JPH06265933A - Liquid crystal display device and its production - Google Patents

Abstract

PURPOSE:To obtain such a device having excellent characteristics of an insulating film formed by anodic oxidation, and to obtain a Ta film or Nb film showing sufficiently slow etching rate than Al for active ion etching with chlorine gas. CONSTITUTION:Wirings and electrodes of the device consist of a two-layered film comprising a lower layer 2 of TaN allay or NbN alloy containing 15-40 atomic % N and an upper layer 3 of Al or Al-alloy. As for wiring terminals, only the upper layer is selectively removed so that the terminals consist of only the lower TaN alloy film or NbN allay film containing a specified amt. of nitrogen. By this method, a liquid crystal display device with high picture quality and high reliability can be produced without increasing the number of processes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a manufacturing method thereof, and more particularly to an electrode wiring of a thin film transistor active matrix used for driving the liquid crystal display device and a manufacturing method thereof.

[0002]

In Japanese Patent Laid-Open No. 64-35421, a scan electrode wiring is formed of an anodizable and low resistance Al film and an anodizable Ta film formed on the Al film, and the scan electrode wiring is formed. Disclosed is a thin film transistor array whose surface is covered with an anodic oxide film and a laminated film made of this anodic oxide film and SiN formed by a chemical vapor deposition method (hereinafter abbreviated as a CVD method) is used as a gate insulating film. In this thin film transistor array, by forming the scanning electrode wiring consisting of two layers by patterning once, it is possible to reduce the number of steps while using low resistance Al for the scanning electrode wiring, and to form an anodic oxide film on the wiring surface. By doing so, it is possible to prevent interlayer short-circuiting due to Al hillocks or protrusions such as whiskers due to thermal stress and increase the manufacturing yield.

Further, the wiring terminal portion of the thin film transistor substrate is generally used in a state of being exposed to various chemicals in the manufacturing process and usually exposed to the atmosphere.
Therefore, in Japanese Patent Laid-Open No. 3-58019, at least the wiring terminal portion is made of a stable metal such as Cr or Ta, the wiring portion other than the terminal portion includes a two-layer structure of Al / Ta, and is formed of Al / Ta. There is disclosed a thin film transistor substrate in which the surface of the formed wiring is covered with an anodic oxide film, and an electrode is formed only from a lower metal film, and a manufacturing method thereof. By creating the wiring terminal portion using a stable metal, it is possible to prevent corrosion of the wiring terminal portion during the manufacturing process and after completion, and to prevent the reliability of the connection with the external drive circuit from being impaired. The wiring resistance can be reduced by using low resistance Al for the wiring. Further, as in the above-mentioned Japanese Patent Laid-Open No. 64-35421, by forming a metal anodic oxide film for forming the scanning electrode wiring on the surface of the scanning electrode wiring, projections such as Al hillocks or whiskers due to thermal stress are formed. It is possible to prevent an interlayer short circuit caused by the above and increase the manufacturing yield.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In Japanese Laid-Open Patent Publication No. 64-35421, an anodization is performed by using a laminated structure of Al and Ta to reduce defects due to interlayer short-circuiting. Ta grows at a rate of / V, while Ta
Since the anodic oxide film of is grown at a rate of 1.7 nm / V,
The cross-sectional shape of the wiring after the anodic oxidation becomes an inverted taper shape that spreads upward. When the scan electrode wiring has a reverse taper shape,
There is a problem that the source electrode and the image signal electrode wiring formed in the upper layer are not formed well, and the wiring is easily broken. Moreover, sufficient consideration has not been given to the problems of leakage current of the anodic oxide film and corrosion of the terminal portion.

In Japanese Patent Laid-Open No. 3-58019 of the above-mentioned prior art, when the electrodes of the scanning electrode wiring, the wiring portion, and the terminal portion are patterned at a time with an Al / Ta laminated film, the Al of the scanning electrode wiring terminal portion is wired. When wet etching using mixed acid is performed in the step of selectively removing the upper insulating film using a mask, the etching rate ratio of Al to Ta is often large, but the etching proceeds isotropically so that the mask is used. An overhang of the insulating film used for is formed, which is not desirable. When the selective etching is performed by using a chlorine-based gas by reactive ion etching having a strong etching anisotropy, it is difficult to increase the etching rate ratio, and the lower Ta film is etched. Causes the problem. Further, there is a problem that the leakage current of the insulating film formed by anodic oxidation on the surface of the scanning electrode wiring formed of the Al / Ta laminated film is larger than the leakage current of the anodic oxide film of the scanning electrode wiring formed by only Al. . Since the electrode part is formed of one lower metal film, there is a problem that the number of photolithography steps is increased once.

