JPH06214255A - Wiring material and liquid crystal display device and production of liquid crystal display device - Google Patents

Abstract

PURPOSE:To provide the thin-film semiconductor device for the liquid crystal display device which is suitable for larger sizes/higher definition, realizes a high yield and can be produced by simple staged. CONSTITUTION:Scanning signal electrodes are constituted of laminated films of Ta electrodes 10 and Al electrodes 11, the main surface of which is oriented to a (220) face. Anodically oxidized films 20, 21 are formed on the front surface/ flanks of the laminated films. External connecting terminal parts are formed by etching away the Al electrodes 11 of the upper layer with the anodically oxidized films 20, 21 as a mask to expose only the Ta electrodes 10. An a-Si:H film 30 and a gate SiN film 22 are worked to the same patterns. Shorting defects are decreased by suppressing the hillock of the surface. The external connecting terminals having high corrosion resistance are realized. This structure is formable by one time of photolithographic stage and the production process is simplified.

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 type liquid crystal display device used as a display device for image information / character information in office automation equipment and the like, a wiring material therefor, and a method for manufacturing the liquid crystal display device.

[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 the reduction in 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 a scanning signal wiring with low resistance which can cope with higher definition / larger screen. The fourth issue 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 Application Laid-Open No. 61-133662 discloses that a gate insulating film of a TFT has a two-layer structure of an anodic oxide film of a gate electrode and a SiN film, and a pinhole of the gate insulating film or the like. Discloses a technique for preventing a short circuit between wirings (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 by using one photomask. It has been disclosed (third prior art).

Regarding the problem of the third technique of forming a low-resistance scanning signal wiring, Japanese Patent Laid-Open No. 2-85826 describes, for example, A.
There is disclosed 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 Al
When 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). ).

[0009]

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, when 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 outside the gate electrode, and the leak current of the TFT increases due to the photocurrent of the semiconductor film, which deteriorates 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, although the mask of the semiconductor film and the gate insulating film can be integrated to reduce the photo mask of one sheet, the semiconductor film is thinned in order to guarantee the image quality that can be practically used. It is necessary to increase the number of photomasks in order to form the channel protective film, and as a result, the process simplification due to the reduction of photomasks cannot be achieved.

When the third conventional technique and the fourth conventional technique are combined, the scanning signal wiring has a two-layer structure of a transparent electrode and an Al electrode which is a low resistance wiring. 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 liquid crystal encapsulation, there is a problem that if an active metal such as Al is used, it will be corroded. 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 also 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, it is not possible to achieve the second problem of reducing the number of steps.

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 wiring material for a liquid crystal display device which has high reliability and good image quality with a minimum number of photomasks and can be manufactured at low cost, a liquid crystal display device using the same, and a liquid crystal display device. Is to provide a method for manufacturing the same.

[0020]

[Means for Solving the Problems]

(1) In order to achieve the above object, the present invention provides (22
An Al film or an Al film in which the volume ratio of the crystal grains oriented so that the (0) 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. The present invention proposes a wiring material containing an alloy film containing as a main component.

(2) In order to achieve the above-mentioned object, the present invention provides that crystal grains oriented so that the (220) plane is parallel to the film surface and the (111) plane is parallel to the film surface. Al whose volume ratio to the oriented crystal grains is 0.5 or more
A wiring material including a film or an alloy film containing Al as a main component is proposed.

(3) In other words, in the present invention, in order to achieve the above object, the second orientation having the second largest content with respect to the volume of the crystal grains having the first orientation direction having the highest content is used. The present invention proposes a wiring material in which the volume ratio of directional crystal grains is approximately 0.5 or more.

(4) In order to achieve the above object, the present invention is specifically 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. It proposes a laminated wiring material.

(5) In the case of the laminated wiring material of (4), Al
Contained in a film or an alloy film containing Al as a main component (22
The volume ratio of the crystal grains oriented so that the (0) plane is parallel to the film surface and the crystal grains oriented so that the (200) plane is parallel to the film surface is preferably 0.5 or more.

(6) In order to achieve the above object, the present invention further comprises a scanning signal electrode formed on an insulating substrate,
A video signal electrode formed so as 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 electrode connected to the thin film transistor, and the liquid crystal is driven by the thin film transistor. In the liquid crystal display device, at least one of the scanning signal electrode and the video signal electrode is oriented so that the (220) plane is parallel to the film surface and the (200) plane is parallel to the film surface. The volume ratio to the crystal grains is 0.
The present invention proposes 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 5 or more.

(7) 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 a scanning signal electrode. In a liquid crystal display device including a thin film transistor formed near an intersection of video signal electrodes and a pixel electrode connected to the thin film transistor, wherein at least one of the scanning signal electrode and the 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-W alloy, T
a first conductive film made of one metal of an aWN alloy, and a first conductive film made of Al or an alloy containing Al as a main component.
The present invention proposes a liquid crystal display device formed of a laminated wiring material composed of a second conductive film formed on the conductive film.

