TW201727748A - Wiring structure, display device, input device, touch panel and sputtering target - Google Patents

Abstract

The present invention provides a wiring structure in which an Al-Ta oxide film is formed on at least one surface and a side surface of an Al-Ta alloy thin film, wherein the Al-Ta alloy thin film has a Ta addition amount of 0.3 atom%. 3.0 atom% and Cu content is 0.03 atom% or less, the film thickness of the Al-Ta oxide film is 3 nm to 10 nm, and the atomic % concentration of Ta in the Al-Ta oxide film is lower than that of the Al-Ta alloy The atomic % concentration of Ta in the film.

Description

Wiring structure and sputtering target

The present invention relates to a wiring structure and a sputtering target for forming an Al alloy thin film in the wiring structure, and more particularly to a wiring structure excellent in chloride ion resistance. In addition, the present invention also relates to a display device, an input device, and a touch panel having the wiring structure.

In a wiring film used for an electrode material such as a liquid crystal display, an organic electroluminescence (EL) display, or a display device such as a touch panel, the use of a low resistivity and a fine processing is advantageous. A wiring structure of an Al alloy thin film using an Al thin film or Al as a base material is used.

For example, Patent Document 1 discloses an electrode or wiring material for a semiconductor device which is excellent in hillock resistance and which comprises an Al-based alloy containing Ta, Ti, Nd, Gd, Fe, or the like. One or more of the group consisting of Co and Ni, and containing 1 atom% to 6.5 atom% of Ar. Further, Patent Document 2 discloses a wiring film characterized by comprising Y, Sc, La, Ce, Nd, Sm, Gd, Tb, Dy, Er, Th, and a range of 0.28 atom% to 23 atom%. At least one of the first elements of Sr, Ti, Zr, Hf, V, Nb, Ta, Mn, Re, Co, Ir, Pt, Cu, Si, and B, and the amount selected from the first element is 1.8. C in the range of atomic ppm to 3,000 atomic ppm, O in the range of 10 atom ppm to 1500 atomic ppm, N in the range of 19 atomic ppm to 3,000 atomic ppm, and at least in the range of 50 atomic ppm to 3.9 atomic % of H. A second element, and the remainder consists essentially of Al. Patent Document 3 discloses an Al alloy film having an Al alloy film for a wiring film or a reflective film on a substrate, and the Al alloy film contains Ta and/or Ti: 0.01 atom% to 0.5 atom%, And rare earth elements: 0.05 atom% to 2.0 atom%. [Prior Art Document] [Patent Literature]

[Patent Document 1] Japanese Patent No. 2917820 [Patent Document 2] Japanese Patent No. 4130418 (Patent Document 3) Japanese Patent No. 5032687

[Problems to be Solved by the Invention] The Al alloy film is likely to be corroded by chloride ions. However, in Patent Document 1 and Patent Document 2, in order to obtain an Al alloy film excellent in protrusion resistance, electrical resistivity, etching property, and the like, there has been no research on corrosion resistance, particularly chloride ion resistance. Further, in Patent Document 3, an Al-Ta-rare-earth alloy or an Al-Ti-rare-earth alloy excellent in salt water resistance is disclosed, but it is mainly assumed to be laminated with indium tin oxide (ITO) or an interlayer insulating film. The situation is the premise of the occurrence of pinholes or cracks.

Accordingly, it is an object of the present invention to provide a wiring structure which, as a novel wiring material, suppresses corrosion of metal wiring caused by chloride ions in a manufacturing process or use environment of a display device or an input device. [Means for solving the problem]

As a result of intensive studies, the inventors of the present invention have found that the composition can be solved by setting the composition of the Al-Ta alloy film and the Al-Ta oxide film formed on the Al-Ta alloy film to a specific composition. Thus, the present invention has been completed.