An object of the present invention is to solve the above-mentioned problems at the same time, and to manufacture a liquid crystal display with high reliability and good image quality, which can be manufactured without increasing the number of steps while using Al having a low resistance as the material of the scanning electrode wiring. An object of the present invention is to provide a structure of a device and a manufacturing method thereof.

[0007]

In the liquid crystal display device using an active matrix substrate having a plurality of scanning electrode wirings, image signal electrode wirings, thin film transistors, and pixel electrodes, scanning of an active matrix image display area is achieved. The electrode wiring pattern or the image signal electrode wiring pattern is formed by a laminated film having a TaN alloy or NbN alloy film containing 15 atomic% to 40 atomic% of nitrogen as a lower layer and Al or an alloy film containing Al as a main component as an upper layer. Then
Achieved by forming the terminal portion of the scan electrode wiring or the image signal electrode wiring from only the TaN alloy or NbN alloy film having the nitrogen content, which is the lower layer of the scan electrode wiring pattern or the image signal electrode wiring pattern, respectively. To be done.

Alternatively, in the liquid crystal display device using an active matrix substrate having a plurality of scanning electrode wirings, image signal electrode wirings, thin film transistors and pixel electrodes,
A scanning electrode wiring pattern including a terminal portion is created by patterning once using the layer film, and then Al or Al of the terminal portion is formed.
Of the TaN alloy or the NbN alloy film containing 15 atomic% or more and 40 atomic% or less of the remaining lower nitrogen by selectively removing only the upper layer made of an alloy whose main component is by reactive ion etching. It is achieved by the manufacturing method of forming.

[0009]

In the laminated film of Al / Ta or Al / Nb, the lower metal film is a nitride alloy film containing nitrogen of 15 atomic% or more and 40 atomic% or less. In the following, the abbreviated selection ratio) will be improved, and selective dry etching of Al at the terminal portion becomes possible. At the same time, it is possible to reduce the leakage current of the anodic oxide film on the surface of the electrode and wiring formed of the laminated film, and to obtain good electrical characteristics.

The expansion coefficient of the upper layer is A when anodized.
Since the nitriding alloy film larger than 1 is used as the lower layer, the cross-sectional shape of the electrode and the wiring after forming the anodic oxide film does not become an inverse taper shape, and the image signal electrode wiring and source electrode formed on the electrode and the wiring It is possible to prevent defects due to disconnection.

Therefore, since a resist mask is not particularly required for the selective etching of Al in the terminal portion, the number of steps can be reduced, and the wiring terminal portion is made of a stable alloy, so that the reliability of the terminal portion can be improved. Can be increased.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of electrodes and wirings in an image display area of an active matrix to which the present invention is applied.

FIG. 2 is a schematic plan view when the present invention is applied to a scanning electrode wiring pattern.

FIG. 3 shows the etching rates of TaN alloy film and Al film with different nitrogen contents when reactive ion etching with a mixed gas of BCl ₃ and Cl ₂ was used. Against Al
FIG. 3 is a diagram showing the relationship between the etching rate ratio and the nitrogen content rate of FIG.

FIG. 4 shows TaN alloy 1 with different nitrogen contents.
The relationship between the measured value of the leakage current when applying a voltage of 80 V and the nitrogen content in the TaN alloy was applied to the insulating film obtained by anodizing the surface of the scanning electrode wiring formed by stacking 00 nm and Al300 nm. It is the figure shown.

In the present invention, in order to solve the above problems at the same time and not to increase the number of steps, a manufacturing process including the following steps is used.

1 ... 1 nitrogen that is strong against corrosion and can be anodized
TaN alloy containing 5 atomic% or more and 40 atomic% or less (hereinafter T
aNx) is used as a lower layer and Al having a low resistance is laminated as an upper layer, and a scan electrode wiring pattern is formed by one-time patterning by reactive ion etching using a mixed gas of BCl ₃ and Cl _2. The process of creating.

