JP2014120487A - Electrode for use in display device or input device, and sputtering target for electrode formation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode for use in a display device or an input device having characteristics of excellent wiring resistance and reflectance, while having excellent adhesion.SOLUTION: An electrode for use in a display device or an input device consists of a lamination film including a first layer composed of an Al alloy formed on the substrate side, a second layer formed thereabove and composed of (a) at least one kind selected from a group consisting of Mo, a Mo alloy, Ti, a Ti alloy, Ta, W, and Nb, and/or (b) an In oxide and/or a conductive oxide including a Zn oxide, and a third layer formed above the second layer and composed of an Ag alloy. The electrode has a thickness of 100-800 nm, the second layer has a thickness of 3-50 nm, the third layer has a thickness of 60-480 nm, and the thickness ratio of the third layer occupying the thickness of the electrode is 10-70%.

Description

  The present invention relates to an electrode of a display device or an input device, and a sputtering target for forming an electrode, and more specifically, an electrode used in a display device such as a liquid crystal display or an organic EL display or an input device such as a touch pad, and formation of the electrode It is related with the sputtering target used for.

  Ag alloy is mainly used as an electrode material. As an electrode, a gate electrode for a thin film transistor in a liquid crystal display (LDC), a source-drain electrode, a gate electrode for a thin film transistor in an organic EL (OELD), and a source-drain electrode And a reflective electrode, a cathode and a gate electrode in a field emission display (FED), an anode electrode in a fluorescent vacuum tube (VFD), an address electrode in a plasma display (PDP), a back electrode in an inorganic EL, and the like. The Ag alloy is also used as an electrode in an input device having an input function such as a touch panel in a display device such as the above-described liquid crystal display or organic EL, or in an input device independent of the display device such as a touch pad. ing.

  In the following, an organic electroluminescence (hereinafter referred to as “organic EL”) display, which is one of self-luminous flat panel displays, will be taken up and explained as a representative display device, but the present invention is not limited to this.

  The organic EL display is an all-solid-type flat panel display formed by arranging organic EL elements in a matrix on a substrate such as a glass plate. In an organic EL display, an anode (anode) and a cathode (cathode) are formed in a stripe shape, and a portion where they intersect corresponds to a pixel (organic EL element). By applying a voltage of several volts from the outside to the organic EL element and causing a current to flow, the organic molecules are pushed up to an excited state, and the excited organic molecules return to the original ground state (stable state). Energy is released as light. This emission color is unique to organic materials.

  The organic EL element is a self-luminous and current-driven element, and there are a passive type and an active type. The passive type has a simple structure, but full color is difficult. On the other hand, the active type can be enlarged and is suitable for full color, but a TFT substrate is required. A TFT such as low-temperature polycrystalline Si (p-Si) or amorphous Si (a-Si) is used for this TFT substrate.

  In the case of this active organic EL display, a plurality of TFTs and wirings become obstacles, and the area that can be used for the organic EL pixel is reduced. As the drive circuit becomes complex and the number of TFTs increases, the effect becomes even greater. Therefore, recently, attention has been focused on a method for improving the aperture ratio by adopting a structure (top emission) in which light is extracted from the upper surface side instead of extracting light from the glass substrate.

  In such an active top emission organic EL display, the anode (anode electrode) on the lower surface (TFT substrate side) of the organic layer is represented by ITO (indium tin oxide) or IZO (indium zinc oxide), which excels in hole injection. A transparent oxide conductive film is used. In addition, the anode electrode has a laminated structure of the transparent oxide conductive film and the reflective film for the purpose of reflecting the light emitted from the light emitting layer. As the reflective film, a reflective metal film such as molybdenum (Mo), chromium (Cr), aluminum (Al) or silver (Ag) is often used. For example, a laminated structure of ITO and a pure Ag film or an Ag alloy film mainly composed of Ag is adopted as a reflective anode electrode in a top emission type organic EL display that has already been mass-produced.

  A pure Ag film or an Ag alloy film is useful because of its high reflectance. However, a pure Ag film or an Ag alloy film does not have sufficient adhesion to an underlying layer (for example, a substrate, an insulating film, a planarizing layer, etc.), and peels off from the underlying layer during the manufacturing process or use, thereby reducing product reliability. There was a problem to do. Further, when the film thickness of the Ag alloy film is increased in order to suppress the wiring resistance, Ag is an expensive noble metal, and an electrode with an increased amount of Ag used is not practical from the viewpoint of manufacturing cost.

  Therefore, a technique for reducing the amount of Ag used while improving the adhesion of the Ag alloy film by stacking the Ag alloy film with another metal film has been proposed.

  For example, Patent Document 1 includes an adhesion layer composed of Al as an anode, and a reflection layer provided above the adhesion layer and composed of an Ag alloy, and includes an end face of the reflection layer and the adhesion layer. An organic EL element has been proposed in which the end face is continuous and the thickness of the reflective layer is from 50 nm to 80 nm.

JP 2011-113758 A

  The present invention has been made paying attention to the above-described circumstances, and the object thereof is to provide a wiring resistance while having good adhesion to an underlying layer (for example, a substrate, an insulating film, a planarizing layer, etc.). It is another object of the present invention to provide an electrode used for a display device or an input device having excellent reflectivity.

  The present invention that has solved the above-mentioned problems is an electrode used in a display device or an input device, and the electrode is formed on and above a first layer made of an Al alloy formed on the substrate side. (A) at least one selected from the group consisting of Mo, Mo alloy, Ti, Ti alloy, Ta, W, and Nb; and / or (b) conductive oxide containing In oxide and / or Zn oxide And a laminated film including a third layer made of an Ag alloy formed above the second layer. The film thickness of the electrode is 100 to 800 nm, and the film thickness of the second layer. Is an electrode having the gist that the thickness of the third layer is 3 to 50 nm, the thickness of the third layer is 60 to 480 nm, and the thickness ratio of the third layer to the thickness of the electrode is 10 to 70%. .

  In addition, the Al alloy of the first layer and / or the second layer includes (1-A) rare earth element in an amount of 0.05 to 1.0 atomic% and / or (1-B) Ti, Ta as an alloy element. It is also a preferred embodiment that contains 0.05 to 0.7 atomic% of at least one selected from the group consisting of, W, and Nb.

  Further, the Ag alloy includes, as an alloy element, [(2-A) rare earth element 0.05 to 1.0 atomic%; (2-B) Bi and / or Cu 0.05 to 1.0 atomic%; (2-C) at least one selected from the group consisting of Pd, Pt, and Au is 0.1 to 1.5 atomic%; and (2-D) Zn and / or In is 0.1 to 1.5 It is also a preferred embodiment to contain at least one selected from the group consisting of [atomic%].

  It is also preferable that the rare earth element is at least one selected from the group consisting of Nd, La, Gd, and Ce.

  In another preferred embodiment, the conductive oxide of the second layer is ITO (indium tin oxide) or IZO (indium zinc oxide).