That is, the present invention relates to the following [1] to [8]. [1] A wiring structure in which an Al-Ta oxide film is formed on at least one surface and a side surface of an Al-Ta alloy thin film, wherein the Al-Ta alloy thin film has a Ta addition amount of 0.3 atom%. 3.0 atom% and Cu content is 0.03 atom% or less, the film thickness of the Al-Ta oxide film is 3 nm to 10 nm, and the atomic % concentration of Ta in the Al-Ta oxide film is lower than that of the Al-Ta alloy The atomic % concentration of Ta in the film. [2] The wiring structure according to [1], wherein the Al-Ta alloy thin film contains 0.05 atom% to 3.0 atom% of a rare earth element. [3] The wiring structure according to [1] or [2], wherein one or more organic groups having at least one of a carboxyl group and an amine group are present on the surface of the Al-Ta oxide film. Compound. [4] The wiring structure according to [3], wherein the organic compound is an amino acid. [5] The wiring structure according to any one of [1] to [4], which has a transparent conductive film as a base layer of a wiring structure, the transparent conductive film containing a material selected from the group consisting of Mo, Mo alloy, Ti, Ti At least one of a group consisting of an alloy and In. [6] A display device or an input device, comprising the wiring structure according to any one of [1] to [5]. [7] A touch panel having the wiring structure according to any one of [1] to [5]. [8] A sputtering target for forming an Al-Ta alloy thin film in the wiring structure according to any one of [1] to [5]. [Effects of the Invention]

According to the present invention, it is possible to realize a wiring structure in which corrosion of an Al alloy thin film caused by chloride ions is suppressed and which has high chloride ion resistance.

<Wiring structure> The wiring structure of the present invention is characterized in that an Al-Ta oxide film is formed on at least one of the surface and the side surface of the Al-Ta alloy thin film, and the Al addition amount of the Al-Ta alloy thin film is 0.3 atom%. 3.0 atom% and Cu content is 0.03 atom% or less, the film thickness of the Al-Ta oxide film is 3 nm to 10 nm, and the atomic % concentration of Ta in the Al-Ta oxide film is lower than that of the Al-Ta alloy The atomic % concentration of Ta in the film.

Ta contributes to stabilization of the surface oxide film of Al, whereby the chloride ion resistance of the Al-Ta alloy film, that is, the wiring structure can be improved. Therefore, the amount of addition of Ta in the Al—Ta alloy thin film is set to 0.3 atom% or more. The amount of addition of Ta is preferably 0.5 atom% or more, more preferably 0.8 atom% or more. In addition, the Al-Ta alloy thin film is generally formed by sputtering, but it is preferably 3.0 atom% or less, and more preferably 2.0, from the viewpoint of the manufacturability of the sputtering target used for the sputtering. Below atomic %.

Further, in the Al-Ta alloy thin film, Cu is contained in a range of 0.03 atom% or less. Cu is known to function as an element for improving the electromigration resistance of Al, but on the other hand, the chloride ion resistance is lowered. When the Cu content is 1/100 (atomic %) or less of the addition amount of Ta, the chloride ion resistance is not affected, so the Cu content in the Al-Ta alloy thin film is set to 0.03 atom% or less, more preferably 0.01 atom. %the following. On the other hand, the lower limit of the Cu content is preferably 0.001 atom% or more.

The Al-Ta oxide film is formed on at least one of the surface and the side surface of the Al-Ta alloy film. Since the wiring structure of the present invention is assumed to be used for a display device or an input device, it is preferable to form an Al-Ta oxide film on one surface of the Al-Ta alloy film or at least a part of the surface and the exposed side surface.

The film thickness of the Al-Ta oxide film is preferably 3 nm or more in terms of stability. On the other hand, in order to obtain good workability, it is preferably 10 nm or less.

