WO2014080933A1

WO2014080933A1 - Electrode used in display device or input device, and sputtering target for use in electrode formation

Info

Publication number: WO2014080933A1
Application number: PCT/JP2013/081261
Authority: WO
Inventors: 博行奥野; 中井　淳一; 後藤　裕史; 田内　裕基; 陽子志田; 裕美岩成
Original assignee: 株式会社コベルコ科研; 株式会社神戸製鋼所
Priority date: 2012-11-21
Filing date: 2013-11-20
Publication date: 2014-05-30
Also published as: TW201426831A

Abstract

This electrode for use in a display device or input device has a laminate film which includes a first layer formed on the substrate side and containing an Al alloy, and a second layer formed on top of the first layer and containing an Ag alloy. The electrode film thickness is 100-800nm, the second layer thickness is 60-480nm, the proportion of the second layer thickness to the electrode film thickness is 10-70%, and the proportion of the first layer thickness to the electrode film thickness is 30% or greater. The Al alloy contains a prescribed amount of a prescribed alloy element.

Description

Electrode used for display device or input device, and sputtering target for electrode formation

The present invention relates to an electrode of a display device or an input device, and a sputtering target for forming an electrode. In particular, the present invention relates to an electrode used for a display device such as a liquid crystal display or an organic EL display or an input device such as a touch pad, and a sputtering target used for forming the electrode.

Ag alloy is mainly used as an electrode material. The electrodes include 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), a source-drain electrode and a reflective electrode, a cathode in a field emission display (FED), and Examples include a gate electrode, an anode electrode in a fluorescent vacuum tube (VFD), an address electrode in a plasma display (PDP), and a back electrode in an inorganic EL. 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-mentioned liquid crystal display or organic EL, or an input device independent of the display device such as a touch pad. It has been.

In the following, an organic electroluminescence (hereinafter referred to as “organic EL”) display, which is one of self-luminous flat panel displays, will be described as a representative display device. However, 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.

Organic EL elements are self-luminous and current-driven elements, and there are passive and active driving methods. The passive type has a simple structure, but full color is difficult. On the other hand, the active type can be increased in size and is suitable for full color, but a TFT substrate is required. For this TFT substrate, TFTs such as low-temperature polycrystalline Si (p-Si) or amorphous Si (a-Si) are used.

In the case of an active organic EL display, a plurality of TFTs and wirings become obstacles, and the area that can be used for organic EL pixels is reduced. As the drive circuit becomes complicated 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, it has been pointed out that a pure Ag or Ag alloy film has a problem in etching characteristics because the etching rate during wet etching is high. For example, an Ag alloy film is etched at a high rate by a wet etching solution such as phosphorous acetic acid, and it is difficult to perform fine processing with high etching accuracy particularly on a large area substrate. In particular, when side etching of the Ag alloy film by isotropic etching is increased, there is a problem in etching accuracy such that the formed side surface becomes uneven, and it is difficult to perform fine processing with high dimensional accuracy. Therefore, since it is difficult to process the Ag alloy film with a desired dimensional accuracy and shape, it causes light emission failure, leakage light, electrical contact failure, and the like, causing a decrease in the reliability of the display device itself such as an organic EL display. It was.

Further, 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, resulting in product reliability. There was a problem of lowering. In order to suppress the wiring resistance, it is desirable to increase the thickness of the Ag alloy film. However, since Ag is an expensive noble metal, an electrode with an increased amount of Ag used from the viewpoint of manufacturing cost is Lack of practicality.

As a technique for solving such a problem, Patent Document 1 discloses, as a technique for accurately controlling the size and shape of an anode made of an Ag alloy, an adhesion layer in which the anode is made of Al, and the adhesion layer. An organic EL element including a reflective layer formed above and made of an Ag alloy, wherein an end surface of the reflective layer and an end surface of the adhesion layer are continuous, and a thickness of the reflective layer is 50 nm or more and 80 nm or less. Proposed.

In the technique of Patent Document 1, the amount of Ag used can be reduced while improving the adhesion of the Ag alloy film by laminating the Ag alloy film with another metal film.

Japanese Unexamined Patent Publication No. 2011-113758

The present invention has been made by paying attention to the above-mentioned circumstances, and its purpose is to have a good electrical resistivity and facilitate high-precision microfabrication that was difficult with an Ag alloy single layer film. It is another object of the present invention to provide an electrode used for a display device or an input device having a high reflectance comparable to that of an Ag alloy film (single layer).

Another object of the present invention is to provide an electrode used for a display device or an input device having good conductivity (low wiring resistance) and high reflectivity.

Another object of the present invention is to provide a display device or an input device having excellent adhesion with a base layer (for example, a substrate, an insulating film, a planarization layer, etc.) and having excellent characteristics in wiring resistance and reflectance. It is to provide an electrode to be used.

The first invention that can solve the above problems is an electrode used in a display device or an input device,
The electrode has a laminated film including a first layer containing an Al alloy formed on the substrate side and a second layer containing an Ag alloy formed above the first layer,
The film thickness of the electrode is 100 nm or more and 800 nm or less, the film thickness of the second layer is 60 nm or more and 480 nm or less, and the film thickness ratio of the second layer in the film thickness of the electrode is 10% or more and 70%. The film thickness ratio of the first layer in the film thickness of the electrode is 30% or more,
The Al alloy is an alloy element,
(1-A) 0.05 atom% or more and 1.0 atom% or less of the rare earth element,
(1-B) at least one selected from the group consisting of Si, Cu, and Ge is 0.5 atomic% or more and 1.5 atomic% or less, and
(1-C) at least one selected from the group consisting of Ti, Ta, W, and Nb is 0.05 atomic% or more and 0.7 atomic% or less,
An electrode having the gist of containing at least one selected from the group consisting of:

The Ag alloy preferably contains 98 atomic% or more and 99.98 atomic% or less of Ag.

The Ag alloy is an alloy element,
(2-A) 0.05 to 1.0 atomic% of the rare earth element,
(2-B) Bi and / or Cu is 0.05 atomic% or more and 1.0 atomic% or less,
(2-C) at least one selected from the group consisting of Pd, Pt and Au is 0.1 atomic% or more and 1.5 atomic% or less, and (2-D) Zn and / or In is 0.1 atomic% 1.5 atomic% or less,
It is preferable to contain at least one selected from the group consisting of:

The rare earth element (1-A) or (2-A) is preferably at least one selected from the group consisting of Nd, La, Gd, and Ce.

According to a second aspect of the present invention, the electrode has a third layer containing an oxide of an Al alloy or a nitride of an Al alloy between the first layer and the second layer. The third layer is an electrode having a gist that the thickness of the third layer is 1 nm or more and 10 nm or less.

The Al alloy of the third layer is an alloy element,
(3-A) 0.05 atomic% to 1.0 atomic% of rare earth elements, or (3-B) 0.05 atomic% of at least one selected from the group consisting of Ti, Ta, W, and Nb 0.7 atomic% or less,
It is preferable to contain.