2 ... Al in the wiring terminal portion is replaced with BCl ₃ and Cl ₂
Step of selectively removing by reactive ion etching using a mixed gas of.

In step 1, scan electrode wiring having a sectional structure in which a TaNx film 2 and an Al film 3 are stacked on a glass substrate 1 as shown in FIG. 1 is formed. Contrary to Japanese Unexamined Patent Publication No. 64-35421, TaN has a larger expansion coefficient during anodic oxidation than Al.
Since x is the lower layer, the cross-sectional shape of the scanning electrode wiring does not have an inverse taper shape when anodized, and defects due to disconnection of the source electrode or the image signal electrode wiring formed in the upper layer can be reduced.

As shown in FIG. 2, the scanning electrode wiring pattern is formed on the glass substrate 1 by scanning electrode wiring 14 in the image display area 16 having the scanning electrode and auxiliary capacitance, and the patterned terminal simultaneously with the scanning electrode wiring. It is composed of the unit 15.

In step 2, whether the coating of the scanning electrode wiring pattern in the image display area 16 is directly drawn with a resist without a photolithography step or an insulating film by anodic oxidation is formed on the surface of the scanning electrode wiring. Alternatively, after performing a method such as forming an insulating film pattern made of silicon nitride or the like on the scan electrode wiring, the Al of the terminal portion 15 is selectively subjected to reactive ion etching using a mixed gas of BCl ₃ and Cl _2. To remove.

In this selective etching, it is practically desirable that the selective ratio is 3 or more. As shown in FIG. 3, since the nitrogen content is set to 15 atomic% or more, BCl ₃ and C
When the mixed gas of l ₂ is used, a selection ratio of 3 or more can be obtained. Therefore, Ta in the lower layer of the terminal portion 15
The upper layer of Al is BCl ₃ without damaging the Nx film.
It can be selectively removed by reactive ion etching using a mixed gas of Cl and Cl ₂ .

When an anodic oxide film is formed on the surface of the scan electrode wiring made of an Al / TaNx laminated film, the leakage current of the anodic oxide film when a voltage of 80 V is applied is measured as shown in FIG. It becomes 1/10 or less of the leakage current of the anodic oxide film of the laminated film made of Ta or TaN alloy containing 50 atomic% of nitrogen. By limiting the nitrogen content in the range of 15 atomic% or more and 40 atomic% or less, an anodized film having excellent electrical characteristics as an insulating film can be obtained.

In the above manufacturing process, the photolithography process required to complete the scan electrode wiring pattern is one.
Since it is only once, while using low resistance Al for wiring,
The terminal portion can be made of stable metal without increasing the number of steps.

The same effect can be obtained by replacing the laminated film with a laminated film of NbN alloy film and Al film. Al film
Al-Pd, Al-Ta, Al-Ti, Al-Si, A
Similar effects can be obtained even with an Al alloy film containing Al such as l-Ti-Ta as a main component. The same effect can be obtained by using the laminated film for the image signal electrode wiring. Even when a mixed gas of HBr and Cl ₂ is used in the reactive ion etching, good selective etching can be similarly performed.

The manufacturing process of the active matrix substrate to which the present invention is applied will be described below with reference to the drawings.

Embodiment 1 FIGS. 5 to 10 are sectional views showing a manufacturing process of an inverted stagger type thin film transistor in an active matrix according to Embodiment 1 of the present invention. 11 to 16 are cross-sectional views showing a manufacturing process of the scan electrode wiring terminal portion of the active matrix. Description will be given below in the order of the figures.

Thin-Film Transistor Manufacturing Process 1 (see FIG. 5) A 100 nm TaN alloy film containing 35 atomic% of nitrogen is deposited on a glass substrate 1 by sputtering. Next, an Al film is formed on the substrate 1 by the sputtering method.
Deposit 0 nm. A resist mask is formed by using a normal photolithography technique, and reactive ion etching is performed by a parallel plate type apparatus using a mixed gas of BCl ₃ and Cl ₂ to remove the resist mask, and the TaN alloy film 2 and A scan electrode wiring pattern composed of the Al film 3 is created.