The Al-Ta oxide film is formed mainly on the oxide of Al, but the Ta atom% concentration in the Al-Ta oxide film is lower than that of the Al-Ta alloy film, thereby making Ta in the Al-Ta alloy film and Al- The interface of the Ta oxide film becomes thick. Thereby, diffusion of Cu from the Al-Ta alloy thin film to the Al-Ta oxide film can be suppressed, and a wiring structure having higher chloride ion resistance can be obtained. Specifically, the atomic % concentration of Ta in the Al—Ta oxide film is preferably 30% or more, more preferably 50% or less lower than the atomic % concentration of Ta in the Al—Ta alloy film. In other words, when the atomic % concentration of Ta in the Al-Ta alloy thin film is 1 atom%, the atomic % concentration of Ta in the Al-Ta oxide film is preferably 0.7 atom% or less, more preferably 0.5 atom%. the following.

The Al-Ta alloy thin film is preferably obtained by further adding a rare earth element to obtain higher chloride ion resistance. It is presumed that the reason is that the Al-Ta oxide film can be more stabilized by the rare earth element. The content of the rare earth element is preferably 0.05 atom% or more, more preferably 0.1 atom% or more. In addition, the upper limit is preferably 3.0 atom% or less, and more preferably 2.0 atom% or less, from the viewpoint of the manufacturability of the sputtering target. The rare earth element is preferably a Sc, Y or lanthanoid element, and more preferably Nd, La or Gd. The rare earth elements may be used singly or in combination of two or more.

The Al-Ta alloy thin film of the present invention may contain other elements than the above components, and the remainder is Al and unavoidable impurities, as long as the effects of the present invention are not impaired. The inevitable impurities can be exemplified by Fe, Si, B, and the like. The content of the unavoidable impurities is preferably 0.1 atom% or less in total. The composition of the Al-Ta alloy film can be identified by Inductively Coupled Plasma (ICP) emission spectroscopy.

The Al-Ta oxide film is preferably an organic compound having at least one functional group of at least one of a carboxyl group and an amine group on the surface. When an organic compound having an amine group is present, the amine group is ionized into NH ₃ ⁺ in the acidic and neutral regions to be bonded to the chloride ion, so that the chloride ion resistance can be further improved. Further, when an organic compound having a carboxyl group is present, the carboxyl group is ionized into COO ⁻ in the neutral and basic regions, and the chloride ion concentration in the vicinity of the surface is lowered in order to maintain electrical neutrality in the vicinity of the surface of the Al—Ta alloy thin film. Thereby, the chloride ion resistance can be further improved. These organic compounds may have a monomolecular layer (one molecular layer), or may be a layer of two or more molecules.

Examples of the organic compound having an amine group on the surface include 1-propylamine, 1,3-propanediamine, 1-propanolamine, and the like. Examples of the organic compound having a carboxyl group on the surface include propionic acid, fumaric acid, tartaric acid, and the like. Further, it may be an organic compound having both an amine group and a carboxyl group on the surface, and examples thereof include an amino acid. The organic compound is more preferably an organic compound having a relatively small molecular size to the extent of amino acid. Further, a form in which two or more organic compounds are bonded to each other may be employed.

The organic compound is more preferably an amino acid in terms of having an amine group and a carboxyl group together and having a small molecular size. The amino acid has a buffering effect on the pH change of the solution by having an amine group and a carboxyl group in the molecule. I.e., chloride ion in the reaction with Al, it is known to generate hydrogen ions due to the vicinity of the film surface became acidic, but by the presence of amino acids, hydrogen ions into ions at neutral environment COO ^- carboxyl groups binding Thereby, the pH change in the vicinity of the film surface can be alleviated.

The Al-Ta oxide film of the present invention may contain other elements than the above components, and the remainder is Al and unavoidable impurities, as long as the effects of the present invention are not impaired. The inevitable impurities can be exemplified by Fe, Si, B, and the like. The content of the unavoidable impurities is preferably 0.1 atom% or less in total. The composition of the Al-Ta oxide film can be identified by ICP emission spectroscopy.

