JP3516138B2 - Liquid crystal display - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film transistor (TFT) active matrix liquid crystal display device used as a display device for image information / character information such as OA equipment, and more particularly to a wiring material thereof.

[0002]

2. Description of the Related Art A liquid crystal display device of active matrix type in which TFTs are formed in a matrix on an insulating substrate such as glass and used as switching elements is expected as a high quality flat panel display.

At present, there are some problems to be solved in the TFT active matrix type display.

The first problem is to improve the manufacturing yield. In particular, a short circuit defect between the scanning signal line and the video signal line is the largest cause, and reduction of this defect is an issue.

The second problem is to reduce the number of manufacturing steps.
In particular, there is a strong demand for reduction in the number of photolithography processes.

A third problem is a technique for forming low-resistance scanning signal wirings which can cope with higher definition / larger screen.

The fourth problem is to secure reliability. Specifically, the issue is to ensure the reliability of the image quality as well as the reliability of the external connection terminals of the wiring against corrosion and the like.

Various proposals have been made for the above problems.

Regarding the first problem of improving the manufacturing yield, for example, Japanese Patent Laid-Open No. 61-133662 discloses that the gate insulating film of a TFT is composed of an anodic oxide film of a gate electrode and a SiN film.
A technique for preventing a short circuit between wirings due to a pinhole or the like in the gate insulating film is disclosed as a layered structure (first conventional technique).

A number of proposals have been made regarding the problem of reducing the number of second photolithography steps. For example, Japanese Patent Laid-Open No. 63-9977 discloses a structure in which a scanning wiring has a two-layer structure of a transparent electrode and a metal film, and a pixel electrode is constituted by the transparent electrode of the scanning wiring. In this method, since the scanning signal wiring and the pixel electrode can be formed by patterning once, it is possible to reduce the photolithography process (second conventional technique).

Further, Japanese Patent Laid-Open No. 62-32651 discloses a method of reducing the number of photolithography steps by processing a gate insulating film and a semiconductor film forming a TFT into the same pattern using a single photomask. It has been disclosed (third prior art).

Regarding the problem of the third technique for forming the scanning signal wiring of low resistance, Japanese Patent Laid-Open No. 2-85826 describes, for example, A.
It discloses an example in which l is used as a scanning wiring and an Al ₂ O ₃ film is used as a gate insulating film and an interlayer insulating film. Low resistance A
When 1 is used as the scanning wiring, the delay of the scanning signal can be suppressed to a practically unproblematic level even if the load of the scanning wiring is increased due to high definition / large screen (fourth prior art).

Further, JP-A-64-35421 discloses A
and Ta formed on Al and Al are used for the scanning wiring,
And a Ta anodic oxide film are used as a gate insulating film and an interlayer insulating film to reduce the resistance of the scanning wiring, reduce interlayer short-circuit defects, and reduce the number of steps (fifth prior art). ).

[0014]

In order to fully popularize the TFT active matrix type liquid crystal display device, it is necessary to solve all the above problems at the same time and realize high image quality / low cost / high reliability. However, the above conventional technology is
Although each of the targeted problems has some effect, each elemental technology often has a trade-off relationship with each other, and cannot meet all of the above problems at the same time. Further, simply combining the individual techniques described above causes a new problem and a desired effect cannot be obtained. I will explain the circumstances.

For example, if the first conventional technique and the second conventional technique are combined, it is necessary to anodize the scanning signal wiring metal on the transparent electrode. When a metal is anodized on the transparent conductive film, there is a problem that the metal film is melted and lost due to a battery reaction due to a difference in standard potential of materials. In addition, a new photomask is required to form a resist mask for selective oxidation at the time of anodization, so that it is not possible to achieve the second problem of reduction in the number of steps.

In the second conventional technique, the semiconductor film which is the active layer has a structure protruding outside the gate electrode.
When the display device is configured, a backlight or external light hits the semiconductor film protruding to the outside of the gate electrode, and the photocurrent of the semiconductor film increases the leak current of the TFT to deteriorate the image quality. In order to prevent this deterioration in image quality, it is effective to thin the semiconductor film. However, as is well known, in order to reduce the thickness of a semiconductor film in a conventional inverted stagger type TFT due to process restrictions, a photomask for forming a channel protective film for protecting the channel portion of the TFT is used. I have to increase the number. Regarding this problem, for example, "Flat Panel Display '91" (Nikkei BP
Company 1990) pp. 88-96.

Therefore, in the second conventional technique, the mask of the semiconductor film and the gate insulating film is integrated to form a photomask.
Although it is possible to reduce the number of sheets, it is necessary to reduce the thickness of the semiconductor film in order to guarantee image quality that can be used practically, and it is necessary to increase the number of photomasks to form the channel protective film. Simplifying the process by reducing the photomask cannot be achieved.

When the third prior art and the fourth prior art are combined, the scanning signal wiring is a transparent electrode and a low resistance wiring A.
It has a two-layer structure with the l electrode. In this case, the Al electrode is used as it is for the external connection terminal portion of the scanning signal wiring, or Al in the upper layer is selectively removed and the transparent electrode is used as the external connection terminal.

Since the external connection terminal portion of the wiring is exposed to various solvents and the like even after the post-process such as encapsulation of liquid crystal, the use of an active metal such as Al causes a problem of corrosion. Further, when the transparent electrode is used for the terminal portion, in joining the transparent electrode which is a metal oxide and the Al of the wiring metal,
Since Al is oxidized by oxygen in the transparent electrode to form an insulating film at the interface, there is a problem that contact reliability is extremely low.

In the fifth conventional technique, T is formed on Al.
Since a is formed, there is no problem of contact, but since Al is still exposed on the side surface of the terminal, there is a problem that corrosion is likely to occur.

Due to the above problems, A
When 1 is used, a barrier metal is often inserted in order to maintain good contact with the transparent electrode at the terminal portion. However, a new photomask is required to process the barrier metal. Therefore, the second
It is not possible to achieve the reduction of the number of steps, which is the issue of.

Further, generally, the gate insulating film and the semiconductor film of the TFT are formed at a temperature of about 300 ° C. by plasma vapor deposition (PCVD). A for scanning signal wiring
When 1 is used, many surface irregularities called hillocks grow due to the thermal history in the PCVD process. The electric field is concentrated on such irregularities, and the dielectric strength between the scanning signal wiring and the video signal wiring is extremely lowered. Therefore, when Al having a low resistance is used for the scanning signal wiring, it is difficult to achieve the first problem, that is, the improvement of the manufacturing yield.

As described above, it is not possible to solve all of the above-mentioned problems at the same time by simply combining conventional techniques.

An object of the present invention is to provide a liquid crystal display device using a wiring material which can be manufactured at low cost while ensuring high reliability and good image quality with a minimum number of photomasks.

