JP2001350159A - Liquid crystal display device and manufacturing method thereof - Google Patents

Abstract

(57) [Summary] When using Al wiring, hillocks are suppressed, good electrical contact with the transparent conductive film is possible, and the shape of the end of the cross section of the wiring is tapered, and a simple process is used. Provide liquid crystal display devices with high production yield. In a liquid crystal display device, an electrode group arranged on at least one of a pair of substrates includes at least a plurality of gate wirings and a plurality of data wirings formed so as to intersect the plurality of gate wirings. A thin film transistor is disposed at each intersection of the plurality of gate lines and the plurality of data lines, and at least one of the gate line and the data line includes an Al alloy film and an Al film on the Al alloy film.
And a transparent conductive film formed by connecting an Al alloy film and a transparent conductive film through a contact hole formed in an insulating film covering the stacked wiring.
The structure in which the concentration distribution of the additional element in the 1 alloy film is higher in the surface layer portion than in the inner layer portion of the Al alloy film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an active matrix type liquid crystal display (TFT-LCD) driven by a thin film transistor (TFT) and a method of manufacturing the same.

[0002]

2. Description of the Related Art The market for a thin film transistor driven liquid crystal display (TFT-LCD) has been expanding as an image display device which can be made thinner, lighter and more precise than a conventional cathode ray tube. The TFT-LCD includes a gate wiring formed on a glass substrate, a gate insulating film, a data wiring, a thin film transistor formed near an intersection of the gate wiring and the data wiring, an insulating protective film, and a transparent electrode connected to the thin film transistor; It comprises a counter substrate and a liquid crystal layer sandwiched between the glass substrate and the counter substrate.

In recent years, as the size of a TFT-LCD screen has increased and the definition has increased, the demands on the performance of wiring materials, such as low resistance, low stress, and workability, have been increasing. Therefore, Al having low resistance and low stress is used as a main wiring material. However, Al lacks heat resistance and has a problem that hillocks are generated on the surface by heating and that electrical contact with a transparent conductive film (for example, ITO: Indium-Tin-Oxide) is poor.

As a method for solving these problems, Al
A method for suppressing hillocks by laminating Mo having good electrical contact with the transparent conductive film on the film and relaxing the tensile stress of Al by the compressive stress of Mo (Japanese Patent Laid-Open No. 11-745).
No. 37), a method of forming a clad structure in which the surface of an Al wiring is coated with a high melting point metal having good electrical contact with a transparent conductive film (for example, JP-A-6-120503), to improve the heat resistance of Al itself. For this purpose, in addition to a method of alloying Al (Japanese Patent Application Laid-Open No. 7-45555), a method of laminating a Mo alloy having good electrical connectivity with a transparent conductive film as an upper layer (for example, Japanese Patent Application Laid-Open No. Hei 4-20930). is there.

[0005]

When Al is used for wiring, hillock formation of Al is suppressed, electrical contact with the transparent conductive film is reduced, and the coverage of the insulating film is improved to improve the production yield. Therefore, it is strongly desired that the cross-sectional end of the wiring be tapered, the process be simplified, and a process margin be ensured.

However, when Al is applied to a TFT-LCD by these methods described in the prior art,
It has unique problems.

In a method in which Mo having good electrical contact with the transparent conductive film is laminated on the Al film and the tensile stress of Al is relaxed by the compressive stress of Mo, the hillock is suppressed. It requires a sufficiently thick upper layer Mo to relax. However, by increasing the thickness of the upper layer, the thickness of the entire wiring is increased, and the upper layer Mo of the wiring is further increased.
Since it is difficult to control the cross-sectional shape of the wiring, the coverage of the insulating film covering the wiring is reduced, and as a result, the frequency of short-circuiting of the wiring is increased, and the production yield is reduced.

In a method of forming a clad structure in which the surface of an Al wiring is covered with a refractory metal having good electrical contact with a transparent conductive film, photolithography for forming an upper refractory metal film after forming an Al wiring pattern is performed. Since it increases once, the process becomes complicated and productivity decreases.