(8) In the case of the liquid crystal display device of (7), A
Included in alloys based on l or Al (220)
Crystal grains oriented so that the plane is parallel to the film surface (20
The volume ratio with the crystal grains oriented so that the (0) plane is parallel to the film surface is 0.5 or more.

(9) In order to achieve the above object, the present invention further comprises a scanning signal electrode formed on an insulating substrate,
A video signal electrode formed so as 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 electrode connected to the thin film transistor, and the liquid crystal is driven by the thin film transistor. In the liquid crystal display device, the scanning signal electrode includes at least an Al film or an alloy film containing Al as a main component.
It is a laminated film of at least one kind of conductive film, Ta, Ta-N alloy,
Nb, Nb-N alloy, Ta-Nb alloy, Ta-Nb-N
Alloy, Ta-Ti alloy, Ta-Ti-N alloy, W, Ta
The present invention proposes a liquid crystal display device in which a conductive film made of one metal of a -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) In the liquid crystal display device according to any one of the above (6) to (9), a coating insulating film containing Al as a base material is formed on the surface and side surfaces of the Al film or an alloy film containing Al as a main component. Can be formed.

(11) Further, in the liquid crystal display device according to any one of (6) to (9), the Al film or the alloy film containing Al as a main component is 0.1 cm from one end of the scanning signal electrode.
It is possible to make them exist only at the positions distant from each other.

(12) Further, in the liquid crystal display device according to any one of the above (6) to (11), the film forming at least one of the scanning signal electrode and the video signal electrode may also serve as the gate electrode of the thin film transistor. Good.

(13) The insulating film containing Al as a base material is specifically an Al oxide film or a nitride film.

(14) 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 to intersect the scanning signal electrode, a scanning signal electrode and an image. A liquid crystal display having a thin film transistor formed near an intersection of signal electrodes, an active matrix substrate including a pixel electrode connected to the thin film transistor, and an external drive circuit connected to the active matrix substrate, and driving a liquid crystal by the thin film transistor. In the device, the connection terminals of the external drive circuit and the video signal electrodes or the scanning signal electrodes are 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 liquid crystal display device including a first conductive film made of one metal of a -WN alloy and a transparent conductive film made of a metal oxide formed on the first conductive film is proposed. Is.

(15) The scanning signal electrode formed by any of the wirings (1) to (5), the gate insulating film of the thin film transistor formed on the scanning signal electrode, and the semiconductor film formed on the gate insulating film. And a video signal electrode formed to intersect with the scanning signal electrode and a pixel electrode connected to a thin film transistor, in a liquid crystal display device that drives liquid crystal by the thin film transistor, a semiconductor film and gate insulation in contact with the semiconductor film. The film can have the same planar shape.

(16) In the case of the liquid crystal display device described in (15), the semiconductor film and the gate insulating film in contact with the semiconductor film are extended under the video signal electrode in a pattern wider than the video signal electrode. It is also possible.

(17) In the liquid crystal display device according to (15) or (16), only one of n-type and p-type impurities is present in the region of the semiconductor film which is in contact with the source and drain metal electrodes. May be introduced, and both n-type and p-type impurities may be introduced into the channel portion.

(18) In the liquid crystal display device according to any one of (15) to (17), the semiconductor film is hydrogenated amorphous Si, hydrogenated amorphous SiGe, hydrogenated amorphous having a film thickness of 60 nm or less. It is one of the quality Ge.

(19) In this case, the concentrations of the n-type and p-type impurities are 10 ²¹ cm to ³ or more on the surface of the semiconductor film and 10 ¹⁹ cm to ³ or less at the interface between the semiconductor film and the gate insulating film. Is desirable.

(20) In the liquid crystal display device according to any one of (15) to (19), the pixel electrode can be arranged under the semiconductor film and the gate insulating film.

(21) Further, the semiconductor film and the gate insulating film can cover only the outer peripheral portion of the pattern of the pixel electrode.

(22) In order to achieve the above object, the present invention further comprises a scanning signal electrode formed on an insulating substrate,
A video signal electrode formed so as 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 electrode connected to the thin film transistor, and the liquid crystal is driven by the thin film transistor. A method of manufacturing a liquid crystal display device, 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. The present invention proposes 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 using an insulating film as a mask.

(23) In the method of manufacturing a liquid crystal display device according to (22), the insulating film is formed by any one of the anodic oxidation method, the plasma oxidation method and the plasma nitriding method.

(24) Further, the insulating film is formed by plasma CVD.
Method or sputtering method.

(25) Further, in the 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, a mixed gas containing hydrogen halide gas is used. Ion etching method is used.

(26) The first conductive film and the Al or alloy film containing Al as a main component can be continuously formed while maintaining a vacuum.