  The electrode is preferably used as a gate electrode, a source-drain electrode, and a reflective electrode. Moreover, the organic EL element provided with the electrode of this invention, a thin-film transistor, and an input device are contained.

  The present invention also includes an Al alloy sputtering target for electrode formation, which includes (1-A) 0.05 to 1.0 atomic% of rare earth elements; and / or (1-B). The main point is to contain 0.05 to 0.7 atomic% of at least one selected from the group consisting of Ti, Ta, W, and Nb.

  Similarly, the present invention includes an Ag alloy sputtering target for electrode formation, which includes [(2-A) rare earth element 0.05 to 1.0 atomic%; (2-B) Cu. 0.05-1.0 atomic%; and / or Bi 0.25-5.0 atomic%; (2-C) at least one selected from the group consisting of Pd, Pt, and Au is 0.1 And (2-D) containing at least one selected from the group consisting of Zn and / or In 0.1 to 1.5 atom%].

  Further, when the Al alloy sputtering target and the Ag alloy sputtering target contain a rare earth element, it is recommended that the rare earth element is at least one selected from the group consisting of Nd, La, Gd and Ce.

  The electrode of the present invention includes a first layer (substrate side) made of an Al alloy, and (a) at least one selected from the group consisting of Mo, Mo alloy, Ti, Ti alloy, Ta, W, and Nb; Or (b) a second layer (an intermediate layer between the first layer and the third layer) made of a conductive oxide containing In oxide and / or Zn oxide; and a third layer made of an Ag alloy; In addition, since the film thickness is appropriately controlled, the film has good adhesion and exhibits high reflectivity and good electrical resistivity. As a result, the electrode according to the present invention has excellent properties in adhesion, reflectance, and wiring resistance, which have been difficult in the past.

  Moreover, according to this invention, it becomes possible to provide the sputtering target suitable for formation of the electrode used for the display apparatus or input device which concerns on the said invention.

FIG. 1 is a schematic view showing an example of an organic EL display provided with the reflective electrode of the present invention. FIG. 2 is a schematic cross-sectional view showing an example of a liquid crystal display. FIG. 3 is a schematic cross-sectional view showing an example of an organic EL display. FIG. 4 is a schematic sectional view showing an example of a field emission display. FIG. 5 is a schematic cross-sectional view showing an example of a fluorescent vacuum tube. FIG. 6 is a schematic cross-sectional view showing an example of a plasma display. FIG. 7 is a schematic cross-sectional view showing an example of an inorganic EL display.

  As a result of intensive research in order to solve the above problems, the inventors of the present invention, in an electrode used for a display device or an input device, in order from the substrate side, the electrode is composed of a first layer made of an Al alloy and an upper portion thereof. (A) at least one selected from the group consisting of Mo, Mo alloy, Ti, Ti alloy, Ta, W, and Nb; and / or (b) In oxide and / or Zn oxide A laminated film including a second layer made of a conductive oxide and a third layer made of an Ag alloy formed above the second layer (the first layer, the second layer, and the third layer are directly The present invention was completed by finding that the thickness of the electrode and the thickness of each layer constituting the electrode may be appropriately controlled.

  The background to the present invention is as follows. In order to achieve low wiring resistance, the film thickness of the Ag alloy film may be increased, but there is a problem that the amount of Ag used increases and the manufacturing cost increases. Further, the adhesion is not improved only by increasing the film thickness. In view of this, a laminated film with Al that has excellent conductivity and has excellent properties in adhesion to an underlayer (for example, a substrate, an insulating film, a planarization layer, etc.) has been proposed (Patent Document 1). . With such a laminated film, it was considered that the wiring resistance and adhesion could be improved without increasing the amount of Ag used.

  However, reflective electrodes used in organic EL displays and the like are required to have high reflectivity in addition to suppressing wiring resistance. For this reason, the conventional technique disclosed in Patent Document 1 is stable because the thickness of the target anode is as thin as about 100 to 300 nm, and the wiring resistance is not sufficient, and the Ag alloy film is also as thin as 50 to 80 nm. It was also difficult to ensure a high reflectivity. Furthermore, although the Al film is useful for improving the adhesion with an underlying layer (for example, a substrate, an insulating film, a flattening layer, etc.), it does not have sufficient reflectivity, and it has been difficult to ensure high reflectivity.

  As a result of studies by the present inventors, in order to ensure good wiring resistance and high reflectance even when the electrode is thickened while securing good adhesion, the first layer provided on the substrate side is made of pure Al (or It was difficult to achieve even when formed with Al oxide or Al intermetallic compound), and it was found useful to use an Al alloy film.

  Further investigations have shown that simply by laminating an Al alloy film and an Ag alloy film, high temperatures in the process of manufacturing thin film transistors and organic EL elements, such as the formation of transparent oxide conductive films such as ITO and insulating films, etc. It was found that due to the thermal history (for example, about 300 ° C.), Al diffuses from the Al alloy film to the Ag alloy film, and the reflectance and wiring resistance deteriorate.

  Therefore, as a result of the study of the configuration by which the present inventors can solve such a problem, as described above, the second layer serving as the intermediate layer between the first layer (Al alloy film) and the third layer (Ag alloy film) is used. Layer ((a) at least one selected from the group consisting of Mo, Mo alloy, Ti, Ti alloy, Ta, W, and Nb; and / or (b) a conductive material containing In oxide and / or Zn oxide. It has been found that it is effective to provide a film made of a conductive oxide; hereinafter referred to as a “diffusion prevention film”. That is, the second layer (diffusion prevention film) provided as an intermediate layer functions as an Al diffusion prevention layer, and Al diffuses from the first layer (Al alloy film) to the third layer (Ag alloy film). It was found that the lowering of the reflectance of the third layer (Ag alloy film) can be suppressed.

  On the other hand, when the second layer (diffusion prevention film) is interposed, there is a problem that the wiring resistance increases when the second layer is thickened to increase the diffusion prevention effect. It was found that by appropriately controlling the thickness, a good wiring resistance can be obtained while exhibiting the above diffusion preventing effect.

  Regarding the effect of forming the intermediate layer, the present inventors have prepared a reflective electrode (laminated layer) in which a first layer (Al alloy film), a second layer (diffusion prevention film), and a third layer (Ag alloy film) are laminated in this order. As a result of studying the reflectance and the wiring resistance, the following knowledge was obtained from Table 1 of Examples described later.

  First, No. 1 in Table 1 was used. 1, it was found that when the second layer (diffusion prevention film) was not provided, Al diffusion could not be prevented, and the reflectance of the reflective electrode and the wiring resistance deteriorated.

  On the other hand, no. When the film thickness of the second layer (diffusion prevention film) was appropriately controlled as in 2 to 4, a sufficient diffusion prevention effect was exhibited, and good reflectance and wiring resistance were obtained.

  However, no. As shown in FIG. 5, when the film thickness of the second layer (diffusion prevention film) becomes too thick, the wiring resistance deteriorated.