In order to improve the heat resistance of Al itself,
In addition to the method of alloying, a method of laminating a Mo alloy having a good electrical connection with the transparent conductive film as an upper layer is performed by using a contact hole of an insulating film covering the wiring (the insulating film is electrically connected to another wiring or an electrode. The upper Mo alloy must have dry etching resistance in order to form a hole to be formed by performing dry etching (hereinafter referred to as a contact hole), and the dry etching resistance is increased by adding Cr to the upper Mo or increasing the thickness of the upper layer. Need to secure. However, the upper layer M
In the method of adding Cr to the o-alloy, the etching rate of the Mo alloy is reduced, so that it is very difficult to control the cross section of the wiring to a favorable taper shape. Even if the optimum conditions for obtaining a good taper shape are found, the process margin is still narrow, and it is difficult to maintain a uniform shape on the surface of a large-sized substrate. As a result, the production yield decreases. Also, increasing the film thickness similarly lowers the production yield for the reasons described above.

[0010] An object of the present invention is to provide a method for using Al wiring,
It is an object of the present invention to provide a liquid crystal display device which can suppress hillocks, make good electrical contact with a transparent conductive film, taper the shape of a cross-sectional end of a wiring, and have a high production yield in a simple process.

[0011]

According to one embodiment of the present invention, at least one of a pair of transparent substrates, a liquid crystal layer sandwiched between the pair of substrates, and at least one of the pair of substrates. A liquid crystal display device having an electrode group arranged in the liquid crystal layer and controlling display by moving liquid crystal of a liquid crystal layer by the electrode group.
The electrode group arranged on the pair of substrates includes at least a plurality of gate wirings and a plurality of data wirings formed so as to intersect the plurality of gate wirings. Each of the plurality of gate wirings and the plurality of data wirings A thin film transistor is arranged corresponding to the intersection of the gate wiring and the data wiring, and at least one of the gate wiring and the data wiring is formed on the Al alloy film and the A
a stacked wiring having an upper layer film of a metal type other than l.
A structure in which the Al alloy film and the transparent conductive film are connected via a contact hole formed in the insulating film covering the stacked wiring,
The concentration distribution of the additive element in the Al alloy film is higher in the surface layer than in the inner layer of the Al alloy film.

Thus, when Al is used as a wiring material, hillocks are suppressed and oxidation at the surface layer portion of the Al alloy film is prevented, so that a liquid crystal display capable of making good electrical contact between the Al wiring and the transparent conductive film. An apparatus can be provided.

Further, by adjusting the concentration of the element added to the Al alloy film, the concentration distribution of the added element in the surface layer portion in the Al alloy film can be further improved. As a result, oxidation of the Al alloy film in the surface layer portion can be further prevented, and the electrical contact between the Al alloy film and the transparent conductive film becomes better.

Further, the thickness of the upper layer film of the laminated wiring is set to 50 nm.
By making the shape of the end of the cross section of the Al alloy film tapered, the coverage of the insulating film covering the laminated wiring is improved, and the short-circuit failure can be further reduced.

Further, the upper layer film is made of an alloy containing Mo as a main component. Thereby, the Al alloy film and the upper layer film can be collectively etched, and the process becomes simpler.

Further, the laminated wiring is a laminated wiring having a lower layer film of another metal type under the Al alloy film. This allows Al
The electrical connection between the alloy wiring and the semiconductor layer is improved.

According to another embodiment of the present invention, at least one of a pair of transparent substrates, a liquid crystal layer sandwiched between the pair of substrates, and an electrode group disposed on at least one of the pair of substrates. In a liquid crystal display device which controls display by moving liquid crystal of a liquid crystal layer by an electrode group, an electrode group arranged on a pair of substrates is provided so as to intersect at least a plurality of gate wirings and a plurality of gate wirings. A thin film transistor is formed corresponding to each intersection of the plurality of gate lines and the plurality of data lines, and a semiconductor layer is formed above the gate line via an insulating film. The data wiring, the drain electrode, and the source electrode are composed of an Al alloy film and a laminated wiring having an upper layer film of a metal species other than Al on the Al alloy film, and are formed on an insulating film covering the laminated wiring. Emissions and tact via hole Al alloy film and the transparent conductive film is connected, the concentration distribution of the additive element in the Al alloy film, a configuration that higher in the surface layer portion than the inner layer portion of the Al alloy film.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments according to the present invention will be described by way of examples. (Embodiment 1) In this embodiment, a two-layer laminated film of an Al alloy film and an upper film is applied to a gate wiring of a liquid crystal display device, and a three-layer laminated film of an Al alloy film, an upper film and a lower film is applied to data wiring. In this example, the electrical contact between the gate wiring and the data wiring and the transparent conductive film and the insulation properties between the gate wiring and the data wiring were evaluated.