Moreover, the 3rd invention which could solve the said subject WHEREIN: The said electrode is between the said 1st layer and the said 2nd layer,
(A) at least one selected from the group consisting of Mo, Mo alloy, Ti, Ti alloy, Ta, W, Nb, or
(B) having a fourth layer containing a conductive oxide containing at least one of In oxide and Zn oxide;
The electrode is characterized in that the film thickness of the fourth layer is 3 nm or more and 50 nm or less.

The conductive oxide of the fourth layer is preferably ITO (indium tin oxide) or IZO (indium zinc oxide).

Similarly, the first invention also includes an Al alloy sputtering target for electrode formation,
(1-A) 0.05 atom% or more and 1.0 atom% or less of the rare earth element,
(1-B) at least one selected from the group consisting of Si, Cu, and Ge is 0.5 atomic% or more and 1.5 atomic% or less, and
(1-C) at least one selected from the group consisting of Ti, Ta, W, and Nb is 0.05 atomic% or more and 0.7 atomic% or less,
The main point is to contain at least one selected from the group consisting of:

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

Similarly, the first invention also includes an Ag alloy sputtering target for electrode formation,
(2-A) 0.05 to 1.0 atomic% of the rare earth element,
(2-B) Cu is 0.05 atomic% or more and 1.0 atomic% or less, and / or Bi is 0.25 atomic% or more and 5.0 atomic% or less,
(2-C) at least one selected from the group consisting of Pd, Pt and Au is 0.1 atomic% or more and 1.5 atomic% or less, and
(2-D) Zn and / or In is 0.1 atomic% or more and 1.5 atomic% or less,
The main point is to contain at least one selected from the group consisting of:

The electrode of the first invention has a laminated film including a first layer (substrate side) made of an Al alloy and a second layer made of an Ag alloy, and the film thickness and component composition are appropriately controlled. In addition to excellent etching characteristics and high reflectivity, it exhibits good electrical resistivity. As a result, the electrode according to the first invention can be easily processed with high precision, which has been difficult with the conventional Ag alloy single layer film, and can exhibit high reflectivity equivalent to that of the Ag alloy single layer. Become.

The electrode of the second invention has a third layer containing an oxide of Al alloy or a nitride of Al alloy between the first layer (substrate side) made of Al alloy and the second layer made of Ag alloy. In addition, since the film thickness is appropriately controlled, it exhibits high reflectivity and good contact resistance between the first layer and the third layer. As a result, the electrode according to the second aspect of the invention can have both high reflectivity and good wiring resistance, which are difficult with a conventional Ag alloy single layer film.

The electrode of the third invention includes (a) Mo, Mo alloy, Ti, Ti alloy, Ta, W, and Nb between the first layer (substrate side) made of an Al alloy and the second layer made of an Ag alloy. And having a fourth layer containing a conductive oxide containing at least one selected from the group consisting of (b) at least one of In oxide and Zn oxide, and controlling the film thickness appropriately. Therefore, it has good adhesion and exhibits high reflectance and good electrical resistivity. As a result, the electrode according to the third aspect of the invention has excellent properties such as adhesion, reflectance, and wiring resistance, which have been difficult in the past.

Further, according to the first to third inventions, it is possible to provide a sputtering target suitable for forming electrodes used in the display device or the input device according to the invention.

FIG. 1 is a schematic view showing an example of an organic EL display provided with the reflective electrode of the first 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. FIG. 8 is a schematic view showing an example of an organic EL display provided with the reflective electrode of the second invention. FIG. 9 is a schematic view showing an example of an organic EL display provided with the reflective electrode of the third invention.

[First invention]
Hereinafter, the first invention will be described in detail.

The inventors of the present invention have made extensive studies to solve the above problems. As a result, the present inventors, in order from the substrate side, the electrodes used in the display device or the input device, the first layer made of an Al alloy, and the second layer made of an Ag alloy formed thereon (the first layer) The electrode, and the first layer (Al alloy film) and the second layer (Ag) constituting the electrode, and the first layer may be in direct contact with one layer or may not be in direct contact with the first layer. It was found that the thickness of each alloy film) and the component composition of the first layer (Al alloy) may be appropriately controlled, and the first invention was completed.

The background of reaching the first invention is as follows. First, for the problem of the conventional Ag alloy film (single layer), that is, the problem that it is difficult to perform fine processing with high etching accuracy during patterning by wet etching using a resist as a mask, the Al film and the Ag alloy film It is known that the etching rate can be adjusted and solved by using a laminated structure (Patent Document 1). This is because the Al film has an etching rate control function because the etching rate of the Al film is slower than the etching rate of the Ag alloy film. According to this technique, the electrode has a laminated structure of an Ag alloy film and an Al film, so that the etching rate can be adjusted, excessive etching of the Ag alloy film can be suppressed, and the dimensions are processed with high accuracy. be able to.

In recent years, however, the electrodes of display devices have been required to have conflicting characteristics such as miniaturization of wiring and suppression of electrical resistivity. Furthermore, reflective electrodes such as organic EL displays are required to have high reflectivity in addition to miniaturization of wiring and suppression of electrical resistivity. In the prior art disclosed in Patent Document 1, although the wiring can be etched with high accuracy, the thickness of the target anode is as thin as about 100 to 300 nm. It was difficult to suppress the electrical resistivity, and it was difficult to secure a stable high reflectivity because the Ag alloy film was as thin as 50 to 80 nm. Furthermore, although the Al film is useful not only for the above etching rate control function but also for improving the adhesion with the lower layer (planarization film), it does not have sufficient reflectivity, so it was difficult to ensure high reflectivity. .

Patent Document 1 does not disclose any high-precision fine processing and reflectivity when the film is thickened, and the structure of Patent Document 1 has a problem of low reflectivity as will be described later. .

As a result of investigations by the present inventors, it is difficult to use pure Al (or Al oxide or Al intermetallic compound) to secure good electrical resistivity and fine workability even when the film thickness is increased in consideration of reflectance. Thus, it has been found useful to use an Al alloy film containing a predetermined amount of a specific alloy element. The present inventors then fabricated a reflective electrode having a laminated film of an Al alloy film (substrate side) and an Ag alloy film, and examined the relationship between reflectance, film thickness, and fine workability (dimensional accuracy when patterning). As a result, the following knowledge was obtained from Table 1 of Examples described later.

