JP2002229065A - Liquid crystal display and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display, having signals lines which satisfy all of the four characteristics imposed on the signal lines of the liquid crystal display device. SOLUTION: This liquid crystal display device has a first substrate 1 and a second substrate 2 and a liquid crystal layer 3, pinched between the first and second substrates 1 and 2 and has plural scanning signal lines 4 and plural video signal lines 8 intersected and arranged in a matrix form in a state of being insulated from each other on the first substrate 1, and thin-film transistors 17 and pixel electrodes 11 disposed respectively at the intersected point segments of the scanning signal lines 4 and the video signal lines 8 and protective insulating films 10 for insulating conductive parts from each other. The respective video signal lines 8 are laminated films, consisting of first conductive films 41 and second conductive films 42. The material, forming the first conductive films 41, is an alloy essentially consisting of molybdenum(Mo) and containing at least one metal from among zirconium(Zr), hafnium(Hf), chromium(Cr) and titanium(Ti), and the material forming the second conductive films 42 is pure molybdenum(Mo).

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 method of manufacturing the liquid crystal display device, and more particularly to obtaining a signal line having various suitable characteristics by selecting a material for forming the signal line. The present invention relates to a thin film transistor driven active matrix type liquid crystal display device and a method of manufacturing an active matrix type liquid crystal display device having such a configuration.

[0002]

2. Description of the Related Art In recent years, an image display device for displaying a predetermined image has been required to have a large display screen and a high definition of the display image. In addition, the image display device has been reduced in thickness and weight. Is required. As an image display device that satisfies such demands, a liquid crystal display device (TFT-LCD) driven by a thin film transistor has come into wide use instead of a conventional image display device using a cathode ray tube.

Such a thin film transistor driven liquid crystal display device mainly comprises a first substrate and a second substrate made of glass and a first substrate.
A liquid crystal layer sandwiched between the substrate and the second substrate,
On the first substrate, a plurality of scanning signal lines and video signal lines are formed and arranged so as to intersect with each other via a gate insulating film, and correspond to each intersection of each scanning signal line and each video signal line. A thin film transistor connected to a scanning signal line and a video signal line, and a pixel electrode connected to the thin film transistor are formed and arranged, and a protective insulating film is formed on the thin film transistor, the pixel electrode, and the like. By appropriately driving the layer by a liquid crystal drive circuit for each pixel, a display image appears through the second substrate.

In a liquid crystal display device driven by a thin film transistor having such a configuration, in order to meet the various demands described above, the resistance of each scanning signal line and each video signal line is reduced, and the production yield is increased. Besides, the manufacturing process is simplified to reduce the manufacturing cost.

In a known liquid crystal display device driven by a thin film transistor, a video signal line connected to a bottom gate type amorphous silicon (Si) thin film transistor includes a video signal line made of a single-layer metal and a laminated metal. Video signal lines were used. In this case, the video signal line made of a single-layer metal is made of titanium (Ti) excluding aluminum (Al), tantalum (T
a), chrome (Cr), molybdenum (Mo), chrome
A metal such as molybdenum (CrMo) is selected, and a video signal line made of a laminated metal is made of Mo-Cr, Al-Cr, Al-Ti, CrMo-
Cr, Mo-Al-Mo, Ti-Al-Ti, Cr-A
Metals such as 1-Cr and MoCr-Al-MoCr have been selected. Here, in the two-layer laminated metal, the left metal is disposed on the upper layer side, the right metal is disposed on the lower layer side, and in the three-layer laminated metal, the left metal is disposed on the upper layer side, the intermediate metal is disposed in the middle, The right metal is located on the lower side. What kind of forming material is used for the video signal line is appropriately selected according to the specification of the wiring resistance required for driving the liquid crystal, the production capacity of the sputtering process, the capacity of the etching apparatus at the time of manufacturing, and the like.

Among these video signal line forming materials, those which can obtain good low resistance characteristics are those using Al, such as Al-Cr, Al-Ti, Mo-Al-Mo, T
i-Al-Ti, Cr-Al-Cr, MoCr-Al-
MoCr and the like, and those which can obtain relatively good low-resistance characteristics according to the low-resistance characteristics, use Mo, and Mo, Mo-Cr, and the like correspond thereto.

[0007] Further, those which can obtain a light load characteristic during the sputtering process are those using a single-layer metal.
i, Ta, Cr, Mo, CrMo, etc. correspond thereto, and those which can obtain light load characteristics according to the above light load characteristics are those using a two-layer laminated metal, such as Mo-Cr, Al-
Cr, Al-Ti, etc. correspond to it.

Further, those which can be selectively wet-etched with the gate insulating film are Cr, Mo, CrMo,
Al-Cr, Mo-Al-Mo, Cr-Al-Cr, M
oCr-Al-MoCr and the like correspond thereto.

In addition, those having dry etching resistance at the time of forming a through hole in a video signal line or a protective insulating film covering a drain electrode and a source electrode formed in the same layer as the video signal line include Ti and Cr. , CrMo, Mo-Cr, T
i-Al-Ti, Cr-Al-Cr, MoCr-Al-
MoCr and the like correspond to this.

[0010]

In a known liquid crystal display device driven by a thin film transistor, a video signal line satisfies one or two of the above four characteristics depending on a material for forming the video signal line. A forming material that satisfies all of the properties has not yet been found.

For example, when Ti is used as a forming material,
In addition to having relatively high resistance characteristics, it is difficult to perform selective wet etching with a gate insulating film because it is corroded by buffered hydrofluoric acid used during wet etching. Further, when Ta is used as the forming material, similarly to the case where Ti is used, it has relatively high resistance characteristics and is corroded by buffered hydrofluoric acid used at the time of wet etching. Not only is it difficult to perform selective wet etching, but also because it is corroded by SF ₆ gas used during dry etching, it is difficult to form through holes in the protective insulating film on video signal lines by dry etching. . In addition, Cr, CrM
o, the case of using a CrMo-Cr, has a relatively high resistance characteristics, in the case of using Mo in the formation material, since the corroded by SF ₆ gas used during dry etching, a video by dry etching It is difficult to form a through hole in a protective insulating film on a signal line.

In addition, when Mo—Cr is used as a forming material, the Mo layer is rapidly dissolved by a ceric ammonium nitrate solution that is a Cr etching solution used at the time of wet etching. It is difficult to use Al-Cr, Al-
In the case of using Ti, it is necessary to form a through hole in the protective insulating film on the video signal line by dry etching and to remove Al at the bottom of the through hole by etching, which complicates the manufacturing process. Further, when Mo-Al-Mo is used as a forming material, since the upper Mo layer is corroded by SF ₆ gas used at the time of dry etching, a through hole is formed in the protective insulating film on the video signal line by dry etching. In addition to the difficulty in performing the sputtering, it is necessary to form a three-layer film, which increases the load in the sputtering process.
i-Al-Ti, Cr-Al-Cr, MoCr-Al-
Even when MoCr is used, it is necessary to form a three-layer film, so that the load at the time of the sputtering process increases.

[0013] The advantages and disadvantages of the characteristics that accompany the material for forming the video signal lines are also the advantages and disadvantages of the characteristics when the scanning signal lines are formed using these materials. .

In addition, a known thin film transistor driven liquid crystal display device includes a pixel electrode made of polycrystalline indium tin oxide, and the pixel electrode is connected to a video signal line. This pixel electrode is usually formed by wet etching using hydrobromic acid, and the material for forming the video signal line is Al-Cr, Al-Ti,
Ti-Al-Ti, Cr-Al-Cr, MoCr-Al
In the case of any of -MoCr, when the pixel electrode is formed by wet etching using hydrobromic acid, the Al component in the video signal line is dissolved by the hydrobromic acid, and the video signal line is disconnected. It often causes defects,
As a result, the production yield of the liquid crystal display device is significantly reduced.

Further, a known liquid crystal display device driven by a thin film transistor is provided with a pixel electrode made of polycrystalline indium tin oxide, and a scan signal line is made of Al—
Cr, Al-Ti, Ti-Al-Ti, Cr-Al-C
r, MoCr-Al-MoCr, when the pixel electrode is formed by wet etching using hydrobromic acid, the hydrobromic acid dissolves the Al component in the scanning signal line. However, the same kind of disconnection failure may occur, albeit slightly, and similarly, the production yield of the liquid crystal display device slightly decreases.

In order to prevent such a disconnection failure of the video signal line and the scanning signal line, the material for forming the pixel electrode may be any of amorphous phase indium tin oxide, indium zinc oxide and indium germanium oxide. If used, the occurrence of disconnection failure can be prevented. This is because when forming the pixel electrode, wet etching using hydrobromic acid is not performed, and a chemical solution that significantly attacks the Al component such as hydrobromic acid is not used as an etchant. is there.

As described above, the known thin film transistor driven liquid crystal display device only satisfies one or two of the above-mentioned four characteristics with the material for forming the video signal line. Was selected based on the most necessary properties, and the other properties were used in an unsatisfactory state.

The present invention has been made in view of such technical background, and a first object of the present invention is to provide a signal line which satisfies all of the various characteristics imposed on the signal line of the liquid crystal display device. An object of the present invention is to provide a liquid crystal display device provided with:

Further, a second object of the present invention is to provide a liquid crystal display device having a signal line structure for improving wet etching of a signal line satisfying the first object (the structure will be described later). Another object of the present invention is to provide a method of manufacturing a liquid crystal display device which can be manufactured using a small number of processes and a simple manufacturing process.

[0020]

In order to achieve the first object, a liquid crystal display device according to the present invention comprises a first substrate and a second substrate, and a liquid crystal layer sandwiched between the first and second substrates. A plurality of scanning signal lines and a plurality of video signal lines, which are arranged in an insulated state and intersect in a matrix on the first substrate, and provided at each intersection of each scanning signal line and each video signal line. A thin film transistor, a pixel electrode connected to the thin film transistor, and a protective insulating film that insulates between conductive portions, wherein each video signal line is a stack of a first conductive film and a second conductive film. An alloy containing molybdenum (Mo) as a main component and at least one metal selected from zirconium (Zr), hafnium (Hf), chromium (Cr), and titanium (Ti). And the second Formation of membrane material pure molybdenum (M
and o) the first means.

According to the first means, each video signal line is a two-layer laminated film composed of the first conductive film and the second conductive film, and the material for forming the first conductive film is molybdenum (Mo). ) As main components, zirconium (Zr), hafnium (H
f), an alloy containing at least one metal among chromium (Cr) and titanium (Ti), and the material for forming the second conductive film is pure molybdenum (Mo). Satisfies all of the various characteristics imposed on the thin film transistor, and at the same time, the contact state between the video signal line and the amorphous silicon layer forming the thin film transistor is improved.

Further, according to the first means, the video signal line can be formed in a forward tapered shape such that the cross-sectional shape becomes wider toward the substrate side. The coverage of the protective insulating film can be improved, which can also contribute to the second object.