FIG. 1 is a plan view schematically showing a liquid crystal display device. In the pixel section 30, a group of gate wiring terminals 31 connected to the gate wiring 1 and a group of data wiring terminals 32 connected to the data wiring 2 are arranged as shown in the figure.

FIG. 2A shows a gate wiring 1 and a data wiring 2.
2B is a cross-sectional view of the thin film transistor near the intersection of FIG. The manufacturing method is described below.

On a glass substrate 10, Al-2 at% Nd as an Al alloy film 101 and Mo as an upper film 102 were successively deposited on a glass substrate 10 by DC sputtering. The substrate temperature was 120 ° C. Subsequently, a resist pattern is formed on the laminated film by photolithography, and phosphoric acid, nitric acid, acetic acid,
The gate wiring 1 was formed by etching the Al alloy film 101 and the upper film 102 with a mixed solution of pure water.

Next, at a substrate temperature of 300 ° C., SiN as a gate insulating film 5 and a semiconductor layer
, Amorphous silicon doped with P as the n ⁺ semiconductor layer 7 was continuously deposited. Subsequently, a resist pattern was formed by photolithography, and the semiconductor layer 6 and the n ⁺ semiconductor layer 7 were processed into an island shape by dry etching.

Next, the lower film 30 is formed by DC sputtering.
Mo was continuously deposited as 3,403, Al-2 at% Nd as Al alloy films 301 and 401, and Mo as upper films 302 and 402. The substrate temperature was 120 ° C. A resist pattern is formed on the laminated film by photolithography, and the lower films 303 and 403, the Al alloy films 301 and 401, and the mixed solution of phosphoric acid, nitric acid, acetic acid and pure water are used.
The upper layers 302 and 402 are etched to form data wirings 2 and 2.
Source electrode 3 and drain electrode 4 were formed. Furthermore, n
^{+ The} semiconductor layer 7 was dry-etched.

Further, SiN was deposited as a protective film 8 at a substrate temperature of 250 ° C. by a plasma CVD apparatus. A resist pattern is formed by photolithography, and the gate insulating film 5, the protective film 8 and the upper film 102 are dried in the contact hole 21 of the gate wiring terminal portion, and the protective film 8, the upper film 302 and 402 are dried in the contact hole 20 of the thin film transistor portion. Etched. After the dry etching, the substrate was sufficiently washed with pure water.

Thereafter, ITO was deposited as a transparent conductive film 9 at a substrate temperature of 215 ° C. by a DC sputtering apparatus. A resist pattern was formed by photolithography, and the ITO was etched to form a transparent conductive film 9. Through the above steps, a TFT for a liquid crystal display device was manufactured.

Table 1 shows whether or not there is electrical contact between the Al alloy wiring film of the gate wiring and the data wiring and the transparent conductive film for the liquid crystal display panel manufactured using the thickness of the upper layer film of the gate wiring as a parameter. 4 shows the result of examining the insulation characteristics between a gate wiring and a data wiring.

[0027]

[Table 1]

A constant low value was obtained for the electrical contact between the Al alloy film and the transparent conductive film regardless of the film thickness. It can be seen that when the thickness of the upper layer is 100 nm or more, the number of short panels is very large and the coverage of the gate insulating film is poor. The thickness range of the upper layer film is 50 nm or less, preferably 20 nm. Also, when there was no upper layer film, electrical connection between the Al alloy film and the transparent conductive film was impossible.

In this embodiment, Mo is used as the upper layer film. However, similar results were obtained when the upper layer film was made of another refractory metal.