  In addition, even if such a tendency was different in the component composition of the 2nd layer (diffusion prevention film), the same tendency was shown (No. 9-28).

  No. Since the component composition of the second layer (diffusion prevention film) 29 to 31 is outside the scope of the present invention, both the reflectance and the wiring resistance were bad.

  From the above results, it was found that it is effective to appropriately control the component composition and film thickness of the second layer (diffusion prevention film) in order to ensure good reflectance and wiring resistance.

  In addition, although the following results are not described in Table 1, it turned out that a reflectance falls, when the film thickness of a 3rd layer (Ag alloy film) becomes thin. This is because when the thickness of the third layer (Ag alloy film) is reduced, more light is transmitted through the third layer (Ag alloy film), and the reflectance at the third layer (Ag alloy film) is reduced. Since the reflectance of the first layer (Al alloy film) and the second layer (diffusion prevention film) with respect to the transmitted light is lower than that of the third layer (Ag alloy film), the reflectance of the entire reflective electrode is reduced. Conceivable.

  In order to secure desired wiring resistance and reflectivity while having good adhesion, the first layer (Al alloy film), the second layer (diffusion prevention film), and the third layer (Ag alloy film) It was found that the ratio of the film thickness of the third layer (Ag alloy film) to the total film thickness of the laminated film must be appropriately controlled within the predetermined film thickness range. .

  Based on the above experimental results, the electrode is thickened (for example, up to about 800 nm) in order to obtain good wiring resistance by appropriately controlling the composition of the electrode, the composition of each layer, and the thickness of each layer. However, the present inventors have found that the above-described favorable characteristics can be secured, and have reached the present invention.

  Next, the present inventors examined the influence of the component composition of the first layer (Al alloy film) constituting the electrode on the reflectance and the wiring resistance (see Table 2).

  First, regarding the first layer (Al alloy film), various alloying elements were added to examine the relationship with the above characteristics. Among the alloying elements, rare earth elements, Ti, Ta, W, and Nb were particularly reflective. It was found that it is suitable for improving the above. Moreover, when adding these alloy elements, it turned out that preferable content exists in relation to a reflectance and wiring resistance.

  No. in Table 2 1 is an example of a pure Al film. In this example, the wiring resistance was good, but the reflectance required for the reflective electrode was not satisfactory.

  On the other hand, no. 2 to 4 are examples in which alloy elements are added. As in these examples, when the alloy element of the first layer (Al alloy film) was appropriately controlled, good reflectance and wiring resistance were obtained.

  No. No. 5 is an example in which the content of the alloy element is excessive. In this example, since the content of the alloy element in the first layer (Al alloy film) was excessive, the wiring resistance was deteriorated.

  In addition, No. The tendency as shown to 1-5 showed the same tendency (No. 9-13, No. 17-21), even if the component composition of a 2nd layer (diffusion prevention film) differs (Mo, Ti, ITO). ).

  Although not shown in the table, the first layer was excellent in adhesion to the substrate regardless of the component composition, and was not peeled off.

  From these results, if the first layer (Al alloy film) is an Al alloy, it exhibits good adhesion and improves the reflectivity, but if the alloy element content becomes too high, the electrical resistivity increases. Since the wiring resistance may be deteriorated, it has been found that it is preferable to appropriately control the addition amount of the alloy element.

  Further, the inventors of the present invention also added various alloy elements to the third layer (Ag alloy film) and investigated the relationship with the above characteristics as in the first layer (Al alloy film). However, it has been found that rare earth elements, Bi, Cu, Pd, Pt, Au, In, and Zn are particularly suitable for improving reflectivity and wiring resistance (see Tables 3A, 3B, and 3C). In addition, when these alloy elements are added, there is a preferable content in relation to reflectance and wiring resistance.

  No. in Table 3A. 1 is an example of a pure Ag film. In this example, the reflectance was low, and the reflectance required for the reflective electrode could not be satisfied.

  On the other hand, no. 2 to 4 are examples in which alloy elements are added. As in these examples, when the alloy element of the third layer (Ag alloy film) was appropriately controlled, good reflectance and wiring resistance were obtained.

  No. No. 5 is an example in which the content of the alloy element is excessive. When the content of the alloy element in the third layer (Ag alloy film) is excessively increased as in this example, the reflectance is lowered.

  In addition, No. The tendency as shown to 1-5 is the same tendency, when the kind of alloy element of a 3rd layer differs (No.7-10 etc.), and when the component composition of a 2nd layer (diffusion prevention layer) differs. (Table 3B, Table 3C).

  From the experimental results shown in Tables 1, 2, 3A, 3B, and 3C, it is necessary to provide a second layer (diffusion prevention layer) having a predetermined component composition with a predetermined film thickness in order to obtain good reflectance and wiring resistance. It was also found that the component composition and film thickness of the first layer (Al alloy film) and the third layer (Ag alloy film) must be controlled appropriately. In the present invention, based on such a result, the film thickness is specified as described later, and a suitable component composition and its content are specified.

Hereinafter, the electrode used for the display apparatus or input device which concerns on this invention is demonstrated.
(Configuration of electrode)
The electrode used for the display device or the input device of the present invention includes a first layer made of an Al alloy formed on the substrate side, and (a) Mo, Mo alloy, Ti, Ti alloy, Ta, At least one selected from the group consisting of W and Nb; and / or (b) a conductive oxide containing In oxide and / or Zn oxide; and above the second layer It is comprised by the laminated film containing the 3rd layer which consists of formed Ag alloy.

  The laminated film of the present invention includes three layers in which the first layer (Al alloy film), the second layer (diffusion prevention film), and the third layer (Ag alloy film) are laminated in this order from the substrate side. A layered structure is also a preferred embodiment.

  In addition, the laminated film of this invention is not limited to this, It is the meaning that arbitrary layers (4th layer) may be included. Therefore, an arbitrary fourth layer (with an arbitrary component composition) is provided between the first layer (Al alloy film) and the second layer (diffusion prevention film), and between the second layer (diffusion prevention film) and the third layer (Ag alloy film). Film) may be formed. Examples of the fourth layer include known adhesion improving films that contribute to improving adhesion.

(Electrode film thickness)
In the present invention, the film thickness of the electrode (laminated film) is 100 to 800 nm. When the film thickness is less than 100 nm, the wiring resistance increases and problems such as the inability to obtain a stable reflectance arise. On the other hand, when the thickness exceeds 800 nm, the coverage of the upper layer film (passivation film or the like) is deteriorated, causing a problem such as a fault. The preferred film thickness of the electrode is 120 nm or more, more preferably 150 nm or more, preferably 700 nm or less, more preferably 500 nm or less.

(Film thickness of first layer (Al alloy film))
The first layer (Al alloy film) is a layer that reflects the light transmitted through the second layer (diffusion prevention film) and the third layer (Ag alloy film) and also improves adhesion to the base layer. Since the Al alloy film has excellent properties of adhesion to the underlayer and the Ag second layer, the peel resistance of the electrode composed of the laminated film of the present invention is improved.