In the wiring structure including the Al-Ta alloy film and the Al-Ta oxide film, the Al-Ta oxide film is more densified and stabilized, and the chloride ion resistance is further improved, and the Al-Ta alloy film is preferably formed. On the base layer of the wiring structure. The base layer is preferably a transparent conductive film containing at least one selected from the group consisting of Mo, Mo alloy, Ti, Ti alloy, and In, and preferably has at least one layer of the transparent conductive film. In addition, the base layer may be present between the Al-Ta alloy film and the substrate, or the Al-Ta alloy film may be present between the base layer and the substrate, in any order, but it is more preferable to form a base layer on the substrate. An Al-Ta alloy thin film is formed thereon.

<Manufacturing Method> In the wiring structure of the present invention, the Al-Ta alloy film and the Al-Ta oxide film are preferably formed by sputtering using a sputtering target. Further, it can also be formed by a vapor deposition method or the like. In the case of forming an Al-Ta alloy thin film by sputtering a target material, it is preferable to use the same composition as the Al-Ta alloy thin film, that is, the Ta addition amount is 0.3 atom% to 3.0 atom% and the Cu content is 0.03 atom%. Hereinafter, a sputtering target having a Ta atomic % concentration higher than an atomic % concentration of Ta in the Al-Ta oxide film. In the case where an Al-Ta oxide film is formed by sputtering a target, it is preferable to use a sputtering target having a Ta atomic % concentration lower than that of an atomic % of Ta in the Al-Ta alloy thin film.

The shape of the sputtering target includes a sputtering target processed into an arbitrary shape (square plate shape, circular plate shape, annular plate shape, cylindrical shape, or the like) according to the shape or structure of the sputtering apparatus. The sputtering target may be a method obtained by producing an ingot containing an Al-Ta alloy by a melt casting method, a powder sintering method, a spray forming method, or a prepreg comprising an Al-Ta alloy. A method obtained by densifying the preform by a densification means after obtaining a preform (an intermediate before the final dense body).

The optimum film thickness of the Al-Ta alloy film can be selected according to the use or specification. For example, in the case of wiring use of the display, the film thickness of the Al-Ta alloy thin film is preferably 100 nm or more, and more preferably 150 nm or more. Further, it is preferably 2 μm or less, more preferably 1 μm or less. The film thickness of the Al-Ta alloy thin film can be adjusted by changing the current value or time of sputtering, the pressure, the distance between the target and the substrate, and the like in the sputtering method.

The film thickness of the Al-Ta oxide film can be adjusted by changing the current value or time of sputtering, the pressure, the distance between the target and the substrate, and the like in the sputtering method. Alternatively, the ratio can be adjusted by changing the ratio of argon gas to oxygen used for sputtering. The Al-Ta oxide film may be formed by a process such as UV washing or oxygen plasma after the film formation of the Al-Ta alloy film.

The film thickness of the obtained Al-Ta alloy film or Al-Ta oxide film can be analyzed by Scanning Electron Microscope (SEM), Secondary Ion Mass Spectroscopy (SIMS), and cross-section. The measurement was performed by a transmission electron microscope (TEM) observation or the like.

Further, an aqueous solution of a salt of a desired organic compound is prepared, and a wiring structure containing an Al-Ta oxide film is immersed in the aqueous solution, whereby a layer of the organic compound can be formed on the surface of the Al-Ta oxide film. The salt of the organic compound may, for example, be a sodium salt or a calcium salt. Among them, a sodium salt can be preferably used in terms of solubility in water or pH. Further, the immersion conditions vary depending on the salt concentration in the aqueous solution, etc., for example, in the case of a 1% aqueous solution, it is preferably immersed for 10 minutes to 24 hours. After immersion, washing and drying are appropriately carried out.

The underlayer of the wiring structure can be formed by a sputtering method or an evaporation method. In the case of being formed by sputtering, it can be formed by sputtering using a sputtering target having the same composition as that of the desired underlayer. For example, a sputtering target containing at least one selected from the group consisting of Mo, Mo alloy, Ti, Ti alloy, and In may be used, and the film formation is selected from the group consisting of Mo, Mo alloy, Ti, Ti alloy, and In. A transparent conductive film of at least one of the constituent groups is used as a base layer. In the case where two or more base layers are formed, they can be formed by sputtering a plurality of sputtering targets using the composition of each layer.