In order to achieve the second object,
The method of manufacturing a liquid crystal display device according to the present invention includes a step of forming a scanning signal line and a gate electrode pattern on a first substrate by etching, a step of forming a thin-film transistor active portion pattern, a method of mainly containing molybdenum (Mo), and a method of forming zirconium ( Zr), hafnium (Hf), chromium (Cr), and a first conductive film made of an alloy containing at least one of titanium (Ti), and pure molybdenum (Mo) formed thereon. Forming a laminated film by depositing the formed second conductive film, forming a video signal line, a drain electrode and a source electrode pattern by wet etching of the laminated film, and forming a gate insulating film and a protective insulating film by dry etching. Forming a transparent pixel electrode pattern by etching, bonding the first substrate and the second substrate with a gap therebetween, A liquid crystal display device is manufactured through a step of sealing a liquid crystal in a gap of a liquid crystal display device and a step of connecting a liquid crystal driving circuit to each terminal of a scanning signal line and a video signal line. Containing phosphoric acid (H ₃ PO ₄ ), nitric acid (HNO ₃ ) and water (H ₂ O), 0.72 times the concentration by weight of nitric acid and the weight% of phosphoric acid
A second means having a sum with the concentration in the range of 68 to 75, and a weight% concentration of the nitric acid in the range of 0.3 to 3;

According to the second means, a laminated film of two layers forming the video signal lines as an etching solution at the time of wet etching with nitric acid (HNO phosphoric acid (H ₃ PO _4)
3 ) and water (H ₂ O) at a concentration of 0.1% by weight of nitric acid.
The sum of the 72 times and the phosphoric acid weight% concentration is in the range of 68 to 75 and the nitric acid weight% concentration is in the range of 0.3 to 3, so that a small side etching can be performed. It is possible to form a video signal line that satisfies all of the various characteristics imposed on the signal line of the liquid crystal display device without causing disconnection, and to manufacture the liquid crystal display device by a simple manufacturing process. Can be.

Further, in order to achieve the second object, a method of manufacturing a liquid crystal display device according to the present invention comprises a step of forming a scanning signal line and a gate electrode pattern on a first substrate by etching, In which molybdenum (Mo) is the main component, zirconium (Zr), hafnium (Hf), chromium (C
r), forming a first conductive film made of an alloy containing at least one of titanium (Ti), and depositing and stacking a second conductive film made of pure molybdenum (Mo) thereon A step of forming a film, a step of forming a video signal line, a drain electrode and a source electrode pattern by wet etching a laminated film using a wet etching apparatus, a step of forming a gate insulating film and a protective insulating film by dry etching, and etching. Forming a transparent pixel electrode pattern, bonding the first substrate and the second substrate in a state having a gap, sealing the liquid crystal in the gap, and connecting a liquid crystal driving circuit to each terminal of the scanning signal line and the video signal line. And a liquid crystal display device is manufactured through the steps of connecting the first substrate to the wet etching device while horizontally transporting the first substrate. A third means for supplying an etchant from the nozzles onto the first substrate in a shower shape, and using a plurality of nozzles swinging in a direction perpendicular to the transport direction of the first substrate. .

According to the third means, as a wet etching apparatus, the etching liquid is supplied from a plurality of nozzles arranged evenly to the first substrate in a shower shape while horizontally transporting the first substrate, and Since the plurality of nozzles oscillate in the direction perpendicular to the transport direction of the first substrate, uniform etching can be performed without causing uneven etching. A video signal line satisfying all of the various characteristics imposed on the signal line can be formed, and the liquid crystal display device can be manufactured by a simple manufacturing process.

[0027]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a first embodiment of a liquid crystal display device according to the present invention.
FIG. 3 is a cross-sectional view showing a main part configuration including one thin film transistor according to the embodiment.

In FIG. 1, reference numeral 1 denotes a lower substrate made of glass.
(First substrate), 2 is an upper substrate also made of glass (second substrate)
Board, 3 is a liquid crystal layer, 4 is a scanning (gate) signal line and a gate.
Electrode 4₁Are the first conductive film, 4_TwoIs the second conductive film, and 5 is
A gate insulating film, 6 is an intrinsic amorphous silicon (a-Si) layer,
7 is a contact layer, 8 is a video signal line and a drain electrode,
8₁Is the first conductive film, 8_TwoIs the second conductive film, and 9 is the source conductive film.
Pole, 9₁Is the first conductive film, 9 _TwoIs the second conductive film and 10 is protected
Insulating film, 10₁Is a through hole, 11 is a transparent pixel electrode,
11₁Is a pixel electrode connection portion, 12 is a color filter, 13
Is a black matrix, 14 is a planarization layer, and 15 is a common electrode.
Pole, 16 is a protective film, 17 is a thin film transistor (TFT)
It is.

In this case, the scanning (gate) signal line and the gate
The electrode 4 is made of anodized aluminum (Al)
Containing 9.8% by weight of neodymium (Nd)
Aluminum alloy₁Is aluminum alloy
Gold, 4_TwoIs an anodized film. Video signal line and drain
The electrode 8 is a first conductive film 8₁And the second conductive film 8_TwoOf two layers
The film and the source electrode 9 are the first conductive film 9₁And the second conductive film 9_Twoof
The first conductive film 8 is a two-layer laminated film.₁, 9₁Are all shaped
The material is molybdenum (Mo) as the main component, 8% by weight
Molybdenum alloy containing zirconium (Zr)
And the second conductive film 8 _Two, 9_TwoMeans that the forming material is pure
Pure molybdenum (Mo) with a degree of 99.9% by weight. Game
The insulating material 5 and the protective insulating film 10 are both formed of a material.
A transparent pixel electrode 11 made of silicon nitride (SiN);
Pixel electrode connection part 11₁Is a polycrystalline phase
Indium tin oxide (ITO).

[0031] Then, the lower substrate 1, a predetermined position of one surface, the first conductive film 4 ₁ and the second conductive film 4 composed of _two two-layer laminated film of the scanning signal line and the gate electrode 4 is provided, Lower substrate 1 including portions where scanning signal lines and gate electrodes 4 are formed
A gate insulating film 5 is coated thereon. An intrinsic amorphous silicon layer 6 is provided on the gate insulating film 5 facing the gate electrode 4, and a contact layer 7 is provided at a required position on the intrinsic amorphous silicon layer 6. The predetermined position on the gate insulating film 5 including the upper contact layer 7, the video signal line and the drain electrode 8 made of laminated film of the first conductive film 8 ₁ and the second conductive film ₈₂ of the two layers, the first conductive the source electrode 9 composed of a laminated film of film 9 ₁ and the second conductive film 9 ₂ bilayer are respectively provided. The protection insulating film 10 is coated on the gate insulating film including the exposed portion of the intrinsic amorphous silicon layer 6, the video signal line and the drain electrode 8, and the source electrode 9. In the protective insulating film 10,
The predetermined position on the source electrode 9, through holes 10 ₁ reaching the first conductive film 9 ₁ is provided through the protective insulating film 10 and the second conductive film 9 _2, the near region including the inside of the through hole 10 ₁ pixel electrode connection portion ₁₁₁ is provided,
Transparent pixel electrodes 11 are provided so as to be connected to the pixel electrode connection portion 11 _1. The thin film transistor 17 is a region including the gate electrode 4, the intrinsic amorphous silicon layer 6, the drain electrode 8, the source electrode 9, and the like.

On the other hand, the color filter 12 and the black matrix 13 are provided alternately on one surface of the upper substrate 2, and the flattening layer 14 is provided on the color filter 12 and the black matrix 13. A common electrode 15 is provided at a required position on the flattening layer 14, and a protective film 16 is coated on the flattening layer 14 including the common electrode 15.

Further, a space is formed between the lower substrate 1 and the upper substrate 2, and a liquid crystal material is sealed in the space to form a liquid crystal layer 3.

In this case, the thin film transistor 17 comprises an intrinsic amorphous silicon layer 6 having a drain electrode 8 and a source electrode 9.
Is formed on the lower layer side of the formation region, so that the drain electrode 8 and the source electrode 9 can be prevented from being disconnected, and the drain electrode 8 and the source electrode 9 and the gate electrode intersecting therewith can be prevented. 4 can be reduced. Similarly, the drain electrode 8 and the source electrode 9
A contact layer is provided on the surface of the intrinsic amorphous silicon layer 6 which contacts the substrate. The source electrode 9 extends to a lower portion of the formation region of the pixel electrode connection portion 11 ₁ , and the first conductive film 9 ₁ extends through the through-hole 10 ₁ provided in the protective insulating film 10. It is conductively connected to the connecting portion 11 _1.

Further, although not shown in FIG. 1, the interface region between the protective insulating film 10 and the liquid crystal layer 3 and the protective film 1
An alignment film that regulates the alignment direction of the liquid crystal composition forming the liquid crystal layer 3 is provided in the interface region between the liquid crystal layer 3 and the liquid crystal layer 3.

Each part of the liquid crystal display device having the above configuration is formed as follows.

With respect to the scanning signal line and the gate electrode 4,
On one surface of the lower substrate 1, aluminum (Al) is used as a main component at a deposition temperature of 120 ° C. by using a sputtering method,
An aluminum alloy layer containing 9.8% by weight of neodymium (Nd) and a molybdenum alloy layer containing molybdenum (Mo) as a main component and containing 8% by weight of zirconium (Zr) are continuously formed. Next, a resist pattern is formed by photolithography in order to obtain a scanning signal line and a gate electrode 4, and a shower etching method using an etching solution containing an aqueous solution to which phosphoric acid or nitric acid, preferably acetic acid or ammonium fluoride is added. , The two-layer film formation was collectively wet-etched. Next, the resist was peeled off, and after covering the terminal portion of the scanning signal line 4, the obtained scanning signal line and gate electrode 4 were immersed in a chemical solution. At this time,
Molybdenum alloy layer is dissolved by the chemical conversion solution, after which the surface of the aluminum alloy layer was uniformly anodized, the scanning signal line and the gate electrode 4 composed of an anode oxide film 4 _2-covered aluminum alloy layer 4 ₁ Tokyo Formed.

For the thin film transistor 17, a gate insulating film made of silicon nitride (SiN), an intrinsic amorphous silicon layer, and a contact layer are formed on the formed scanning signal line and the gate electrode 4 by plasma enhanced chemical vapor deposition (PVCD). Is continuously formed. Next, in order to obtain an intrinsic amorphous silicon layer and a contact layer, a resist pattern is formed by photolithography, and the intrinsic amorphous silicon layer and the contact layer are etched into an island shape by a dry etching method. The quality silicon layer 6 and the contact layer 7 were formed.