(27) In order to achieve the above object, the present invention further provides a scanning signal electrode formed on an insulating substrate, a video signal electrode formed so as to intersect the scanning signal electrode, and a scanning signal. A method of manufacturing a liquid crystal display device comprising a thin film transistor formed near an intersection of an electrode and a video signal electrode, and a pixel electrode connected to the thin film transistor, wherein a liquid crystal is driven by the thin film transistor. 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 of the -W-N alloys 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. Step of stacking and processing into a predetermined pattern to form a scanning signal electrode or a video signal electrode b. Step of forming an insulating film covering a part of the scanning signal electrode or the video signal electrode c. The present invention proposes 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) In order to achieve the above-mentioned object, the present invention further comprises a scanning signal electrode formed on an insulating substrate,
A video signal electrode formed so as 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 electrode connected to the thin film transistor, and the liquid crystal is driven by the thin film transistor. A method of manufacturing a liquid crystal display device, 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. Step of forming an insulating film covering a part of the scanning signal electrode or the video signal electrode f. The present invention proposes 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) 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 a scanning signal electrode. A method of manufacturing a liquid crystal display device, comprising a thin film transistor formed near an intersection of video signal electrodes and a pixel electrode connected to the thin film transistor, wherein the thin film transistor drives liquid crystal. 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 on an insulating substrate in a vacuum and processing them 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 the side surface of the scanning signal electrode c. Step of removing only Al or an alloy film containing Al as a main component among the conductive films forming the scanning signal electrode 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. 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 of manufacturing a liquid crystal display device including a step of irradiating a semiconductor film with an ion beam containing boron at an energy of 5 keV or less and introducing boron into the semiconductor film using the pattern of the image signal electrode and the source electrode as a mask. is there.

(30) The present invention provides the above (6) to (21).
Any one of the liquid crystal display devices described above or (22) to (2) above.
The present invention proposes an information processing apparatus including a liquid crystal display manufactured by any one of the manufacturing methods 9) as a display means, such as a workstation or a personal computer.

[0050]

[Function] First, which has the highest content, such as (1), (2) and (3)
An Al film or an alloy film containing Al as a main component, in which the volume ratio of the crystal grains having the second orientation direction is approximately 0.5 or more with respect to the volume of the crystal grains having the second orientation direction. The inclusion of the wiring material can suppress the generation of hillocks on the Al surface. 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.

More specifically, as in (4), (5), (6) and (8), Ta, Ta-N alloy, Nb, Nb-N alloy and Ta are used.
-Nb alloy, Ta-Nb-N alloy, Ta-Ti alloy, T
A first conductive film made of one metal selected from a-Ti-N alloy, W, Ta-W alloy, and W-Ta-N alloy, and Al or Al formed on the first conductive film as a main component. And a second conductive film made of an alloy of
In the Al film or the alloy film containing Al as a main component, the (220) plane is oriented so that the (220) plane is parallel to the film surface, and
When the volume ratio of the crystal grains oriented so that the (0) plane is parallel to the film surface is 0.5 or more, 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.

When the laminated wiring is used for the scanning signal electrode of the liquid crystal display device as in (7), 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.

As shown in (9), Ta, Ta-N alloy, N
b, Nb-N alloy, Ta-Nb alloy, Ta-Nb-N alloy, Ta-Ti alloy, Ta-Ti-N alloy, W, Ta-
If one metal of the W alloy and the W-Ta-N alloy is arranged not only in the lower layer of Al or an alloy containing Al as a main component but also in the upper layer, hillock growth on the Al surface is suppressed and short-circuit defects are reduced. it can.

When the surface of Al is entirely covered with an insulating film having Al as a base material as in (10), Al is not exposed to chemicals and the like, so that corrosion resistance can be secured and Al can be secured. Generation of hillocks on the surface can be further suppressed. A
As an insulating film using l as a base material, as shown in (13), Al
The oxide film or the nitride film can be used.

As shown in (11), Al is formed only at a position separated by 0.1 cm or more from one end of the scanning signal electrode, and Ta, Ta-N alloy, Nb, Nb-N alloy is arranged in the lower layer of Al. , Ta-Nb alloy, Ta-Nb-N alloy, Ta-Ti
Alloy, Ta-Ti-N alloy, W, Ta-W alloy, W-
If the external connection terminal is made of one metal of the Ta-N alloy and Al, which is easily corroded, is not exposed to chemicals, the corrosion resistance at the terminal portion is improved.

As shown in (14), Ta, Ta-N alloy, N
b, Nb-N alloy, Ta-Nb alloy, Ta-Nb-N
Alloy, Ta-Ti alloy, Ta-Ti-N alloy, W, Ta
When the external connection terminal is composed of the transparent conductive film made of one metal of the -W alloy and the W-Ta-N alloy and the metal oxide formed on the upper layer thereof, the chemical resistance of the terminal is improved and the transparent conductive film is formed. The insulating barrier layer is less likely to be formed at the interface due to the reaction between the metal and the metal. Therefore, it is possible to prevent an increase in contact resistance of the connection terminal and obtain a highly reliable connection terminal.

The structures (9) and (10) can be formed by etching away Al 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.

When the laminated film forming the scanning signal electrode is also used as the gate electrode of the thin film transistor as in (12), the scanning signal electrode and the gate electrode of the thin film transistor can be formed by one photoetching step. The number can be reduced.