That is, it was found that when the thickness of the Ag alloy film is reduced, the reflectance of the Ag alloy film is decreased, and the amount of light transmitted through the Ag alloy film and reflected by the Al alloy film is increased. When the transmittance of the Ag alloy film increases, the proportion of light reflected by the Al alloy film increases. However, the Al alloy film has a lower reflectance than the Ag alloy film, and a part of the light reflected by the Al alloy film. Was reflected without passing through the Ag alloy film, it was found that the reflectance of the reflective electrode was reduced (No. 1). On the other hand, when the thickness of the Ag alloy film is increased, the reflectivity of the reflective electrode is improved (90% or more), but it has been found that highly accurate fine processing becomes difficult (No. 12). Furthermore, in the laminated film of the Al alloy film and the Ag alloy film, it was found that the film thickness ratio of the Al alloy film and the Ag alloy film with respect to the film thickness of the laminated film affects the fine workability. That is, when the thickness ratio of the Ag alloy film exceeds 70%, the Ag alloy film to be etched increases, so that the fine workability deteriorates (No. 5, 9, 12). Similarly, when the film thickness ratio of the Al alloy film was less than 30%, the etching rate control function could not be sufficiently exhibited, and the fine workability deteriorated (No. 5, 9, 12). This tendency occurred when the ratio to the laminated film exceeded 70% (or when the Al alloy film was less than 30%) regardless of the thickness of the Ag alloy film. From these results, in order to ensure good fine workability and reflectivity, not only simply laminating an Ag alloy film and an Al alloy film, but within a predetermined film thickness range, Ag relative to the film thickness of the laminated film It was found that it is necessary to appropriately control the film thickness ratio of the alloy film or the Al alloy film. By appropriately controlling the film thickness in this manner, even when the electrode is thickened (for example, up to about 800 nm) in order to obtain a good electrical resistivity, a good reflectance and fine workability can be ensured.

Next, the present inventors examined the influence of the component composition of the first layer (Al alloy film) and the second layer (Ag alloy film) constituting the electrode on the reflectance, fine workability, and electrical resistivity. First, regarding the first layer (Al alloy film), various alloy elements were added and the relationship with the above characteristics was examined. As shown in Table 2, rare earth elements, Si, Cu, Ge, Ti, Ta, W , And Nb were found to be effective in improving fine workability. Moreover, when adding these alloy elements, there existed preferable content with respect to a reflectance or an electrical resistivity. That is, the pure Al film containing no alloy element (No. 21) had good electrical resistivity but low reflectivity and could not satisfy the reflectivity required for the reflective electrode. Moreover, even when the above alloy elements were added, it was found that when the content was too large, the electrical resistivity deteriorated, the reflectance of the Al alloy film decreased, and the reflectance of the reflective electrode also decreased ( No. 25, 29, 32).

As for the second layer (Ag alloy film), as in the first layer (Al alloy film), various alloy elements were added and the relationship with the above characteristics was examined. , Bi, Cu, Pd, Pt, Au, Zn, and In were found to be effective in improving fine workability. In addition, these alloy elements have preferable contents in relation to reflectance and electrical resistivity. That is, the pure Ag film to which no alloy element is added (No. 51; an example simulating the adhesion layer of Patent Document 1) has a low reflectance and cannot satisfy the reflectance required for the reflective electrode. In addition, even when the above alloy elements were added, it was found that when the content was too large, the electrical resistivity decreased and the reflectance also decreased (No. 55, 60, 64, 70, 74). ).

From these experimental results, it has been found that the electrical resistivity tends to be improved by increasing the film thickness, and that the fine workability is improved by adding a specific alloy element. On the other hand, the present inventors may deteriorate the electrical resistivity and reflectivity depending on the alloy element added to the first layer (Al alloy film) or the second layer (Ag alloy film) and the content thereof. For this reason, it has been found as a result of experiments that the alloy elements and their contents need to be appropriately controlled. And in this invention, based on such a result, it prescribed | regulated about the alloy element and its content so that it may mention later.

In addition, as a characteristic of the electrode according to the present invention, the electrical resistivity is preferably about 7.0 μΩcm or less, more preferably 5 μΩcm or less.

Hereinafter, electrodes used in the display device or the input device according to the present invention will be described.

(Configuration of electrode)
An electrode used for a display device or an input device is composed of a laminated film including a first layer made of an Al alloy formed on the substrate side and a second layer made of an Ag alloy formed thereabove. .

The laminated film of the present invention preferably has a two-layer structure in which the first layer (Al alloy film) and the second layer (Ag alloy film) are laminated in this order from the substrate side.

The laminated film of the present invention is preferably a laminated film composed of the first layer (Al alloy film) and the second layer (Ag alloy film), but is not limited thereto, and an arbitrary layer (third layer) is formed. May be included. Therefore, an arbitrary third layer may be formed between the first layer (Al alloy film) and the second layer (Ag alloy film). Examples of the third layer include an adhesion improving film that contributes to improving the adhesion between the first layer (Al alloy film) and the second layer (Ag alloy film).

(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, if it exceeds 800 nm, the fine workability deteriorates and the coverage of the upper layer film (passivation film or the like) deteriorates, causing problems such as faults. 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. According to the present invention, even if the electrode is a thick film as described above, good electrical resistivity, reflectance, and fine workability can be exhibited.

(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 (Ag alloy film) and plays a role as an etching rate control layer during wet etching. In order to exhibit such an effect, the thickness of the first layer (Al alloy film) is preferably 50 nm or more, more preferably 100 nm or more. On the other hand, when the film thickness of the first layer (Al alloy film) becomes too thick, the film thickness of the second layer (Ag alloy film) becomes too thin in relation to the film thickness of the electrode, and the reflectance decreases. . Therefore, the film thickness of the first layer (Al alloy film) is preferably 650 nm or less, and more preferably 450 nm or less.

(Film thickness of second layer (Ag alloy film))
The second layer (Ag alloy film) plays a role as a reflective film particularly in the reflective electrode. In order to ensure high reflectance, the film thickness of the second layer needs to be 60 nm or more, preferably 90 nm or more, and more preferably 100 nm or more. On the other hand, if the film thickness of the second layer (Ag alloy film) is too thick, the etching amount during wet etching increases, and a desired wiring width cannot be obtained, resulting in poor fine workability. Therefore, the film thickness of the second layer needs to be 480 nm or less, preferably 400 nm or less, more preferably 300 nm or less.

The relationship between the film thicknesses of the first layer (Al alloy film) and the second layer (Ag alloy film) is not particularly limited. The film thicknesses of the first layer (Al alloy film) and the second layer (Ag alloy film) may be the same or different. If they are different, the first layer (Al alloy film) may be thicker or thinner than the second layer (Ag alloy film). In order to achieve more accurate microfabrication, the film thickness of the first layer (Al alloy film) is made larger than the film thickness of the second layer (Ag alloy film) (first layer> second layer), Or it is preferable to set it as the same film thickness (1st layer = 2nd layer). That is, the thickness of the first layer (Al alloy film) is preferably set to be equal to or greater than the thickness of the second layer (Ag alloy film) (first layer ≧ second layer).