In this embodiment, the Al alloy film is
Although 2 at% Nd was used, Nd is an element whose solid solubility limit with respect to Al is as small as 0.01 at%. Similarly, Al
, La, Ce, P, which are elements having a small solid solubility limit for
r, Sm, Eu, Gd, Tb, Dy, Ho, Er, T
The same results as in this example were obtained when an Al alloy film to which m, Yb, and Lu were added was employed. (Embodiment 2) In the present embodiment, the contact hole 20 of FIG. 2 where the Al alloy film (Al-2 at% Nd) and the transparent conductive film (ITO) of the liquid crystal display device manufactured in Embodiment 1 make electrical contact. FIG. 3 (a) shows the result of composition analysis of the portion where the Al alloy film 401 and the transparent conductive film 9 are in direct contact by Auger electron spectroscopy in the depth direction. FIG. 3 (b) shows the result of composition analysis by Auger electron spectroscopy in the depth direction of the portion where the Al film and the transparent conductive film are in direct contact in the contact hole of the liquid crystal display device manufactured in FIG.

In FIG. 3A, the concentrations of In and O, which are constituent elements of the transparent conductive film, decrease at the interface of the Al alloy film.
Instead, Al and Nd, which are constituent elements of the Al alloy film, are detected, and a high concentration region exists in the surface layer. Further, although Mo used for the upper layer film was not detected, it is considered that this was removed during dry etching for forming a contact hole. In FIG. 3B, the oxygen concentration is high in the region between the broken lines in the figure, and oxygen is detected near the surface of the Al film, which is an Al oxide film (alumina). From the above, the following can be said.

First, the structure shown in FIG.
The configuration is such that the distribution of oxygen in the alloy film is very small, and the surface layer portion where the concentration of Nd as an additive element of the Al alloy film is high is in contact with ITO. The configuration shown in FIG. 6B is a configuration in which a contact portion between the Al alloy film and the ITO has an Al oxide film (alumina) having a high insulating property.

Since the surface layer portion having a high Nd concentration distribution in FIG. 6A prevents oxidation of the Al alloy film, it is presumed that electrical connection between the Al alloy film and the transparent conductive film is possible. You. The Al oxide film (alumina) in FIG. 6B is formed as a natural oxide film when the contact hole 21 is formed and the device is brought into the atmosphere after the contact hole 21 is formed, or an ITO oxide and an Al film are laminated. It is presumed that oxygen in the ITO diffused toward the Al film side. In any case, it is inferred that electrical contact between the Al film and the transparent conductive film is impossible because there is no layer for preventing oxidation on the surface of the Al film.

Further, the cross section of the Al alloy wiring prepared in Example 1 was observed with a transmission electron microscope, and the composition of the interface between the Al alloy film and the upper layer film was analyzed. FIG. 4 is a schematic diagram showing the result of enlarging the region A in FIG. 2A and observing it with a transmission electron microscope. In the figure, black circles and numbers in the circles represent observation points and point numbers in energy dispersive X-ray analysis, and Table 2 shows the results of elemental analysis.

[0035]

[Table 2]

This result indicates that the Al alloy film to which the Nd element is added in excess of the solid solubility limit has a low Nd concentration distribution in the inner layer,
It supports the analysis result of Auger electron spectroscopy in FIG. 3 that the surface layer portion 33 has a high area. (Embodiment 3) In this embodiment, the electrical contact between the Al alloy film and the transparent conductive film is examined using the substrate temperature at the time of deposition of the insulating film covering the Al alloy film as a parameter.

FIG. 5 shows the Al alloy wiring 50 and the transparent conductive film 5.
FIG. 4 is a schematic plan view of a wiring pattern for examining electrical contact with the wiring pattern 2; Using four electrode pads 53, electrical contact at the contact hole 54 was evaluated by a four-terminal needle method.

FIGS. 6A and 6B are schematic views of a cross section taken along the line AA 'in FIG.
FIG. 6A shows the case where the Al alloy wiring is a laminate of the upper layer film and the Al alloy film, and FIG. 6B shows the case where the Al alloy wiring is a single layer of the Al alloy film. The manufacturing method is described below.