2 (see FIG. 6) In the scan electrode wiring pattern, a resist mask is formed in a portion where the oxide insulating film is not formed on the surface. The substrate is placed in the aqueous solution as an anode side electrode, the Pt plate is placed as a cathode side electrode, a current is supplied to the scanning electrode wiring pattern to oxidize the pattern surface using an anodic oxidation method to form an Al oxide film. 5 and T
An oxide film 4 of aN alloy is formed. Remove the resist.

3 (see FIG. 7) Indium-Tin-Oxide (hereinafter abbreviated as ITO) 1 was formed on the substrate by a sputtering method.
00 nm is deposited, a resist mask is formed using a normal photolithography technique, and wet etching is performed.
Next, the resist mask is removed to form the pixel electrode 6.

5 (see FIG. 8) A silicon nitride film of 200 nm, an amorphous silicon (hereinafter abbreviated as a-Si) film of 100 nm, and a-Si containing 1% of P (hereinafter n + a) are formed on the substrate. A film (abbreviated as -Si) having a thickness of 50 nm is deposited by the CVD method. Next, a resist mask is formed by using a normal photolithography technique, and the a-Si film and the impurity-containing semiconductor film are etched and processed into an island shape to obtain the semiconductor layer 8 and the impurity-containing semiconductor layer 9. After removing the resist, a resist mask is formed by the photolithography technique, the silicon nitride film is etched to remove the resist, and the pattern of the insulating film 7 is obtained.

6 (see FIG. 9) Al was deposited to a thickness of 400 nm on the substrate by the sputtering method, a resist mask having a predetermined pattern was formed by using the photolithography technique, etching was performed, and then the resist pattern was removed. Thus, the image signal electrode wiring pattern 10 and the source electrode pattern 11 are formed. A silicon nitride film is formed on the substrate by the CVD method.
Then, a resist mask having a predetermined pattern is formed by photolithography, and the resist pattern is removed to form a pattern of the insulating protective film 12.

Manufacturing process of scan electrode wiring terminal portion 1 '... (see FIG. 10) Simultaneously with the patterning of the scan electrode wiring in the step 1, scanning is performed with a laminated film of TaN alloy film 2 and Al film 3 containing 35 atomic% of nitrogen. Create a terminal part that is continuous with the electrode wiring.

2 '... (see FIG. 11) At the time of forming the anodic oxide film in the step 2, it is covered with a resist pattern so that the entire terminal portion is not covered with the anodic oxide film.

3 '... (see FIG. 12) BC between the steps 2 and 3 using the parallel plate type device with the anodic oxide film 5 formed on the surface of the scanning electrode wiring pattern as a mask.
Reactive ion etching is performed with a mixed gas of l ₃ and Cl ₂ to remove the Al film 3 exposed at the terminal portion from the T
It is selectively removed while leaving the aN alloy film 2.

4 '... (see FIG. 13) ITO in step 3
At the time of forming the pixel electrode by the film, on the TaN alloy film 2 in the terminal portion, the Al film end which remains exposed under the anodic oxide film of the terminal portion after the selective dry etching in the step 3 ′ is covered, The ITO terminal pattern 13 is created.

5 '... (see FIG. 14) When the pattern of the silicon nitride film, the a-Si film and the n + a-Si film is formed in step 4, the pattern of the insulating film 7 is formed.

6 '... (see FIG. 15) At least the insulating film 7 is formed when the insulating protective film pattern 12 is formed in the step 5.
The insulating protective film pattern 12 is formed so as to cover the above pattern and not to cover all the ITO terminals used for external connection.

After that, an alignment film and the like are formed to form a liquid crystal display device, but the subsequent manufacturing process of the display panel is omitted because it is out of the scope of the present invention.

In the present embodiment, in addition to the effects of the present invention described above, the Al film edge left exposed under the anodic oxide film of the terminal portion after the selective dry etching is formed into an ITO film in the next step. By covering with a film, it is possible to prevent corrosion of Al in the wiring portion due to a chemical solution in a later step. Further, in the terminal portion, TaNx and I containing 15 atomic% or more of nitrogen are added.
The TO films are stacked and then connected to an external drive circuit.
Since the barrier layer formed at the interface between the TaNx and ITO is not completely insulated, the contact resistance thereof is much smaller than that in the case of the combination of Al and ITO. Further, TaNx and ITO have almost no change in contact resistance due to heat treatment, so that an extremely stable connection terminal can be formed.