[0025]

In order to achieve the above object, the present invention provides a scanning signal electrode formed on an insulating substrate, a video signal electrode formed so as to intersect the scanning signal electrode, and scanning. In a liquid crystal display device having a thin film transistor formed near an intersection of a signal electrode and a video signal electrode, scanning signal electrodes are substantially the same except for a connection terminal portion.
It is composed of a metal first conductive film having a plane pattern and a second conductive film of Al or an alloy containing Al as a main component, which is arranged on the first conductive film, and is connected to an external drive circuit. And the second conductive film is an external drive circuit.
On the second conductive film at the connection terminal portion between the scanning signal electrode and
From the same position as the edge of the formed insulation film pattern, the insulation substrate is
The outer peripheral side of the plate is removed, and the connection terminal between the external drive circuit and the scanning signal electrode is composed of the first conductive film and the transparent conductive film arranged on the first conductive film. Patta
A liquid crystal display device is proposed in which the end portion of the screen is covered with an insulating film and a transparent conductive film extending from a connection terminal portion between the external drive circuit and the scanning signal electrode.

The second conductive film may have its upper surface mainly covered with an insulating film and its side surfaces mainly covered with a transparent conductive film.

It is desirable that the first conductive film of the scanning signal electrode and the first conductive film of the connection terminal portion are continuously formed.

In order to achieve the above object, the present invention also provides a scanning signal electrode formed on an insulating substrate, a video signal electrode formed to intersect the scanning signal electrode, a scanning signal electrode and an image. In a liquid crystal display device having a thin film transistor formed in the vicinity of an intersection of signal electrodes, the scanning signal electrode includes a metal first conductive film and Al or Al disposed on the first conductive film as a main component. The second conductive film made of an alloy is formed by being etched using the insulating film formed on the second conductive film as a mask, and is connected to an external drive circuit, and is connected to the external drive circuit and the scanning signal electrode. Of the connection terminal portion is formed of a first conductive film and a transparent conductive film disposed on the first conductive film, and the transparent conductive film of the connection terminal portion is formed on the second conductive film of the scanning signal electrode. Insulation film formed on It proposes a liquid crystal display device which is formed extending to the upper.

Also in this case, it is desirable that the first conductive film of the scanning signal electrode and the first conductive film of the connection terminal portion are continuously formed.

In any of the above cases, the transparent conductive film is specifically ITO.

In the present invention, since the wiring material including the Al film or the alloy film containing Al as a main component is used, the generation of hillocks on the Al surface can be suppressed. Therefore, it is possible to reduce a short circuit between wirings when a display device or the like is configured. Such a phenomenon has not been known so far, and has been clarified for the first time by experiments by the inventors.

When the laminated wiring is used for the scanning signal electrode of the liquid crystal display device, the interlayer dielectric strength between the scanning signal electrode and the video signal electrode is increased. As a result, short-circuit defects can be reduced and the resistance of the scanning signal electrode can be reduced, so that the display screen can be increased in size / definition.

When the surface of Al is entirely covered with an insulating film containing Al as a base material, Al is not exposed to chemicals and the like, so that corrosion resistance can be secured and
Generation of hillocks on the Al surface can be further suppressed.

When the external connection terminal is composed of a transparent conductive film composed of one metal and a metal oxide formed on the upper layer thereof, the chemical resistance of the terminal is improved and an insulating barrier due to a reaction between the transparent conductive film and the metal. Layers are less likely to form at the interface. Therefore, it is possible to prevent an increase in contact resistance of the connection terminal and obtain a highly reliable connection terminal.

Such a structure can be formed by removing Al by etching using the insulating film formed on the Al surface as a mask. Therefore, the above structure can be formed by only one photomask, and at the same time, the effects of reducing the number of steps, ensuring corrosion resistance, reducing short-circuit defects, lowering the resistance of the scanning signal electrode, and the like can be obtained.

A pixel electrode made of a transparent conductive film is arranged under the semiconductor film and the gate insulating film, and the semiconductor film and the gate insulating film are extended along the video signal electrode in a pattern wider than the video signal electrode to form a pixel. By covering only the peripheral portion of the electrode pattern, the pixel electrode and the video signal electrode can be separated. By doing so, even if the distance between the pixel electrode and the video signal electrode is reduced while preventing the short circuit between the pixel electrode and the video signal electrode, the pixel defect due to the short circuit can be reduced. In addition, the width of the pixel electrode is expanded and the pixel aperture ratio is improved. Therefore, in addition to features such as reduction in the number of processes, high yield, low resistance wiring, and improved reliability of the terminal part, low defects,
A high-brightness liquid crystal display device can be realized.

After forming the Ta film, the inventors formed an Al film continuously in vacuum while maintaining the cleanliness of the surface, and the (111) orientation became weak, resulting in (220).
It was discovered that the planes grow preferentially and at the same time the hillocks on the film surface become smaller. The manufacturing method of the present invention is based on this finding. That is, in the method for manufacturing a liquid crystal display device of the present invention, Al that grows on the Ta surface is not affected by the adsorption layer and is directly affected by the underlying Ta film, so that it does not occur under normal conditions (220). Realization of preferential growth of the plane. When the (220) plane grows preferentially, the orientation changes as a whole to random orientation, and hillocks on the film surface decrease.

The characteristics and / or effects of other modifications of the present invention will be apparent from the following description of the embodiments.

[0039]

DETAILED DESCRIPTION OF THE INVENTION

Embodiment 1 FIG. 1 is a perspective view of an embodiment of a laminated wiring material of a liquid crystal display device according to the present invention. The laminated wiring material of this embodiment is Ta-based by the magnetron sputtering method.
A film 10 and an Al film 11 are sequentially laminated on the glass substrate 1,
It is processed and formed into the same pattern.

The upper Al film 11 has a crystal orientation oriented to the (220) plane under the influence of the base. It is conventionally known that when Al, which is a face-centered cubic lattice (fcc), is grown on Ta (110) having a body-centered cubic lattice (bcc), it is oriented in (111). According to the experiments by the inventors, after the Ta film 10 is formed, when the Al film 11 is continuously formed in a vacuum while keeping the cleanliness of the surface thereof, the (111) orientation becomes weak and the (220) It has been found that the face grows preferentially. At the same time, it was also discovered that the hillocks on the film surface became smaller.

FIG. 2 is a diagram showing a comparison of surface irregularities of the Al film 11 formed on the glass substrate 1 and the Ta film 10, respectively. In the Al film 11 formed on the glass substrate 1, some hillocks having a height of about 100 nm are seen, whereas in the Al film 11 formed on the Ta film 10,
Although there are many minute irregularities, no large hillocks are seen. This difference is probably due to the growth of Al under the influence of the Ta underlayer having fine crystal grains, and as a result, the crystal grains do not grow large, so that the internal stress of the film is relaxed, and when hillocks grow. It is presumed that many minute hillocks are generated.

In order to grow the (220) plane, care must be taken during film formation. It has been confirmed by experiments that Ta and Al do not appear (220) orientation unless the Ta surface is kept clean and the Ta surface is continuously grown with almost no time. After Ta film is formed and the discharge is stopped and left for several minutes or more, even if the vacuum is not released, T
An adsorption layer of H ₂ O or the like is formed on the a surface, and preferential growth of the (220) plane does not occur. The inventors obtained (220) orientation for the first time by slowly moving Ta and Al in a chamber during sputtering. In such a method, Ta and Al are continuously formed in the vicinity of the interface while being mixed with each other to some extent.
No adsorption layer of H ₂ O or the like is formed on the surface. That is, Al grown on the Ta surface is not affected by the adsorption layer and is directly affected by the underlying Ta film, so that the preferential growth of the (220) plane, which does not occur under normal conditions, is realized.