In the liquid crystal display device having the scanning signal electrodes of the structures (4) and (5) as described in (15), when the gate insulating film and the semiconductor film are formed in the same pattern, the gate insulating film and the semiconductor film are formed. And can be formed in one photoetching step, and the number of steps can be further reduced.

At this time, as in (17), n-type impurities are introduced into the portions of the semiconductor film which are in contact with the source and drain metal electrodes, and n-type impurities are introduced into the channel portion of the TFT.
By introducing both p-type impurities, n in the channel portion of the TFT
When the p-type impurity and the p-type impurity are mutually compensated, the semiconductor film in the channel portion has a high resistance, and the source and drain electrodes are electrically connected without the conventional etching process of the n-type a-Si film. Can be separated. Conventionally, n
The intrinsic a-Si film could not be thinned because the selection ratio between the type a-Si film and the intrinsic a-Si film was small. Intrinsic a-
In order to reduce the thickness of the Si film, as described above, it was necessary to add one photomask and protect the channel portion of the TFT with the SiN film or the like. On the other hand, in the structure of the present invention, n
The etching of the mold a-Si film becomes unnecessary. Therefore,
The semiconductor film can be thinned without using a photomask for forming the protective film of the channel portion. As a result, even if the gate insulating film and the semiconductor film are formed in the same pattern, it is possible to prevent a decrease in the off-resistance of the TFT due to a photocurrent, reduce the number of manufacturing steps, and ensure good image quality.

In order to make ohmic contact between the source and drain metal electrodes and the semiconductor film in the TFT having the above structure, the n-type impurity concentration in the semiconductor film is 10 ²¹ cm 2.
Must be ~ ³ or higher. Further, in order to compensate for the n-type impurities in the channel region, it is necessary to introduce the p-type impurities of about the same concentration. Hydrogenated amorphous Si and hydrogenated amorphous S
In a material such as iGe, if impurities are introduced to control the conductivity, the defect density in the film increases in proportion to the 1/2 power of the impurity concentration. Therefore, if these n-type impurities and p-type impurities are uniformly introduced into the semiconductor film, the impurity concentration near the interface between the semiconductor serving as the carrier storage layer and the gate insulating film also becomes a high concentration of about 10 ²¹ cm ^-3. Because it will
The defect density in the semiconductor film increases and the characteristics of the TFT deteriorate.

Therefore, as in (19), the concentration of the introduced n-type impurities and p-type impurities is 10 ²¹ cm to ³ or more on the film surface and 10 ¹⁹ cm to ³ or less on the interface between the semiconductor and the gate insulating film. To do. That is, by increasing the impurity concentration in the portion in contact with the metal electrode and decreasing the impurity concentration near the interface between the semiconductor serving as the carrier storage layer and the gate insulating film, the interface is maintained while maintaining good ohmic contact between the semiconductor film and the metal electrode. The increase in the defect density in the nearby semiconductor film can be suppressed, and TF
It is possible to suppress the deterioration of the T characteristic.

As in (16), (19) and (20), the 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 imaged along the video signal electrode. The pixel electrode and the video signal electrode can be separated by extending the pattern wider than the signal electrode and covering only the peripheral portion of the pattern of the pixel electrode. 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 a reduction in the number of steps, high yield, low resistance wiring, and improved reliability of terminals, a liquid crystal display device with low defects and high brightness can be realized.

After forming the Ta film, the inventors formed an Al film continuously in vacuum while keeping 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 description of the following embodiments.

[0066]

【Example】

Example 1 FIG. 1 is a perspective view of an example of a laminated wiring material according to the present invention. The laminated wiring material of this embodiment is formed by sequentially laminating a Ta film 10 and an Al film 11 on a glass substrate 1 by a magnetron sputtering method and processing them 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 because Al grows under the influence of a 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 hillocks grow. At this time, 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, so that an adsorption layer of H ₂ O or the like is not formed on the Ta surface as in the conventional case. 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 of the (0) diffraction peak to the (111) diffraction peak was 0.15 in the conventional Al film.
In the l film, it becomes as large as 0.7 or more. Conventional Al
It can be seen that in the Al film of the present invention, the diffraction peak from the (220) plane is larger and the diffraction peak from the (111) plane is smaller than that of the film. In the Al film of the present invention, the crystal grains strongly oriented in the (111) plane in the conventional Al film are
It is considered that the growth of the (220) plane causes a random orientation as a whole. 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 was, for example, about 0.5 in the conventional Al film, but in the present invention, it is about 0.5. It goes from 7 to 1.0. For this reason,
It is presumed that the average crystal grain size became slightly smaller and the variation in grain size also became smaller, resulting in uniformization.

In the conventional Al wiring used in LSI, if the crystal grains of Al are miniaturized, the resistance to electromigration and stress migration is reduced. 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.

As the material of the base, not only Ta but also bc
Any metal having a crystal structure of c may be used. For example, Ta
-N alloy, Nb, Ta-Nb alloy, Nb-N alloy, Ta
Similar effects can be obtained by using -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 T surface.
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.