Since the pixel electrode is formed after forming the anodic oxide film on the surface of the scanning electrode wiring, the pixel electrode and the image signal electrode wiring are formed in different layers, and the ITO residue during etching is the main cause of the pixel electrode and the image signal. It is possible to reduce defects caused by a short circuit with the electrode wiring.

Although TaN alloy is used in this embodiment, Nb is used.
The same effect can be obtained by using N alloy. Al film is A
l-Pd, Al-Ta, Al-Ti, Al-Si, Al
Similar effects can be obtained even with an Al alloy film containing Al such as -Ti-Ta as a main component. Further, the same effect can be obtained by using a mixed gas of HBr and BCl ₃ instead of the mixed gas of BCl ₃ and Cl _{2 in} the reactive ion etching. In the first embodiment, the portion of the terminal portion used for connection to the outside is completely covered with the ITO film, but TaNx or the niobium nitride alloy may be left exposed without being completely covered. Although the present invention is applied to the scanning electrode wiring of the reverse stagger type thin film transistor in this embodiment, the same effect can be obtained by applying it to the image signal electrode wiring or the thin film transistor of another method such as the positive stagger type.

Embodiment 2 FIGS. 16 to 20 are sectional views showing a process flow of an inverted stagger type thin film transistor in an active matrix according to another embodiment of the present invention, and FIGS. 21 to 26 are the liquid crystal display devices. FIG. 6 is a cross-sectional view showing the process flow of the terminal portion of the scan electrode wiring of the active matrix of FIG. Description will be given below in the order of the figures.

Thin-Film Transistor Manufacturing Process 1 (see FIG. 16) A TaN alloy film containing 35 atomic% of nitrogen is deposited to 100 nm on the glass substrate 1 by sputtering. Next, an Al film of 300 nm is deposited on the substrate 1 by the sputtering method. A resist mask is formed by using a normal photolithography technique, and reactive ion etching is performed by a parallel plate type apparatus using a mixed gas of BCl ₃ and Cl ₂ to remove the resist mask.
A scan electrode wiring pattern composed of the N alloy film 2 and the Al film 3 is created.

2 (see FIG. 17) In the scan electrode wiring pattern, a resist mask is formed on the surface where the oxide insulating film is not formed. The substrate is placed in the aqueous solution as an anode side electrode, the Pt plate is placed as a cathode side electrode, a current is supplied to the scanning electrode wiring pattern to oxidize the pattern surface using an anodic oxidation method to form an Al oxide film. 5 and the oxide film 4 of the TaN alloy are formed. Remove the resist.

3 (see FIG. 18) A silicon nitride film of 200 nm and amorphous silicon (hereinafter a-Si) is formed on the substrate.
A) Si containing 100 nm of film and 1% of P
A film (hereinafter abbreviated as n + a-Si) having a thickness of 50 nm is deposited by a chemical vapor deposition method (hereinafter abbreviated as a CVD method). next,
A resist mask is formed by using a normal photolithography technique, the a-Si film and the impurity-containing semiconductor film are etched and processed into an island shape, and the semiconductor layer 8 and the impurity-containing semiconductor layer 9 are formed.
To get After removing the resist, a resist mask is formed by the photolithography technique, the silicon nitride film is patterned, and a pattern of the insulating film 7 covering the anodic oxide films 4 and 5 formed in step 2 is obtained.

4 (see FIG. 19) An ITO film having a thickness of 100 nm is deposited on the substrate by a sputtering method, a resist mask is formed by a normal photolithography technique, wet etching is performed, and then the resist mask is removed. Then, the pixel electrode 6 is formed.

5 (see FIG. 20) An Al film having a thickness of 400 nm is deposited on the substrate by a sputtering method, a resist mask having a predetermined pattern is formed by a photolithography technique, and etching is performed. Next, a resist pattern is formed. After removal, the image signal electrode wiring pattern 10 and the source electrode pattern 11 are formed. A silicon nitride film is deposited to a thickness of 500 nm on the substrate by a CVD method, a resist mask having a predetermined pattern is formed by using a photolithography technique, and the resist pattern is removed by etching to form a pattern of the insulating protective film 12.