Further, after the underlayer is formed by sputtering, a heat treatment for crystallization may be performed. When a film of, for example, an indium tin oxide (ITO) film is formed as the underlayer, it is preferred to carry out heat treatment at 150 to 250 ° C for 10 minutes or more in a nitrogen atmosphere.

The obtained wiring structure of the present invention can be preferably used for a display device or an input device. Among them, it can be more preferably used for a touch panel. A display device or an input device having the wiring structure of the present invention includes a thin film transistor (TFT) having the wiring structure, a reflective film, an anode electrode for an organic EL, and a touch panel sensor (touch panel). A display device such as a sensor or an input device or the like. In these devices, other constituent elements than the wiring structure portion of the present invention can appropriately select constituent elements generally used in the technical field within the range in which the effects of the present invention are not impaired. For example, a semiconductor layer used for a TFT substrate may be polycrystalline germanium or amorphous silicon. The substrate used for the TFT substrate is not particularly limited, and examples thereof include a glass substrate and a tantalum substrate. Further, the present invention can be applied to an organic EL display device including a reflective anode electrode, a display device including a thin film transistor, a display device including a reflective film, and a touch panel including an Al-Ta alloy film and an Al-Ta oxide film on the ITO film. And other devices.

<Evaluation of Corrosion Resistance> The corrosion resistance of the wiring structure of the present invention can be evaluated by a salt water dropping test. Specifically, a 1% sodium chloride aqueous solution was dropped onto a sample using a dropper, and allowed to stand at room temperature for 168 hours to be evaluated. The sample was washed with water after 168 hours, and then observed with an optical microscope. The smaller the corrosion area, the more preferable, specifically, it is preferably 8% or less, more preferably 5% or less, still more preferably 2% or less (1% saline dropping test). Further, it is also effective to carry out a corrosion resistance test using an aqueous solution of sodium chloride containing an amino acid sodium salt. In this case, the evaluation of the corrosion resistance when the salt adhered to the human body was simulated was compared with the 1% saline dropping test. Specifically, the corrosion area was measured in the same manner as in the 1% saline dropping test except that a 1% aqueous sodium chloride solution to which 1% of an amino acid sodium salt was added was used. The smaller the corrosion area, the better, preferably 8% or less, more preferably 5% or less, still more preferably 2% or less. [Examples]

In the following, the present invention will be specifically described by way of examples, but the present invention is not limited to the embodiments, and may be modified within the scope of the gist of the present invention, and these are all included in the technical scope of the present invention. .

[Example 1-1] Al-Ta alloy was formed on a non-alkali glass substrate (4 in. diameter, 0.7 mm in thickness) by a direct current (DC) magnetron sputtering method. film. The Al-Ta alloy thin film had a Ta addition amount of 0.3 atom%, a Cu content of 0.01 atom%, and the balance being Al and unavoidable impurities. When the film is formed, the environment in the chamber is temporarily adjusted to an ultimate vacuum degree before film formation: 3 × 10 ^-6 Torr, and then a diameter of 4 inches which is the same composition as that of the Al-Ta alloy film is used. The disc-shaped sputtering target was sputtered under the following conditions. (Sputtering conditions) ・Ar gas pressure: 2 mTorr ・Ar gas flow rate: 30 sccm ・Sputter power: 500 W ・Substrate temperature: room temperature ・Film formation temperature: Room temperature: Film thickness: 300 nm The identification of the composition of the Al-Ta alloy thin film was carried out by ICP emission spectrometry.

Then, the Al-Ta oxide film was formed on the surface of the Al-Ta alloy film by UV washing the surface of the Al-Ta alloy film. The concentration of Ta atoms in the obtained Al-Ta oxide film was 0.1 atom%, and the film thickness was 3 nm. In addition, the film thickness of the obtained Al-Ta oxide film was confirmed by TEM observation of the wiring cross section.