With respect to the video signal line, the drain electrode 8 and the source electrode 9, after the formed resist is removed,
A molybdenum alloy layer containing molybdenum (Mo) as a main component and containing 8% by weight of zirconium (Zr) and a pure molybdenum (Mo) are formed on the formed contact layer 7 by a sputtering method at a film forming temperature of 120 ° C. The layers are continuously formed. Next, a resist pattern is formed by photolithography in order to obtain a video signal line, a drain electrode 8 and a source electrode 9, and an etching solution comprising an aqueous solution containing phosphoric acid or nitric acid, preferably acetic acid or ammonium fluoride is used. The two-layer film formation was collectively wet-etched by the shower etching method. Next, the formed resist was peeled off, and a video signal line, a drain electrode 8 and a source electrode 9 were formed.

For the transparent pixel electrode 11, a polycrystalline transparent conductive film is formed by a sputtering method. Next, a resist pattern was formed in order to obtain the transparent pixel electrode 11, and the portion where the transparent pixel electrode was formed was etched. Next, the formed resist is removed, and the transparent pixel electrode 11 is removed.
Was formed.

The components other than the scanning signal line and the gate electrode 4, the thin film transistor 17, the video signal line and the drain electrode 8, and the source electrode 9 are substantially the same as those in the manufacturing process performed by a known liquid crystal display device. Since it is manufactured by a process, the description of the manufacturing process of these components will be omitted.

According to the first embodiment, the video signal line, the drain electrode 8 and the source electrode 9 are each formed of a two-layer structure composed of the first conductive films 8 ₁ and 9 ₁ and the second conductive films 8 ₂ and 9 _2. and the laminated film, the first conductive film 8 _1, 9 ₁ of forming material, a main component of molybdenum (Mo), using a molybdenum alloy containing 8% by weight of zirconium (Zr), the second conductive film 8 ₂ , 9 ₂ forming material, by using a pure molybdenum (Mo), the four properties, i.e., good low-resistance characteristics, selective wet etching can performance, good light load characteristics during the sputtering process, a protective insulating The dry etching of the film makes it possible to satisfy all of the performances that can form a through-hole.
Good contact with the intrinsic amorphous silicon layer 6 can be achieved.

Next, FIG. 2 is a plan view showing a main configuration of one pixel portion in the liquid crystal display device shown in FIG.

In FIG. 2, reference numeral 18 denotes a counter voltage supply line,
Reference numeral 9 denotes an additional capacitor, and the same components as those shown in FIG. 1 are denoted by the same reference numerals.

The opposing voltage supply line 18 is disposed between the adjacent scanning signal lines 4 in parallel with the scanning signal line 4, and the additional capacitance 19 is provided between the transparent pixel electrode 11 and the opposing voltage supply line 18.
Connected between them. The additional capacitance 19 is for keeping the video signal component accumulated in the transparent pixel electrode 11 for a long time when the thin film transistor 17 is turned off. Each transparent pixel electrode 11 is provided at a portion surrounded by the corresponding scanning signal line 4, counter voltage supply line 18, and video signal line 8, and the thin film transistor 17 is provided at one corner of a portion where the transparent pixel electrode 11 is formed. .

The scanning signal line (and gate electrode) 4 is
The first conductive film 4 ₁ and a laminated film of the second conductive film 4 ₂ and the two layers, the video signal line 8 and the drain electrode 8 shown in the
A first conductive film 8 ₁ shown in Fig. 1 consists of two layers laminated film of the second conductive film _82, similarly, the source electrode 9, the first conductive film 9 ₁ and shown in Figure 1 the It has a laminated film of two layers of a second conductive film 9 _2. Further, the counter voltage supply line 18 is formed of a two-layer laminated film having the same configuration as the scanning signal line (and the gate electrode) 4.

In this case, the semiconductor layer 6 is formed so that a part thereof enters the lower layer of the region where the drain electrode 8 and the source electrode 9 are formed, and prevents the drain electrode 8 and the source electrode 9 from being disconnected as described above. , The capacitance between the drain electrode 8 and the source electrode 9 and the gate electrode 4 intersecting therewith is reduced.

In the above configuration, at a predetermined timing, a scanning signal is supplied to the scanning signal line 4, a video signal is supplied to the video signal line 8, and a counter voltage is supplied to the counter voltage supply line 18 to drive the thin film transistor 17 in a time-division manner. The means for supplying a predetermined applied voltage to the corresponding transparent pixel electrode 11 by driving the thin film transistor 17 and driving the liquid crystal layer 3 corresponding to the transparent pixel electrode 11 to display an image is a known liquid crystal display device of this type. Since this is the same as the image display means, the description of this point is omitted.

Next, FIGS. 3A and 3B are cross-sectional views showing respective configuration examples of the scanning signal line terminal and the video signal line terminal in the liquid crystal display device shown in FIG. 1, and FIG. FIG. 3B shows an example of a signal line terminal, and FIG.

In FIG. 3, reference numerals 10 ₂ and 10 ₃ denote through holes, reference numeral 20 denotes a transparent terminal film, and other components that are the same as those shown in FIG.

[0051] As shown in FIG. 3 (a), the scanning signal line terminal, the second conductive film 4 hole surface _{of 2} to reach through the layers of the protective insulating film 10 and the gate insulating film 5 in the terminal forming portion and a through hole 10 ₂ transparent terminal film 21 around is formed thereof.

[0052] Further, as illustrated in FIG. 3 (b), the video signal line terminal, the first conductive film 8 ₁ through the protective insulating film 10 and the second conductive film 8 _{and second} layers to the terminal forming portion having through holes 10 ₂ to the surface and the transparent terminal film 21 around the hole is formed reached.

In this case, the scanning signal line terminal and the video signal line terminal are connected to the scanning signal line 4 and the video signal line 8, respectively.
A through-hole resist pattern is formed thereon using a single photomask, and each layer of the protective insulating film 10 and the gate insulating film 5 and the protective insulating film 10 are formed by dry etching.
And the second conductive film ₈₂ of each layer are simultaneously etched using. In the scanning signal line terminal, since the protective insulating film 10 has a higher etching rate than the gate insulating film 5, the protective insulating film 1
0 is preferentially side-etched, and dry-etched so that the end surfaces of the protective insulating film 10 and the gate insulating film 5 become forward tapered holes. Video signal line terminal, when the dry etching, the second conductive film 8 of the video signal lines 8 ₂
Since it pure molybdenum (Mo) has no resistance to dry etching with, is the second conductive film ₈₂ is also etched simultaneously during dry etching of the protective insulating film 10, the protective insulating film 10 and the end surface of the second conductive film 8 ₂ shape Is dry-etched so as to form a forward tapered hole. Since molybdenum alloy molybdenum (Mo) is a first conductive film 8 ₁ of the video signal line 8 as a main component, and contained 8 wt% of zirconium (Zr) is to have a dry etching resistance,
Never first conductive film 8 ₁ are simultaneously etched.

After the holes are formed, the resist is peeled off, and the transparent conductive film 2 serving as a scanning signal line terminal portion and a video signal line terminal portion is removed.
A film of No. 0 is formed by sputtering polycrystalline indium tin oxide to form a scanning signal line terminal and a video signal line terminal. Depending deposition of indium tin oxide in this case, also simultaneously formed part made of a transparent pixel electrode 11 and its connection part 11 _1.

[0055] In the arrangement, the scanning signal line and the gate electrode 4 and the first conductive film 4 ₁ a two-layer laminated film consisting of a second conductive film 4 ₂ Metropolitan, the first conductive film 4 ₁ forming material, aluminum (Al) as a main component, an aluminum alloy containing 9.8 wt% of neodymium (Nd), the second conductive film 4 ₂ forming material, a main component of molybdenum (Mo), 8 wt% Since a molybdenum alloy containing zirconium (Zr) is used, it has good low resistance characteristics of about 400 Ωμm ² . In the pixel area other than the terminal area, since the scanning signal lines are anodized, the anodized film blocks hydrobromic acid, and the lower layers are not attacked by hydrobromic acid. When forming the transparent pixel electrode 11 and the transparent conductive film 20 made of indium tin oxide,
There is no disconnection between the scanning signal line and the gate electrode 4.

FIG. 4 shows a second embodiment of the liquid crystal display device according to the present invention, and is a cross-sectional view showing the configuration of a main part including one thin film transistor.

In FIG. 4, 4 'is a scanning signal line and a gate electrode, 4 ₁ ' is a first conductive film, 4 ₂ 'is a second conductive film, 1'
1 ′ is a transparent pixel electrode, 11 ₁ ′ is a connection part, and other components that are the same as those shown in FIG. 1 are given the same reference numerals.

The difference between the configuration of the first embodiment (hereinafter, referred to as Embodiment 1) and the configuration of the second embodiment (hereinafter, referred to as Embodiment 2) is that the scanning signal lines and the gate electrodes 4, 4 'the second conductive film 4 ₂ in, 4 _2' in the formation material, while aluminum is used alloy embodiment 1 is anodized, the second embodiment is the first conductive film 4 ₁ and the second conductive film in the laminated film of 4 ₂ bilayer, the first conductive film 4 ₁ is mainly composed of aluminum (Al), an aluminum alloy containing 9.8 wt% of neodymium (Nd), the second conductive film 4 ₂ Is molybdenum (Mo) as the main component, 8% by weight
Embodiment 1 is based on the point that a molybdenum alloy containing zirconium (Zr) is used and the material for forming the transparent pixel electrodes 11 and 11 ′ and the connecting portions 11 ₁ and 11 ₁ ′ is polycrystalline indium tin oxide. Embodiment 2 uses only indium zinc oxide (IZO), whereas (ITO) is used. In addition, the difference between Embodiment 1 and Embodiment 2 is that Absent. Therefore, the configuration of the second embodiment will not be described further.

The difference between the manufacturing process of the first embodiment (Embodiment 1) and the manufacturing process of the second embodiment (Embodiment 2) is that the manufacturing process of the second conductive films 4 ₂ and 4 ₂ ′ is different. In the first embodiment, a two-layer laminated film made of an aluminum alloy and a molybdenum alloy is immersed in a chemical conversion solution to obtain an anodized aluminum alloy, whereas in the second embodiment, a first conductive film 4 made of an aluminum alloy is obtained. ₁ ′ and a second conductive film 4 ₂ ′ made of a molybdenum alloy, and a manufacturing process of the transparent pixel electrodes 11, 11 ′ and the connecting portions 11 ₁ , 11 ₁ ′. In, after forming a transparent conductive film by a sputtering method, a resist pattern is formed to obtain a transparent pixel electrode 11,
When etching the transparent pixel electrode forming portion with an etchant, Embodiment 1 uses hydrobromic acid as an etchant, whereas Embodiment 2 uses an oxalic acid solution as an etchant. In addition, there is no difference in the manufacturing process between the first embodiment and the second embodiment. Therefore, the manufacturing process according to the second embodiment will not be described further.