Manufacturing process of scan electrode wiring terminal portion 1 '(see FIG. 21) At the same time as the patterning of the scan electrode wiring in the step 1, a laminated film of TaN alloy film 2 and Al film 3 containing 35 atomic% of nitrogen is used. , A terminal portion continuous with the scan electrode wiring is created.

2 '... (see FIG. 22) At the time of forming the anodic oxide film in the step 2, it is covered with a resist pattern and the anodic oxide film is not formed on the terminal portion.

3 '... (see FIG. 23) When the silicon nitride and the a-Si and n + a-Si film patterns are formed in the step 3, at least the anodic oxide film end of the scanning electrode wiring terminal portion is covered, but not entirely. Thus, the pattern of the insulating film 7 is created.

4 '(see FIG. 24) During the steps 3 and 4, BCl ₃ is formed by using a parallel plate type device with the insulating film 7 formed on the upper layer of the scanning electrode wiring pattern as a mask.
Reactive ion etching is performed with a mixed gas of Cl and Cl ₂ to remove the Al film 3 exposed at the terminal portion from the TaN film.
The alloy film 2 is selectively removed while leaving the alloy film 2.

5 '... (see FIG. 25) ITO in step 4
The TaN alloy film 2 of the terminal portion when the pixel electrode is formed by the film
And A exposed at least under the pattern edge of the insulating film 7.
The ITO terminal pattern 13 is formed so as to cover the 1 end.

6 '... (see FIG. 26) At the time of forming the insulating protective film pattern 12 in the step 5, at least the insulating film 7 is formed.
The insulating protective film pattern 12 is formed so as to cover the above pattern and not all of the ITO terminals used for connection with the outside.

After that, an alignment film or the like is formed to form a liquid crystal display device, but the subsequent manufacturing process of the display panel is omitted because it is out of the scope of the present invention.

In the present embodiment, in addition to the effects of the present invention and the effects of the first embodiment described above, selective etching of the Al film 3 in the terminal portion using the insulating film 7 as a mask is performed by mixing BCl ₃ and Cl _2. Since it is performed by dry etching using gas,
There is an effect that the anodic oxide film 5 of Al is not corroded and deterioration of the electrical characteristics of the insulating film can be prevented.

In this embodiment, TaN alloy is used, but Nb is used.
The same effect can be obtained by using N alloy. Similar effects can be obtained by using an alloy containing Al as a main component instead of Al. Also, during reactive ion etching, B
The same effect can be obtained by using a mixed gas of HBr and BCl ₃ instead of the mixed gas of Cl ₃ and Cl ₂ . Further, in the present embodiment, the portion used for connection with the outside in the terminal portion is IT.
Although it is completely covered with the O film, the TaN alloy film or the niobium nitride alloy film may be left exposed without being completely covered.
Although the present invention is applied to the scanning electrode wiring of the inverted stagger type thin film transistor in this embodiment, the image signal electrode wiring,
Alternatively, the same effect can be obtained by applying the method to a thin film transistor of another method such as a positive stagger type.

[0059]

As described above, according to the present invention, T
By limiting the amount of nitrogen contained in the aN alloy film or the NbN alloy film to the range of 15 atom% or more and 40 atom% or less, the TaN alloy film or the NbN alloy film and Al or A
A good anodic oxide film can be obtained in the electrode and wiring made of a two-layer film of l-alloy, and selective etching of Al or Al alloy film in the terminal portion by reactive ion etching becomes possible. Therefore, it is possible to accurately manufacture a thin film semiconductor device capable of protecting Al or Al alloy having poor corrosion resistance without increasing the number of masks while using Al or Al alloy having low resistivity for electrodes and wirings.

[Brief description of drawings]

FIG. 1 is a sectional view of an electrode or wiring to which the present invention is applied.

FIG. 2 is a plan view showing a scanning electrode wiring pattern to which the present invention is applied.

FIG. 3: Nitrogen content in TaN alloy film, BCl ₃ and C
It is a figure showing the relation of selection ratio with Al when using reactive ion etching with a mixed gas of l ₂ .

FIG. 4 is a diagram showing the relationship between the nitrogen content in the TaN alloy film and the magnitude of the leakage current of the anodic oxide film on the wiring surface when 80 V is applied.