The film thickness ratio of the second layer (Ag alloy film) to 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 second layer (Ag alloy film) decreases, the desired reflectance cannot be obtained. Therefore, the film thickness ratio of the second layer (Ag alloy film) needs to be 10% or more, preferably 15 % Or more, more preferably 20% or more. On the other hand, if the ratio of the second layer (Ag alloy film) becomes too high, the above-mentioned etching rate control effect by the first layer (Al alloy film) cannot be sufficiently obtained, and the amount of etching during wet etching increases, resulting in high accuracy. Fine processing becomes difficult. Therefore, the film thickness ratio of the second layer (Ag alloy film) needs to be 70% or less, preferably 50% or less, more preferably 40% or less, and further preferably 30% or less.

In order to exhibit the etching rate control effect of the first layer (Al alloy film), the film thickness ratio of the first layer (Al alloy film) needs to be 30% or more, preferably 50% or more. More preferably, it is 60% or more, and still more preferably 70% or more. The upper limit of the film thickness ratio of the first layer (Al alloy film) is not particularly limited, and may be defined in relation to the film thickness ratio of the second layer (Ag alloy film).

(Component composition of the first layer (Al alloy film))
In the present invention, the first layer (Al alloy film) contains the following alloy elements in a predetermined range in order to exhibit good reflectance, electrical resistivity, and fine workability while increasing the thickness of the electrode. There is a need.

The alloy element added to the Al alloy is at least one selected from the group consisting of [(1-A) rare earth element 0.05 to 1.0 atomic%, (1-B) Si, Cu, and Ge. .5 to 1.5 atomic%, (1-C) at least one selected from the group consisting of Ti, Ta, W and Nb is at least one selected from the group consisting of 0.05 to 0.7 atomic%] It is. These elements may be added alone or in combination of any two or more. That is, any one of the (1-A) group, the (1-B) group, and the (1-C) group may be used alone, or any combination of two groups or all (three groups). ) May be used in combination. Moreover, the element which comprises each group can be used individually or in combination with arbitrary 2 or more types.

In addition, the content of each group is a single content when it is included alone, and is a total amount when it includes a plurality of elements. The same applies to the second layer (Ag alloy film).

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

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 percent of rare earth elements
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 effects, the rare earth element content is 0.05 atomic% or more, preferably 0.1 atomic% or more, more preferably 0.15 atomic% or more. From the viewpoint of suppressing the coarsening of the structure, the higher the content of the rare earth element, the better. However, if the content is too large, the electrical resistivity deteriorates and the reflectivity may also decrease. Therefore, the content is 1.0 atomic% or less, preferably 0.8 atomic% or less, more 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) 0.5 to 1.5 atomic% of at least one selected from the group consisting of Si, Cu, and Ge
Si, Cu, and Ge are elements that contribute 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 content of at least one selected from the group consisting of Si, Cu, and Ge is 0.5 atomic% or more, preferably 0.6 atomic% or more, more preferably 0.00. 7 atomic% or more. From the viewpoint of suppressing the coarsening, the higher the content of Si, Cu, and Ge, the better. However, if the content is too large, the electrical resistivity may deteriorate and the reflectance may also decrease. Therefore, the content is 1.5 atomic% or less, preferably 1.2 atomic% or less, more preferably 1.0 atomic% or less. Among these, a preferable element is Cu.

(1-C) 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 reduction in reflectance by suppressing the coarsening of the structure, like the rare earth elements, Si, Cu, and Ge. In order to exert such an effect, the content of at least one selected from the group consisting of Ti, Ta, W and Nb is 0.05 atomic% or more, preferably 0.1 atomic% or more, more preferably 0. .15 atomic% or more. From the viewpoint of suppressing the coarsening, the higher the content of Ti, Ta, W and Nb, the better. However, if the content is too large, the electrical resistivity may deteriorate and the reflectance may also decrease. Therefore, the content is 0.7 atomic% or less, preferably 0.5 atomic% or less, more preferably 0.4 atomic% or less. Among these, preferred elements are Ti and Ta.

As the component composition of the preferred first layer (Al alloy film) containing the alloy elements of groups (1-A) to (1-C), Al-0.2Nd and Al-0.2Nd-0.3Ta are used. Illustrated.

(Component composition of the second layer (Ag alloy film))
In the present invention, the component composition of the second layer (Ag alloy film) is not particularly limited, and the conventionally used component composition of the Ag alloy film can be adopted. However, in order to exhibit good reflectivity, electrical resistivity, and fine workability while increasing the thickness of the electrode, it is preferable to contain the following alloy elements in a predetermined range.

The second layer is preferably 0.05 to 1.0 atom% of [(2-A) rare earth element and 0.05 to 1.0 atom of (2-B) Bi and / or Cu as an alloy element. %, (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 At least one selected from the group consisting of [atomic%]. These elements may be added singly or in combination of two or more kinds as in the case of the first layer (Al alloy film). Further, the content of each group is a single content or a total amount as described above.

In relation to the above effects, as a more preferable embodiment, the Ag alloy is adjusted so that 98 atomic% or more and 99.98 atomic% or less of the Ag alloy is Ag. If the Ag content is too low, the reflectance of the Ag alloy film may be lowered.

The Ag alloy constituting the second layer preferably contains the above elements, with the balance being Ag and inevitable impurities.

(2-A) 0.05 to 1.0 atomic% of rare earth elements
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 effects, the rare earth element content 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 above effect, the higher the content of the rare earth element, the better. However, if the content is too large, the reflectance may decrease instead. Therefore, the content 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.

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 effects, the Bi and / or Cu content 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 above effects, the higher the Bi and Cu content, the better. However, if the content is too high, the reflectance may decrease instead. The content of 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, the content of 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 atomic% or more. From the viewpoint of improving the effect, the higher the content of Pd, Pt, and Au, the better. However, if the content is too large, the reflectance may be lowered instead. Therefore, the content is preferably 1.5 atomic percent or less, more preferably 1.0 atomic percent or less, and still 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 exert such an effect, the content of 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, the higher the Zn and In contents, the better. However, if the content is too high, the reflectivity may be lowered. Therefore, the content is preferably 1.5 atomic percent or less, more preferably 1.3 atomic percent or less, and even more preferably 1.1 atomic percent or less. Among these, a preferable element is Zn.

As a preferred component composition of the second layer (Ag alloy film) containing the alloy elements of groups (2-A) to (2-D), Ag-0.3Bi-0.5Nd is exemplified.

(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) to (1-C) constituting the first layer (Al alloy film) Use of a sputtering target is useful. Specifically, at least one selected from the group consisting of [(1-A) rare earth element 0.05 to 1.0 atomic%, (1-B) Si, Cu, and Ge is 0.5 to 1. Al containing at least one selected from the group consisting of 0.05 to 0.7 atomic%] at least one selected from the group consisting of 5 atomic%, (1-C) Ti, Ta, W, and Nb An alloy sputtering target is desirable.

Basically, if an Ag alloy sputtering target containing these elements and having the same composition as the desired Al alloy film is used, an Al alloy film having a desired component composition can be formed without fear of composition deviation. .