  The film thickness of the first layer (Al alloy film) may be appropriately adjusted so as to be within the range of the film thickness of the electrode in relation to the second layer (diffusion prevention film) and the third layer (Ag alloy film). . The film thickness of the first layer (Al alloy film) is preferably 27 nm or more, more preferably 33 nm or more, and further preferably 42 nm or more. On the other hand, if the film thickness of the first layer (Al alloy film) becomes too thick, the film thickness of the third layer (Ag alloy film) becomes too thin in relation to the film thickness of the electrode, and the reflectance decreases. In addition, the effect of the second layer (diffusion prevention film) cannot be sufficiently obtained. Therefore, the upper limit of the film thickness of the first layer (Al alloy film) is preferably 717 nm or less, more preferably 627 nm or less, and still more preferably 447.

(Film thickness of second layer (diffusion prevention film))
The second layer (diffusion prevention film) plays a role as an Al diffusion prevention layer from the first layer (Al alloy film) to the third layer (Ag alloy film). From the viewpoint of ensuring a sufficient diffusion barrier property, the film thickness needs to be 3 nm or more, preferably 4 nm or more, more preferably 5 nm or more. On the other hand, if the thickness of the second layer (diffusion prevention film) becomes too thick, the ratio of the second layer having a high electrical resistivity to the entire wiring increases, so that the wiring resistance increases. And is preferably 30 nm or less, more preferably 20 nm or less.

(Thickness of the third layer (Ag alloy film))
The third layer (Ag alloy film) plays a role as a reflective film particularly in the reflective electrode. In order to ensure a high reflectance, it is necessary to set the thickness to 60 nm or more, preferably 90 nm or more, and more preferably 100 nm or more. On the other hand, the upper limit is not limited from the viewpoint of improving the reflectance and wiring resistance, but even if the thickness of the third layer (Ag alloy film) is excessively increased, the surface roughness increases, so the effect of improving the reflectance is saturated. At the same time, the production cost increases with the increase in the amount of Ag used.

(Thickness ratio of the third layer)
The film thickness ratio of the third layer (Ag alloy film) in the film thickness (100 to 800 nm) of the electrode (laminated film) according to the present invention is 10 to 70%. If the film thickness ratio of the third layer (Ag alloy film) decreases, the desired reflectance cannot be obtained. Therefore, the film thickness ratio of the third layer (Ag alloy film) needs to be 10% or more, preferably 15 % Or more, more preferably 20% or more. On the other hand, when the ratio of the third layer (Ag alloy film) becomes too high, the effect of improving the reflectance is saturated, and the manufacturing cost increases as the amount of Ag used increases. Therefore, the film thickness ratio of the third layer (Ag alloy film) needs to be 70% or less, preferably 50% or less, more preferably 40% or less, and still more preferably 30% or less.

(Component composition of the first layer (Al alloy film))
In the present invention, the component composition of the first layer (Al alloy film) is not particularly limited, and the conventionally used component composition of the Al alloy film can be adopted, but good adhesion and reflection are possible. In order to exhibit the rate and the wiring resistance, it is desirable to contain the following alloy elements in a predetermined range.

  The alloy element added to the first layer (Al alloy) is [(1-A) 0.05 to 1.0 atomic% of rare earth element; and / or (1-B) Ti, Ta, W and Nb. It is desirable to contain at least one selected from the group of 0.05 to 0.7 atomic%. These elements may be added alone or in combination of any two or more. That is, any one group may be used independently among (1-A) group and (1-B) group, and all (2 groups) may be used together. Moreover, the element which comprises each group can be used individually or in combination with 2 or more types (it is the same also in the sputtering target mentioned later).

  In addition, content of each group is a single content when it is contained alone, and is a total amount when it contains a plurality of elements (second layer (diffusion prevention film), third layer (Ag alloy film)) The same for).

  In relation to the above effects, it is desirable to adjust the Al alloy so that preferably 90 atomic% or more, more preferably 95 atomic% or more is Al.

  The Al alloy constituting the first layer preferably contains the above elements, and the balance is Al and inevitable impurities.

(1-A) 0.05 to 1.0 atomic% of rare earth element
The rare earth element is an element that contributes to suppressing the decrease in reflectance by suppressing the coarsening of the structure of the Al alloy. In order to exert such an effect, the rare earth element is preferably 0.05 atomic% or more, more preferably 0.1 atomic% or more, and further preferably 0.15 atomic% or more. From the viewpoint of suppressing the coarsening of the structure, the content of the rare earth element is preferably as large as possible. However, if the content is too large, the reflectivity may be lowered or the electrical resistivity may be deteriorated. More preferably, it is 0.8 atomic% or less, and further preferably 0.6 atomic% or less.

  The rare earth element means an element group in which Sc (scandium) and Y (yttrium) are added to a lanthanoid element (a total of 15 elements from La with atomic number 57 to Lu with atomic number 71 in the periodic table). . A preferred rare earth element is at least one selected from the group consisting of Nd, La, Gd, and Ce (more preferred rare earth elements are Nd, La).

(1-B) 0.05 to 0.7 atomic% of at least one selected from the group consisting of Ti, Ta, W, and Nb
Ti, Ta, W, and Nb are elements that contribute to the suppression of the decrease in reflectance by suppressing the coarsening of the structure, like the rare earth elements. In order to exert such an effect, at least one selected from the group consisting of Ti, Ta, W, and Nb is preferably 0.05 atomic% or more, more preferably 0.1 atomic% or more, and still more preferably It is 0.15 atomic% or more. The content of Ti, Ta, W, and Nb is preferably as large as possible from the viewpoint of suppressing the coarsening. However, if the content is too large, the reflectivity may be decreased or the electrical resistivity may be deteriorated. It is 7 atomic% or less, More preferably, it is 0.5 atomic% or less, More preferably, it is 0.4 atomic% or less. Among these, preferred elements are Ti and Ta.

  The component composition of a preferable first layer (Al alloy film) containing the alloy elements of the above (1-A) and (1-B) groups is Al-0.2 atomic% Nd, Al-0.2 atomic% Nd. -0.3 atomic% Ta is exemplified.

(Component composition of second layer (diffusion prevention film))
The second layer (diffusion prevention film) is a layer that prevents diffusion of Al from the first layer (Al alloy) to the third layer (Ag alloy) and contributes to the development of good reflectivity and wiring resistance. In order to exert such an effect, it is necessary to have the following component composition.

  That is, the component composition constituting the second layer is [(a) at least one selected from the group consisting of Mo, Mo alloy, Ti, Ti alloy, Ta, W, and Nb; and (b) In oxide, And / or a conductive oxide containing Zn oxide]. Among the groups (a) and (b), any one group may be used alone, or two groups may be used in combination, and the elements constituting each group may be single or any two kinds The above can be used together (the same applies to the sputtering target described later).