FIG. 3 is a diagram showing a comparison between the X-ray diffraction pattern of the Al thin film used for the wiring of the present invention and the X-ray diffraction pattern of the conventional Al film. The height of the peak of the diffraction pattern is proportional to the volume of crystal grains oriented so that the planes indicated at the respective peak positions are parallel to the film surface. (22
The intensity ratio between the (0) diffraction peak and the (111) diffraction peak is
In the conventional Al film, it was 0.15, but in the Al film of the present invention, it was as large as 0.7 or more. Conventional A
It can be seen that the Al film of the present invention has a larger diffraction peak from the (220) plane and a smaller diffraction peak from the (111) plane than the l film. In the conventional Al film, (1
It is considered that, in the Al film of the present invention, the crystal grains strongly oriented in the (11) plane are changed to a random orientation as a whole due to the growth of the (220) plane. That is, the ratio of the intensity of the surface having the maximum diffraction peak intensity to the intensity of the surface having the second highest intensity is, for example, about 0.5 in the conventional Al film.
However, in the present invention, it is about 0.7 to 1.0.
For this reason, the average crystal grain size is slightly reduced, the variation in grain size is also reduced, and it is presumed that the grains are made uniform.

In the conventional Al wiring used in the LSI, if the crystal grains of Al are miniaturized, the resistance to electromigration and stress migration is lowered. Therefore, Al is preferentially oriented to (111) to enlarge the crystal grains. ing. In such an Al film, a large hillock grows because there are few triple points of crystal grains that are sites for relaxing stress. In a TFT array for a liquid crystal display device, the wiring width is about 10 μm, which is larger than that of an LSI, and therefore electromigration and stress migration do not pose a problem so much.
Rather, it is important to suppress hillocks on the Al surface to suppress interlayer shorts. Therefore, the present invention (220)
Suppression of hillocks by orientation and miniaturization of crystal grains is
Very desirable as a wiring for FT array.

FIG. 4 is a diagram showing the relationship between the intensity ratio of the (220) diffraction peak and the (200) diffraction peak obtained from the X-ray diffraction of the Al film and the surface hillock density.
It can be seen that the hillock density decreases as the (220) / (200) ratio increases, and that the hillock almost disappears when the (220) / (200) ratio becomes 1.0 or more.

Not only Ta but also b is used as the base material.
Any metal having a cc crystal structure may be used. For example, T
a-N alloy, Nb, Ta-Nb alloy, Nb-N alloy, T
Similar effects can be obtained with a-Nb-N alloy, Ta-Ti alloy, Ta-Ti-N alloy, W, Ta-W alloy, and Ta-W-N alloy. The material of the upper layer is not only pure Al but also A such as Al-Pd, Al-Ta, Al-Ta-Ti.
An l-alloy film may be used.

The Al film of the present invention has a clean surface T
In addition to the method capable of growing on the alloy containing a and continuously forming a film after forming a base film, there is also a method of performing a film formation after cleaning the formed base surface by sputter etching or the like. Can be adopted.

[0048]

[Embodiment 2] FIG. 5 is a plan view of a scanning signal wiring for a liquid crystal display device, which is constructed by using the laminated wiring material of the present invention. FIG. 6 is a cross-sectional view of the external connection terminal portion of the scanning signal wiring of FIG. FIG. 7 is a cross-sectional view of the AA plane of FIG. 6 viewed from the arrow direction.

A Ta electrode 10 and an Al electrode 11 are formed on a glass substrate 1, and the surface and side surface of these are Ta ₂ O ₅
It is covered with a film 20 and an Al ₂ O ₃ film 21. Here, the Al ₂ O ₃ film 21 is formed so as to cover the entire surface of the Al electrode 11, which is the upper layer film of the two-layer conductive film. Further, the Al electrode 11 as the upper layer film is formed from a position separated by a distance X or more from the end portion of the scanning signal electrode (distance X
Was 1.0 cm in this example), and the Al electrode 11 was excluded from the end contacting the external member.

According to this embodiment, the Al electrode, which is easily corroded, is completely covered with the Al ₂ O ₃ film, and the scanning signal electrode has a low resistance A while being removed from the end portion in contact with the external member.
Since the l electrode can be used, high definition / large size of the display device can be achieved. In order to reliably connect with an external member, X may be 0.1 cm or more. Also, Al, which is easily corroded
Ta with high corrosion resistance is placed under the electrode, and Al ₂ O ₃
The structure is such that the end faces of the film and the Al electrode are aligned, and Al ₂ O
_Since the external connection terminals are formed by etching away the Al electrodes at the ends using the _three films as a mask, a photomask for metal-working the connection terminals is unnecessary, and the number of steps can be reduced. Further, the Al electrode having (220) orientation with few hillocks is used as the upper layer film, and the interlayer short circuit defect can be reduced. Thus, since a high quality Al ₂ O ₃ film can be used as an interlayer insulating film, interlayer short circuit defects can be further reduced.

[0051]

Third Embodiment FIG. 8 is a sectional view showing an end portion of another embodiment of the scanning signal electrode of the liquid crystal display device according to the present invention.
FIG. 9 is a cross-sectional view of the AA plane of FIG. 8 viewed from the arrow direction.

The scanning signal electrode of the present embodiment has a two-layer Ta layer.
The electrode 10 and the Al electrode 11 sandwiched by these electrodes are formed of a three-layer conductive film. Similar to the above-described embodiment, the surface and side surface of these films are Ta ₂ O ₅ film 20 and Al ₂ O ₃ film.
The surface of the Ta electrode 10, which is covered with the film 21 and is the uppermost film, is entirely covered with the Ta ₂ O ₅ film 20. Further, the Ta electrode 10 and the Al electrode 11 of the upper layer film were formed at a position separated by 1.0 cm or more from the end of the scanning signal electrode, and the Al electrode 11 was excluded from the end contacting the external member.

According to the present embodiment, in addition to the effect similar to that of the first embodiment, the Ta ₂ O ₅ film having a large relative dielectric constant can be used as a part of the gate insulating film of the TFT.
The transconductance of the TFT is improved. Further, the Ta electrode 10 in the upper layer can further suppress the occurrence of hillocks in the Al electrode 11 and reduce interlayer short circuit defects.

[0054]

Fourth Embodiment FIG. 10 is a schematic cross-sectional view of a unit pixel of a liquid crystal display device configured by using scanning signal electrodes having the structure of the second embodiment.

A scanning signal electrode composed of a Ta electrode 10 and an Al electrode 11 is formed on a glass substrate 1, and the surface and side surface of these are covered with a Ta ₂ O ₅ film 20 and an Al ₂ O ₃ film 21. There is. Si on these scanning signal electrodes
N film 22, a-Si: H film 30, n-type a-Si: H film 31
And the video signal electrode 14 and the source electrode 15 are formed on the n-type a-Si: H film 31, and the pixel electrode 13 made of an ITO film is connected to the source electrode. A capacitance electrode 16 is connected to the pixel electrode 13, and the scanning signal electrode 11 and the capacitance electrode 16 form an additional capacitance. Further, the whole of them is covered with a protective SiN film 23.