With respect to the obtained wiring structure including the Al-Ta alloy thin film and the Al-Ta oxide film, patterning by photolithography and wet etching was performed to prepare a wiring width of 10 μm. A stripe-like wiring pattern with a wiring interval of 10 μm.

[Example 1-2 to Example 1-15 and Comparative Example 1-1 to Comparative Example 1-4] The composition of the Al-Ta alloy thin film or the composition or film thickness of the Al-Ta oxide film was changed as shown in Table 1. A wiring structure was obtained in the same manner as in Example 1-1 except that the composition or the film thickness was changed, and a wiring pattern was produced. Further, in Comparative Example 1-4, the film thickness of the Al-Ta oxide film was set to 0 nm, and the natural oxide film formed on the surface of the Al-Ta alloy film was in an alkaline solution (tetramethyl hydroxide). The ammonium group: TMAH 2.38%) was removed by immersion for 30 seconds at room temperature. Further, the numerical values in the "Al alloy species" in the table indicate the atomic % concentration of each element.

The obtained wiring structure after patterning was evaluated for corrosion resistance (1% saline dropping test). The test was carried out by dropping a 1% sodium chloride aqueous solution with a dropper and allowing it to stand at room temperature for 168 hours. After 168 hours, the sample was washed with water, and then observed by an optical microscope to determine the corrosion area. With respect to Comparative Example 1-4, a dropping test of a 1% sodium chloride aqueous solution was carried out immediately after immersion in an alkaline solution. The film thickness of the Al-Ta oxide film at this time was not measured by TEM observation. However, the dropping test was carried out immediately after the natural oxide film was removed by immersion in an alkaline solution, and it was judged that there was no Al-Ta oxide film ( The oxide film thickness is 0 nm). The evaluation results are shown in Table 1. In Table 1, the corrosion area is 2% or less, ◎, more than 2% and 5% or less is 〇, more than 5% and 8% or less is Δ, and more than 8% is ×. In addition, "at%" in the table is synonymous with "atomic%".

[Table 1]

As a result, it was found that in Examples 1-1 to 1-15, the corrosion area ratio was 8% or less, and good corrosion resistance was obtained. In Comparative Example 1-1, the wiring film was a film of pure Al and not an Al-Ta alloy film, and corrosion resistance was low, so that corrosion occurred. Comparative Example 1-2 contained Ta, but since the content thereof was as small as 0.2 at%, the desired corrosion resistance was not obtained. In Comparative Example 1-3, since the Cu content was large, the desired corrosion resistance was not obtained. In Comparative Example 1-4, since the Al-Ta oxide film on the surface was thin (absence), the desired corrosion resistance was not obtained.

[Example 2-1] In the same manner as in Example 1-1, an Al-Ta alloy film (film) having a Ta addition amount of 0.3 at%, a Cu content of 0.01 at%, and the balance being Al and unavoidable impurities was formed. 300 nm thick). Then, in the same manner as in Example 1-1, film formation of an Al-Ta oxide film was performed on the surface of the Al-Ta alloy film. The concentration of Ta atoms in the obtained Al-Ta oxide film was 0.1 atom%, and the film thickness was 3 nm. The wiring structure including the Al-Ta alloy film and the Al-Ta oxide film was patterned by photolithography and wet etching, and a stripe wiring pattern having a wiring width of 10 μm and a wiring interval of 10 μm was produced. . In addition, the identification of the Al-Ta alloy film and the Al-Ta oxide film and the measurement of the film thickness were carried out in the same manner as in Example 1-1.

Next, the sodium salt of an amino acid as an organic compound containing a carboxyl group and an amine group is a 1% aqueous solution for preparing sodium L-glycolate. Further, the sodium salt is selected from the viewpoints of solubility in water and pH. The obtained sample was immersed in the aqueous solution for 1 hour. After immersion, it was washed with water for 1 minute and allowed to dry. Thereby, a wiring structure in which L-glycine which is an amino acid exists on the surface of the Al-Ta oxide film is obtained. Further, the thickness of the amino acid was confirmed to be one molecular layer or more by a scanning tunneling microscope (Scanning Tunneling Microscope). The obtained wiring structure was subjected to the same corrosion resistance evaluation as in Example 1-1 (1% saline dropping test).