[0060] According to the second embodiment, like the first embodiment, the video signal lines and the drain electrode 8, the first conductive film 8, respectively source electrodes 9 _1, 9 ₁ and the second conductive film 8
_2, 9 ₂ and a two-layer laminated film consisting of a Metropolitan, the first conductive film 8 _1, 9 ₁ of forming material, a main component of molybdenum (Mo), a molybdenum alloy containing 8% by weight of zirconium (Zr) used, the second conductive film 8 _2, 9 ₂ forming material, by using a pure molybdenum (Mo), the 4
It is possible to satisfy all of the three characteristics, namely, good low resistance characteristics, selectable wet etching processing performance, good light load characteristics during the sputtering process, and through hole formation performance by dry etching of the protective insulating film. Moreover, good contact with the intrinsic amorphous silicon layer 6 of the thin film transistor 17 can be achieved.

Further, according to the second embodiment, the scanning signal line and the gate electrode 4 ′ are formed as a two-layer laminated film composed of the first conductive film 4 ₁ ′ and the second conductive film 4 ₂ ′. 'the formation material, aluminum (Al) as a main component, an aluminum alloy containing 9.8 wt% of neodymium (Nd), the second conductive film 4 _2' 1 conductive film 4 ₁ to forming material, A molybdenum alloy containing molybdenum (Mo) as a main component and containing 8% by weight of zirconium (Zr) is used.
Since indium zinc oxide is used as a material for forming the transparent pixel electrode 11 ′, the scanning signal line and the gate electrode 4 ′ have good low-resistance characteristics and the transparent pixel electrode 11 ′.
Can be used instead of hydrobromic acid as an etchant when etching is performed, so that the scan signal line and the gate electrode 4 ′ are affected by the etchant when the transparent pixel electrode 11 ′ is formed. There is no disconnection between the scanning signal line and the gate electrode 4 '.

In the second embodiment, the transparent pixel electrode 11 'is formed using indium zinc oxide as an example of an oxalic acid solution as an etchant. The material for forming the transparent pixel electrode 11 ′ in which an oxalic acid solution can be used as a liquid is not limited to the example of indium zinc oxide, but amorphous phase indium tin oxide (ITO) or indium germanium oxide (IGO) Can also achieve the same function as when indium zinc oxide is used.

Next, FIG. 5 shows a third embodiment of the liquid crystal display device according to the present invention.
FIG. 3 is a cross-sectional view illustrating a configuration of a main part including a plurality of thin film transistors.

In FIG. 5, 4 ″ is a scanning signal line and a gate electrode, 4 ₁ ″ is a first conductive film, 4 ₂ ″ is a second conductive film, and other components are the same as those shown in FIG. Components are given the same reference numerals.

Then, the first embodiment (Embodiment 1)
The difference between the first embodiment and the third embodiment (hereinafter, referred to as a third embodiment) is that the first embodiment is an anodized aluminum alloy as a material for forming the scanning signal lines and the gate electrodes 4 and 4 ″. On the other hand, the third embodiment is a two-layer laminated film composed of the first conductive film 4 ₁ ″ and the second conductive film 4 ₂ ″, and the material for forming the first conductive film 4 ₁ ″ is molybdenum (M
o) is used as a main component, and a molybdenum alloy containing 8% by weight of zirconium (Zr) is used. The material for forming the second conductive film 4 ₂ ″ is pure molybdenum (Mo) having a purity of 99.9% by weight.
There is no difference in the configuration between the first embodiment and the third embodiment except for the use of. Therefore, the second
The configuration of this embodiment will not be described further.

The difference between the manufacturing processes of the first embodiment (Embodiment 1) and the third embodiment (Embodiment 3) is that the manufacturing process of the scanning signal lines and the gate electrodes 4 and 4 ″ is different. , Sputtering temperature of 120 ° C by sputtering method
Embodiment 1 uses a two-layered conductive film made of an aluminum alloy and a molybdenum alloy as a material for forming the film, while Embodiment 3 uses molybdenum containing 8% by weight of zirconium (Zr). Using a two-layer conductive film made of an alloy and pure molybdenum (Mo); and
The laminated film of the resulting two-layer, whereas Embodiment 1 is immersed in a laminated film of two layers conversion solution, and the second conductive film 4 ₂ to anodized aluminum alloy, the embodiment 3
However, there is no difference in the manufacturing process between the first embodiment and the third embodiment only in that such processing is not performed. Therefore, the manufacturing process of the third embodiment will not be described further.

According to the third embodiment, the scanning signal line 4 ″, the video signal line and the drain electrode 8, the source electrode 9 are respectively connected to the first conductive films 4 ₁ ″, 8 ₁ , 9 ₁ and the second conductive film. 4
₂ ″, 8 ₂ , 9 _2, and the first conductive film 4 ₁ ″, 8 ₁ , 9 ₁ was formed of molybdenum (M
o) as a main component, using a molybdenum alloy containing 8% by weight of zirconium (Zr), the second conductive film 4 ₂ ", 8
By using pure molybdenum (Mo) as the material for forming ₂ , 9 ₂ , the above four properties, namely, good low resistance property, selective wet etching workability, good light load property at the time of sputtering process, and protection. Dry etching of the insulating film satisfies all of the performances in which a through hole can be formed, and also achieves good contact with the intrinsic amorphous silicon layer 6 of the thin film transistor 17.

Next, FIG. 6 is a cross-sectional view showing a configuration example of a scanning signal line terminal in the liquid crystal display device shown in FIG.

In FIG. 6, reference numeral 10 ₄ denotes a through-hole, and the same components as those shown in FIGS. 3 and 5 are denoted by the same reference numerals.

As shown in FIG. 6, a scanning signal line terminal
Indicates that the protective insulating film 10 and the gate insulating film 5
Penetrate each layer, and further form a second conductive film 4_TwoThrough the first
Electromembrane 4 ₁Transparent terminal on the surface of the hole reaching to "and around it
Through hole 10 with film 20 formed_FourHaving.

In this case, the scanning signal line terminal is formed by forming a through-hole resist pattern on the scanning signal line 4 ″ forming the terminal by using a single photomask, and forming each layer of the protective insulating film 10 and the gate insulating film 5 by dry etching. And the respective layers of the second conductive film 4 ₂ ″ are simultaneously etched.
In the scanning signal line terminal, the protective insulating film 10 has a higher etching rate than the gate insulating film 5 and the second conductive film 4
_Since pure molybdenum (Mo), which is ₂ ″, does not have dry etching resistance, the protective insulating film 10, the gate insulating film 5, and the second conductive film 4 ₂ ″ are side-etched in order of priority to form the protective insulating film 10 and the gate insulating film. 5 and second conductive film 4
Dry etching is performed so that the end face shape of ₂ ″ becomes a forward tapered hole. The first conductive film 4 of the scanning signal line 4 ″ is formed.
₁ "molybdenum (Mo) as a main component, 8% by weight
Since the molybdenum alloy containing zirconium (Zr) has dry etching resistance, the first conductive film 4 ₁ ″ is not etched at the same time.

After the holes are formed, the resist is peeled off, and a transparent conductive film 20 serving as a scanning signal line terminal portion is formed of polycrystalline indium tin oxide (ITO) by a sputtering method. It is formed. At this time, the transparent pixel electrode 11 is formed by forming the indium tin oxide.
And parts made from the connection portion 11 ₁ is also deposited simultaneously.

In the above structure, the scanning signal line and the gate electrode 4 ″ are formed as a two-layer laminated film composed of the first conductive film 4 ₁ ″ and the second conductive film 4 ₂ ″, and the first conductive film 4 ₁ ″ is formed. Since a molybdenum alloy containing molybdenum (Mo) as a main component and 8% by weight of zirconium (Zr) is used as a material, and pure molybdenum (Mo) is used as a material for forming the second conductive film 4 ₂ ″. , About 400 Ωμm ^2, and a transparent pixel electrode 11 formed by etching polycrystalline indium tin oxide using hydrobromic acid.
When the transparent conductive film 20 and the transparent conductive film 20 are formed, the first conductive film 4 ₂ ″, which is a molybdenum alloy, has an etching resistance to hydrobromic acid. In some cases, there is no disconnection between the scanning signal line and the gate electrode 4 ″.

In each of the first to third embodiments,
The first conductive film 4₁, 4₁’, 4 ₁", 8₁, 9₁To
Zirconium contained in the molybdenum alloy (Z
r) is 8% by weight.
Zirconium (Zr) content is 8 wt%
The content is not limited to 4% by weight to 1% by weight.
If the content is within the range of 4% by weight, the content is 8% by weight.
It is possible to achieve almost the same function as in the case. Ma
The first conductive film 8₁, 9₁Has a film thickness of 10 nm or more.
And the second conductive film 8_Two, 9_TwoHas a film thickness of 90 nm or more.
It is possible to satisfy the above four characteristics in good condition
It is.

FIG. 7 is a plan view showing a wiring structure near one pixel of the active matrix substrate of the liquid crystal display device according to the present invention, and corresponds to the configuration shown in FIG.

In FIG. 7, reference numeral 21 denotes a display area, and the same components as those shown in FIG. 2 are denoted by the same reference numerals.

As shown in FIG. 7, the central portion of the lower substrate 1 excluding the periphery constitutes a display area 21, and an image is displayed by the liquid crystal layer 3. The display area 21 is provided with the scanning signal lines 4 and the counter voltage supply lines 18 extending in the horizontal (X) direction and the video signal lines 8 extending in the vertical (Y) direction. . The scanning signal line 4 and the counter voltage supply line 18 are respectively insulated from the video signal line, the drain electrode 8 and the source electrode 9.

The area surrounded by each scanning signal line 4 and each video signal line 8 constitutes one pixel area, and the display area 21 is formed by an aggregate of a large number of one pixel areas arranged in a matrix. Is formed. Each one pixel area is
The thin film transistor 17 includes a thin film transistor 17 that is turned on by the supply of a scanning signal from the scanning signal line 4 and a pixel electrode 11 to which a video signal from the video signal line 8 is supplied via the turned on thin film transistor 17. The additional capacitance 19 is connected between the counter voltage supply line 18 and the pixel electrode 11 and holds the video signal accumulated in the pixel electrode 11 when the thin film transistor 17 is turned off.

FIGS. 8A and 8B are cross-sectional views showing a partial configuration of a liquid crystal display device according to the present invention when a driver IC is mounted, and FIG. (B) Drain driver IC 31
And shows an example of mounting on a lower substrate by a chip-on-glass (COG) method via an anisotropic conductive film (ACF) 24. Note that this implementation example corresponds to the configuration shown in FIG.

8A and 8B, reference numeral 22 denotes a scanning signal line terminal, 32 denotes a gate side bus line, 23 denotes a video signal line terminal, 33 denotes a drain side bus line, 22 ₁ and 32.
₁ , 23 ₁ and 33 ₁ are first conductive films, 22 ₂ , 32 ₂ and 2
3 _2, 33 ₂ and the second conductive film, 24 is an anisotropic conductive film (ACF), 25 is transparent conductive film, the conductive particles 26, 34
Denotes a bump, 30 denotes a gate driver IC, 31 denotes a drain driver IC, and other components that are the same as those shown in FIG.