Example 2 FIG. 5 is a plan view of a scanning signal wiring for a liquid crystal display device 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 a Ta ₂ O ₅ film is formed on the surface and side surface of these.
20 and an Al ₂ O ₃ film 21. Here, the Al ₂ O ₃ film 21 is an upper layer film of the two-layer conductive film.
It was formed so as to cover the entire surface of the electrode 11. 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 of the scanning signal electrode (the distance X is 1.0 cm in this example), and from the end in contact with the external member. The Al electrode 11 was eliminated.

According to this embodiment, the Al electrode, which is easily corroded, is completely covered with the Al ₂ O ₃ film, and the Al electrode having a low resistance is used as the scanning signal electrode while excluding it from the end portion in contact with the external member. Since it can be used, high definition / large size of the display device can be achieved. X is 0.1c for reliable connection with external members
It should be m or more. Further, Ta having high corrosion resistance is arranged under the Al electrode which is easily corroded, and the structure is such that the end faces of the Al ₂ O ₃ film and the Al electrode are aligned with each other, and the Al ₂ O ₃ film is used as a mask for the Al electrode at the end. Since the external connection terminal is formed by etching away, the photomask for metal working the connection terminal is not required, 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.

<< Embodiment 3 >> 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 is composed of a two-layer Ta electrode 10 and an Al electrode 11 sandwiched therebetween.
The layer is made of a conductive film. Similar to the above embodiment, the surface and side surface of these films are covered with the Ta ₂ O ₅ film 20 and the Al ₂ O ₃ film 21, and the surface of the Ta electrode 10 as the uppermost film is
All are 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 portion of the scanning signal electrode, and the Al electrode 11 was excluded from the end portion in contact with the external member.

According to this embodiment, in addition to the same effect as that of the first embodiment, a Ta ₂ O ₅ film having a large relative dielectric constant is used as a TF film.
Since it can be used as a part of the gate insulating film of T,
The mutual conductance of 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.

<Embodiment 4> FIG. 10 is a schematic cross-sectional view of a unit pixel of a liquid crystal display device using the scanning signal electrode having the structure of Embodiment 2.

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. A SiN film 22, an a-Si: H film 30, and an n-type a-Si: H film 31 are formed on these scanning signal electrodes, and a video signal electrode 14 and an image signal electrode 14 are formed on the n-type a-Si: H film 31. A source electrode 15 is formed, 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, among the scanning signal electrodes, the surface of the upper Al electrode 11 is Al ₂
The Ta electrode 10 is covered with an O ₃ film 21 and the Ta electrode 10 is covered with an Al ₂ O ₃ film 2
1 is extended to the outside to form an external connection terminal. The Ta electrode 10 is covered with the ITO electrode 13.
In this embodiment, Ta / I is produced by the reaction between Ta and ITO.
Since the barrier layer formed at the TO interface does not have perfect insulation, the contact resistance between Ta and ITO is, for example, Al.
Compared with the case where ITO and ITO are combined, the size is significantly 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 the present embodiment, Ta was used as the base metal, but other than Ta, Ta-N alloy, Nb, Ta-Nb alloy, Nb-N alloy, Ta-Nb-N alloy, Ta-Ti alloy, Ta-Ti-N alloy, W, Ta-W alloy, Ta-W
Similar effects can be obtained even with -N alloy. In particular, Ta-
When a metal nitride such as N or Ti-N is used, the metal and ITO
The reaction can be further suppressed and the contact resistance can be made extremely small.

12 to 16 are views showing a manufacturing process 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.
The Ta ₂ O ₅ film 2 is formed on the surface and the side surface of the film 10 and the Al film 11.
0 and an Al ₂ O ₃ film 21 are formed.

In FIG. 14, with 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, a-Si: H film 30, and 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 by using the Al ₂ O ₃ film as a mask, the photomask for processing the external connection terminal metal, which has been conventionally required, is not required, and the number of steps can be reduced. Furthermore, by suppressing hillocks on the Al surface,
Since it is possible to reduce interlayer short-circuit and use a low-resistance Al electrode for the scanning signal electrode, it is possible to realize high definition / large size of the liquid crystal display device.

In the above embodiments, Ta and Al were used for the scanning signal electrode, but the present invention is not limited to this combination, and W, Nb or an alloy containing them, such as Ta, is used instead of Ta.
The same applies when N, Nb-N, Ta-Nb-N, Ta-Ti-N or the like is used. Further, not only pure Al but also Al-
You may use alloys, such as Pd, Al-Ta, and Al-Ti-Ta.

Further, in the above-mentioned embodiment, a method of exposing the Ta electrode of the external connection terminal is used by using the Al ₂ O ₃ film formed on the surface of Al as a mask, but 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.

Example 5 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.
FIG. 17 is a sectional view of a pixel of an embodiment in which the wiring material according to the present invention is applied to the video signal wiring. In the present embodiment, in addition to the structure of the first embodiment, the Ta film 141, 151, 161 includes the video signal wiring, the source electrode and the capacitor electrode.
And a laminated electrode of Al films 142, 152, 162. By adopting such a structure, the Al film 14
Since 2, 152 and 162 have a (220) orientation, for the reasons already described, Al by heat treatment during the formation of the protective film 23 is formed.
The growth of whiskers and hillocks from the film can be prevented.