[Example 2-2 to Example 2-4] As a sodium salt of an amino acid containing an organic compound of a carboxyl group and an amine group, a 1% aqueous solution of sodium L-tryptamine (Example 2-2), L- A 1% aqueous solution of sodium asparagate (Example 2-3) or a 1% aqueous solution of sodium tartrate (Example 2-4) which is an organic compound containing a carboxyl group, and Example 2-1 The wiring structure was obtained in the same manner, and the corrosion resistance evaluation (1% saline dropping test) was performed in the same manner.

The evaluation results are shown in Table 2. In Table 2, when the corrosion area is 2% or less, it is ◎, more than 2% and 5% or less is 〇, more than 5% and 8% or less is Δ, and more than 8% is ×. In addition, "at%" in the table is synonymous with "atomic%".

[Table 2]

As a result, it was found that the corrosion area ratio of each of Examples 2-1 to 2-4 was 2% or less, and very good corrosion resistance was obtained.

[Example 3-1] In the same manner as in Example 1-1, an Al-Ta alloy film (film) having a Ta addition amount of 0.3 atom%, a Cu content of 0.01 atom%, and a balance of Al and unavoidable impurities was formed. 300 nm thick). Then, in the same manner as in Example 1-1, film formation of an Al-Ta oxide film was performed on the surface of the Al-Ta alloy film. The concentration of Ta atoms in the obtained Al-Ta oxide film was 0.1 atom%, and the film thickness was 3 nm. The wiring structure including the Al—Ta alloy thin film and the Al—Ta oxide film obtained was patterned by photolithography and wet etching, and a stripe wiring pattern having a wiring width of 10 μm and a wiring interval of 10 μm was produced. In addition, the identification of the Al-Ta alloy film and the Al-Ta oxide film and the measurement of the film thickness were carried out in the same manner as in Example 1-1.

Secondly, the corrosion resistance evaluation was carried out by a salt water dropping test. As a saline solution, a solution in which sodium L-glycolate was added to a 1% sodium chloride aqueous solution was dropped by a dropper, and the mixture was allowed to stand at room temperature for 168 hours to be evaluated. After 168 hours, the sample was washed with water, and then observed by an optical microscope to determine the corrosion area.

[Example 3-2 and Example 3-3] As a corrosion resistance evaluation, the dropping test solution was used instead of a solution in which 1% of sodium L-glycolate was added to a 1% sodium chloride aqueous solution. a solution of 1% sodium L-tryptamine added to a sodium chloride aqueous solution (Example 3-2) or 1% sodium L-aspartate added to a 1% sodium chloride aqueous solution A wiring structure was obtained in the same manner as in Example 3-1 except for the solution (Example 3-3), and the corrosion resistance was evaluated.

The evaluation results are shown in Table 3. In Table 3, when the corrosion area is 2% or less, it is ◎, more than 2% and 5% or less is 〇, more than 5% and 8% or less is Δ, and more than 8% is ×. In addition, "at%" in the table is synonymous with "atomic%".

[table 3]

As a result, it was found that the corrosion area ratio of each of Examples 3-1 to 3-3 was 2% or less, and very good corrosion resistance was obtained.

[Example 4-1] A pure Mo film of 30 nm was formed as a base layer by DC magnetron sputtering on an alkali-free glass substrate (4 inches in diameter and 0.7 mm in thickness). When film formation, the environment in the chamber was temporarily adjusted to the ultimate vacuum before film formation: 3 × 10 ^-6 Torr, using a disc-shaped pure Mo sputtering target having a diameter of 4 inches, and splashing under the following conditions plating. (Sputtering conditions) ・Ar gas pressure: 2 mTorr ・Ar gas flow rate: 30 sccm ・Sputter power: 500 W ・Substrate temperature: room temperature ・Film formation temperature: room temperature ・Thickness: 30 nm

A wiring structure including an Al-Ta alloy thin film and an Al-Ta oxide film was obtained in the same manner as in Example 1-1 except that the Al-Ta alloy thin film was formed thereon, and photolithography was further carried out. And patterning of wet etching. In addition, the identification of the Al-Ta alloy film and the Al-Ta oxide film and the measurement of the film thickness were carried out in the same manner as in Example 1-1. The corrosion resistance evaluation (1% salt water dropping test) was performed in the same manner as in Example 1-1 with respect to the obtained wiring structure.