[0081] As shown in FIG. 8 (a), the mounting portion of the gate driver IC30 is stacked film of the first conductive film 22 ₁ and the second conductive film 22 ₂ of the two layers formed on the lower substrate 1 a scanning signal line terminal 22 consisting of the first conductive film 32 ₁ and the gate-side bus line 3 composed of a stacked film of the second conductive film 32 ₂ of the two layers
2, the scanning signal line terminal 22 and the gate side bus line 32
A gate insulating film 5 and a protective insulating film 10 sequentially coated thereon
And a transparent conductive film 25 coated so as to reach the second conductive films 22 ₂ and 32 ₂ through holes provided in the gate insulating film 5 and the protective insulating film 10, and into the holes so as to contact the transparent conductive film 25. The conductive particles 26 are arranged, the anisotropic conductive film 24 is formed on the surface area excluding the place where the conductive particles 26 are arranged, and the bumps 34 are arranged so as to be in contact with the conductive particles 26.

Further, as shown in FIG. 8B, the mounting portion of the drain driver IC 31 includes the gate insulating film 5,
The first conductive film 23 is formed on the gate insulating film 5 ₁ and the second
The video signal line terminal 2 made of laminated films of the conductive film 23 ₂ of the two layers
3, the first conductive film 33 ₁ and the drain-side bus line 33 made of a laminate film of the second conductive film 33 ₂ of the two layers formed on the lower substrate, and the protective insulating film 10, provided in the protective insulating film 10 It was to reach the ₂ second conductive film 23 through a hole or a protective insulating film 10 and the second through hole formed in the gate insulating film 5,
And the coated transparent conductive film 25 reaches the conductive film 33 _2, the conductive particles 26 that is disposed on the hole so as to be in contact with the transparent conductive film 25, formed on the surface region excluding the placement point of the conductive particles 26 Anisotropic conductive film 24 and conductive particles 2
6 and the bumps 34 arranged so as to come into contact therewith.

The scanning signal line terminal 32, gate side bus line 22, and drain side bus line 33 are
Of the same configuration as the scanning signal line 4 illustrated in the first conductive film 32 _1, 22 _1, 33 ₁ of the forming material, a main component of aluminum (Al), 9.8 wt% of neodymium (N
d) is an aluminum alloy containing the second conductive film 3
The material forming 22 ₂ , 22 ₂ and 33 ₂ is molybdenum (M
This is a molybdenum alloy containing o) as a main component and containing 8% by weight of zirconium (Zr). Video signal line terminal 23
Is of the same configuration as the video signal lines and the drain electrode 8 of FIG. 1, the _first forming material first conductive film 23, a main component of molybdenum (Mo), 8 wt% of zirconium (Zr) a molybdenum alloy containing, ₂ forming material second conductive film 23, a pure molybdenum (Mo).
The transparent conductive film 25 is made of polycrystalline indium tin oxide (IT) having the same configuration as the transparent pixel electrode 11 shown in FIG.
O).

In this case, the scanning signal line terminal 32, the gate-side bus line 22, and the drain-side bus line 33 can be formed by the same process when forming the scanning signal line and the gate electrode 4. The line terminal 23 can be formed by the same process when forming the video signal line, the drain electrode 8 and the source electrode 9. Further, the transparent conductive film 25 can be formed by the same process when forming the transparent pixel electrode 11 and the transparent conductive film 20.

With this configuration, the sheet resistance of the gate-side bus line 32 and the drain-side bus line 33 is set to 0.3Ω / □, the contact resistance between the gate-side bus line 32 and the transparent conductive film 25 is reduced, And the drain side bus line 33
And the transparent conductive film 25 have a contact resistance of 400Ωμ, respectively.
m ^2, and the contact resistance between the transparent conductive film 25 and the anisotropic conductive film 24 can be reduced. By realizing such a low bus line resistance and a contact portion, it becomes possible to transfer data, voltage, and the like by a bus line connecting between the gate driver ICs 30 and between the drain driver ICs 31, and a flexible printed circuit (FPC) And the connection reliability is improved.

FIGS. 9A and 9B are cross-sectional views showing a part of a liquid crystal display device according to the present invention when a driver IC is mounted on the liquid crystal display device. FIG. (B) is a drain driver IC3
1 shows an example in which the mounting portion 1 is mounted on a lower substrate by a chip-on-glass (COG) method via an anisotropic conductive film (ACF) 24. Note that this implementation example corresponds to the configuration shown in FIG.

In FIGS. 9A and 9B, reference numeral 25 'denotes a transparent conductive film, and the same components as those shown in FIGS. 8A and 8B are denoted by the same reference numerals. ing.

The mounting examples shown in FIGS. 9A and 9B (hereinafter referred to as the mounting examples in FIG. 9) and FIGS. 8A and 8B
8 is different from the mounting example shown in FIG. 8 (hereinafter, referred to as the mounting example in FIG. 8) in that the mounting example in FIG. 8 uses polycrystalline indium tin oxide (IT) as a material for forming the transparent conductive films 25 and 25 ′.
O), the mounting example in FIG. 9 is indium zinc oxide (IZO), and the transparent connection films 25 and 25 ′.
8 is that the mounting example of FIG. 8 has a bottom surface portion, while the mounting example of FIG. 9 has a bottom surface opening. FIG.
The reason why the mounting example has a bottom opening is that IZO and ACF
Due to high contact resistance with That is, the contact resistance is reduced by directly contacting the second conductive films 22 ₂ , 32 ₂ , 23 ₂ , and 33 ₂ with the ACF.
In addition, there is no difference in configuration between the example of FIG. 8 and the example of FIG. Therefore, further description of the configuration of the mounting example in FIG. 9 is omitted.

In the mounting example of FIG. 9, since the gate side bus line 32 and the drain side bus line 33 are made of an aluminum alloy similarly to the mounting example of FIG. 8, their sheet resistance is set to 0.3Ω /. Can be □. Further, at the connection portions between the gate-side bus line 32 and the drain-side bus line 33 and the ACF, the transparent conductive film 2
Since a bottom opening is provided in 5 ′ and the second conductive films 32 ₂ and 33 ₂ are directly connected to the conductive particles 26, the second conductive films 32 ₂ and 33 ₂ and the transparent conductive film are interposed through the conductive particles 26. 2
The contact resistance value with 5 ′ can be made about 800Ωμm ^2, and the contact resistance value between transparent conductive film 25 ′ and anisotropic conductive film 24 can also be reduced.

Next, FIG. 10 shows a fourth embodiment of the liquid crystal display device of the present invention. The second embodiment shown in FIG. 4 is different from the in-plane switching type (IP).
S, a lateral electric field type, and is a cross-sectional view showing a configuration of a main part including one thin film transistor.

FIG. 11 is a plan view showing a configuration of a main part of one pixel portion in a liquid crystal display device according to a fourth embodiment of the present invention.

In FIGS. 10 and 11, 9 'is a pixel electrode, 29 is a counter electrode, and the same components as those shown in FIGS. 2 and 4 are denoted by the same reference numerals.

The difference between the configuration of the fourth embodiment shown in the sectional view of FIG. 10 (hereinafter referred to as the fourth embodiment) and the configuration of the first embodiment (the first embodiment) shown in the sectional view of FIG. Is for the through hole 10 ₁ formed on the source electrode 9.
Embodiment 1, while having the through holes 10 _1, embodiment 4, an only point that lack this through hole 10 _1, the other, the embodiment 4 and embodiment 1
There is no structural difference between and. Therefore, a further description of the configuration of the fourth embodiment illustrated in FIG. 10 will be omitted.

As shown in FIG. 11, in the fourth embodiment, the opposing voltage supply lines 18 are arranged between the adjacent scanning signal lines 4 in parallel with the scanning signal lines 4, and a plurality of opposing voltage supply lines 18 Are drawn out in a comb-like shape.
The pixel electrode 9 ′ has a U-shape as a whole, and a protruding portion is arranged in parallel with the counter electrode 29.

As shown in FIG. 10, the scanning signal lines (and
And gate electrode) 4 is an anodized aluminum alloy
The counter voltage supply line 18 is connected to a scanning signal line (and
The configuration is the same as that of the gate electrode 4. Video signal line and drain
The in-electrode 8 is a first conductive film 8 ₁And the second conductive film 8_TwoAnd two
It consists of a laminated film of layers.

[0096] In this case, the first conductive film 8 ₁ forming material, a main component of molybdenum (Mo), a molybdenum alloy containing 8% by weight of zirconium (Zr), the second conductive film 8 ₂ And the forming material is pure molybdenum (Mo).

In the above configuration, at a predetermined timing, a scanning signal is supplied to the scanning signal line 4, a video signal is supplied to the video signal line 8, and a counter voltage is supplied to the counter voltage supply line 18 to drive the thin film transistor 17 in a time division manner. The means for supplying an in-plane electric field between the corresponding pixel electrode 9 and the counter electrode by driving the thin film transistor 17 and driving the liquid crystal layer 3 to display an image is a means for displaying an image in a known in-plane liquid crystal display device. Since this is the same as the means, description of this point is omitted.

In the liquid crystal display device having the above structure, each part is formed as follows.

The scanning signal line and the gate electrode 4, the counter voltage supply line 18 and the counter electrode 29 are formed on one surface of the lower substrate 1 by sputtering at a film forming temperature of 120 ° C. and mainly containing aluminum (Al). , An aluminum alloy layer containing 9.8% by weight of neodymium (Nd), and 8% by weight of zirconium (Z) containing molybdenum (Mo) as a main component.
A molybdenum alloy layer containing r) is continuously formed. Next, a resist pattern is formed by photolithography to obtain the scanning signal line and the gate electrode 4, the counter voltage supply line 18 and the counter electrode 29, and an aqueous solution of phosphoric acid or nitric acid, preferably acetic acid or ammonium fluoride is added. These films were collectively wet-etched by a shower etching method using an etching solution consisting of Next, the resist is peeled off, the scanning signal line 4 and the terminal portion of the counter voltage supply line 18 are covered, and the obtained scan signal line and gate electrode 4, the counter voltage supply line 18 and the counter electrode 29 are immersed in a chemical solution. And anodized. At this time, the molybdenum alloy layer is dissolved and then uniformly form an anode oxide film 4 ₂ in the aluminum alloy layer 4 _first surface, the scanning signal line and the gate electrode 4 similar configuration counter voltage supply line 18 and it, A counter electrode 29 was formed.

The thin film transistor 17 has a gate insulating film made of silicon nitride (SiN) formed on the formed scanning signal line and gate electrode 4, the counter voltage supply line 18 and the counter electrode 29 by plasma enhanced chemical vapor deposition (PVCD). An intrinsic amorphous silicon film and a contact film are continuously formed.
Next, in order to obtain an intrinsic amorphous silicon layer and a contact layer 7, a resist pattern is formed by a photolithography method, and the intrinsic amorphous silicon film and the contact film are etched into an island shape by a dry etching method. The crystalline silicon layer 6 and the contact layer 7 were formed, and then the resist was stripped.