<Embodiment 6> FIG. 18 is a sectional view of a pixel portion of an embodiment of another liquid crystal display device configured by using the scanning signal electrode having the structure of Embodiment 2 shown in FIG. FIG. 19
FIG. 19 is a plan view of the embodiment of FIG. 18.

As in the above-mentioned embodiment, Ta was formed on the glass substrate 1.
A scanning signal electrode composed of the electrode 10 and the Al electrode 11 is formed. 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 planar shape, and the video signal electrode 14 is formed on the a-Si: H film 30. And the source electrode 15 are formed. The source electrode 15 has an IT
The pixel electrode 13 made of an O film is connected.

The pixel electrode 13 is arranged under the SiN film 22, and the a-Si: H film 30 and the SiN film 22 extend under 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 line AA in FIG.
a-Si: it is a diagram showing the concentration distribution in the depth direction of ³¹ P and ¹¹ B 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 sharp concentration profile that exponentially decreases from the surface. Further, in the AA cross section which is the channel region of the TFT, the amount of ³¹ P is almost equal.
¹¹ B has been introduced.

With the above structure, the present embodiment has the following effects in addition to the effects described above. a. Conventionally, patterning was performed using separate photomasks
Since the Si: H film 30 and the gate SiN film 31 are patterned into the same shape with one photomask, the photolithography process is reduced by one time, and the number of processes can be reduced.
Manufacturing cost can be reduced. b. In the channel region of the TFT, ³¹ P and ¹¹ B are mutually compensated to increase the resistance, so that the n-type a-
Since the source electrode and the drain electrode can be separated without etching the Si: H film, the a-Si: H film 30 can be thinned. When the 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. Further, when the a-Si: H film 30 is thinned, it is not necessary to form a channel protective film, which has been conventionally required, so that the number of manufacturing steps is not increased. c. The pixel electrode 13 and the video signal electrode 14 are a-Si: H.
Since the film 30 and the gate SiN film 22 are separated from each other, the pixel electrode 13 and the video signal electrode 14 are not short-circuited. Therefore, mainly the pixel electrode 13 and the video signal electrode 1
It is possible to reduce the pixel defect caused by the short circuit with No. 4. 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, the glass substrate 1
A Ta film 10 and an Al film 11 are deposited thereon by sputtering and patterned into a predetermined shape by using a photolithography technique. Next, the Ta film and the A film are anodized.
A Ta ₂ O ₅ film 20 and an Al ₂ O ₃ film 21 are formed on the surface and side surfaces of the I film.

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 plasma CVD, and a-Si:
The H film 30 is formed to 50 nm.

[0105] 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-S
Introduce P into the i: 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 video 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-mentioned 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, is 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 one row of TFTs, while an image signal is applied to the liquid crystal layer from the video signal electrode. 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 capacitance and an additional capacitance 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 T. 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, an example using an inverted staggered type thin film transistor has been described, but 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. Opposed glass substrate 5 that is opposed to the liquid crystal layer 506.
On the 08, a counter electrode 510 made of ITO, a color filter 507, a color filter protective film 511, and a light shielding film 512 to be a black matrix pattern for light shielding are formed. The sealing material SL shown on each of the left side and the right side of FIG. 32 is formed along the entire edges of the glass substrates 1 and 508 excluding the liquid crystal filling port (not shown) so as to seal the liquid crystal layer 506. There is. 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 sealed 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.

[0121]

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.

FIG. 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 Example 2 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 example. 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 above 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 above 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 above 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 above 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 example in which the wiring material of the present invention is applied to video signal wiring.

FIG. 18 is a cross-sectional view of a pixel portion of another embodiment of the liquid crystal display device configured by 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.

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

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

FIG. 25 is a cross-sectional view showing the manufacturing process of the embodiment of 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 of 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 Oriented on (220) Surface 13 Pixel Electrode 14 Video Signal Electrode 15 Source Electrode 16 Capacitive 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 terminal 141, 151, 161 Ta film 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 the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01L 29/784

Claims (31)