However, it is not necessary for one sputtering target to contain all the elements corresponding to the component composition of the Al alloy film. Simultaneous sputtering (co-sputtering) of a sputtering target containing a predetermined amount of an element is also useful for forming an Al alloy film having a desired component composition.

The method for producing the Al alloy sputtering target includes 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 uniformity of the composition and 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 (Ag alloy film))
As a method for forming the second layer (Ag alloy film) constituting the reflective electrode, various film forming methods can be employed as in the case of the first layer (Al alloy film). However, for the same reason as the first layer (Al alloy film), it is desirable to form the second layer (Ag alloy film) using a sputtering target by a sputtering method.

When forming the second layer (Ag alloy film) 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) rare earth element is 0.05 to 1.0 atomic%, (2-B) Cu is 0.05 to 1.0 atomic%, and / or Bi is 0.25 to At least one selected from the group consisting of 5.0 atomic% (2-C) Pd, Pt and Au is 0.1 to 1.5 atomic%, and (2-D) Zn and / or In is 0.1 to An Ag alloy sputtering target containing at least one selected from the group consisting of 1.5 atom%] may be used.

Basically, if an Ag alloy sputtering target containing these elements and having the same composition as the desired second layer (Ag alloy film) is used, there is no risk of composition deviation and an Ag alloy film having a desired component composition can be obtained. Can be formed. 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 amount of Bi in the Ag alloy film is contained in the sputtering target. preferable. Corresponding to the Bi content in the film, the Bi content is preferably 0.25 atomic% or more, more preferably 0.35 atomic% or more, and further preferably 0.5 atomic% or more. Is 5.0 atomic percent or less, more preferably 3.5 atomic percent or less, and even more preferably 2.5 atomic percent or less.

However, it is not necessary for one sputtering target to contain all the elements corresponding to the component composition of the Ag alloy film. Simultaneous sputtering (co-sputtering) of a sputtering target containing a predetermined amount of an element is also useful for forming an 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.

The second layer (Ag alloy film) may be formed by sputtering after the first layer (Al alloy film) is formed by sputtering.

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

The shape of the Al alloy sputtering target and the Ag alloy sputtering target is processed into an arbitrary shape (square plate shape, circular plate shape, donut plate shape, etc.) according to the shape and structure of the sputtering apparatus. Is included.

As described above, the first layer (Al alloy film) and the second layer (Ag alloy film) constituting the laminated film which is a characteristic part of the present invention have been described. Hereinafter, an organic EL element in which an electrode used for a display device or an input device using a laminated film including the first layer (Al alloy film) and the second layer (Ag alloy film) is used as a reflective electrode of the organic EL. The structure of 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.

Using the organic EL display shown in FIG. 1 as an example, an organic EL including, as a reflective electrode, an electrode composed of a laminated film including the first layer (Al alloy film) and the second layer (Ag alloy film) of the present invention. The element will be described. Although the case where this organic EL element is applied to an organic EL display will be described below, the organic EL element is not limited to application to an organic EL display, and may be applied to organic EL lighting or the like. it can. FIG. 1 shows an example of an organic EL display. In the present invention, the reflective electrode is composed of a laminated film including the first layer (Al alloy film) and the second layer (Ag alloy film), and each film thickness of the reflective electrode, the first layer, and the second layer, And it is characterized in that the configuration of the first layer is appropriately controlled. The other configuration is not limited to the configuration shown in FIG. 1, and a known configuration usually used in the field of organic EL displays can be adopted. 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. Via the contact hole 5, 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 electrically connected.

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

Next, an organic layer 9 is formed on the second layer (Ag alloy film) 7. In addition to the organic light emitting layer, the organic layer 9 may include, for example, a hole transport layer and an electron transport layer. Further, a cathode electrode 10 is formed on the organic layer 9. In the case of FIG. 1, the material constituting the cathode electrode 10 is not particularly limited and can be constituted by a conventionally used material.

In the said organic EL display, since the light radiated | emitted from the organic light emitting layer in the organic layer 9 was reflected efficiently by the reflective anode electrode (especially 2nd layer (Ag alloy film) 7) of this invention, it was excellent. Light emission brightness can be realized. The reflective electrode (first layer (Al alloy film) 6 + second layer (Ag alloy film) 7) should have a higher reflectance, and generally 90% or more, preferably 92% or more is required. .

Further, the higher the hole injection property to the organic layer 9 is, the more preferable the reflective anode electrode is.

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 electrodes of the display device of the present invention described above can be used as electrodes of various display devices (including input devices). Examples of applicable electrodes include a gate electrode for a thin film transistor and a source-drain electrode (source electrode and drain electrode) in the liquid crystal display (LDC) illustrated in FIG. 2, for example, an organic EL display (OELD) illustrated in FIG. The gate electrode for the thin film transistor, the source-drain electrode, for example, the cathode electrode in the field emission display (FED) illustrated in FIG. 4, and the gate electrode, for example, the anode electrode in the fluorescent vacuum tube (VFD) illustrated in FIG. An address electrode in the plasma display (PDP) illustrated in FIG. 6, for example, a back electrode in the inorganic EL display illustrated in FIG.

In FIG. 2, the transparent electrode is connected to the liquid crystal. In FIG. 2, semiconductor silicon, a gate insulating film, and a gate electrode that are in contact with a source electrode and a drain electrode described later are formed on a glass substrate via an insulating film. Then, a source electrode and a drain electrode are disposed via an insulating protective film, and a transparent electrode that is in contact with the drain electrode is disposed via an insulating protective film.

In FIG. 3, the anode electrode is connected to the organic layer. In FIG. 3, semiconductor silicon, a gate insulating film, and a gate electrode that are in contact with a source electrode and a drain electrode described later are formed on a glass substrate via an insulating film. Then, the source electrode and the drain electrode are disposed via the insulating protective film, and the anode electrode that is in contact with the drain electrode is further disposed via the insulating protective film.

In FIG. 4, a cathode electrode and a resistance layer are laminated on a glass substrate. In addition, an emitter separated by a stacked insulating layer and a gate electrode is disposed while being sealed by the seal layer. Above that, a phosphor layer partitioned by a black matrix, a transparent electrode, and a glass substrate are further laminated.

In FIG. 5, an insulating film is laminated on a glass substrate. Then, the anode wiring, the anode electrode, and the phosphor are further laminated while being sealed by the seal layer. A grid electrode is disposed on the anode electrode, a filament is disposed thereon, and a transparent electrode and a surface glass substrate are further laminated.

In FIG. 6, an address electrode and a dielectric layer are formed on the rear glass substrate. A plurality of phosphor layers separated by barrier ribs are formed on the dielectric layer, and a dielectric layer, a display electrode, and a surface glass substrate are laminated thereon.