The video signal line and the drain electrode 8, the source electrode 9, and the pixel electrode 9 'are formed by sputtering.
At a film forming temperature of 120 ° C., a molybdenum (Mo) alloy layer containing molybdenum (Mo) as a main component and containing 8% by weight of zirconium (Zr) and a pure molybdenum (Mo) layer are continuously formed. Next, in order to obtain a video signal line and a drain electrode 8, a source electrode 9, and a pixel electrode 9 ', a resist pattern is formed by photolithography, and a solution containing phosphoric acid or nitric acid, preferably acetic acid or ammonium fluoride, In the case of this example, these films were collectively wet-etched by a shower etching method using an etching solution containing 70% by weight of phosphoric acid, 2% by weight of nitric acid, and 4% by weight of acetic acid.

Here, FIG. 12A is a side view showing a schematic structure of a wet etching apparatus used for performing the wet etching, and FIG. 12B is a side view showing a case where the wet etching apparatus is used. FIG. 3 is a characteristic diagram showing etching characteristics.

In FIG. 12A, 35 is a shower nozzle, 36 is an etching solution, and 37 is a substrate to be processed.
In FIG. 12B, the lower part shows the relationship between the shower flow rate distribution when the shower nozzle is swung and the side etching amount, and the upper part shows the shower flow rate when the shower nozzle is not swung. It shows the relationship between the distribution and the amount of side etching.

A plurality of shower nozzles 35 shown in FIG. 12A are arranged along the transport direction of the substrate 37, and are perpendicular to the transport direction of the substrate 37 when the etching liquid 36 is jetted. It swings in the direction.

In this wet etching apparatus,
When the processing substrate 37 on which a molybdenum alloy layer containing molybdenum (Mo) as a main component and containing 8% by weight of zirconium (Zr) and a pure molybdenum (Mo) layer are transported in the transport direction, a shower is performed. With the nozzle 35 oscillating, an etching solution 36 is sprayed onto the substrate 37 to be processed in the form of a shower, and the film formation is collectively wet-etched.

In the horizontal electric field type liquid crystal display device, since the scanning signal line 4, the counter voltage supply line 18 and the counter electrode 29 are provided at the same layer position, the video signal line 8, the scanning signal line 4 and the The area where the voltage supply line 18 intersects with the liquid crystal display device of the vertical electric field type is twice as large as that of the vertical electric field type liquid crystal display device. On the other hand, if the video signal line 8 is formed by using the wet etching apparatus shown in FIG. 12A, the shower flow distribution and the side etching amount change as shown in the lower part of FIG. Since a constant value is obtained without performing the etching, the side etching is reduced as a whole, and uniform etching processing without processing unevenness can be performed, and the probability that the video signal line 8 is disconnected can be extremely reduced.

After that, the formed resist is peeled off,
A video signal line, a drain electrode 8, a source electrode 9, and a pixel electrode 9 'were formed.

Subsequently, plasma enhanced chemical vapor deposition (PVC)
By D), an insulating film made of silicon nitride (SiN) is formed. Thereafter, by dry etching to form through holes 10 _3, respectively on the terminal area of the scanning signal lines 4 and the terminal area of the video signal line 8. During the dry etching, pure molybdenum constituting the second conductive film ₈₂ of the upper layer of the video signal lines and the drain electrode 8 (Mo) is to no Doraiechingu resistance, through-holes 10
The second conductive film ₈₂ at the bottom of the ₃ but is etched, a main component of molybdenum (Mo) constituting the first conductive film ₈₂ of the lower layer, a molybdenum alloy containing 8% by weight of zirconium (Zr) is etching is prevented by the second conductive film 8 ₂ in order to have a dry etching resistance. After such a dry etching, the resist is removed to form a through-hole 10 _3.

For the transparent electrode films (not shown) of the scanning signal line terminal portion and the video signal line terminal portion, polycrystalline indium tin oxide (ITO) is formed by a sputtering method. In order to obtain a transparent pixel electrode 11 ″, a resist pattern is formed by photolithography, and this film is etched using a hydrobromic acid solution. The formed resist is peeled off to form a transparent pixel electrode 11 ″. did. Note that as a material for forming the transparent conductive film, indium zinc oxide (IZO) may be used instead of polycrystalline indium tin oxide,
An oxalic acid solution is used for the etching at this time.

The other components are manufactured by almost the same manufacturing process as that of a known liquid crystal display device of this type. Description is omitted.

[0111] In an embodiment of the first to fourth, as the first conductive film 8 ₁ of the material for forming the video signal lines 8,
Although an example using a molybdenum alloy containing molybdenum (Mo) as a main component and containing 8% by weight of zirconium (Zr) is described, in the present invention, a metal contained in molybdenum to form a molybdenum alloy is used. Is not limited to zirconium (Zr), but other metals such as hafnium (Hf) and chromium (C
r) or any one of titanium (Ti), or two or more of these metals including zirconium (Zr).

Hereinafter, the video signal line and the first conductive films 8 ₁ and 9 ₁ of the drain electrode 8 and the source electrode 9 of the liquid crystal display device according to the present invention are provided with any one of these metals or any two of them. The reason why a molybdenum alloy containing at least one species is suitable will be described.

[0113] The video signal described as an object of the present invention.
Line and the drain electrode 8 and the source electrode 9
The laminated film has low resistance characteristics, dry etching resistance,
Selectable wet etching property with edge film, sputter
It must satisfy the light load characteristics at the time of switching. So
Therefore, regarding the low resistance characteristics, the second conductive film 8_Two, 9 _Two
About 10μΩcm using pure molybdenum (Mo)
For dry etching resistance, the first conductive
Membrane 8₁, 9₁Using a molybdenum (Mo) alloy
ing. Also, select wet etchant with gate insulating film
The characteristic that can be mixed is that the etching solution is mixed with phosphoric acid, nitric acid, and water.
Liquid, preferably a mixed acid solution with acetic acid
Light load characteristics during sputtering
Is realized by using a two-layer laminated film
I have. In addition, manufacturing when performing wet etching
In the process, to improve the production yield, two layers
It is preferable that the sectional processing shape of the laminated film is formed in a tapered shape.
New

The present inventors have proposed that molybdenum (Mo) be replaced with tantalum (T) in order to realize such various characteristics.
a), chromium (Cr), titanium (Ti), zirconium (Zr), hafnium (Hf), tungsten (W),
It is considered that when a metal such as niobium (Nb) is added, dry etching resistance and a tapered shape in a cross-section processing shape can be obtained in accordance with the amount of addition. A laminated film of layers was formed and viewed.

FIG. 13 is a characteristic diagram showing an etching rate when tantalum (Ta), chromium (Cr), titanium (Ti), zirconium (Zr), and hafnium (Hf) are added to molybdenum (Mo). .

In FIG. 13, the horizontal axis represents the wet etching rate in nm / s for the mixed acid solution.
The vertical axis indicates the dry etching rate in nm / s for SF ₆ gas. The lower detection limit of the dry etching rate was 0.02 nm / s.

The molybdenum alloy used for the video signal lines and the first conductive layers 8 ₁ , 9 ₁ of the drain electrode 8 and the source electrode 9 has a dry etching resistance of silicon nitride forming the gate insulating film 5 and the protective insulating film 10. An etching selectivity to (SiN) of 14 or more is required. In this case, since the dry etching rate by SF ₆ gas of a silicon nitride (SiN) is 19 nm / s, the first conductive layer 8 _1, 9 ₁ of dry etching rate 1.4 nm / s
If it is below, the required dry etching resistance is satisfied. Therefore, looking at the required addition amount of other metals to the molybdenum alloy from the characteristic diagram shown in FIG. 13, zirconium (Zr) is at least 4.0% by weight and hafnium (Hf)
Is 7.3% by weight or more, titanium (Ti) is 2.5% by weight or more, and chromium (Cr) is 1.3% by weight or more. In addition,
The molybdenum alloy to which tantalum (Ta) is added cannot be used for the first conductive layers 8 ₁ and 9 ₁ because the dry etching rate is high regardless of the amount of tantalum added. Although not shown in FIG. 13, tungsten (W), molybdenum alloy obtained by adding, niobium (Nb) for even higher molybdenum alloy dry etching rate in the same way with the addition of the first conductive layer 8 _1, 9 Cannot be used for ₁ .

As shown in FIG. 13, molybdenum (Mo) is replaced by tantalum (Ta), chromium (Cr), titanium (Ti), zirconium (Zr), and hafnium (H).
When f) is added, the wet etching rate for the mixed acid solution decreases. Therefore, even in the case of a two-layer laminated film, when the upper layer film is made of a molybdenum alloy and the lower layer film is made of pure molybdenum, the cross-sectional processed shape of the two-layer laminated film becomes an inversely tapered shape during wet etching, which is not desirable. . Therefore, when the lower layer film is made of a molybdenum alloy and the upper layer film is made of pure molybdenum, the cross-sectional processed shape is desirably tapered. Further, when the wet etching rate of the lower layer film is extremely slow as compared with the upper layer film, the side surface of the lower layer film is processed into a shape spread like a flange of a hat, which is not desirable.

Therefore, a molybdenum alloy containing chromium (Cr) satisfying dry etching resistance, chromium (C
r), a molybdenum alloy containing titanium (Ti), a molybdenum alloy containing zirconium (Zr), and a molybdenum alloy containing hafnium (Hf), a wet etching rate of pure molybdenum. It is desirable to choose the molybdenum alloy closest to the rate. In this case, a molybdenum alloy containing zirconium (Zr) provides a wet etching rate close to that of pure molybdenum when compared at the same dry etching resistance. Also, a molybdenum alloy containing hafnium (Hf) can provide a substantially equivalent wet etching rate, but hafnium (Hf) is expensive and disadvantageous in terms of cost.

[0120] Therefore, the first conductive layer 8 _1, 9 ₁ of forming material, molybdenum alloy containing chromium (Cr),
Molybdenum alloy containing chromium (Cr), titanium (T
Molybdenum alloy containing zirconium (Zr)
And a molybdenum alloy containing hafnium (Hf). Among them, a molybdenum alloy containing zirconium (Zr) is most preferable. In addition, even if it is a molybdenum alloy containing zirconium (Zr), if the amount of zirconium (Zr) added is 23% by weight or more, residue may occur after wet etching using the mixed acid solution,
The upper limit of the amount of zirconium (Zr) is 23% by weight.

[0121] When configuring the scanning signal line and the gate electrode 4 of the laminated film of two layers, the second conductive film 4 ₂ of the upper layer,
Molybdenum (Mo) as the main component, zirconium (Z
using a molybdenum alloy containing r), the first conductive film 4 ₁ of the lower layer, the main component of aluminum (Al), 9.8
In the case where an aluminum alloy containing neodymium (Nd) by weight is used and the two-layer laminated film is processed into a tapered shape by batch wet etching using the mixed acid solution, zirconium (Z) in the molybdenum alloy is used.
The addition amount of r) is most preferably 8% by weight. in this way,
A main component and molybdenum (Mo), a molybdenum alloy containing 8% by weight of zirconium (Zr) is in a first conductive film 8 _1, 9 suitable composition range as ₁ as described above,
In addition, the composition is most desirable from the viewpoint of sharing a sputtering target.