FIG. 11 is a sectional view of the external connection terminal of the scanning signal electrode of the thin film transistor substrate. Here, of the scanning signal electrodes, the surface of the upper Al electrode 11 is Al ₂
Coated with O ₃ film 21, thereby extending the Ta electrode 10 to the outside of the _Al 2 _{O 3} film 21, and constitutes the external connection terminals.
The Ta electrode 10 is covered with the ITO electrode 13. In this embodiment, since the barrier layer formed at the Ta / ITO interface due to the reaction between Ta and ITO does not have perfect insulation, the contact resistance between Ta and ITO is lower than that when Al and ITO are combined, for example. , Much smaller. Further, with Ta and ITO, there is almost no increase in contact resistance due to heat treatment, so that an extremely stable connection terminal can be obtained.

In this embodiment, Ta is used as the base metal, but other than Ta, Ta-N alloy, Nb, Ta-Nb are used.
Alloy, Nb-N alloy, Ta-Nb-N alloy, Ta-Ti
Alloy, Ta-Ti-N alloy, W, Ta-W alloy, Ta-
Similar effects can be obtained with a WN alloy or the like. In particular, Ta
When metal nitride such as -N or Ti-N is used, metal and IT
The reaction of O can be further suppressed and the contact resistance can be made extremely small.

12 to 16 are views showing manufacturing steps of the thin film semiconductor device of the above embodiment. The right side of these figures is a diagram showing a cross section in each step of the scanning signal electrode terminal portion.

In FIG. 12, Ta is placed on the glass substrate 1.
The film 10 and the Al film 11 are continuously deposited by sputtering and patterned into a predetermined shape by using a photolithography technique.

In FIG. 13, Ta is obtained by the anodic oxidation method.
A Ta ₂ O ₅ film 20 and an Al ₂ O ₃ film 21 are formed on the surfaces and side surfaces of the film 10 and the Al film 11.

In FIG. 14, using the Al ₂ O ₃ film 21 as a mask, the Al film 11 in the scanning signal electrode terminal portion is removed by etching to expose the Ta electrode 10. At this time, according to the reactive ion etching method using the mixed gas plasma of hydrogen bromide (HBr) and boron trichloride (BCl ₃ ), the etching selection ratio of Al and Ta can be made large, so that the etching workability is high. And the yield is improved. Subsequently, an ITO film is deposited by sputtering and patterned by using a photolithography technique to form a protective film 131 for the pixel electrode 13 and the terminal Ta.

In FIG. 15, the gate SiN film 22, the a-Si: H film 30, the n-type a are formed by the plasma CVD method.
-Si: H film 31 is deposited, a-Si: H film 30, n-type a
The -Si: H film 31 is patterned into a predetermined shape, and then the gate SiN film 22 on the pixel electrode 13 and the terminal electrode is removed.

In FIG. 16, a Ti film is deposited by sputtering and patterned into a predetermined shape to obtain a video signal electrode 14, a source electrode 15 and a capacitor electrode 16. Finally, the protective SiN film 23 is formed by the plasma CVD method.
Are formed to complete the thin film semiconductor device.

According to this embodiment, since Ta having high corrosion resistance can be used for the external connection terminal, high reliability can be secured. Further, since the Ta electrode of the external connection terminal portion is exposed using the Al ₂ O ₃ film as a mask, a photomask for metal processing of the external connection terminal, which has been conventionally required, is not required, and the number of steps can be reduced. Further, by suppressing hillocks on the Al surface, it is possible to reduce interlayer short-circuiting and use a low-resistance Al electrode for the scanning signal electrode, so that the liquid crystal display device can be made finer and larger.

In the above embodiment, the scanning signal electrode is Ta.
And Al were used, but the present invention is not limited to this combination, and Ta
Instead of W, Nb or alloys containing them, such as T
The same applies when aN, Nb-N, Ta-Nb-N, Ta-Ti-N and the like are used. Further, not only pure Al but also A
You may use alloys, such as 1-Pd, Al-Ta, and Al-Ti-Ta.

Further, in the above-described embodiment, the method of exposing the Ta electrode of the external connection terminal by using the Al ₂ O ₃ film formed on the surface of Al as a mask is adopted. However, the Ta electrode of the external connection terminal is exposed. The process may be performed after removing the gate SiN film 22 on the terminal electrode. Even in this case, since the photoresist for processing the gate SiN film 22 can be used as it is as a mask for exposing the Ta electrode 10, the number of steps is not increased.

Since the gate SiN film and the Al ₂ O ₃ film are not directly exposed to the plasma when the Ta electrode is exposed,
Since the film is not damaged by plasma, good insulation characteristics can be maintained.

[0068]

Fifth Embodiment The wiring material according to the present invention can be applied not only to the scanning signal wiring but also to the video signal wiring. Figure 17
FIG. 6 is a cross-sectional view of a pixel of an embodiment in which a wiring material according to the present invention is applied to video signal wiring. In the present embodiment, in addition to the structure of the first embodiment, the video signal wiring, the source electrode, and the capacitor electrode are formed of Ta films 141, 151, 161 and Al.
It is composed of a laminated electrode of the films 142, 152 and 162. By adopting such a structure, the Al films 142, 15
Since 2, 162 have a (220) orientation, it is possible to prevent whiskers and hillocks from growing from the Al film due to the heat treatment at the time of forming the protective film 23 for the reasons already described.

[0069]

Sixth Embodiment FIG. 18 is a sectional view of a pixel portion of another embodiment of a liquid crystal display device configured by using the scanning signal electrode having the structure of the second embodiment shown in FIG. 19 is a plan view of the embodiment of FIG.

Similar to the embodiment, the scanning signal electrode composed of the Ta electrode 10 and the Al electrode 11 is formed on the glass substrate 1. The surfaces and side surfaces of these electrodes are covered with a Ta ₂ O ₅ film 20 and an Al ₂ O ₃ film 21. The SiN film 22 having a film thickness of 400 nm and the a-Si: H film 30 having a film thickness of 50 nm are formed on these scanning signal electrodes in the same plane shape, and the video signal electrode 14 is formed on the a-Si: H film 30. And the source electrode 15 are formed. The pixel electrode 13 made of an ITO film is connected to the source electrode 15.

The pixel electrode 13 is arranged below the SiN film 22, and the a-Si: H film 30 and the SiN film 22 extend below the video signal electrode 14 along the video signal electrode 14, The a-Si: H film 30 and the SiN film 22 form the pixel electrode 1
Only the peripheral portion of the pattern No. 3 is covered. Pixel electrode 1
A capacitance electrode 16 is connected to 3, and the scanning signal electrode 11 and the capacitance electrode 16 form an additional capacitance. All of these are covered with a protective SiN film 23.

FIG. 20 is a sectional view taken along the line AA in FIG.
It is a figure which shows the concentration distribution of ³¹ P and ¹¹ B in the depth direction in the a-Si: H film 30. FIG. 21 is a diagram showing the concentration distribution of ³¹ P and ¹¹ B in the a-Si: H film 30 in the depth direction in the BB cross section in FIG. 18.