Al-2 at% Nd was deposited as an Al alloy film 501 on the glass substrate 55 by DC sputtering. In the case of a laminated film, Mo was further continuously deposited as the upper layer film 502. The substrate temperature was 120 ° C. Subsequently, a resist pattern was formed on the laminated film by photolithography, and the Al alloy film 501 was etched with a mixed solution of phosphoric acid, nitric acid, acetic acid, and pure water to form an Al alloy wiring 50. In the laminated film, the upper film 502 was also etched. Next, SiN was deposited as an insulating film 51 by a plasma CVD apparatus. Here, the substrate temperature for depositing the insulating film was used as a parameter. Subsequently, a resist pattern was formed by photolithography, and the insulating film 51 was dry-etched to form a contact hole. In the case of a stacked wiring, the insulating film 51 and the upper film 502 were dry-etched. Thereafter, ITO was deposited as a transparent conductive film 52 at a substrate temperature of 215 ° C. by a DC sputtering apparatus. Subsequently, a resist pattern was formed by photolithography, and the ITO was etched to form a transparent conductive film 52.

Table 3 shows the results. In the table, × is not allowed, ○
Means good, and ◎ means very good.

[0041]

[Table 3]

When the Al alloy wiring was a single layer, contact with the transparent conductive film was impossible at any substrate temperature at the time of depositing any insulating film. This is presumably because, as described in the second embodiment, a dense Al oxide film (alumina), which is an insulator, is formed on the surface of the Al film simply by putting the Al alloy film out of the apparatus after the deposition, and then putting the film into the atmosphere. Is done. This is also shown in the results of Example 1.

When the Al alloy wiring is laminated, the substrate temperature at the time of depositing the insulating film is 200 ° C. or more, preferably 250 ° C.
At a temperature equal to or higher than 0 ° C., electrical contact between the Al alloy film and the transparent conductive film becomes possible. This is because, on the surface of the Al alloy film that is not oxidized because of the continuously deposited upper layer film, the concentration distribution of the added element in the Al alloy film is increased in the surface layer due to the heating of the substrate during the deposition of the insulating film. It is presumed that even if the upper layer film is removed during the formation of the contact hole, it is hardly oxidized. In addition, when the substrate temperature during the deposition of the insulating film is high, the additional element in the Al alloy film easily moves to the surface layer, and thus the concentration of the additional element is further increased in the surface layer, and it is presumed that the oxidation becomes more difficult. .

In this embodiment, the upper layer film is made of Mo. However, when the upper layer film is made of a metal other than Mo, the concentration distribution of the added element in the Al alloy film is similarly increased in the surface layer, and the result of preventing oxidation is obtained. As a result, electrical contact between the Al alloy film and the transparent conductive film was possible.

In this embodiment, the Al alloy film is made of Al-2 at% Nd, which is an alloy of Nd which is a very small element having a solid solubility limit of 0.01 at% for Al. Similarly, Y, La, and C, which are elements having a small solid solubility limit with respect to Al,
e, Pr, Sm, Eu, Gd, Tb, Dy, Ho, E
Even when an Al alloy film to which r, Tm, Yb, and Lu are added is employed, the concentration distribution of the added element in the Al alloy film is increased in the surface layer portion as in this embodiment, and the result of oxidation prevention is obtained.
Electrical contact between the 1 alloy film and the transparent conductive film was possible.

Even in the case of a single layer, after depositing the Al alloy film, it is necessary to continuously reduce or oxidize the surface of the Al alloy film in an ultra-high vacuum atmosphere before breaking the vacuum into the atmosphere. By performing heat treatment without increasing the concentration of the additional element in the Al alloy in the surface layer portion, oxidation of the Al alloy surface could be prevented, and electrical contact with the transparent conductive film was possible. (Embodiment 4) This embodiment is an example in which electrical contact between an Al alloy film and a transparent conductive film was examined using the amount of elements added to the Al alloy film as a parameter.

A wiring pattern as shown in FIG. 5 was prepared in the same manner as in Example 3. The Al alloy wiring 50 was formed by DC sputtering at a substrate temperature of 120 ° C. and an Al alloy film 501 and an upper layer film.
Mo was continuously deposited as 502. Nd for Al
The addition amount was used as a parameter. The substrate temperature during the deposition of the insulating film was set to 300 ° C. Using this, the electrical contact at the contact hole 54 was evaluated by a four-terminal needle method using four electrode pads 53. Table 4 shows the results. In the table, x means not good, o means good, and ◎ means extremely good.