  These component compositions have an effect of preventing Al diffusion and contribute to an improvement in reflectance and a reduction in wiring resistance.

  As a preferred component composition of the second layer, Mo is exemplified. Further, examples of preferable alloy components of the Mo alloy and Ti alloy constituting the second layer include a Mo—Nb alloy, a Mo—Ta alloy, and a Mo—Ti alloy.

  The conductive oxide constituting the second layer includes In oxide and / or Zn oxide, preferably ITO (indium tin oxide) or IZO (indium zinc oxide). is there.

  The metal elements constituting the second layer are preferably the above elements and the balance: inevitable impurities.

(Component composition of the third layer (Ag alloy film))
In the present invention, the component composition of the third layer (Ag alloy film) is not particularly limited, and a conventionally used component composition of the Ag alloy film can be adopted. In order to exhibit the resistivity, it is preferable to contain the following alloy elements in a predetermined range.

  The alloy element is preferably [(2-A) 0.05 to 1.0 atomic% of rare earth element; (2-B) Bi and / or Cu of 0.05 to 1.0 atomic%; ) 0.1-1.5 atomic% of at least one selected from the group consisting of Pd, Pt, and Au; and (2-D) 0.1-1.5 atomic% of Zn and / or In] And at least one selected from the group consisting of: Among the groups (2-A) to (2-D), any one group may be used alone, or a plurality (any two or more groups) may be used in combination. Further, the elements constituting each group may be used alone or in combination of two or more kinds, and the content of each group is a single content or a total amount as described above (a sputtering target described later). The same applies to the above).

  In a relationship with the above effect (particularly reflectance), a more preferable embodiment is to adjust the Ag alloy so that 98 atomic% or more and 99.98 atomic% or less becomes Ag.

  The Ag alloy constituting the third layer preferably contains the above elements, and the balance is Ag and inevitable impurities.

(2-A) 0.05 to 1.0 atomic% of rare earth element
The rare earth element is an element that suppresses the growth of Ag crystal grains due to thermal history and suppresses a decrease in reflectance and contributes to the suppression of aggregation (halogen resistance) caused by halogen ions. In order to exert such an effect, the rare earth element is preferably 0.05 atomic% or more, more preferably 0.1 atomic% or more, and further preferably 0.15 atomic% or more. From the viewpoint of improving the effect, it is preferable that the content of the rare earth element is large. However, if the content is too large, the reflectivity may be lowered. Therefore, it is preferably 1.0 atomic% or less, more preferably 0.7 atomic%. Hereinafter, it is more preferably 0.5 atomic% or less.

  The rare earth element means a lanthanoid element, Sc, Y as in the first layer, and a preferred rare earth element is at least one selected from the group consisting of Nd, La, Gd, and Ce (more preferred rare earth elements are , Nd, La).

(2-B) 0.05 to 1.0 atomic% of Bi and / or Cu
Bi and Cu are elements that contribute to the suppression of the growth of Ag crystal grains and the improvement of halogen resistance, like the rare earth elements. In order to exert such an effect, Bi and / or Cu is preferably 0.05 atomic% or more, more preferably 0.07 atomic% or more, and further preferably 0.1 atomic% or more. From the viewpoint of improving the effect, it is preferable that the content of Bi and Cu is large. However, if the content is too large, the reflectance may be lowered. Bi and / or Cu is preferably 1.0 atomic percent or less, more preferably 0.7 atomic percent or less, and still more preferably 0.5 atomic percent or less. Among these, a preferable element is Bi.

(2-C) 0.1 to 1.5 atomic% of at least one selected from the group consisting of Pd, Pt, and Au
Pd, Pt, and Au are elements that contribute to the suppression of growth of Ag crystal grains and the improvement of halogen resistance, like the rare earth elements and Bi and Cu. In order to exert such an effect, at least one selected from the group consisting of Pd, Pt, and Au is preferably 0.1 atomic% or more, more preferably 0.15 atomic% or more, and still more preferably 0.2 atoms. % Or more. From the viewpoint of improving the effect, it is preferable that the contents of Pd, Pt, and Au are large. However, if the content is too large, the reflectance may be lowered, so that it is preferably 1.5 atomic% or less, more preferably 1 0.0 atomic percent or less, more preferably 0.8 atomic percent or less. Among these, preferable elements are Pd and Pt.

(2-D) 0.1 to 1.5 atomic% of Zn and / or In
Zn and In are elements that contribute to the suppression of growth of Ag crystal grains and the improvement of halogen resistance, as well as to the improvement of oxidation resistance and sulfidation resistance, as in the above elements. In order to exhibit such an effect, Zn and / or In is preferably 0.1 atomic% or more, more preferably 0.3 atomic% or more, and further preferably 0.5 atomic% or more. From the viewpoint of improving the effect, it is preferable that the content of Zn and In is large. However, if the content is too large, the reflectivity may be lowered. Therefore, it is preferably 1.5 atomic% or less, more preferably 1.3 atoms. % Or less, more preferably 1.1 atomic% or less. A preferred element is Zn.

  A preferred composition of the third layer (Ag alloy film) containing the alloy elements of groups (2-A) to (2-D) is Ag-0.3 atomic% Bi-0.5 atomic% Nd. Is done.

(Method for forming first layer (Al alloy film))
Examples of the method for forming the first layer (Al alloy film) included in the laminated film constituting the electrode according to the present invention include a sputtering method and a vacuum deposition method. In the present invention, the first layer (Al alloy film) is sputtered by a sputtering method from the viewpoints of thinning and homogenization of alloy components in the film and easy control of the amount of added elements. It is desirable to form using.

  When forming the first layer (Al alloy film) by sputtering, an Al alloy containing a predetermined amount of elements corresponding to (1-A) and (1-B) constituting the first layer (Al alloy film) Use of a sputtering target is useful. Specifically, [(1-A) rare earth element is 0.05 to 1.0 atomic%; and / or (1-B) at least one selected from the group consisting of Ti, Ta, W, and Nb is 0. 0.05 to 0.7 atomic%] is desirable.

  Basically, if an Ag alloy sputtering target containing these elements and having the same composition as the desired first layer (Al alloy film) is used, there is no risk of composition deviation, and the first layer (the desired component composition) Al alloy film) can be formed.

  However, the sputtering target need not contain all the elements corresponding to the component composition of the first layer (Al alloy film) in one sputtering target, and a sputtering target containing a predetermined amount of elements can be sputtered simultaneously (for example, by chip-on). Co-sputtering is also useful for forming the first layer (Al alloy film) having a desired component composition.

  Examples of the method for producing the Al alloy sputtering target include a vacuum melting method and a powder sintering method, but the production by the vacuum melting method is particularly desirable from the viewpoint of ensuring the composition and the uniformity of the structure in the target surface.