In the BB cross section in contact with the source electrode 15, only ³¹ P is introduced with a steep concentration profile that exponentially decreases from the surface. Also, TFT
The A-A cross-section that is the channel region, substantially equal amounts of ³¹
P and ¹¹ B are introduced.

With the above structure, the present embodiment has the following effects in addition to the effects described above.

A. The a-Si: H film 30 and the gate SiN film 31, which have been conventionally patterned by different photomasks,
Since the same pattern is patterned by one photomask, the number of photolithography steps is reduced by one, the number of steps can be reduced, and the manufacturing cost can be reduced.

B. The channel region of the TFT is ³¹ P
^{Since 11} B is mutually compensated to have a high resistance, the source electrode and the drain electrode can be separated without the etching of the n-type a-Si: H film which has been conventionally required.
The film 30 can be thinned. When the film thickness of the a-Si: H film 30 is 60 nm or less, it is possible to prevent a decrease in the off resistance of the TFT due to a photocurrent and obtain a good image quality. Also, a
When the Si: H film 30 is thinned, it is not necessary to form a channel protection film, which has been conventionally required, and the number of manufacturing steps is not increased.

C. Since the pixel electrode 13 and the video signal electrode 14 are separated by the a-Si: H film 30 and the gate SiN film 22, the pixel electrode 13 and the video signal electrode 14 are not short-circuited. For this reason, it is possible to reduce pixel defects mainly caused by the short circuit between the pixel electrode 13 and the video signal electrode 14. Further, the distance between the pixel electrode 13 and the video signal electrode 14 can be reduced, and the area of the pixel electrode 13 can be increased by that amount, and the pixel aperture ratio is improved. As a result, higher brightness of the display can be achieved.

22 to 29 are sectional views showing the manufacturing process of the embodiment shown in FIG.

In FIG. 22, Ta is placed on the glass substrate 1.
The film 10 and the Al film 11 are deposited by sputtering and patterned into a predetermined shape by using a photolithography technique. Next, the Ta ₂ O ₅ film 20 and the Al ₂ O ₃ film 2 are formed on the surface and the side surface of the Ta film and the Al film by the anodic oxidation method.
1 and 1.

In FIG. 23, an ITO film is deposited to a thickness of 110 nm by sputtering and patterned to form the pixel electrode 13.

In FIG. 24, the gate SiN film 22 is deposited to 400 nm by the plasma CVD method, and a-S
The i: H film 30 is formed to 50 nm.

[0082] In FIG. 25, by irradiating PH + without mass separation withdrawn from the discharge plasma of PH ₃ gas, the ions of the PH ₂ +, etc. with a low energy of about 2 keV, a-
P is introduced into the Si: H film 30. As an impurity doping technique using such an ion beam that does not perform mass separation, for example, Japanese Patent Laid-Open No. 2-199824 discloses a method using a magnetic bucket type ion source.

In FIG. 26, the gate SiN film 22 and the a-Si: H film 30 are processed into the same planar shape by the photolithography technique.

In FIG. 27, a Ti electrode is formed by sputtering and patterned to form a video signal electrode 14.
Then, the source electrode 15 and the capacitor electrode 16 are obtained.

In FIG. 28, using the pattern of the image signal electrode 14 and the source electrode 15 as a mask, ions such as BH + and B ₂ H ₂ + that do not undergo mass separation are irradiated at a low energy of about 2 keV to obtain a-Si: H. B is introduced into the channel region of the membrane 30. This can be easily realized by using a gas containing B such as B ₂ H ₆ as the discharge gas in the technique described above.

In FIG. 29, a protective SiN film is formed to complete the device.

If the above manufacturing process is adopted, as described above, the formation of the channel protective film, which has been conventionally required when thinning the a-Si: H film 30, becomes unnecessary, so that the manufacturing process is simplified. it can. In particular, when an ion beam of low energy that does not undergo mass separation is used as the impurity introduction method, the impurities can be efficiently introduced into a large area, so that the production efficiency is improved.

FIG. 30 is an equivalent circuit of the TFT substrate in the liquid crystal display device of the present invention. On the glass substrate 1, a plurality of scanning signal electrodes 10/11, a plurality of video signal electrodes 14 orthogonal thereto, and TFTs connected to these electrodes.
And a liquid crystal capacitance and an additional capacitance connected to the TFT. Scan signal electrode 10/11 and video signal electrode 1
A terminal 140 for connecting an external member is provided at either one of the end portions 4 and 4.

To display an image, the scanning signal electrode 10 /
A pulse signal is sequentially applied to 11 to turn on the TFTs for one row, and an image signal is applied from the video signal electrode to the liquid crystal layer during that time. This operation is repeated for each line.

FIG. 31 is an equivalent circuit of another TFT substrate in the liquid crystal display device of the present invention. A plurality of scanning signal electrodes 10 and 11 on the glass substrate 1, a plurality of video signal electrodes 14 orthogonal to the scanning signal electrodes 10 and 11, and TFTs connected to these electrodes.
And a liquid crystal capacitor and an additional capacitor connected to the TFT are the same as in the above example, but in the present embodiment, the scanning signal circuit 200 for driving the TFT is provided on the glass substrate 1. And the video signal circuit 210 is
It is formed using FT. By integrating the drive circuit on the glass substrate 1 as described above, the number of external parts is significantly reduced, and thus the overall cost can be significantly reduced. It is needless to say that the wiring material of the present invention can be applied in the same manner even when the number of such external connection terminals is small.

In the above-mentioned embodiments, the example using the inverted staggered type thin film transistor has been described. However, the wiring material of the present invention is not limited to this, and can be applied to a thin film transistor having a staggered type or coplanar type electrode structure. It is applicable in the same way and the same effect can be obtained.

FIG. 32 is a diagram showing a schematic cross section of a liquid crystal display device constituted by the thin film semiconductor device according to the present invention.
The central portion of FIG. 32 shows a cross section of one pixel portion, and the left side is
The left side edge of the pair of glass substrates 1 and 508 shows a cross section of a portion where the external lead terminal exists, and the right side shows a cross section of a right edge of the pair of glass substrates 1 and 508 where the external lead terminal does not exist. ing.

Scan signal electrodes 11 and video signal electrodes 14 are formed in a matrix on the lower glass substrate 1 based on the liquid crystal layer 506. The TFT formed near the intersection drives the pixel electrode 13 made of ITO.
Opposing glass substrate 508 which is opposed to the liquid crystal layer 506 with it sandwiched
A counter electrode 510 made of ITO, a color filter 507, a color filter protective film 511, and a light shielding film 512 serving as a black matrix pattern for light shielding are formed on the top. Sealing material S shown on each of the left and right sides of FIG.
The L is formed along the entire edges of the glass substrates 1 and 508 except for the liquid crystal filling port (not shown) so as to seal the liquid crystal layer 506. The sealing material is, for example, an epoxy resin.

Counter electrode 510 on counter glass substrate 508 side
Are connected to the external lead wiring formed on the glass substrate 1 by the silver paste material SIL at at least one place. The external connection wiring is formed in the same manufacturing process as the scanning signal wiring 10, the source electrode 15, and the video signal electrode 14. The respective layers of the alignment films ORI1, ORI2, the pixel electrode 13, the protective film 23, the color filter protective film 511, and the gate SiN film 21 are formed inside the seal material SL. The polarizing plate 505 is formed on the outer surface of each of the pair of glass substrates 1 and 508.