[0048]

[Table 4]

When the amount of Nd added is 0.2 at% or more, the electrical contact is good, and when it is 0.8 at% or more, the electrical contact is further improved.

This is because N, which is an additive element in the Al alloy film,
Since the height of the concentration distribution of d in the surface layer increases depending on the amount of Nd added, the result of antioxidation is improved, and it is presumed that the electrical contact between the Al alloy film and the transparent conductive film is further improved. You. Further, no electrical contact is possible with no Nd addition, that is, pure Al. It is presumed that this is because the surface of the Al alloy film is oxidized when the device is brought into the air after forming the contact hole or when the device comes into contact with ITO.

In the present embodiment, the upper layer film was made of Mo. However, when the upper layer film was made of a metal other than Mo, the concentration distribution of the added element in the Al alloy film was similarly increased in the surface layer, and the result of preventing oxidation was obtained. As a result, electrical contact between the Al alloy film and the transparent conductive film was possible.

In this embodiment, the Al alloy film is made of an alloy of Nd, an element whose solid solubility limit with respect to Al is as small as 0.01 at%. Similarly, Y, La, Ce, Pr, Sm, Eu, and G, which are elements having a small solid solubility limit for Al.
In the case where an Al alloy film to which d, Tb, Dy, Ho, Er, Tm, Yb, and Lu are added is employed, A
The concentration distribution of the added element in the l-alloy film was increased in the surface layer portion, and the result of oxidation prevention was obtained, and electrical contact between the Al alloy film and the transparent conductive film was possible. (Embodiment 5) In this embodiment, the Mo film of the upper layer film of the Al alloy wiring is used.
This is an example of examining the shape of a wiring cross section using the composition of the alloy as a parameter.

By a DC sputtering method, Al-2 at% Nd having a film thickness of 2 as an Al alloy film 42 is formed on a glass substrate 41.
A Mo alloy having a thickness of 20 nm was continuously formed as the upper layer 43. The substrate temperature was 120 ° C. Subsequently, a resist pattern is formed on the laminated film by photolithography, and the resist pattern is collectively etched with a mixed solution of phosphoric acid, nitric acid, acetic acid, and pure water to form an Al alloy wiring 44. And observed.

FIGS. 7A and 7B are schematic views of a cross section of the Al alloy wiring. The taper angle of the Al alloy film and the presence or absence of an eave were observed. The taper angle is the angle of the end 45 of the Al alloy film 42, and the eaves indicate a state in which the upper film 43 protrudes from the Al alloy film 42 as shown in FIG. 7B. Table 5 shows the observation results.

[0055]

[Table 5]

In order to impart dry etching resistance to the Mo alloy, Cr must be added to a certain amount (about 3 wt% or more).
need to be added to o. However, Mo-3wt
In the case of a laminated wiring with an Al alloy film having% Cr as the upper layer film, an eaves are generated, and the coverage of the insulating film covering the laminated wiring is reduced. The cause of this eaves generation is that the wet etching rate is reduced if it is added only to have dry etching resistance. On the other hand, if the dry etching resistance of the Mo alloy is not a necessary condition, C
By adding an appropriate amount of r, W, Nb, Ta, or the like, the taper shape can be controlled without generating an eave.

According to the embodiment of the present invention,
When the Al wiring is used, the problems of hillock generation, poor electrical contact with the transparent conductive film, and difficulty in controlling the cross-sectional shape of the laminated wiring can be solved. Further, it is possible to arbitrarily control the tapered shape of the Al alloy film, whereby the wiring shape suitable for the process can be freely designed.

Accordingly, the process margin is high, the wiring shape can be controlled stably, and there is no short circuit between the electrodes, so that the production yield is increased and the liquid crystal display device can be provided at low cost.

[0059]

According to the present invention, a liquid crystal display device having a good production yield can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing a liquid crystal display device according to the present invention.

FIG. 2 is a sectional view of a thin film transistor portion and a gate terminal portion of the liquid crystal display device according to the present invention.

