will be described.

FIG. 3 is a plan view showing the surface of the TFT array substrate in the vicinity of the intersection of the gate line and the common line for forming the auxiliary capacitance of the liquid crystal display device according to the second embodiment of the present invention. FIG. 4 shows the liquid crystal display device B- of FIG.
FIG. 9 is a cross-sectional view taken along line B ′, showing a cross section of an intersection of a gate line and a common line (screen end common line).

As shown in FIGS. 3 and 4, the second embodiment
In the liquid crystal display device according to the second aspect, the in-screen common line 2 is connected to the pattern 5c formed of the second conductive film for forming the pixel electrode in the through hole 6a at the screen end (the right end in FIG. 3). Has been done. The pattern 5c is connected to the pattern 4a formed of the conductive film for forming the source line in the through hole 6b. Further, the pattern 4a is connected to the screen end common line 5a formed of the second conductive film for forming the pixel electrode in the contact hole 6. That is, between the adjacent crossing portions, the common line is formed by a two-layer wiring in which a conductive film for forming the source line and a conductive film for forming the pixel electrode are stacked, and both conductive films are formed in the contact hole 6. Electrically connected to each other. Thus, all in-screen common lines 2 are connected to one screen end common line 5a via the patterns 5c and 4a. In this way, the common line 2 in each screen, each pattern 5c, and each pattern 4
a and the screen end common line 5a are integrated to form a common line for forming the auxiliary capacitance. Other configurations are similar to those of the liquid crystal display device according to the first embodiment.

A method of manufacturing the liquid crystal display device shown in FIGS. 3 and 4 will be described below. In the manufacturing process of this liquid crystal display device, first, the gate line 1 and the in-screen common line 2 each made of the first conductive film for forming the gate line are formed on the glass substrate 9. Then, the gate insulating film 10 is formed on the glass substrate 9 so as to cover the gate line 1 and the in-screen common line 2.
Deposit. Next, the semiconductor layer 3 is formed on the gate insulating film 10.
Deposit. Then, the semiconductor layer 3 is etched so that the semiconductor layer 3 remains only at the intersection of the gate line 1 and the screen end common line 5a. Next, the gate insulating film 1
Pattern 0 made of a conductive film for forming a source line on 0
a is formed. Further, a protective insulating film 11 is deposited on the gate insulating film 10 so as to cover the semiconductor layer 3, the in-screen common line 2 and the pattern 4a, and then contact holes 6, 6a and 6b are formed.

Then, the protective insulating film 11 or the pattern 4 is formed.
After a second conductive film for forming a pixel electrode is deposited on a (a portion exposed in the contact hole 6), it is etched to form a screen edge common line 5a. Further, at positions corresponding to the contact holes 6a and 6b, the protective insulating film 11, the in-screen common line 2 (portion exposed in the contact hole 6a), and the pattern 4a (contact hole 6).
2) for forming the pixel electrode on the
After depositing the conductive film, the pattern 5c is formed by etching the conductive film. As a result, all the in-screen common lines 2 are connected to the screen end common line 5a via the patterns 5c and 4a. After that, the source line 4 and the pixel electrode 7 are formed.

In the liquid crystal display device having the structure shown in FIGS. 3 and 4, the same action and effect as those of the liquid crystal display device according to the first embodiment can be obtained. Further, since there is no common line formed of the first conductive film in the vicinity of the gate line 1, even if the conductive film remains when forming a pattern with the first conductive film, A short circuit with the common line is prevented, and an excellent liquid crystal display device can be realized.

[0023]

As described above, according to the present invention, at the intersection of the gate line and the common line for forming the auxiliary capacitance, the interlayer insulating film between the gate line and the common line is the gate insulating film and the protective insulating film. It has a structure of two or more layers including and. Therefore, in the manufacturing process of the liquid crystal display device, even if conductive foreign matter is mixed in during the deposition of the insulating film or static electricity is generated, the insulating property between the gate line and the common line is well maintained, and the insulating property is improved. An excellent liquid crystal display device can be realized. Further, the yield loss can be reduced, and the manufacturing cost of the liquid crystal display device can be reduced. Further, by sharing the conductive film of the common line and the conductive film of the pixel electrode, the above effect can be realized without increasing the manufacturing process.

In addition, a first conductive film or a second conductive film is used to form a two-layer wiring between the intersection of the gate line and the common line and the intersection of the adjacent gate line and the common line. By electrically connecting to the line, the resistance of the common line can be reduced and the delay of the common signal can be reduced, so that an excellent liquid crystal display device can be realized.

[Brief description of drawings]

FIG. 1 is a plan view of a TFT array substrate of a liquid crystal display device according to a first exemplary embodiment of the present invention.

2 is a cross-sectional view of the liquid crystal display device shown in FIG. 1 taken along the line AA '.

FIG. 3 is a plan view of a TFT array substrate of a liquid crystal display device according to a second exemplary embodiment of the present invention.

4 is a cross-sectional view of the liquid crystal display device shown in FIG. 3 taken along the line BB ′.

FIG. 5 is a plan view of a TFT array substrate of a conventional liquid crystal display device.

6 is a cross-sectional view taken along line CC ′ of the liquid crystal display device shown in FIG.

[Explanation of symbols]

1 gate line formed by the first conductive film 2 in-screen common line formed by the first conductive film 3 semiconductor layer 4 source line 4a formed by the second conductive film 4a pattern 5a conductive for pixel electrode formation Screen common line 5b formed of film Common line 5c formed of second conductive film 5 Pattern 6 Contact hole 6a Contact hole 6b Contact hole 7 Pixel electrode 8 Conductive film for forming pixel electrode 9 Glass substrate 10 Gate insulating film 11 Protective insulation film

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) G09F 9/35 G09F 9/35 H01L 21/336 H01L 29/78 612D 29/786 612A F term (reference) 2H090 JB02 LA04 2H092 GA29 JA24 JA37 JA46 JB61 KB25 NA16 NA25 NA27 PA01 5C094 AA13 AA21 AA42 AA44 BA03 BA43 CA19 DA14 DA15 DB01 EA04 EA07 EB02 FB12 FB14 FB15 5F110 AA12 AA26 AA30 BB01 CC05 CC07 DD02 NN02 Q0106NN73

Claims (5)

[Claims] 1. A gate line made of a first conductive film, and a common line made of a second conductive film having a conductivity type different from that of the first conductive film and intersecting the gate line for forming an auxiliary capacitance. At least two interlayer insulating films including at least a gate insulating film and a protective insulating film are formed between the gate line and the common line at the intersection of the gate line and the common line. Liquid crystal display device. 2. The liquid crystal display device according to claim 1, wherein the second conductive film is a conductive film for forming a pixel electrode. 3. At the intersection of the gate line and the common line,
The liquid crystal display device according to claim 1 or 2, wherein a semiconductor layer is provided between the gate line and the common line. 4. A common line between the adjacent intersections,
4. The first conductive film and the second conductive film are formed by a two-layer wiring which is laminated, and both conductive films are electrically connected to each other in a contact hole.
7. The liquid crystal display device according to any one of 1. 5. A common line between the adjacent intersections,
The conductive film for forming a source line and a second conductive film are laminated to form a two-layer wiring, and both conductive films are electrically connected to each other in a contact hole. 3. The liquid crystal display device according to any one of 1 to 3.