Although the film-forming conditions by sputtering method are not specifically limited, For example, it is preferable to employ the following conditions.
-Substrate temperature: Room temperature to 150 ° C
Atmospheric gas: Inert gas such as Ar, nitrogen, etc. (Ar) gas pressure during film formation: 1.0 to 5.0 mTorr
・ Sputtering power: 100-2000W
-Ultimate vacuum: 1 x ^10-5 Torr or less

(Method for forming second layer (diffusion prevention film))
The method for forming the second layer (diffusion prevention film) included in the laminated film constituting the electrode according to the present invention is not particularly limited, and a sputtering method or the like can be employed as in the case of the first layer (Al alloy film).

  Preferably, for the same reason as the first layer (Al alloy film), it is preferable to form the second layer (diffusion prevention film) using a sputtering target by a sputtering method.

  In the case of forming the second layer (diffusion prevention film), there is a risk of composition shift or the like when the sputtering target having the component composition corresponding to the above (a) and (b) constituting the second layer (diffusion prevention film) is used. The second layer (diffusion prevention film) having a desired component composition can be formed. Specifically, [(a) at least one selected from the group consisting of Mo, Mo alloy, Ti, Ti alloy, Ta, W, and Nb; and / or (b) In oxide and / or Zn oxidation A sputtering target made of a conductive oxide containing an object] is preferable. Of course, as with the first layer (Al alloy film), simultaneous sputtering (co-sputtering) is also a useful film forming method.

Although the film-forming conditions by sputtering method are not specifically limited, For example, it is preferable to employ the following conditions.
-Substrate temperature: Room temperature to 150 ° C
Atmospheric gas: Inert gas such as Ar, nitrogen, etc. (Ar) gas pressure during film formation: 1.0 to 5.0 mTorr
・ Sputtering power: 100-2000W
-Ultimate vacuum: 1 x ^10-5 Torr or less

(Method for forming third layer (Ag alloy film))
As the formation method of the third layer (Ag alloy film) constituting the electrode, various film formation methods can be adopted in the same manner as the first layer (Al alloy film), but for the same reason as the first layer (Al alloy film), The third layer (Ag alloy film) is also preferably formed by a sputtering method using a sputtering target.

  When the third layer (Ag alloy film) is formed by sputtering, it is useful to use an Ag alloy sputtering target containing a predetermined amount of any of the elements (2-A) to (2-D).

  Specifically, [(2-A) 0.05 to 1.0 atomic% of rare earth element; (2-B) 0.05 to 1.0 atomic% of Cu, and / or Bi of 0.25 to 5 0.1 atomic percent; at least one selected from the group consisting of (2-C) Pd, Pt, and Au; 0.1 to 1.5 atomic percent; and (2-D) Zn and / or In An Ag alloy sputtering target containing at least one selected from the group consisting of 1 to 1.5 atomic% may be used.

  Basically, if an Ag alloy sputtering target having the same composition as the desired third layer (Ag alloy film) is used, there is no risk of composition deviation, and the third layer (Ag alloy film) having the desired component composition is formed. it can. However, since Bi is an element that is easily scattered during the film formation process and is easily concentrated in the vicinity of the film surface, about 5 times as much Bi as the Bi amount in the third layer (Ag alloy film) is contained in the sputtering target. Corresponding to the Bi content in the film, Bi is preferably 0.25 atomic% or more, more preferably 0.35 atomic% or more, still more preferably 0.5 atomic% or more. Preferably, it is 5.0 atomic% or less, more preferably 3.5 atomic% or less, and still more preferably 2.5 atomic% or less.

  Of course, like the first layer (Al alloy film), co-sputtering (co-sputtering) is also useful for forming the third layer (Ag alloy film) having a desired component composition.

  As the method for producing the Ag alloy sputtering target, the above-mentioned various methods can be mentioned, but the vacuum melting method is desirable like the Al alloy sputtering target.

Although the film-forming conditions by sputtering method are not specifically limited, For example, it is preferable to employ the following conditions.
-Substrate temperature: Room temperature to 150 ° C
・ Atmospheric gas: inert gas such as Ar, nitrogen, etc. (Ar) gas pressure during film formation: 1 to 5 mTorr
・ Sputtering power: 100-2000W
-Ultimate vacuum: 1 x ^10-5 Torr or less

  In addition, the shape of the sputtering target to be used includes one processed into an arbitrary shape (a square plate shape, a circular plate shape, a donut plate shape, a cylindrical shape, or the like) according to the shape or structure of the sputtering apparatus.

  The first layer (Al alloy film), the second layer (diffusion prevention film), and the third layer (Ag alloy film) constituting the laminated film, which is a characteristic part of the present invention, have been described above.

  Hereinafter, an electrode used for a display device or an input device using a laminated film including the first layer (Al alloy film), the second layer (diffusion prevention film), and the third layer (Ag alloy film) is referred to as an organic EL. The structure of the organic EL element used as the reflective electrode will be described.

  However, the present invention is not intended to be limited to the above structure, and can be applied to electrodes such as a gate electrode and a source-drain electrode (source electrode, drain electrode) in addition to the reflective electrode.

  The organic EL display shown in FIG. 1 is used as an example, and it is composed of a laminated film including the first layer (Al alloy film), the second layer (diffusion prevention film) and the third layer (Ag alloy film) of the present invention. An organic EL element including an electrode as a reflective anode electrode will be described. In the following, the case where the organic EL element of the present invention is applied to an organic EL display will be described, but the application of the organic EL element of the present invention is not limited to the organic EL display. Various known configurations can be employed. Furthermore, the reflective electrode according to the present invention is not limited to the reflective anode electrode, and can be used for other reflective electrodes.

  First, as shown in FIG. 1, a TFT 2 and a passivation film 3 are formed on a substrate 1, and a planarization layer 4 is further formed thereon. A contact hole 5 is formed on the TFT 2, and the source-drain electrode (not shown) of the TFT 2 and the first layer (Al alloy film) 6 constituting the reflective electrode according to the present invention are formed through the contact hole 5. Electrically connected.

  Further, a second layer (diffusion prevention film) 7 is formed immediately above the first layer (Al alloy film) 6, and a third layer (Ag alloy film) 8 is formed immediately above. The first layer (Al alloy film) 6, the second layer (diffusion prevention film) 7, and the third layer (Ag alloy film) 8 can be formed by the method described above.

  Next, an organic layer 9 is formed on the third layer (Ag alloy film) 8. The organic layer 9 may include, for example, a hole transport layer and an electron transport layer in addition to the organic light emitting layer. Further, a cathode electrode 10 is formed on the organic layer 9. In the case of this FIG. 1, the material which comprises the cathode electrode 10 is not ask | required in particular, The conventionally used thing can be used.