Next, the dry etching resistance and the first conductivity
Membrane 8₁, 9₁And the second conductive film 8_Two, 9_TwoRelationship with film thickness
, When molybdenum (Mo) is the main component, 8 weight
% Molybdenum alloy containing zirconium (Zr)
First conductive layer 8 made of₁, 9₁Film thickness of 10 nm or less
When forming the through hole, the first conductive layer 8₁, 9
₁Was sometimes lost by dry etching. This
The first conductive layer 8 ₁, 9₁The lower limit of the film thickness is 10n
m.

[0123] Now, a first conductive layer 8 _1, 9 ₁ of the film thickness, and 40nm in view of the margin, pure molybdenum (Mo)
The sheet resistance of the two-layer laminated film was measured while changing the thickness of the second conductive films 8 ₂ and 9 ₂ composed of. The target value of the sheet resistance is set to 0.9Ω / □. At this time, the sheet resistance value is one of the low resistance characteristics (the resistivity of about 18 μΩcm) among the low resistance characteristics, dry etching resistance, selective wet etching characteristics with the protective insulating film, and the light load characteristics at the time of sputtering, which are the objects of the invention. This is a sheet resistance value when chromium (Cr) satisfying each characteristic other than the above) is used with a film thickness of 200 nm which can be formed with a high yield.

[0124] The sheet resistance value decreases as the film thickness of the second conductive film 8 _2, 9 ₂ becomes thicker, its thickness is 100
If it is not less than nm, the sheet resistance value will be 0.9 Ω / □ or less. Therefore, the low-resistance characteristics of the multilayer films of two layers, the thickness of the second conductive film 8 _2, 9 ₂ is achieved when more than 100 nm.

Here, an example in which the liquid crystal display device according to the present invention is manufactured using a single sputtering apparatus having three film forming chambers will be described. In this case, the scanning signal line and the gate electrode 4, the first conductive film 4 ₁ forming material, aluminum (Al) as a main component, an aluminum alloy containing 9.8 wt% of neodymium (Nd), the second conductive film 4 ₂ forming material, a main component of molybdenum (Mo), a molybdenum alloy containing 8% by weight of zirconium (Zr), also, the video signal lines and the drain electrode 8, the source electrode 9 , the first conductive film 8 _1, 9 ₁ of forming material, a main component of molybdenum (Mo), a molybdenum alloy containing 8% by weight of zirconium (Zr), the second conductive film 8 _2, 9 ₂ The forming material is pure molybdenum (M
o).

First, an aluminum alloy containing aluminum (Al) as a main component and 9.8% by weight of neodymium (Nd) was formed on the surface of the lower substrate 1 using the first film forming chamber of the sputtering apparatus. Then, a molybdenum alloy containing molybdenum (Mo) as a main component and containing 8% by weight of zirconium (Zr) was formed into a film using the second film forming chamber of the sputtering apparatus. A scanning pattern and a gate electrode 4 were formed by forming and etching a resist pattern on these laminated films.

Next, the plasma enhanced chemical vapor deposition (PCV)
D), a gate insulating film made of silicon nitride (SiN), an intrinsic amorphous silicon film and a doped amorphous silicon film are successively formed, and the intrinsic amorphous silicon layer and the doped amorphous silicon film are formed. The silicon layer was processed into an island shape.

Next, using a second film forming chamber of a sputtering apparatus in which a two-layer laminated film serving as the scanning signal line and the gate electrode 4 was formed, 8 wt% of zirconium (Zr ), And then pure molybdenum (Mo) was formed using the third film forming chamber of the sputtering apparatus. A resist pattern was formed on the two-layered film, and the two-layered film was etched to form a video signal line, a drain electrode 8 and a source electrode 9.

Next, after the channel portion of the thin film transistor 17 is formed, silicon nitride (SiN) serving as the protective insulating film 10 is formed by plasma enhanced chemical vapor deposition (PCVD).
A film was formed. Then, on the source electrode 9, the scanning signal line 4
A through hole was formed by dry etching on the terminal region of No. 1 and on the terminal region of the video signal line.

Next, using a sputtering apparatus different from the above-mentioned sputtering apparatus, indium tin oxide (IT
O) A film was formed, a resist pattern was formed thereon, and the film was etched to form a transparent pixel electrode 11.

The lower substrate 1 manufactured by the above manufacturing method and the upper substrate 2 manufactured by the known manufacturing method are bonded together with a gap therebetween, and the liquid crystal is sealed in the gap to form the liquid crystal layer 3. A liquid crystal display device is manufactured by connecting a liquid crystal driving circuit to the terminal regions of the scanning signal lines 4 and the video signal lines 8.

According to the above-described manufacturing method, the scanning signal line and the gate electrode 4 composed of a two-layer laminated film and the video signal line and the drain electrode 8 and the source electrode 9 composed of a two-layer laminated film are formed into three chambers. The liquid crystal display device can be formed with a single sputtering apparatus having a film formation chamber, and a liquid crystal display device can be manufactured with a high operating efficiency of the sputtering apparatus.

Further, the first film forming chamber of the sputtering apparatus,
By arranging the second film-forming chamber and the third film-forming chamber in this order, between the film-forming step of the scanning signal line and the gate electrode 4 and the film-forming step of the video signal line and the drain electrode 8 and the source electrode 9. Since the lower substrate 1 does not run backward in the sputtering apparatus, the production efficiency can be further improved.

Next, an example of manufacturing a liquid crystal display device according to the present invention using one sputtering apparatus having one film forming chamber and three types of targets will be described. In this case, the scanning signal line and the gate electrode 4, the first conductive film 4 ₁ forming material, aluminum (Al) as a main component, an aluminum alloy containing 9.8 wt% of neodymium (Nd) There, the second conductive film 4 ₂ forming material, a main component of molybdenum (Mo), a molybdenum alloy containing 8% by weight of zirconium (Zr), also, the video signal lines and the drain electrode 8, the source electrode 9 is
The first conductive film 8 _1, 9 ₁ of forming material, molybdenum (M
o) as a main component, a molybdenum alloy containing 8% by weight of zirconium (Zr), the second conductive film 8 _2, 9 ₂
Is pure molybdenum (Mo).

First, a first target in the film forming chamber of the sputtering apparatus, that is, an aluminum alloy target containing aluminum (Al) as a main component and 9.8% by weight of neodymium (Nd) was used, and the lower substrate was used. On the surface of No. 1, the molybdenum alloy was formed into a film. Next, using a second target in the film formation chamber, that is, a target for molybdenum alloy containing molybdenum (Mo) as a main component and containing 8% by weight of zirconium (Zr), the molybdenum alloy was formed on the aluminum alloy film. Was formed. A scanning pattern and a gate electrode 4 were formed by forming and etching a resist pattern on these laminated films.

Next, plasma chemical vapor deposition (PCV)
D), a gate insulating film made of silicon nitride (SiN), an intrinsic amorphous silicon film and a doped amorphous silicon film are successively formed, and the intrinsic amorphous silicon layer and the doped amorphous silicon film are formed. The silicon layer was processed into an island shape.

Next, a second target, that is, molybdenum (Mo) was used by using a film forming chamber of a sputtering apparatus in which a two-layer laminated film serving as a scanning signal line and a gate electrode 4 was formed.
Was formed using a molybdenum alloy target containing 8% by weight of zirconium (Zr) as a main component. Subsequently, using a third target in the film formation chamber, that is, a target for pure molybdenum (Mo), the pure molybdenum (M
o) was deposited. A resist pattern was formed on the two-layered film, and the two-layered film was etched to form a video signal line, a drain electrode 8 and a source electrode 9.

Next, after the channel portion of the thin film transistor 17 is formed, silicon nitride (SiN) serving as the protective insulating film 10 is formed by plasma enhanced chemical vapor deposition (PCVD).
A film was formed. Then, on the source electrode 9, the scanning signal line 4
A through hole was formed by dry etching on the terminal region of No. 1 and on the terminal region of the video signal line.

Subsequently, using a sputtering apparatus different from the above-mentioned sputtering apparatus, indium tin oxide (IT
O) A film was formed, a resist pattern was formed thereon, and the film was etched to form a transparent pixel electrode 11.

The lower substrate 1 manufactured by the above manufacturing method and the upper substrate 2 manufactured by the known manufacturing method are bonded together with a gap therebetween, and the liquid crystal is sealed in the gap to form the liquid crystal layer 3. A liquid crystal display device is manufactured by connecting a liquid crystal driving circuit to the terminal regions of the scanning signal lines 4 and the video signal lines 8.

According to the above-described manufacturing method, the scanning signal line and the gate electrode 4 composed of a two-layer laminated film and the video signal line and the drain electrode 8 and the source electrode 9 composed of a two-layer laminated film are combined into one. It can be formed by a single sputtering apparatus having a film formation chamber and three targets therein.
A liquid crystal display device can be manufactured with a high operating efficiency of the sputtering device.

In the film forming chamber of the sputtering apparatus,
By arranging the first target, the second target, and the third target in this order, between the process of forming the scanning signal line and the gate electrode 4 and the process of forming the video signal line and the drain electrode 8 and the source electrode 9. As the lower substrate 1 does not run backward in the film forming chamber, the production efficiency can be further improved.

[0143]

As described above, according to the liquid crystal display device of the present invention, each video signal line is a two-layer laminated film composed of the first conductive film and the second conductive film. Is an alloy containing molybdenum (Mo) as a main component and containing at least one metal selected from zirconium (Zr), hafnium (Hf), chromium (Cr), and titanium (Ti). Of pure molybdenum (Mo)
Therefore, it satisfies all of the various characteristics imposed on the signal line of the liquid crystal display device, and at the same time, has a good contact state between the video signal line and the amorphous silicon layer forming the thin film transistor. Has the effect of becoming

Further, according to the method of manufacturing a liquid crystal display device according to the present invention, phosphoric acid (H ₃ PO ₄ ) and nitric acid (HNO ₃ ) are used as an etchant for wet-etching a two-layer laminated film forming an image signal line. ₃ ) and water (H ₂ O), the sum of 0.72 times the concentration by weight of nitric acid and the concentration by weight of phosphoric acid is in the range of 68 to 75, and the concentration by weight of nitric acid is Since the one in the range of 0.3 to 3 is used, an image which satisfies all of the various characteristics imposed on the signal line of the liquid crystal display device with little side etching and without disconnection. There is an effect that a signal line can be formed and a liquid crystal display device can be manufactured by a simple manufacturing process.