FIG. 5 is a cross-sectional view showing the thin film transistor in the manufacturing process of Example 1 of the present invention.

FIG. 6 is a cross-sectional view showing the thin film transistor in the manufacturing process of Embodiment 1 of the present invention.

FIG. 7 is a cross-sectional view showing the thin film transistor in the manufacturing process of Embodiment 1 of the present invention.

FIG. 8 is a cross-sectional view showing the thin film transistor in the manufacturing process of Example 1 of the present invention.

FIG. 9 is a cross-sectional view showing the thin film transistor in the manufacturing process of Example 1 of the present invention.

FIG. 10 is a cross-sectional view showing a scan electrode wiring terminal portion in the manufacturing process of the first embodiment of the present invention.

FIG. 11 is a cross-sectional view showing a scan electrode wiring terminal portion in the manufacturing process of the first embodiment of the present invention.

FIG. 12 is a cross-sectional view showing the scan electrode wiring terminal portion in the manufacturing process of the first embodiment of the present invention.

FIG. 13 is a cross-sectional view showing the scanning electrode wiring terminal portion in the manufacturing process of the first embodiment of the present invention.

FIG. 14 is a cross-sectional view showing the scan electrode wiring terminal portion in the manufacturing process of the first embodiment of the present invention.

FIG. 15 is a cross-sectional view showing the scan electrode wiring terminal portion in the manufacturing process of the first embodiment of the present invention.

FIG. 16 is a cross-sectional view showing a thin film transistor in a manufacturing process of Example 2 of the present invention.

FIG. 17 is a cross-sectional view showing the thin film transistor in the manufacturing process of Embodiment 2 of the present invention.

FIG. 18 is a cross-sectional view showing the thin film transistor in the manufacturing process of Example 2 of the present invention.

FIG. 19 is a cross-sectional view showing the thin film transistor in the manufacturing process of Example 2 of the present invention.

FIG. 20 is a cross-sectional view showing the thin film transistor in the manufacturing process of Example 2 of the present invention.

FIG. 21 is a cross-sectional view showing a scan electrode wiring terminal portion in the manufacturing process of Embodiment 2 of the present invention.

FIG. 22 is a cross-sectional view showing a scan electrode wiring terminal portion in the manufacturing process of Embodiment 2 of the present invention.

FIG. 23 is a cross-sectional view showing a scan electrode wiring terminal portion in the manufacturing process of Embodiment 2 of the present invention.

FIG. 24 is a cross-sectional view showing a scan electrode wiring terminal portion in the manufacturing process of Embodiment 2 of the present invention.

FIG. 25 is a cross-sectional view showing a scan electrode wiring terminal portion in a manufacturing process of a second embodiment of the present invention.

FIG. 26 is a cross-sectional view showing the scan electrode wiring terminal portion in the manufacturing process of Embodiment 2 of the present invention.

[Explanation of symbols]

1 ... Glass substrate, 2 ... TaNx film, 3 ... Al film, 4 ... T
aNx anodic oxide film, 5 ... Al anodic oxide film, 6 ... Pixel electrode, 7 ... Insulating film, 8 ... Semiconductor layer, 9 ... Impurity-containing semiconductor layer, 10 ... Image signal electrode wiring, 11 ... Source electrode, 1
2 ... Insulating protective film, 13 ... ITO terminal, 14 ... Scan electrode wiring pattern, 15 ... Scan electrode wiring terminal portion, 16 ... Image display area.

Claims (13)