[Claims] 1. The volume ratio of the crystal grains oriented so that the (220) 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. A wiring material containing the Al film or an alloy film containing Al as a main component. 2. The volume ratio of the crystal grains oriented so that the (220) plane is parallel to the film surface and the crystal grains oriented so that the (111) plane is parallel to the film surface is 0.5 or more. A wiring material containing the Al film or an alloy film containing Al as a main component. 3. The volume ratio of the crystal grains having the second highest 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. A wiring material characterized by being present. 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. The laminated wiring material according to claim 4, wherein the (220) plane included in the Al film or the alloy film containing Al as a main component is oriented so that the (220) plane is parallel to the film surface. A laminated wiring material having a volume ratio to a crystal grain oriented such that a (200) plane is parallel to the film surface is 0.5 or more. 6. 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. A liquid crystal display device comprising a thin film transistor and a pixel electrode connected to the thin film transistor, wherein liquid crystal is driven by the thin film transistor, wherein at least one of the scanning signal electrode and the video signal electrode has a (220) plane parallel to a film surface. The Al film or the alloy film containing Al as a main component, in which the volume ratio of the crystal grains oriented so that the (200) plane is parallel to the film surface is 0.5 or more. A liquid crystal display device characterized by being formed of a wiring material containing the same. 7. A scanning signal electrode formed on an insulating substrate, a video signal electrode formed so as to intersect the scanning signal electrode, and formed near an intersection of the scanning signal electrode and the video signal electrode. A liquid crystal display device comprising a thin film transistor and a pixel electrode connected to the thin film transistor, wherein liquid crystal is driven by the thin film transistor, wherein at least one of the scanning signal electrode and the 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-W alloy, Ta-W-N alloy, a first conductive film made of one metal, and Al or an alloy containing Al as a main component. A liquid crystal display device, comprising a laminated wiring material formed of a second conductive film formed on the film. 8. The liquid crystal display device according to claim 7, wherein the Al is contained in the Al or an alloy containing Al as a main component.
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. Liquid crystal display device. 9. A scan signal electrode formed on an insulating substrate, a video signal electrode formed so as to intersect the scan signal electrode, and formed near an intersection of the scan signal electrode and the video signal electrode. A liquid crystal display device comprising a thin film transistor and a pixel electrode connected to the thin film transistor, wherein liquid crystal is driven by the thin film transistor, wherein the scanning signal electrodes include at least two kinds including an Al film or an alloy film containing Al as a main component. A laminated film of conductive films of Ta, Ta-N alloy, Nb, Nb-N alloy, Ta-Nb
Alloy, Ta-Nb-N alloy, Ta-Ti alloy, Ta-T
The conductive film made of one of i-N alloy, W, Ta-W alloy, and Ta-W-N alloy is the Al film or Al.
A liquid crystal display device, wherein the liquid crystal display device is arranged in an upper layer and a lower layer of an alloy film containing as a main component. 10. The liquid crystal display device according to claim 6, wherein a coating insulating film containing Al as a base material is formed on a surface and a side surface of the Al film or an alloy film containing Al as a main component. A liquid crystal display device comprising: 11. The liquid crystal display device according to claim 6, wherein the Al film or an alloy film containing Al as a main component is separated from one end of the scanning signal electrode by 0.1 cm or more. A liquid crystal display device characterized in that it is present only at a certain position. 12. The liquid crystal display device according to claim 6, wherein a film forming at least one of the scanning signal electrode and the video signal electrode is a gate electrode of the thin film transistor. Characteristic liquid crystal display device. 13. The liquid crystal display device according to claim 6, wherein the insulating film containing Al as a base material is an oxide film or a nitride film of Al. apparatus. 14. A scanning signal electrode formed on an insulating substrate, a video signal electrode formed so as to intersect the scanning signal electrode, and a thin film transistor formed near an intersection of the scanning signal electrode and the video signal electrode. A liquid crystal display device having an active matrix substrate composed of a pixel electrode connected to the thin film transistor, and an external drive circuit connected to the active matrix substrate, wherein the thin film transistor drives liquid crystal. And a connection terminal between the video signal electrode or the scanning 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-W alloy, Ta-
A liquid crystal display comprising a first conductive film made of one metal of a W-N alloy and a transparent conductive film made of a metal oxide formed on the first conductive film. apparatus. 15. A scanning signal electrode formed by the wiring according to claim 1, a gate insulating film of a thin film transistor formed on the scanning signal electrode, and a gate insulating film formed on the gate insulating film. A semiconductor film, a video signal electrode formed so as to intersect with the scanning signal electrode, and a pixel electrode connected to the thin film transistor, wherein the thin film transistor drives liquid crystal. A liquid crystal display device, wherein the gate insulating film in contact with the semiconductor film has the same planar shape. 16. The liquid crystal display device according to claim 15, wherein the semiconductor film and a gate insulating film in contact with the semiconductor film extend under the video signal electrode in a pattern wider than the video signal electrode. A liquid crystal display device characterized in that 17. The liquid crystal display device according to claim 15, wherein only one of n-type and p-type impurities is present in a region of the semiconductor film which is in contact with the source and drain metal electrodes. Introduced in the channel part n
A liquid crystal display device in which both type and p-type impurities are introduced. 18. The liquid crystal display device according to claim 15, wherein the semiconductor film is a hydrogenated amorphous S having a film thickness of 60 nm or less.