The liquid crystal layer 506 is enclosed between the lower alignment film ORI1 and the upper alignment film ORI2 that set the orientation of the liquid crystal molecules, and is sealed by the sealing material SL. The lower alignment film ORI1 is formed on the protective film 23 on the glass substrate 1 side. On the inner surface of the counter glass substrate 508,
Light-shielding film 512, color filter 507, color filter protective film 511, counter electrode 510, upper alignment film ORI2
Are sequentially stacked.

In this liquid crystal display device, the glass substrate 1 side and the counter glass substrate 508 side layer are separately formed, and then the upper and lower glass substrates 1 and 508 are superposed, and the liquid crystal 506 is sealed between them. To be When the transmission of light from the backlight BL is adjusted at the pixel electrode 13 part, the TFT
A drive type color liquid crystal display device is formed.

Since the liquid crystal display device of the present invention can use the scanning signal electrode made of Al having a low resistance, it is suitable for a large size / high definition. In addition, since it can be manufactured with a high yield by a simple manufacturing process, it is possible to significantly reduce the cost and provide an inexpensive liquid crystal display device.

The characteristic construction of the present invention is exemplified as follows.

1. An Al film in which the volume ratio of the crystal grains oriented such that the (220) plane is parallel to the film surface and the crystal grains oriented such that the (200) plane is parallel to the film surface is 0.5 or more. A wiring material including an alloy film containing Al as a main component.

2. An Al film in which the volume ratio of the crystal grains oriented so that the (220) plane is parallel to the film surface and the crystal grains oriented such that the (111) plane is parallel to the film surface is 0.5 or more. A wiring material including an alloy film containing Al as a main component.

3. A wiring material in which the volume ratio of the crystal grains having the second-largest content in the second orientation direction to the volume of the crystal grains having the highest content in the first orientation direction is approximately 0.5 or more.

4. Ta, Ta-N alloy, Nb, Nb-N
Alloy, Ta-Nb alloy, Ta-Nb-N alloy, Ta-T
i alloy, Ta-Ti-N alloy, W, Ta-W alloy, Ta
A first conductive film made of one metal of a --W--N alloy, and a second conductive film made of Al or an alloy containing Al as a main component and formed on the first conductive film. Laminated wiring material.

5. In the laminated wiring material as described in 4 above, crystal grains oriented so that the (220) plane contained in the Al film or an alloy film containing Al as a main component is parallel to the film surface and the (200) plane is the film surface. A laminated wiring material having a volume ratio of 0.5 or more with respect to the crystal grains oriented so as to be parallel to.

6. The scanning signal electrode formed on the insulating substrate, the video signal electrode formed so as to intersect the scanning signal electrode, the thin film transistor formed near the intersection of the scanning signal electrode and the video signal electrode, and connected to the thin film transistor In a liquid crystal display device comprising a pixel electrode and driving a liquid crystal by a thin film transistor, at least one of a scanning signal electrode and a video signal electrode has crystal grains oriented so that a (220) plane is parallel to a film surface and a (200) crystal grain. The volume ratio with the crystal grains oriented so that the plane is parallel to the film surface is
A liquid crystal display device formed of a wiring material including an Al film or an alloy film containing Al as a main component, which is 0.5 or more.

7. The scanning signal electrode formed on the insulating substrate, the video signal electrode formed so as to intersect the scanning signal electrode, the thin film transistor formed near the intersection of the scanning signal electrode and the video signal electrode, and connected to the thin film transistor In a liquid crystal display device including a pixel electrode and driving a liquid crystal by a thin film transistor, at least one of a scanning signal electrode and a video signal electrode is Ta, Ta-N alloy,
Nb, Nb-N alloy, Ta-Nb alloy, Ta-Nb-N
Alloy, Ta-Ti alloy, Ta-Ti-N alloy, W, Ta
A first conductive film made of one metal of a -W alloy and a Ta-W-N alloy, and a second conductive film made of Al or an alloy containing Al as a main component and formed on the first conductive film. A liquid crystal display device formed of a laminated wiring material composed of a film.

8. In the liquid crystal display device described in 7 above, it is contained in Al or an alloy containing Al as a main component (2
A liquid crystal display device in which the volume ratio of the crystal grains oriented so that the (20) plane is parallel to the film surface and the crystal grains oriented so that the (200) plane is parallel to the film surface is 0.5 or more.

9. The scanning signal electrode formed on the insulating substrate, the video signal electrode formed so as to intersect the scanning signal electrode, the thin film transistor formed near the intersection of the scanning signal electrode and the video signal electrode, and connected to the thin film transistor In a liquid crystal display device including a pixel electrode and driving liquid crystal by a thin film transistor, the scanning signal electrode is
A laminated film of two or more kinds of conductive films including at least an Al film or an alloy film containing Al as a main component, and Ta, Ta-N alloy, Nb, Nb-N alloy, Ta-Nb alloy, Ta-Nb.
-N alloy, Ta-Ti alloy, Ta-Ti-N alloy, W,
A liquid crystal display device in which a conductive film made of one metal of a Ta-W alloy and a Ta-W-N alloy is arranged above and below an Al film or an alloy film containing Al as a main component.

10. 10. The liquid crystal display device according to any one of 6 to 9 above, wherein a coating insulating film containing Al as a base material is formed on a surface and a side surface of an Al film or an alloy film containing Al as a main component.

11. 10. The liquid crystal display device according to any one of 6 to 9 above, wherein the Al film or an alloy film containing Al as a main component is present only at a position separated by 0.1 cm or more from one end of the scanning signal electrode.

12. 12. The liquid crystal display device according to any one of 6 to 11, wherein the film forming at least one of the scanning signal electrode and the video signal electrode is a gate electrode of a thin film transistor.

13. 13. The liquid crystal display device according to any one of 6 to 12 above, wherein the insulating film containing Al as a base material is
A liquid crystal display device which is an oxide film or a nitride film of Al.

14. A scanning signal electrode formed on an insulating substrate, a video signal electrode formed to intersect the scanning signal electrode, a thin film transistor formed near the intersection of the scanning signal electrode and the video signal electrode, and a pixel connected to the thin film transistor. In a liquid crystal display device having an active matrix substrate composed of electrodes and an external drive circuit connected to the active matrix substrate, and driving a liquid crystal by a thin film transistor, a connection terminal between the external drive circuit and a video signal electrode or a scanning signal electrode. , Ta, Ta-N alloy,
Nb, Nb-N alloy, Ta-Nb alloy, Ta-Nb-N
Alloy, Ta-Ti alloy, Ta-Ti-N alloy, W, Ta
-W alloy and Ta-W-N alloy liquid crystal display including a first conductive film made of one metal and a transparent conductive film made of a metal oxide formed on the first conductive film apparatus.

15. The scanning signal electrode including the wiring according to any one of 1 to 5 above, the gate insulating film of the thin film transistor formed on the scanning signal electrode, the semiconductor film formed on the gate insulating film, and the scanning signal electrode. In a liquid crystal display device including a video signal electrode formed as described above and a pixel electrode connected to a thin film transistor, in which a liquid crystal is driven by the thin film transistor, a semiconductor film and a gate insulating film in contact with the semiconductor film have the same plane. Shaped liquid crystal display device.