FIG. 3 shows an Al alloy film 40 in the contact hole 20 of FIG.
Elemental analysis results in the depth direction of a portion where the transparent conductive film 9 and the transparent conductive film 1 are in direct contact with each other. It is the schematic which shows the elemental analysis result of the depth direction of the part which performs.

FIG. 4 is a schematic view showing a region A of FIG. 1 observed.

FIG. 5 is a schematic plan view of a wiring pattern for examining electrical contact in a third embodiment.

FIG. 6 is a schematic view of a cross section taken along line AA ′ in FIG. 5;

FIG. 7 is a schematic view of a cross section of a wiring according to a fifth embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Gate wiring, 2 ... Data wiring, 3 ... Source electrode, 4
... Drain electrode, 5 ... Gate insulating film, 6 ... Semiconductor layer, 7
... n ⁺ semiconductor layer, 8 ... protective film, 9, 52 ... transparent conductive film,
DESCRIPTION OF SYMBOLS 10 ... Glass substrate, 20 ... Contact hole (thin film transistor part), 21 ... Contact hole (gate terminal lead part), 30 ... Pixel part, 31 ... Gate wiring terminal group, 32
... data wiring terminal group, 33 ... surface part of Al alloy film, 41
... Glass substrate, 42,501 ... Al alloy film, 43,50
2 upper layer film, 44 Al alloy wiring, 45 end of Al alloy film, 50 Al alloy wiring, 51 insulating film, 53 electrode pad, 54 contact hole, 101 Al alloy film (gate wiring portion) ), 102 ... upper layer film (gate wiring portion),
301: Al alloy film (source electrode portion), 302: upper layer film (source electrode portion), 303: lower layer film (source electrode portion),
Reference numeral 401 denotes an Al alloy film (drain electrode portion), 402 denotes an upper layer film (drain electrode portion), and 403 denotes a lower layer film (drain electrode portion).

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) H01L 29/786 H01L 29/78 616U 616V 617U 617M (72) Inventor Takeshi Sato 7-chome, Omikacho, Hitachi City, Ibaraki Prefecture No. 1-1 Inside Hitachi, Ltd. Hitachi Research Laboratory (72) Inventor Takao Hidaka 1-1-1, Omikacho, Hitachi City, Ibaraki Prefecture Inside Hitachi, Ltd. Hitachi Research Laboratory (72) Inventor Kenichi Onizawa Ibaraki Prefecture 7-1-1, Omika-cho, Hitachi City F-term in Hitachi Research Laboratory, Hitachi Ltd. (Reference) 2H092 JA26 JA34 JA37 JA41 JA44 JA46 JB24 JB33 KA05 KA18 KB04 MA05 MA08 MA17 MA37 NA27 5C094 AA21 AA42 AA43 BA03 BA43 CA19 DA13 EA03EA04 EA05 EA07 FA02 FB02 FB12 GB01 JA08 5F033 GG04 HH10 HH20 HH38 JJ01 JJ38 KK10 KK20 MM05 MM08 MM19 NN17 PP15 QQ0 8 QQ09 QQ11 QQ19 RR06 SS15 VV06 VV15 WW02 WW03 WW04 XX02 XX09 XX16 XX20 XX31 5F110 AA26 AA30 BB01 CC07 DD02 EE04 EE06 EE14 EE23 EE44 FF03 FF30 GG02 GG15 NG45 HK45 HK45 HK04 HK45 HK04 HK45

Claims (18)