[Claims] 1. A liquid crystal display device using an active matrix substrate comprising a plurality of scanning electrode wirings, image signal electrode wirings, thin film transistors, and pixel electrodes, wherein the scanning electrode wirings or the image signal electrode wirings contain nitrogen of 15 atomic% or more. 40
A liquid crystal display device, characterized in that a TaN alloy or NbN alloy containing at most atomic% is used as a lower layer and a laminated film having Al or an alloy mainly containing Al as an upper layer. 2. A liquid crystal display device using an active matrix substrate comprising a plurality of scanning electrode wirings, image signal electrode wirings, thin film transistors and pixel electrodes, wherein the scanning electrode wirings or image signal electrode wirings in the image display region are made of nitrogen. 15
TaN alloy or N containing at least 40 atomic%
It is formed by a laminated film having a bN alloy film as a lower layer and Al or an alloy film containing Al as a main component as an upper layer, and the terminal portion of the scan electrode wiring or the image signal electrode wiring has TaN alloy or NbN having the above nitrogen content. A liquid crystal display device characterized by being formed only from an alloy film. 3. A liquid crystal display device using an active matrix substrate having a plurality of scanning electrode wirings, image signal electrode wirings, thin film transistors, and pixel electrodes, including the following steps. . (1) A step of depositing a film of TaN alloy or NbN alloy containing 15 atomic% or more and 40 atomic% or less of nitrogen on a transparent insulating substrate. (2) A step of depositing Al or an alloy film containing Al as a main component to a predetermined thickness on the substrate. (3) A step of forming a scanning electrode wiring pattern formed on the substrate by the film composed of the two layers. (4) Al or an alloy film containing Al as a main component in the upper layer of the scanning electrode wiring terminal portion formed of the laminated film is selectively removed by reactive ion etching, and the terminal portion is adjusted to have a nitrogen content of the lower layer. TaN alloy or NbN
A process that uses only an alloy film. 4. The method for manufacturing a liquid crystal display device according to claim 3, wherein when Al or an alloy film containing Al as a main component in the terminal portion of the scanning electrode wiring pattern is selectively removed by reactive ion etching, A method of manufacturing a liquid crystal display device, wherein etching is performed by using an insulating film pattern formed so as to cover at least a crossing portion of the scanning electrode wiring and the image signal electrode wiring. 5. The method for manufacturing a liquid crystal display device according to claim 4, wherein the insulating film on the scan electrode wiring pattern is made of a metal oxide film using a metal forming the scan electrode wiring as a base material. Method for manufacturing liquid crystal display device. 6. The method of manufacturing a liquid crystal display device according to claim 4, wherein the insulating film on the scanning electrode wiring pattern is an insulating film containing Si as a main component. 7. The method for manufacturing a liquid crystal display device according to claim 4, wherein the insulating film on the scan electrode wiring pattern comprises a metal oxide film containing a metal forming the scan electrode wiring as a base material, and S.
A method of manufacturing a liquid crystal display device, comprising: two layers of an insulating film containing i as a main component. 8. The method for manufacturing a liquid crystal display device according to claim 3, wherein Al or an alloy containing Al as a main component in the upper layer of the scanning electrode wiring terminal portion formed of a laminated film is selectively subjected to reactive ion etching. When removing BC
A method of manufacturing a liquid crystal display device, which comprises using a mixed gas of l ₃ and Cl ₂ . 9. The method of manufacturing a liquid crystal display device according to claim 3, wherein Al or an alloy containing Al as a main component in the upper layer of the scanning electrode wiring terminal portion formed of a laminated film is selectively subjected to reactive ion etching. HB when removing
A method of manufacturing a liquid crystal display device, which comprises using a mixed gas of r and BCl ₃ . 10. The liquid crystal display device according to claim 2,
The scanning electrode wiring or the image signal electrode wiring terminal portion is characterized by comprising a TaN alloy film or NbN alloy film containing nitrogen of 15 atomic% or more and 40 atomic% or less and a first conductive film formed thereon. Liquid crystal display device. 11. The method for manufacturing a liquid crystal display device according to claim 3, wherein after the step 4, the TaN alloy film or the NbN alloy film containing nitrogen of 15 atomic% or more and 40 atomic% or less is included in the scanning electrode wiring terminal portion. And a step of forming a first conductive film pattern, the method of manufacturing a liquid crystal display device. 12. The method for manufacturing a liquid crystal display device according to claim 3, wherein after the step 4, the TaN alloy film or the NbN alloy film containing nitrogen of 15 atomic% or more and 40 atomic% or less of the scanning electrode wiring terminal portion is formed. And a step of forming a first conductive film pattern so as to cover the end of Al or an alloy film containing Al as a main component exposed under the end of the insulating film used as a mask during the selective etching. Liquid crystal display device manufacturing method. 13. The method of manufacturing a liquid crystal display device according to claim 10, 11 or 12, wherein the first conductive film is Indium-Tin-Oxide.