16. 16. The liquid crystal display device according to the above 15, wherein the semiconductor film and the gate insulating film in contact with the semiconductor film extend under the video signal electrode in a pattern wider than the video signal electrode.

17. In the liquid crystal display device according to the above 15 or 16, only one of an n-type impurity and a p-type impurity is introduced into a region of the semiconductor film, which is in contact with the source and drain metal electrodes, and a channel portion is introduced. A liquid crystal display device in which both n-type and p-type impurities are introduced.

18. 18. The liquid crystal display device according to any one of 15 to 17 above, wherein the semiconductor film has a film thickness of 60 n.
A liquid crystal display device made of any of hydrogenated amorphous Si of m or less, hydrogenated amorphous SiGe, and hydrogenated amorphous Ge.

19. In the liquid crystal display device described in the above 18, the concentration of n-type and p-type impurities is 10 ²¹ cm ⁻³ or more on the surface of the semiconductor film and 10 ¹⁹ cm ⁻³ or less at the interface between the semiconductor film and the gate insulating film. A liquid crystal display device.

20. 20. The liquid crystal display device according to any one of 15 to 19 above, wherein the pixel electrode is arranged under the semiconductor film and the gate insulating film.

21. 21. The liquid crystal display device according to the above 20, wherein the semiconductor film and the gate insulating film cover only the outer peripheral portion of the pixel electrode pattern.

22. The scanning signal electrode formed on the insulating substrate, the video signal electrode formed so as to intersect the scanning signal electrode, the thin film transistor formed near the intersection of the scanning signal electrode and the video signal electrode, and connected to the thin film transistor A method of manufacturing a liquid crystal display device, which comprises a pixel electrode and drives a liquid crystal by a thin film transistor, comprising: a. Ta, Ta-N alloy, Nb, Nb-N on insulating substrate
Alloy, Ta-Nb alloy, Ta-Nb-N alloy, Ta-T
i alloy, Ta-Ti-N alloy, W, Ta-W alloy, Ta
A first conductive film made of one metal of a WN alloy and Al or an alloy film containing Al as a main component are successively laminated in a vacuum, processed into a predetermined pattern, and a scan signal is formed. Forming at least one of an electrode and a video signal electrode b. Step of forming an insulating film covering a part of the scanning signal electrode c. A method for manufacturing a liquid crystal display device, which includes a step of removing only Al or an alloy film containing Al as a main component, out of a conductive film forming a scanning signal electrode using an insulating film as a mask.

23. 23. The method for manufacturing a liquid crystal display device according to the above 22, wherein the insulating film is formed by any one of an anodic oxidation method, a plasma oxidation method and a plasma nitriding method.

24. 23. The method for manufacturing a liquid crystal display device according to the above 22, wherein the insulating film is formed by a plasma CVD method or a sputtering method.

25. 23. In the method of manufacturing a liquid crystal display device according to the above 22, the step of removing only Al or an alloy film containing Al as a main component in the conductive film forming the scanning signal electrode using the insulating film as a mask is performed by using a hydrogen halide gas. A method for manufacturing a liquid crystal display device, which is an ion etching method using a mixed gas containing the same.

26. 23. The method for manufacturing a liquid crystal display device according to the above item 22, wherein the first conductive film and Al or an alloy film containing Al as a main component are continuously formed while maintaining a vacuum.

27. The scanning signal electrode formed on the insulating substrate, the video signal electrode formed so as to intersect the scanning signal electrode, the thin film transistor formed near the intersection of the scanning signal electrode and the video signal electrode, and connected to the thin film transistor A method of manufacturing a liquid crystal display device, which comprises a pixel electrode and drives a liquid crystal by a thin film transistor, comprising: a. Ta, Ta-N alloy, Nb, Nb-N on insulating substrate
Alloy, Ta-Nb alloy, Ta-Nb-N alloy, Ta-T
i alloy, Ta-Ti-N alloy, W, Ta-W alloy, Ta
A first conductive film made of one metal of a -W-N alloy is formed, and Al or an alloy film containing Al as a main component is formed on the first conductive film while keeping the surface of the first conductive film clean. Stacked
Process of forming a scanning signal electrode or a video signal electrode by processing into a predetermined pattern b. Step of forming an insulating film covering a part of the scanning signal electrode or the video signal electrode c. A method of manufacturing a liquid crystal display device, which includes a step of removing only Al or an alloy film containing Al as a main component in a conductive film forming a scanning signal electrode or a video signal electrode using an insulating film as a mask.

28. The scanning signal electrode formed on the insulating substrate, the video signal electrode formed so as to intersect the scanning signal electrode, the thin film transistor formed near the intersection of the scanning signal electrode and the video signal electrode, and connected to the thin film transistor A method of manufacturing a liquid crystal display device, which comprises a pixel electrode and drives a liquid crystal by a thin film transistor, comprising: a. Ta, Ta-N alloy, Nb, Nb-N on insulating substrate
Alloy, Ta-Nb alloy, Ta-Nb-N alloy, Ta-T
i alloy, Ta-Ti-N alloy, W, Ta-W alloy, Ta
A step of forming a first conductive film made of one metal of a -W-N alloy b. Step of removing a part of the surface layer of the first conductive film c. Step of stacking Al or an alloy film containing Al as a main component on the first conductive film from which a part of the surface layer is removed d. Step of processing the laminated film into a predetermined pattern to form a scanning signal electrode or a video signal electrode e. A step of forming an insulating film covering a part of the scanning signal electrode or the video signal electrode f. A method of manufacturing a liquid crystal display device, which includes a step of removing only Al or an alloy film containing Al as a main component in a conductive film forming a scanning signal electrode or a video signal electrode using an insulating film as a mask.

29. The scanning signal electrode formed on the insulating substrate, the video signal electrode formed so as to intersect the scanning signal electrode, the thin film transistor formed near the intersection of the scanning signal electrode and the video signal electrode, and connected to the thin film transistor A method of manufacturing a liquid crystal display device, which comprises a pixel electrode and drives a liquid crystal by a thin film transistor, comprising: a. Step of forming a scanning signal electrode by sequentially stacking a first conductive film and Al or an alloy film containing Al as a main component in a vacuum on an insulating substrate and processing into a predetermined pattern b. Step of forming an insulating film having a base material of a material forming each conductive film on a part of the surface and side surfaces of the scanning signal electrode c. Step of removing only Al or an alloy film containing Al as a main component from the conductive film forming the scanning signal electrode by using the insulating film as a mask d. Step of forming a transparent electrode film on the entire surface of the substrate and processing it into a predetermined shape to form a pixel electrode e. Step of forming a gate insulating film and a semiconductor film on the entire surface of the substrate f. A step of irradiating the semiconductor film with an ion beam containing phosphorus at an energy of 5 keV or less to introduce phosphorus into the semiconductor film g. Step of processing gate insulating film and semiconductor film into the same pattern h. Step of depositing a conductive film and processing it into a predetermined pattern to form a video signal electrode and a source electrode i. A method for manufacturing a liquid crystal display device, which comprises the step of irradiating a semiconductor film with an ion beam containing boron at an energy of 5 keV or less by using the pattern of the video signal electrode and the source electrode as a mask to introduce boron into the semiconductor film.