  In the organic EL display, the light emitted from the organic light emitting layer in the organic layer 9 is efficiently reflected by the reflective anode electrodes 6 to 8 (particularly the third layer (Ag alloy film) 8) of the present invention. Excellent emission brightness can be achieved. The higher the reflectivity of the reflective electrode (first layer (Al alloy film) 6, second layer (diffusion prevention film) 7, third layer (Ag alloy film) 8), the better, generally 90% or more, Preferably, a reflectance of 93% or more is required.

  In addition, the higher the hole injection property into the organic layer 9, the better the reflective anode electrode.

  In the above, the reflective electrode provided with the electrode of this invention and the organic EL element provided with this electrode were demonstrated.

  The electrode of the display device of the present invention described above can be used as an electrode of various display devices (including input devices). For example, a gate electrode and a source-drain electrode (source electrode and drain electrode) for a thin film transistor in the liquid crystal display (LDC) illustrated in FIG. 2, for example, a gate electrode for a thin film transistor in the organic EL display (OELD) illustrated in FIG. Source-drain electrodes, eg, cathode electrodes in the field emission display (FED) illustrated in FIG. 4, and gate electrodes, eg, anode electrodes in the fluorescent vacuum tube (VFD) illustrated in FIG. 5, such as illustrated in FIG. An address electrode in a plasma display (PDP), for example, a back electrode in an inorganic EL display exemplified in FIG.

  The electrode of the present invention can also be applied to an input device. Examples of the input device include an input device provided with input means in the display device, such as a touch panel, and an input device that does not have a display device such as a touch pad. Specifically, an input device that operates the device by combining the various display devices and the position input means and presses a display on the screen, or a display device that is separately installed corresponding to the input position on the position input means. The electrode of the present invention can also be used for an electrode of an input device to be operated (for example, various electrodes described above). As the position input means, various known operating principles such as a matrix switch, a resistive film method, a surface acoustic wave method, an infrared method, an electromagnetic induction method, and a capacitance method can be adopted.

  It has been confirmed by experiments that the predetermined effect can be obtained when the electrodes according to the present invention are used as the electrodes of these display devices or input devices.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples, but may be appropriately modified within a range that can meet the purpose described above and below. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention.

(Film formation)
On the glass substrate (non-alkali glass, plate thickness 0.7 mm, diameter 4 inches), the first layer (Al alloy film: balance of the composition shown in Tables 1 to 3 (all alloy component contents are atomic%)) A film was formed under the following sputtering conditions using a DC magnetron sputtering apparatus using a sputtering target (a disk type having a diameter of 4 inches) having the same composition as Al and inevitable impurities. Subsequently, immediately above the first layer (Al alloy film), a sputtering target having the same component composition as the second layer (diffusion prevention film: including unavoidable impurities in addition to predetermined components) having the composition shown in Tables 1 to 3 Using the same sputtering apparatus as the first layer, a film was formed under the following sputtering conditions.

  Subsequently, just above the second layer (diffusion prevention film), a sputtering target (4 inches in diameter) having the same components as the third layer (Ag alloy film: the balance is Ag and inevitable impurities) having the composition shown in Tables 1 to 3 A sample was prepared by forming a film under the following sputtering conditions using a disk shape of:

  In Table 1, No. No. 1 did not form the second layer (diffusion prevention film). In Table 2, No. The first layers of Nos. 1, 9, and 17 are pure Al sputtering targets. No. 1 in Table 3B. 33, No. 3 in Table 3C. For the third layer 65, a pure Ag sputtering target was used. The Bi content in the sputtering target when Bi is contained in the third layer (Ag alloy film) was added so as to be 5 times the Bi content in the third layer (Ag alloy film) (for example, In No. 1 of Table 2, using a sputtering target of Ag-0.5 atomic% Bi-1.0 atomic% Zn, a third layer of Ag-0.1 atomic% Bi-1.0 atomic% Zn (Ag Alloy film)).

  The composition of the first layer (Al alloy film), the second layer (diffusion prevention film), and the third layer (Ag alloy film) after film formation is confirmed by inductively coupled plasma (ICP) mass spectrometry. did.

(First layer: Al alloy sputtering conditions)
・ Substrate temperature: room temperature ・ Ar gas flow rate: 30 sccm
Ar gas pressure: 2 mTorr
・ Sputtering power: 260W
・ Achieved vacuum: 3 × 10 ⁻⁶ Torr
(Second layer: sputtering conditions)
(A) Mo, Mo alloy, Ti, Ti alloy, Ta, W, and Nb
・ Substrate temperature: room temperature ・ Ar gas flow rate: 27 sccm
Ar gas pressure: 2 mTorr
・ Sputtering power: 260W
・ Achieved vacuum: 3 × 10 ⁻⁶ Torr
(B) Conductive oxide containing In oxide and / or Zn oxide Substrate temperature: room temperature Ar + O ₂ gas flow rate: 19 sccm
・ O ₂ ratio = 5%
Ar + O ₂ gas pressure: 2 mTorr
・ Spatter power: 200W
・ Achieved vacuum: 3 × 10 ⁻⁶ Torr
(Third layer: Ag alloy sputtering conditions)
・ Substrate temperature: room temperature ・ Ar gas flow rate: 30 sccm
Ar gas pressure: 2 mTorr
・ Spatter power: 130W
・ Achieved vacuum: 3 × 10 ⁻⁶ Torr

(Measuring method of film thickness)
The thicknesses of the first layer (Al alloy film), the second layer (diffusion prevention film), and the third layer (Ag alloy film) were measured with a stylus step meter (manufactured by KLA-Tencor, Alpha-step). . The film thickness was measured at a total of three film thicknesses at intervals of 5 mm from the center of the thin film in the radial direction, and the average value was defined as “thin film thickness” (nm). Further, the film thickness of the first layer (Al alloy film) and the film thickness of the second layer (diffusion prevention film) and the third layer (Ag alloy film) were summed to form the film thickness of the laminated film (in the table, “total” "). The film thickness ratio of the third layer was calculated from the total film thickness (“third layer film thickness ratio” in the table).

(Measurement of reflectance after heat treatment)
After heat-treating the prepared sample at 300 ° C. for 60 minutes, the visible light reflectance was measured with a spectrophotometer (manufactured by JASCO Corporation: Visible / Visible Light) with light having a wavelength of 380 to 780 nm based on JIS R 3106. An ultraviolet spectrophotometer “V-570”) was used. Specifically, with respect to the reflected light intensity of the reference mirror, the reflected light intensity (measured value) of the prepared sample is “reflectance” (= [reflected light intensity of sample / reflected light intensity of reference mirror] × 100. %). In this example, the reflectance of the sample at λ = 450 nm was evaluated according to the following criteria, and “◯” was determined to be acceptable.
○: 90% or more ×: less than 90%

(Wiring resistance)
The prepared samples were heat treated at 300 ° C. for 60 minutes, and then the sheet resistance of each sample was measured. Specifically, sheet resistance was measured by a commonly used four-point probe method. The electrical resistivity was calculated from the sheet resistance and the film thickness. In this example, a comparison was made with an Al alloy single layer film (composition: Al-0.2 atomic% Nd) prepared separately and an example in which the second layer (diffusion prevention film) was not provided (No. 1 in Table 1). Then, the case where the wiring resistance was high was evaluated as x (failed), and the case where the wiring resistance was the same or low was evaluated as ◯ (passed).