Further, according to the method of manufacturing a liquid crystal display device according to the present invention, as a wet etching device, the etching liquid is showered onto the first substrate from a plurality of nozzles evenly arranged while horizontally transporting the first substrate. Supply
In addition, since the plurality of nozzles oscillate in a direction perpendicular to the transport direction of the first substrate, uniform etching can be performed without causing uneven etching. Video signal lines satisfying all of the various characteristics imposed on the signal lines of the device can be formed, and the liquid crystal display device can be manufactured by a simple manufacturing process.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of a liquid crystal display device according to the present invention, and is a cross-sectional view showing a configuration of a main part including one thin film transistor.

FIG. 2 is a plan view showing a main configuration of one pixel portion in the liquid crystal display device shown in FIG.

3 is a cross-sectional view showing each configuration example of a scanning signal line terminal and a video signal line terminal in the liquid crystal display device shown in FIG.

FIG. 4 is a cross-sectional view showing a second embodiment of the liquid crystal display device according to the present invention and showing a main part configuration including one thin film transistor.

FIG. 5 is a cross-sectional view showing a third embodiment of the liquid crystal display device according to the present invention and showing a configuration of a main part including one thin film transistor as in FIG.

6 is a cross-sectional view illustrating a configuration example of a scanning signal line terminal in the liquid crystal display device illustrated in FIG.

FIG. 7 is a plan view showing a wiring structure near one pixel of an active matrix substrate of the liquid crystal display device according to the present invention, corresponding to the configuration shown in FIG.

FIG. 8 is a sectional view showing a partial configuration of a liquid crystal display device according to the present invention when a driver IC is mounted.

FIG. 9 is a sectional view showing a partial configuration of a liquid crystal display device according to the present invention when a driver IC is mounted.

FIG. 10 shows a fourth embodiment of the liquid crystal display device of the present invention, in which the second embodiment shown in FIG. 4 is applied to a horizontal electric field type and includes one thin film transistor. It is sectional drawing which shows a main part structure.

FIG. 11 is a plan view showing a main configuration of one pixel portion in a liquid crystal display device according to a fourth embodiment of the present invention.

FIG. 12 is a side view showing a schematic configuration of a wet etching apparatus used when performing wet etching, and a characteristic diagram showing etching characteristics when the wet etching apparatus is used.

FIG. 13: Molybdenum (Mo), tantalum (Ta),
Chromium (Cr), titanium (Ti), zirconium (Z
r) is a characteristic diagram showing an etching rate when hafnium (Hf) is added.

[Explanation of symbols]

1 the lower substrate (first substrate) 2 upper substrate (second substrate) 3 liquid crystal layer 4, 4 ', 4 "scanning (gate) signal line and the gate electrode 4 _1, 4 _1', 4 _1" first conductive film 4 ₂ , 4 ₂ ′, 4 ₂ ″ Second conductive film 5 Gate insulating film 6 Intrinsic amorphous silicon (a-Si) layer 7 Contact layer 8 Video signal line and drain electrode 8 ₁ First conductive film 8 ₂ Second Conductive film 9 Source electrode 9 ₁ First conductive film 9 ₂ Second conductive film 10 Protective insulating film 10 ₁ , 10 ₂ , 10 ₃ Through holes 9 ′, 11, 11 ′ Pixel electrode 11 ₁ Pixel electrode connection part 12 Color filter 13 Black matrix 14 Flattening layer 15 Common electrode 16 Protective insulating film 17 Thin film transistor (TFT) 18 Counter voltage supply line 19 Additional capacitance 20 Transparent terminal film 21 Display area 22 Scan signal line terminal 22 ₁ First conductive film 22 ₂ Second conductive film 23 Video signal line Child 23 ₁ first conductive film 23 ₂ second conductive film 24 anisotropic conductive film (ACF) 25, 25 'the transparent conductive film 26 conductive particles 29 counter electrode 30 the gate driver IC 31 drain driver IC 32 gate side bus line 32 ₁ First conductive film 32 ₂ Second conductive film 33 Drain-side bus line 33 ₁ First conductive film 33 ₂ Second conductive film 34 Bump 35 Shower nozzle 36 Etching solution 37 Substrate to be processed

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/28 301 H01L 21/28 301L 301R 21/3205 21/88 M 29/786 29/78 617L 21 / 336 617M 627C (72) Inventor Tomoya Kato 7-1-1, Omikacho, Hitachi City, Ibaraki Prefecture Inside the Hitachi Research Laboratory, Hitachi, Ltd. (72) Kenichi Onizawa 7-1-1, Omikamachi, Hitachi City, Ibaraki Prefecture Hitachi, Ltd., Hitachi Laboratory (72) Inventor, Toshiki Kaneko 3300, Hayano, Mobara, Chiba Prefecture, Japan Hitachi Display Co., Ltd. (72) Inventor Hideaki Yamamoto 3300, Hayano, Mobara, Chiba Prefecture, Hitachi, Ltd. F term (reference) 2H092 GA14 GA29 GA48 GA49 GA60 JA24 JA41 JA46 KB04 MA05 MA07 MA17 MA18 MA19 NA27 PA08 PA09 4M104 AA09 BB36 CC05 DD12 DD37 DD64 DD65 DD67 EE03 EE17 FF13 GG09 HH16 5C094 AA43 AA45 BA03 BA43 CA19 DA13 DA15 EA04 EA07 FB03 FB12 FB15 FB20 JA01 5F033 HH07 HH08 HH10 HH20 JJ01 KK07 KK10 MM05 PP15 QQ11 QQ19 QQ35 QQ37 RR06 SS15 VV04 VV06 VV07 VV10 VV15 XX33 5F110 AA03 AA30 BB01 CC07 DD02 EE04 EE06 EE14 EE23 EE44 FF03 FF09 FF24 FF30 GG02 GG15 GG35 HK04 HK06 HK21 HK33 HL07 HL23 HM03 Q05 NN72 Q04

Claims (12)

[Claims] A first substrate and a second substrate; and a plurality of liquid crystal layers sandwiched between the first and second substrates. A plurality of scanning signal lines and a plurality of video signal lines, a thin film transistor provided at each intersection of each of the scanning signal lines and each of the video signal lines, a pixel electrode connected to the thin film transistor, and insulation between conductive portions. In a liquid crystal display device having a protective insulating film, each of the video signal lines is a laminated film including a first conductive film and a second conductive film, and a material for forming the first conductive film is mainly molybdenum (Mo). As components, zirconium (Zr), hafnium (Hf), chromium (C
r), an alloy containing at least one metal of titanium (Ti), and a material for forming the second conductive film is pure molybdenum (Mo). 2. A material for forming each of the scanning signal lines is aluminum (Al) or an aluminum alloy that has been subjected to anodization, and a material for forming each of the pixel electrodes is indium tin oxide in a polycrystalline phase. 2. The method according to claim 1, wherein
3. The liquid crystal display device according to 1. 3. The forming material of each of the scanning signal lines includes aluminum (Al) or an aluminum alloy, and the forming material of each of the pixel electrodes is indium tin oxide, indium zinc oxide, indium in an amorphous phase. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is one of germanium oxides. 4. A material for forming each of the pixel electrodes is indium zinc oxide, and a wiring terminal portion of each of the scanning signal lines and each of the video signal lines is connected to a corresponding one of the scanning signal lines and each of the video signal lines. The liquid crystal display device according to claim 3, wherein the constituent metal is directly connected to the anisotropic conductive film mounted on the first substrate by a chip-on-glass method. 5. The liquid crystal according to claim 1, wherein in each of the video signal lines, the first conductive film is a lower film, and the second conductive film is an upper film. Display device. 6. The liquid crystal according to claim 5, wherein each of the pixel electrodes is conductively connected to a corresponding first conductive film of the video signal line through a through hole provided in the protective insulating film. Display device. 7. The liquid crystal display according to claim 1, wherein a common electrode is disposed on the first substrate in a portion facing each of the pixel electrodes, and a reference voltage is supplied to the common electrode to perform a lateral electric field type liquid crystal driving. The liquid crystal display device according to claim 1. 8. A material for forming the first conductive film, the material mainly comprising molybdenum (Mo) and containing zirconium (Zr) in a range of 4 to 14% by weight. Item 8. A liquid crystal display device according to any one of Items 1 to 7. 9. The semiconductor device according to claim 1, wherein the first conductive film has a thickness of 10 nm or more, and the second conductive film has a thickness of 100 nm or more. A liquid crystal display device according to any one of the above. 10. A step of forming a scanning signal line and a gate electrode pattern on a first substrate by etching, a step of forming a thin film transistor active portion pattern, and a step of forming molybdenum (M).
o) as a main component and a first conductive film made of an alloy containing at least one of zirconium (Zr), hafnium (Hf), chromium (Cr), and titanium (Ti). The second made of pure molybdenum (Mo)
Forming a laminated film by depositing a conductive film, forming a video signal line, a drain electrode and a source electrode pattern by wet etching of the laminated film, forming a gate insulating film and a protective insulating film by dry etching, A step of forming a transparent pixel electrode pattern by etching, a step of bonding the first substrate and the second substrate in a state having a gap, and a step of sealing liquid crystal in the gap; and a step of attaching each terminal of the scanning signal line and the video signal line. A method for manufacturing a liquid crystal display device in which a liquid crystal display device is manufactured through a step of connecting a liquid crystal driving circuit, wherein the etching solution for the wet etching includes phosphoric acid (H ₃ PO ₄ ) and nitric acid (HNO ₃ ). and a water (H ₂ O), in the range sum of 68 to 75 with 0.72 wt.% concentration of phosphoric acid in the weight% concentration of nitric acid, and the weight of nitric acid Method of manufacturing a liquid crystal display device, wherein the concentration is in the range of 0.3 to 3. 11. The liquid crystal display device according to claim 15, wherein the etching solution for wet etching further contains acetic acid (CH ₃ COOH) and ammonium fluoride (NH ₄ F). Production method. 12. A step of forming a scanning signal line and a gate electrode pattern on a first substrate by etching, a step of forming a thin film transistor active portion pattern, and a step of forming molybdenum (M).
o) as a main component, and a first conductive film made of an alloy containing at least one of zirconium (Zr), hafnium (Hf), chromium (Cr), and titanium (Ti) is formed. Second using pure molybdenum (Mo) as material
Depositing a conductive film to form a laminated film, wet-etching the laminated film using a wet etching apparatus to form a video signal line, a drain electrode and a source electrode pattern, and dry-etching to form a gate insulating film and protection. A step of forming an insulating film, a step of forming a transparent pixel electrode pattern by etching, a step of bonding the first substrate and the second substrate with a gap therebetween, and a step of sealing liquid crystal in the gap; A method of manufacturing a liquid crystal display device, in which a liquid crystal display device is manufactured through a step of connecting a liquid crystal drive circuit to each terminal of a video signal line, wherein the wet etching device horizontally transports the first substrate, An etching liquid is supplied in a shower shape from a plurality of nozzles arranged substantially evenly onto the first substrate, and the plurality of nozzles are provided on the first substrate. Method of manufacturing a liquid crystal display device, characterized in that is to swing in the direction perpendicular to the conveying direction.