30. An information processing apparatus comprising the liquid crystal display device according to any one of 6 to 21 as display means.

31. An information processing apparatus comprising the liquid crystal display manufactured by the manufacturing method according to any one of the above 22 to 29 as display means.

[0130]

According to the present invention, with a minimum photolithography process, a low-resistance scanning signal electrode with few hillocks and an external connection terminal with high corrosion resistance are provided, and the pixel defect density is small and the pixel aperture ratio is large. The liquid crystal display device can be obtained, and the liquid crystal display device can be increased in size / definition / cost at the same time.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a laminated wiring material according to the present invention.

FIG. 2 is a diagram showing a comparison of surface irregularities of an Al film 11 formed on a glass substrate 1 and a Ta film 10, respectively.

FIG. 3 is a diagram showing an X-ray diffraction pattern of an Al thin film used for the wiring of the present invention in comparison with an X-ray diffraction pattern of a conventional Al film.

FIG. 4 Obtained from X-ray diffraction of the Al film (220)
It is a figure which shows the relationship between the intensity ratio of a diffraction peak of (2), and a (200) diffraction peak, and surface hillock density.

FIG. 5 is a plan view of a scanning signal wiring for a liquid crystal display device configured by using the laminated wiring material of the present invention.

6 is a cross-sectional view of an external connection terminal portion of the scanning signal wiring of FIG.

7 is a cross-sectional view of the plane AA of FIG. 6 viewed from the arrow direction.

FIG. 8 is a cross-sectional view showing an end portion of another embodiment of the scanning signal electrode of the liquid crystal display device according to the present invention.

9 is a cross-sectional view of the plane AA of FIG. 8 viewed from the arrow direction.

10 is a schematic cross-sectional view of a unit pixel of a liquid crystal display device configured by using the scanning signal electrode having the structure of the second embodiment shown in FIG.

FIG. 11 is a sectional view of an external connection terminal of a scanning signal electrode of a thin film transistor substrate.

FIG. 12 is a diagram showing a manufacturing process of the thin-film semiconductor device of the embodiment. The right side of the drawing is a diagram showing a cross section in each step of the scanning signal electrode terminal portion.

FIG. 13 is a diagram showing a manufacturing process of the thin-film semiconductor device of the embodiment. The right side of the drawing is a diagram showing a cross section in each step of the scanning signal electrode terminal portion.

FIG. 14 is a diagram showing a manufacturing process of the thin-film semiconductor device of the embodiment. The right side of the drawing is a diagram showing a cross section in each step of the scanning signal electrode terminal portion.

FIG. 15 is a diagram showing a manufacturing process of the thin-film semiconductor device of the embodiment. The right side of the drawing is a diagram showing a cross section in each step of the scanning signal electrode terminal portion.

FIG. 16 is a diagram showing a manufacturing process of the thin-film semiconductor device of the embodiment. The right side of the drawing is a diagram showing a cross section in each step of the scanning signal electrode terminal portion.

FIG. 17 is a cross-sectional view of a pixel of an embodiment in which the wiring material of the present invention is applied to a video signal wiring.

18 is a cross-sectional view of a pixel portion of another embodiment of the liquid crystal display device configured using the scanning signal electrode having the structure of the second embodiment shown in FIG.

FIG. 19 is a plan view of the embodiment of FIG.

20 is a diagram showing the concentration distribution of ³¹ P and ¹¹ B in the a-Si: H film 30 in the depth direction in the AA cross section in FIG. 18.

FIG. 21 is a diagram showing the concentration distribution of ³¹ P and ¹¹ B in the a-Si: H film 30 in the depth direction in the BB cross section in FIG. 18;

22 is a cross-sectional view showing the manufacturing process of the embodiment in FIG. 18. FIG.

23 is a cross-sectional view showing the manufacturing process of the embodiment in FIG. 18. FIG.

FIG. 24 is a cross-sectional view showing the manufacturing process of the embodiment in FIG.

FIG. 25 is a cross-sectional view showing the manufacturing process of the embodiment in FIG.

FIG. 26 is a cross-sectional view showing the manufacturing process of the embodiment in FIG.

FIG. 27 is a cross-sectional view showing the manufacturing process of the embodiment in FIG.

FIG. 28 is a cross-sectional view showing the manufacturing process of the embodiment in FIG.

FIG. 29 is a cross-sectional view showing the manufacturing process of the embodiment in FIG.

FIG. 30 is an equivalent circuit of a TFT substrate in the liquid crystal display device of the present invention.

FIG. 31 is an equivalent circuit of another TFT substrate in the liquid crystal display device of the present invention.

FIG. 32 is a diagram showing a schematic cross section of a liquid crystal display device constituted by a thin film semiconductor device according to the present invention.

[Explanation of symbols]

1 Glass Substrate 10 Ta Electrode 11 Al Electrode 13 Oriented to (220) Surface Pixel Electrode 14 Video Signal Electrode 15 Source Electrode 16 Capacitance Electrode 20 Ta ₂ O ₅ Film 21 Al ₂ O ₃ Film 22 Gate SiN Electrode 23 Protective SiN Film 30 a-Si: H film 31 n-type a-Si: H film 140 External connection terminals 141, 151, 161 Ta films 142, 152, 162 Al film 200 Scan signal circuit 210 Video signal circuit 505 Polarizing plate 506 Liquid crystal layer 507 Color filter 508 Counter glass substrate 510 Counter electrode 511 Color filter protective film 512 Light-shielding film BL backlight ORI Alignment film SL Seal material SIL Silver paste material

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02F 1/1345 G02F 1/1362 G02F 1/1343 G02F 1/13 101

Claims (3)

(57) [Claims] 1. A scanning signal electrode formed on an insulating substrate, a video signal electrode formed so as to intersect with the scanning signal electrode, and formed near an intersection of the scanning signal electrode and the video signal electrode. In a liquid crystal display device having a thin film transistor, the scanning signal electrodes are substantially the same except for a connection terminal portion.
It is composed of a metal first conductive film having a surface pattern and a second conductive film of Al or an alloy containing Al as a main component, which is disposed on the first conductive film. The second conductive film is connected to the external drive circuit and the scan signal.
It is formed on the second conductive film at the connection terminal portion with the electrode.
From the same position as the end of the insulating film pattern
The outer peripheral side is removed, and the connection terminal between the external drive circuit and the scanning signal electrode is
It is composed of the first conductive film and a transparent conductive film arranged on the first conductive film, and the pattern end portion of the second conductive film has the insulating film, the external drive circuit and the A liquid crystal display device characterized by being covered with a transparent conductive film extending from a connection terminal portion with a scanning signal electrode. 2. The liquid crystal display device according to claim 1, wherein the second conductive film has an upper surface mainly covered with an insulating film and a side surface mainly covered with the transparent conductive film. Liquid crystal display device. 3. The liquid crystal display device according to claim 1, wherein the first conductive film of the scanning signal electrode and the first conductive film of the connection terminal portion are continuously formed. A liquid crystal display device characterized by the above.