In FIG. 7, a back electrode, an insulating layer, a phosphor layer, a transparent electrode, and a surface glass substrate are laminated on a back glass substrate.

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 having no display device such as a touch pad. Specifically, an input device for operating the device by combining the various display devices and the position input means and pressing a display on the screen, or a display device 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 (for example, various electrodes described above) of an input device that operates the above. As the position input means, various known operation principles such as a matrix switch, a resistance film method, a surface acoustic wave method, an infrared method, an electromagnetic induction method, and a capacitance method can be employed.

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.

[First embodiment]
Hereinafter, the first invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples as a matter of course, and appropriate modifications are made within a range that can meet the purpose described above and below. Of course, it is also possible to implement them, and they are all included in the technical scope of the present invention.

(Film formation)
A sputtering target (disk type with a diameter of 4 inches) having the same component composition as the first layer (Al alloy film: the balance is Al and inevitable impurities) having the component composition shown in Tables 1 to 3 was prepared. Using this sputtering target, a first layer was formed on a glass substrate (non-alkali glass, plate thickness 0.7 mm, diameter 4 inches) under the following sputtering conditions using a DC magnetron sputtering apparatus. Subsequently, by using a sputtering target (disk shape with a diameter of 4 inches) having the same component as the second layer (Ag alloy film: the balance is Ag and inevitable impurities) having the composition shown in Tables 1 to 3, the following sputtering conditions are used. Then, a second layer was formed immediately above the first layer to prepare a sample. In Table 2, No. The first layer of No. 21 is a pure Al sputtering target. For the second layer 51, a pure Ag sputtering target was used. Further, the Bi content in the target was set to be 5 times the Bi content in the second layer (Ag alloy film). For example, No. 2 in Table 2. In No. 21, a second layer (Ag alloy film) of Ag-0.1 atomic% Bi-1.0 atomic% Zn is formed using a sputtering target of Ag-0.5 atomic% Bi-1.0 atomic% Zn. did.

The composition of the first layer (Al alloy film) and the second layer (Ag alloy film) after film formation was confirmed by inductively coupled plasma (ICP) mass spectrometry. In the table, the contents in the “first layer” and the “second layer” are both atomic%.

(Al alloy sputtering conditions)
・ Substrate temperature: room temperature ・ Ar gas flow rate: 30 sccm
Ar gas pressure: 2 mTorr
・ Sputtering power: 260W
Ultimate vacuum: 3 × 10 ⁻⁶ Torr
(Ag alloy sputtering conditions)
・ Substrate temperature: room temperature ・ Ar gas flow rate: 30 sccm
Ar gas pressure: 2 mTorr
・ Spatter power: 130W
Ultimate vacuum: 3 × 10 ⁻⁶ Torr

(Measuring method of film thickness)
The film thicknesses of the first layer (Al alloy film) and the second layer (Ag alloy film) were measured with a stylus type step meter (manufactured by KLA Tencor, Alpha-step). A total of three film thicknesses were measured 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). The film thickness of the first layer (Al alloy film) and the film thickness of the second layer (Ag alloy film) were summed to obtain the film thickness of the laminated film (“total” in the table).

(Processability evaluation)
A 10 μm wide line-and-space resist pattern was formed on the prepared sample (laminated film), and the etching processability was evaluated. Specifically, the laminated film is immersed in a mixed acid etching solution (phosphoric acid: nitric acid: acetic acid: water = 50: 0.2: 30: 19.8) after heating to 40 ° C., etching completion time + 20 seconds (over) Etching was performed during the etching time. The wiring pattern dimension after etching was observed with an optical microscope (1000 times magnification), and the wiring dimension was measured to evaluate side etching. In this example, evaluation was made according to the following criteria, and ◎ or ○ was determined to be acceptable (good etching property) and x was determined to be unacceptable (“fine workability” in the table).
◎: 9 μm or more ○: 8 μm or more, less than 9 μm ×: less than 8 μm

(Measurement of reflectance)
Based on JIS R 3106, visible light reflectance was measured with a spectrophotometer (manufactured by JASCO Corporation: visible / ultraviolet spectrophotometer “V-570”) using light having a wavelength of 380 to 780 nm with a D65 light source. Specifically, the reflectance was determined as follows from the reflected light intensity (measured value) of the prepared sample with respect to the reflected light intensity of the reference mirror.
“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 and “×” was determined to be unacceptable.
○: 90% or more ×: less than 90%

(Electric resistivity)
The electrical resistivity was measured using a sample formed in a line and space pattern having a width of 10 μm on the laminated film. Specifically, the electrical resistivity was measured by a commonly used four-terminal method. In this example, evaluation was made according to the following criteria, and ○ was determined to be acceptable and × was determined to be unacceptable.
○: 7 μΩcm or less ×: More than 7 μΩcm

The test results are shown in Tables 1-3.

Table 1 shows the results of investigating the influence on the reflectivity and fine workability by changing only the film thickness with the same component composition of the first layer (Al alloy film) and the second layer (Ag alloy film). It is. Table 1 shows the following.

No. 1 and No. No. 2 has the same total film thickness of 100 nm, but the second layer (Ag alloy film) is thin. In 1 (50 nm), the reflectance decreased. From this, it can be seen that if the second layer (Ag alloy film) is at least 60 nm or more, a desired reflectance can be obtained.

Note that focusing only on the reflectance, the reflectance was good when the thickness of the second layer (Ag alloy film) was 60 nm or more (No. 2 to 12).

No. 12 is within the range of the total film thickness defined in the present invention (800 nm or less), but exceeds the upper limit (480 nm or less) of the film thickness of the second layer (Ag alloy film), and the second layer (Ag alloy film). This is an example of a high film thickness ratio. In this example, since the film thickness ratio of the first layer (Al alloy film) was less than 30% (the ratio of the second layer (Ag alloy film) was high), the etching rate could not be appropriately controlled with the Al alloy film. The fine workability deteriorated.

No. 5 and no. 9 is an example in which the total film thickness defined in the present invention and the film thickness of the second layer (Ag alloy film) are satisfied, but the film thickness ratio of the second layer (Ag alloy film) is high. These examples are also No. Since the film thickness ratio of the first layer (Al alloy film) is less than 30% (the ratio of the second layer (Ag alloy film) is high), the etching rate cannot be controlled properly and the fine workability deteriorates. did.

When the thickness of the first layer (Al alloy) is larger than that of the second layer (Ag alloy film) (first layer thickness> second layer thickness), it is even more accurate. Etching process (“fine workability” is ◎) (No. 3, 4, 7, 8).

From the above results, in order to satisfy the reflectance and fine workability, not only the film thickness of the second layer (Ag alloy film) is controlled (No. 1, No. 12), but also the total film thickness of the laminated film and It can be seen that the Ag alloy film thickness ratio needs to be controlled within a predetermined range (No. 5, 9, 12).