  The 10 μm wide line and space is first heated to 40 ° C. and immersed in a mixed acid etching solution (phosphoric acid: nitric acid: acetic acid: water = 50: 0.2: 30: 19.8) and etched. Completion time + 20 seconds (overetching time) Etching was performed.

(Adhesion)
The presence or absence of peeling of the substrate and the laminated film of each of the prepared samples was visually confirmed. As a result, none of the samples could confirm the peeling of the laminated film, and the adhesion was good.

  The said test result is shown to Tables 1-3.

  Table 1 shows the reflectance by changing the film thickness of the first layer (Al alloy film), the second layer (diffusion prevention film) and the third layer (Ag alloy film) and the component composition (diffusion prevention film) of the second layer. It is the result of investigating the influence on wiring resistance. Table 1 shows the following.

  No. No. 1 was an example in which the second layer (diffusion prevention film) was not formed, and the reflectance and wiring resistance were also poor.

  No. For 5, 12, and 24, the desired wiring resistance could not be obtained because the thickness of the second layer (diffusion prevention film) was too thick.

  No. 29 to 31 are examples in which the component composition of the second layer (diffusion prevention film) deviates from the definition of the present invention. In these examples, both reflectivity and wiring resistance were bad.

  On the other hand, no. Examples 2 to 4, 6 to 11, 13 to 23, and 25 to 28 are examples that satisfy all of the component composition and other requirements of the second layer of the present invention, and good wiring resistance and reflectance were obtained.

  Table 2 shows the results of examining the influence on the reflectance and wiring resistance by appropriately changing the component composition of the first layer (Al alloy). Table 2 shows the following.

  No. 1, 9, and 17 are examples in which pure Al is the first layer. In this example, the wiring resistance was good, but the reflectance was low.

  No. 5, 13, and 21 are examples in which the content of the alloy element is excessive, and the wiring resistance deteriorated.

  No. 2 to 4, 6 to 8, 10 to 12, 14 to 16, 18 to 20, and 22 to 24 are examples that satisfy all of the component composition and other requirements of the first layer of the present invention. Reflectance was obtained.

  Tables 3A, 3B, and 3C show the results of examining the influence on the reflectance and the wiring resistance by appropriately changing the component composition of the third layer (Ag alloy film). Tables 3A, 3B and 3C show the following.

  No. Nos. 1, 33 and 65 are examples in which a pure Ag film is the third layer. In this example, the wiring resistance was good, but the reflectance was low.

  No. 5, 10, 14, 20, 24, 37, 42, 46, 52, 56, 69, 74, 78, 84, 88 are examples in which the alloy element content is excessive, and the reflectivity decreased.

  On the other hand, examples other than the above are examples that satisfy all the component composition and other requirements of the third layer (Ag alloy film) of the present invention, and good wiring resistance and reflectivity were obtained.

  Table 3A is an example using pure Mo for the second layer, Table 3B is an example using a pure Ti film for the second layer, Table 3B is an example using an ITO film for the second layer, and Although the component composition of the layer (Ag alloy) is also changed, it is understood that if the predetermined requirements of the present invention are satisfied, the desired reflectance and wiring resistance can be obtained even if the component compositions are used in appropriate combinations. It was.

1 Substrate 2 TFT
3 Passivation film 4 Planarization layer 5 Contact hole 6 First layer (Al alloy film)
7 Second layer (diffusion prevention film)
8 Third layer (Ag alloy film)
9 Organic layer 10 Cathode electrode

Claims (15)

An electrode used for a display device or an input device,
The electrode is
A first layer made of an Al alloy formed on the substrate side;
(A) at least one selected from the group consisting of Mo, Mo alloy, Ti, Ti alloy, Ta, W, and Nb formed thereon; and / or (b) In oxide and / or Zn oxidation Conductive oxides containing matter;
A second layer comprising:
A laminated film including a third layer made of an Ag alloy formed above the second layer;
The electrode has a thickness of 100 to 800 nm,
The film thickness of the second layer is 3 to 50 nm,
The thickness of the third layer is 60 to 480 nm, and the thickness ratio of the third layer to the thickness of the electrode is 10 to 70%. The Al alloy is an alloy element,
(1-A) 0.05 to 1.0 atomic% of a rare earth element; and / or (1-B) 0.05 to 0.00 at least one selected from the group consisting of Ti, Ta, W, and Nb. 7 atomic percent;
The electrode according to claim 1, comprising: The Ag alloy is an alloy element,
(2-A) 0.05 to 1.0 atomic% of a rare earth element;
(2-B) 0.05 to 1.0 atomic% of Bi and / or Cu;
(2-C) 0.1 to 1.5 atomic% of at least one selected from the group consisting of Pd, Pt, and Au; and (2-D) Zn and / or In of 0.1 to 1.5 atom%;
The electrode according to claim 1, which contains at least one selected from the group consisting of:   The electrode according to claim 2 or 3, wherein the rare earth element (1-A) and / or (2-A) is at least one selected from the group consisting of Nd, La, Gd, and Ce.   The electrode according to any one of claims 1 to 4, wherein the conductive oxide of the second layer is ITO (indium tin oxide) or IZO (indium zinc oxide).   The electrode according to claim 1, wherein the electrode is a gate electrode.   The electrode according to claim 1, wherein the electrode is a source-drain electrode.   The electrode according to claim 1, wherein the electrode is a reflective electrode.   The organic EL element provided with the electrode in any one of Claims 1-5.   A thin film transistor comprising the electrode according to claim 1.   An input device comprising the electrode according to claim 1. An Al alloy sputtering target used for forming the electrode according to claim 1,
(1-A) 0.05 to 1.0 atomic% of a rare earth element; and / or (1-B) 0.05 to 0.00 at least one selected from the group consisting of Ti, Ta, W, and Nb. 7 atomic percent;
An Al alloy sputtering target for forming an electrode, comprising:   The sputtering target according to claim 12, wherein the rare earth element is at least one selected from the group consisting of Nd, La, Gd, and Ce. An Ag alloy sputtering target used for forming the electrode according to claim 1,
(2-A) 0.05 to 1.0 atomic% of a rare earth element;
(2-B) 0.05 to 1.0 atomic% Cu and / or 0.25 to 5.0 atomic% Bi;
(2-C) 0.1 to 1.5 atomic% of at least one selected from the group consisting of Pd, Pt, and Au; and (2-D) Zn and / or In of 0.1 to 1.5 atom%;
An Ag alloy sputtering target for forming an electrode, comprising at least one selected from the group consisting of:   The sputtering target according to claim 14, wherein the rare earth element is at least one selected from the group consisting of Nd, La, Gd, and Ce.