i, hydrogenated amorphous SiGe, or hydrogenated amorphous Ge. 19. The liquid crystal display device according to claim 18, wherein the concentrations of the n-type and p-type impurities are 10 ²¹ cm to ³ or more on the surface of the semiconductor film, and at the interface between the semiconductor film and the gate insulating film. A liquid crystal display device characterized by having a size of 10 ¹⁹ cm to ³ or less. 20. The liquid crystal display device according to claim 15, wherein the pixel electrode is arranged in a lower layer of the semiconductor film and the gate insulating film. . 21. The liquid crystal display device according to claim 20, wherein the semiconductor film and the gate insulating film cover only an outer peripheral portion of the pattern of the pixel electrode. 22. A scanning signal electrode formed on an insulating substrate, a video signal electrode formed to intersect with the scanning signal electrode, and formed near an intersection of the scanning signal electrode and the video signal electrode. A method of manufacturing a liquid crystal display device, comprising a thin film transistor and a pixel electrode connected to the thin film transistor, wherein liquid crystal is driven by the thin film transistor, comprising: a. Ta, Ta-N alloy, Nb, Nb on the insulating substrate
-N alloy, Ta-Nb alloy, Ta-Nb-N alloy, Ta
-Ti alloy, Ta-Ti-N alloy, W, Ta-W alloy,
A first conductive film made of one metal of the Ta-W-N alloy and Al or an alloy film containing Al as a main component are successively and successively laminated in a vacuum, and processed into a predetermined pattern. Forming at least one of a scanning signal electrode and the video signal electrode b. Forming an insulating film covering a part of the scanning signal electrode c. A method of manufacturing a liquid crystal display device, comprising: a step of removing only Al or an alloy film containing Al as a main component in a conductive film forming the scanning signal electrode using the insulating film as a mask. 23. The method for manufacturing a liquid crystal display device according to claim 22, wherein the insulating film is formed by any one of an anodic oxidation method, a plasma oxidation method, and a plasma nitriding method. Method. 24. The method of manufacturing a liquid crystal display device according to claim 22, wherein the insulating film is formed by a plasma CVD method or a sputtering method. 25. The method for manufacturing a liquid crystal display device according to claim 22, wherein only Al or an alloy film containing Al as a main component is removed from the conductive film forming the scanning signal electrode by using the insulating film as a mask. A method of manufacturing a liquid crystal display device, wherein the step is an ion etching method using a mixed gas containing a hydrogen halide gas. 26. The method of manufacturing a liquid crystal display device according to claim 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. A method for manufacturing a characteristic liquid crystal display device. 27. A scanning signal electrode formed on an insulating substrate, a video signal electrode formed so as to intersect the scanning signal electrode, and formed near an intersection of the scanning signal electrode and the video signal electrode. A method of manufacturing a liquid crystal display device, comprising a thin film transistor and a pixel electrode connected to the thin film transistor, wherein liquid crystal is driven by the thin film transistor, comprising: a. Ta, Ta-N alloy, Nb, Nb on the insulating substrate
-N alloy, Ta-Nb alloy, Ta-Nb-N alloy, Ta
-Ti alloy, Ta-Ti-N alloy, W, Ta-W alloy,
A first conductive film made of one metal of the Ta-W-N alloy is formed, and Al or an alloy containing Al as a main component is formed on the first conductive film while maintaining the cleanliness of the surface of the first conductive film. Stacking films and processing them into a predetermined pattern to form the scanning signal electrodes or the video signal electrodes b. Forming an insulating film covering a part of the scanning signal electrode or the video signal electrode c. Al or A of the conductive film forming the scanning signal electrodes or the video signal electrodes using the insulating film as a mask
A method of manufacturing a liquid crystal display device, which comprises a step of removing only an alloy film containing 1 as a main component. 28. A scanning signal electrode formed on an insulating substrate, a video signal electrode formed so as to intersect the scanning signal electrode, and formed near an intersection of the scanning signal electrode and the video signal electrode. A method of manufacturing a liquid crystal display device, comprising a thin film transistor and a pixel electrode connected to the thin film transistor, wherein liquid crystal is driven by the thin film transistor, comprising: a. Ta, Ta-N alloy, Nb, Nb on the insulating substrate
-N alloy, Ta-Nb alloy, Ta-Nb-N alloy, Ta
-Ti alloy, Ta-Ti-N alloy, W, Ta-W alloy,
Step of forming first conductive film made of one metal of Ta-W-N alloy b. Step of removing a part of the surface layer of the first conductive film c. A is formed on the first conductive film from which a part of the surface layer is removed.
a step of laminating an alloy film containing 1 or Al as a main component d. Process the laminated film into a predetermined pattern to form the scanning signal electrode or the video signal electrode e. Forming an insulating film covering a part of the scanning signal electrode or the video signal electrode f. Al or A of the conductive film forming the scanning signal electrodes or the video signal electrodes using the insulating film as a mask
A method of manufacturing a liquid crystal display device, which comprises a step of removing only an alloy film containing 1 as a main component. 29. 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. A method of manufacturing a liquid crystal display device, comprising a thin film transistor and a pixel electrode connected to the thin film transistor, wherein liquid crystal is driven by the 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 on an insulating substrate in a vacuum and processing them 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 the side surface of the scanning signal electrode c. Step of removing only Al or an alloy film containing Al as a main component among the conductive films forming the scanning signal electrode 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 the gate insulating film and the 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 of manufacturing a liquid crystal display device, comprising 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. Method. 30. An information processing apparatus comprising the liquid crystal display device according to claim 6 as a display means. 31. An information processing device comprising a liquid crystal display device manufactured by the manufacturing method according to claim 22 as display means.