[Example 4-2 and Example 4-3] A pure Mo film of 30 nm was formed as a base layer by DC magnetron sputtering on an alkali-free glass substrate (4 inches in diameter and 0.7 mm in thickness). Al-Ta was obtained in the same manner as in Example 1-2 (Example 4-2) or Example 1-3 (Example 4-3) except that an Al-Ta alloy thin film was formed thereon. The wiring structure of the alloy thin film and the Al-Ta oxide film is further patterned by photolithography and wet etching. In addition, the identification of the Al-Ta alloy film and the Al-Ta oxide film and the measurement of the film thickness were carried out in the same manner as in Example 1-1. The corrosion resistance evaluation (1% salt water dropping test) was performed in the same manner as in Example 1-1 with respect to the obtained wiring structure.

[Example 4-4 to Example 4-6] The base layer was a pure Ti film having a thickness of 30 nm (Example 4-4) and a Mo-10 atomic % Nb alloy film having a thickness of 30 nm (Example) 4-5) or an ITO film having a film thickness of 30 nm (Examples 4 to 6), which were respectively formed by DC magnetron sputtering, and wiring structures were obtained in the same manner as in Example 4-2, respectively. And conduct corrosion resistance evaluation.

The evaluation results are shown in Table 4. In Table 4, the corrosion area is 2% or less, ◎, more than 2% and 5% or less is 〇, more than 5% and 8% or less is Δ, and more than 8% is ×. In addition, "at%" in the table is synonymous with "atomic%".

[Table 4]

As a result, it was found that the average area ratio of each of Examples 4-1 to 4-6 was 5% or less, and very good corrosion resistance was obtained.

The present invention has been described in detail above with reference to the specific embodiments thereof. It is understood that various changes and modifications may be made without departing from the spirit and scope of the invention. The present application is based on a Japanese patent application filed on Jan. 25,,,,,,,,,,,,,,

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Claims (10)

A wiring structure in which an Al-Ta oxide film is formed on at least one surface and a side surface of an Al-Ta alloy film, wherein the Al-Ta alloy film has a Ta addition amount of 0.3 atom% to 3.0 atom%. And the Cu content is 0.03 atomic % or less, the film thickness of the Al-Ta oxide film is 3 nm to 10 nm, and the atomic % concentration of Ta in the Al-Ta oxide film is lower than that in the Al-Ta alloy film The atomic % concentration of Ta. The wiring structure according to claim 1, wherein the Al-Ta alloy thin film contains 0.05 atom% to 3.0 atom% of a rare earth element. The wiring structure according to claim 1, wherein an organic compound having at least one functional group of at least one of a carboxyl group and an amine group is present on the surface of the Al-Ta oxide film. The wiring structure according to claim 2, wherein an organic compound having at least one functional group of at least one of a carboxyl group and an amine group is present on the surface of the Al-Ta oxide film. The wiring structure according to claim 3, wherein the organic compound is an amino acid. The wiring structure according to claim 4, wherein the organic compound is an amino acid. The wiring structure according to claim 1, wherein the transparent conductive film has at least one transparent conductive film as a base layer selected from the group consisting of Mo, Mo alloy, Ti, Ti alloy, and In. At least one of the groups. A display device or an input device having the wiring structure as described in claim 1 of the patent application. A touch panel having the wiring structure as described in claim 1 of the patent application. A sputtering target for forming an Al-Ta alloy thin film in a wiring structure as described in claim 1 of the patent application.