[Claims] An electrode group disposed on at least one of the pair of substrates; a liquid crystal layer sandwiched between the pair of substrates; and an electrode group disposed on at least one of the pair of substrates. A liquid crystal display device that controls display by moving liquid crystal in the liquid crystal layer, wherein the electrode group disposed on at least one of the pair of substrates intersects at least a plurality of gate wirings and the plurality of gate wirings. A plurality of data wirings formed so as to form a plurality of data wirings, and a thin film transistor is arranged at each intersection of the plurality of gate wirings and the plurality of data wirings. At least one of the gate wirings and the data wirings ,
An Al alloy film and a multilayer wiring having an upper layer film of a metal type other than Al on the Al alloy film, wherein the Al alloy film and the transparent conductive film are formed through a contact hole formed in an insulating film covering the multilayer wiring. A liquid crystal display device having a connection structure, wherein the concentration distribution of the additive element in the Al alloy film is higher in a surface layer portion than in an inner layer portion of the Al alloy film. 2. The liquid crystal display device according to claim 1, wherein the concentration of the element added to the Al alloy film is equal to or higher than the solid solubility limit. 3. The liquid crystal display device according to claim 1, wherein an element added to said Al alloy film has a solid solubility limit in Al of 0.1 at% or less. 4. The Al alloy film is made of Y, La, Ce, P
r, Nd, Sm, Eu, Gd, Tb, Dy, Ho, E
2. The liquid crystal display device according to claim 1, wherein at least one of r, Tm, Yb, and Lu is added in a total amount of 0.2 at% or more. 5. The liquid crystal display device according to claim 1, wherein the thickness of the upper layer film of said laminated wiring is 50 nm or less. 6. The liquid crystal display device according to claim 1, wherein said upper layer film is an alloy containing Mo as a main component. 7. The liquid crystal display device according to claim 1, wherein at least one of the data wiring and the gate wiring is a laminated wiring having a lower layer film of another metal type under the Al alloy film. 8. The liquid crystal display device according to claim 1, wherein the end of the cross section of the Al alloy film has a tapered shape that is wider as it is closer to the substrate side. 9. The electrode group comprising: a pair of substrates, at least one of which is transparent; a liquid crystal layer sandwiched between the pair of substrates; and an electrode group disposed on at least one of the pair of substrates. In the liquid crystal display device that controls display by moving the liquid crystal of the liquid crystal layer, the electrode group disposed on at least one of the pair of substrates includes at least a plurality of gate wirings and a plurality of gate wirings. A plurality of data lines formed so as to intersect; a thin film transistor is arranged corresponding to each of intersections of the plurality of gate lines and the plurality of data lines; A data layer, a drain electrode and a source electrode are formed of Al.
An aluminum alloy film and a layered wiring having an upper layer film of a metal species other than Al on the Al alloy film, wherein the Al alloy film and the transparent conductive film are formed through a contact hole formed in an insulating film covering the stacked wiring. Wherein the concentration distribution of the added element in the Al alloy film is higher in the surface layer portion than in the inner layer portion of the Al alloy film. 10. The liquid crystal display device according to claim 1, wherein the concentration of the element added to the Al alloy film is equal to or higher than the solid solubility limit. 11. The element Al added to the Al alloy film.
2. The liquid crystal display device according to claim 1, wherein a solid solubility limit of the liquid crystal is 0.1 at% or less. 12. The Al alloy film is made of Y, La, Ce, P
r, Nd, Sm, Eu, Gd, Tb, Dy, Ho, E
2. The liquid crystal display device according to claim 1, wherein at least one of r, Tm, Yb, and Lu is added in a total amount of 0.2 at% or more. 13. A film thickness of an upper layer film of said laminated wiring is 50 nm.
2. The liquid crystal display device according to claim 1, wherein: 14. The liquid crystal display device according to claim 1, wherein said upper film is an alloy containing Mo as a main component. 15. The liquid crystal display device according to claim 1, wherein at least one of the data wiring and the gate wiring is a stacked wiring having a lower layer film of another metal type under the Al alloy film. 16. The liquid crystal display device according to claim 1, wherein the end of the cross section of the Al alloy film has a tapered shape that becomes wider as it approaches the substrate side. 17. A step of continuously depositing a gate wiring without breaking a vacuum of an Al alloy film and an upper film formed on the Al alloy film, and forming an insulating film covering the gate wiring on a substrate having a substrate temperature of 200 ° C. or more. And a step of forming a contact hole by removing the insulating film and the upper layer film by dry etching. 18. A process for continuously depositing a lower layer film, an Al alloy film and an upper layer film of a data wiring, a drain electrode and a source electrode without breaking a vacuum, and an insulating film covering the data wiring, the drain electrode and the source electrode. And a step of forming a contact hole by removing the insulating film and the upper layer film by dry etching.