Table 2 shows the composition of the second layer (Ag alloy film), the film thickness, and the ratio of the Ag alloy film thickness, and the component composition of the first layer (Al alloy) is appropriately changed. It is the result of investigating the influence on the property and electrical resistivity. Table 2 shows the following.

No. Reference numeral 21 is an example in which pure Al not containing a compound element is used as the first layer. In this example, both electrical resistivity and fine workability were good, but the reflectance was low. On the other hand, when the alloy element contained at least about the lower limit defined in the present invention (No. 22, 27, 30, 33), a predetermined reflectance was obtained. Therefore, it can be seen that it is effective to contain the alloy element in the first layer (Al alloy film).

No. 22 to 25 are examples in which the content of the alloy element in the first layer (Al alloy film) is changed. Among these, if the content of the alloy element is within a predetermined range, good results can be obtained in terms of reflectance, fine workability, and electrical resistivity (No. 22 to 24), but the content of the alloy element is When it increased too much, the reflectance and electrical resistivity deteriorated (No. 25). Similar results are shown in No. 27-29 and 30-32, it can be seen that if the content of the alloy element contained in the first layer (Al alloy film) becomes too large, the reflectance and electrical resistivity will be adversely affected.

In addition, if the alloy element of a 1st layer (Al alloy film) is in a predetermined range, even if it combines several alloy elements (No. 38), it turns out that the said desired effect can be show | played.

Table 3 shows the composition of the first layer (Al alloy film), the film thickness, and the Ag alloy film thickness ratio, and the component composition of the Ag alloy is changed as appropriate. These are the reflectivity, fine workability, and electrical resistivity. It is the result of investigating the influence on the. Table 3 shows the following.

No. 51 is an example in which pure Ag containing no alloying elements is used as the second layer. In this example, both electrical resistivity and fine workability were good, but the reflectivity was low. On the other hand, when the alloy element contained at least about the lower limit specified in the present invention (No. 52, 57, 61, 67, etc.), a predetermined reflectance was obtained. Therefore, it can be seen that it is effective to contain the alloy element in the second layer (Ag alloy film).

No. 52 to 55 are examples in which the content of the alloy element (Nd) in the second layer (Ag alloy film) is changed. Among these, if the content of the alloy element is within a predetermined range, good results can be obtained in terms of reflectance, fine workability, and electrical resistivity (No. 52 to 54). When it increased too much, the reflectance and the electrical resistivity deteriorated (No. 55). Similar results are shown in No. 57-60, 61-64, 67-70, 71-74, and when the content of the alloy element contained in the second layer (Ag alloy film) becomes excessive, the reflectance and the electrical resistivity It can be seen that it adversely affects

The alloy element of the second layer (Ag alloy film) can achieve the desired effect even if a plurality of alloy elements are combined (No. 75 to 82) as long as they are within a predetermined range.

[Second invention]
Hereinafter, the second invention will be described in detail.

The inventors of the present invention made further studies to solve the above problems. As a result, the inventors of the present invention have an electrode used for a display device or an input device, in order from the substrate side, a first layer made of an Al alloy and an oxide or nitride of an Al alloy formed thereabove. A laminated film including a second layer and a third layer made of an Ag alloy formed above the second layer (the first layer, the second layer, and the third layer may be in direct contact with each other) And the film thickness of the electrode and the thickness of each layer constituting the electrode may be appropriately controlled, and the second invention has been completed.

The background to the second invention is as follows. First, for the problem of the conventional Ag alloy film (single layer), that is, the problem that it is difficult to perform fine processing with high etching accuracy during patterning by wet etching using a resist as a mask, the Al film and the Ag alloy film It is known that the etching rate can be adjusted and solved by using a laminated structure (Patent Document 1). This is because the Al film has an etching rate control function because the etching rate of the Al film is slower than the etching rate of the Ag alloy film. According to this technique, the electrode has a laminated structure of an Ag alloy film and an Al film, so that the etching rate can be adjusted, excessive etching of the Ag alloy film can be suppressed, and the dimensions are processed with high accuracy. be able to.

In recent years, however, the electrodes of a display device have been required to have conflicting characteristics such as miniaturization of wiring and suppression of wiring resistance. Furthermore, a reflective electrode used for an organic EL display or the like is required to have high reflectance in addition to miniaturization of wiring and suppression of wiring resistance. Although the conventional technology as disclosed in Patent Document 1 can etch the wiring with high accuracy, the Ag alloy film of the target anode is as thin as 50 to 80 nm, so a stable high reflectance is ensured. It was also difficult to do. Furthermore, although the Al film has the above-described etching rate control function, it does not have sufficient reflectivity, and it has been difficult to ensure high reflectivity.

As a result of investigations by the present inventors, the first layer provided on the substrate side is formed of pure Al (or Al oxide or Al intermetallic compound) in order to ensure good fine workability while considering the reflectance. In some cases, it is difficult to form the first layer using an Al alloy film.

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

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. It has been found that providing a layer (Al alloy oxide film or nitride film) is effective. That is, the second layer (Al alloy oxide film or nitride film) provided as an intermediate layer exhibits a function as an Al diffusion preventing layer, and the first layer (Al alloy film) to the third layer (Ag alloy). It was found that Al can be prevented from diffusing into the film), and a decrease in the reflectance of the third layer (Ag alloy film) can be suppressed.

On the other hand, when the second layer (Al alloy oxide film or nitride film) is interposed, an oxide or nitride insulating layer is formed, which may cause a problem that the contact resistance increases. It was found that by appropriately controlling the film thickness of the two layers, a good contact resistance can be obtained, and a low wiring resistance can be achieved while exhibiting the above diffusion preventing effect.

As for the effect of the formation of the intermediate layer, the present inventors made the first layer (Al alloy film), the second layer (Al alloy oxide film or nitride film), the third layer (Ag alloy film) A reflective electrode (laminated film) laminated in order was prepared, and the reflectance, fine workability (dimensional accuracy when patterning, presence of residue), and contact resistance were examined. As a result, the following knowledge was obtained from Table 4 of Examples described later.

First, No. 4 in Table 4. It was found that when the second layer (Al alloy oxide film or nitride film) was not provided as in 101, Al diffusion could not be prevented and the reflectance of the reflective electrode deteriorated.

On the other hand, providing the second layer (Al alloy oxide film or nitride film) exhibits a diffusion preventing effect and improves the reflectance (No. 102 to 104), but if the film thickness becomes too thick. There was a tendency for fine workability and contact resistance to deteriorate (No. 105).

From the above results, it is effective to appropriately control the thickness of the second layer (Al alloy oxide film or nitride film) in order to ensure good reflectivity, fine workability, and contact resistance. I understood.

For the third layer (Ag alloy film), No. From the comparison of 106, 107, 112, and 113, it was found that the reflectance decreases as the film thickness decreases. 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 reflectivity at the third layer (Ag alloy film) is reduced. In addition, it is considered that the reflectivity of the first layer (Al alloy film) and the second layer (Al alloy oxide film or nitride film) with respect to the transmitted light is low.

Although not described in Table 4, the reflectance of the reflective electrode increases as the thickness of the third layer (Ag alloy film) increases, but the etching rate control function by the first layer (Al alloy). However, it was found that high-precision microfabrication is difficult because of insufficient effects.

As a result of further experiments, it was found that the relationship between the film thickness ratios of the first layer (Al alloy film) and the third layer (Ag alloy film) affects the fine workability. That is, when the film thickness ratio of the third layer (Ag alloy film) exceeds 70%, the third layer (Ag alloy film) to be etched increases, so that the fine workability deteriorated. This tendency occurred when the ratio of the electrode (laminated film) to the film thickness exceeded 70% regardless of the film thickness of the third layer (Ag alloy film).

From these results, the first layer (Al alloy film), the second layer (Al alloy oxide film or nitride film), the third layer are required to ensure good contact resistance, fine workability, and reflectivity. In addition to simply laminating (Ag alloy film), it is necessary to appropriately control the ratio of the thickness of the third layer (Ag alloy film) to the total thickness of the laminated film within a predetermined film thickness range. I found out. By properly controlling the film thickness in this way, the present inventors can secure the above characteristics even when the electrode is thickened (for example, up to about 800 nm) in order to obtain good wiring resistance. The headline, the present invention has been reached.

Next, the inventors of the present invention have component compositions of the first layer (Al alloy film), the second layer (Al alloy oxide film or nitride film), and the third layer (Ag alloy film) constituting the electrode. The effects on reflectivity, fine workability, and contact resistance were investigated.

First, regarding the first layer (Al alloy film), various alloy elements were added and the relationship with the above characteristics was examined. Among the alloy elements, particularly rare earth elements, Ti, Ta, W, and Nb were reflected. It was found to be suitable for improving the rate, fine workability, and contact resistance (see Table 5).

In addition, when these alloy elements were added, there was a preferable content in relation to reflectance and contact resistance. That is, the pure Al film not containing an alloy element (No. 121 in Table 5) had good fine workability and contact resistance, but could not satisfy the reflectance required for the reflective electrode. In addition, even when the above alloying element was added, it was found that if the content was too large, the alloy component remained as a residue in the first layer after etching (Al alloy film), and the fine workability deteriorated (Table 5). No. 125, 129, 132).

If other requirements are satisfied and the second layer has an appropriate film thickness, an Al alloy oxide film (No. 122 to 124, No. 126 to 128 in Table 5), an Al alloy nitride Any of the films (Nos. 130, 131, and 133 in Table 5) can provide desired reflectance, fine workability, and contact resistance.

Furthermore, the present inventors also examined the relationship with the above characteristics by adding various alloy elements to the third layer (Ag alloy film). As a result, it was found that among the alloy elements, rare earth elements, Bi, Cu, Pd, Pt, Au, In, and Zn are particularly suitable for improving the reflectance and contact resistance (see Tables 6A and 6B).

In addition, when these alloy elements were added, there was a preferable content in relation to reflectance and contact resistance. That is, the pure Ag film to which no alloy element was added (No. 201, No. 233 in Table 6A) had low reflectance, and could not satisfy the reflectance required for the reflective electrode. Even when the above alloying elements were added, it was found that when the content was too large, the reflectance tends to decrease (for example, No. 202 → No. 205 in Table 6A).

From the experimental results shown in Tables 4, 5, 6A, and 6B, it was found that the reflectance and fine workability can be improved by appropriately controlling the alloy elements and the film thickness of the Al alloy film and the Ag alloy film. The reflectance is improved by providing a second layer (Al alloy oxide film or nitride film). However, if the second layer (Al alloy oxide film or nitride film) is too thick, contact resistance is increased. It turned out that fine workability worsened and desired wiring resistance and workability could not be obtained. And in this invention, based on such a result, it prescribed | regulated about the alloy element and its content so that it may mention later.

(Configuration of electrode)
The electrode used in 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, a second layer made of an oxide or nitride of an Al alloy formed thereon, And a third layer made of an Ag alloy formed above the second layer.

The laminated film of the present invention includes, in order from the substrate side, the first layer (Al alloy film), the second layer (Al alloy oxide film or nitride film), and the third layer (Ag alloy film). A three-layer structure laminated in this order is preferable.

The laminated film of the present invention is not limited to this, and may include an arbitrary layer (fourth layer). Therefore, the first layer (Al alloy film) and the second layer (Al alloy oxide film or nitride film), the second layer (Al alloy oxide film or nitride film) and the third layer (Ag alloy film) Between these, arbitrary 4th layer (film | membrane of arbitrary component compositions) 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, in order to exhibit good wiring resistance, reflectivity, and fine workability, the film thickness of the electrode (laminated film) needs to be in the range of 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, if it exceeds 800 nm, the fine workability deteriorates and the coverage of the upper layer film (passivation film or the like) deteriorates, causing problems such as faults. 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) reflects the light transmitted through the second layer (Al alloy oxide film or nitride film) and the third layer (Ag alloy film) and has an etching rate during wet etching. This layer plays a role as a control layer. The film thickness of the first layer (Al alloy film) is within the range of the film thickness of the electrode in relation to the second layer (Al alloy oxide film or nitride film) or the third layer (Ag alloy film). What is necessary is just to adjust suitably so that it may become. The film thickness of the first layer (Al alloy film) is preferably 29 nm or more, more preferably 35 nm or more, and further preferably 44 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. Further, the effect of the second layer (Al alloy oxide film or nitride film) cannot be sufficiently obtained. Therefore, the film thickness of the first layer (Al alloy film) is preferably 729 nm or less, more preferably 629 nm or less, and further preferably 449 nm or less.

(The film thickness of the second layer (Al alloy oxide film or nitride film))
The second layer (Al alloy oxide film or nitride film) serves as an Al diffusion prevention layer from the first layer (Al alloy film) to the third layer (Ag alloy film). From the viewpoint of securing a sufficient diffusion barrier property, the film thickness needs to be 1 nm or more, preferably 2 nm or more, more preferably 3 nm or more. On the other hand, if the film thickness of the second layer (Al alloy oxide film or nitride film) becomes too thick, the ratio of the second layer having a high electrical resistivity to the entire wiring increases, so that the first layer to the first layer are increased. The contact resistance between the three layers increases, or etching residues are generated and the fine workability deteriorates. For this reason, the thickness of the second layer needs to be 10 nm or less, preferably 8 nm or less, more preferably 6 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, the film thickness of the third layer needs to be 70 nm or more, preferably 90 nm or more, more preferably 100 nm or more. On the other hand, if the film thickness of the third layer (Ag alloy film) is too thick, the etching amount during wet etching increases, and a desired wiring width cannot be obtained, resulting in deterioration of fine workability. Therefore, the thickness of the third layer needs to be 480 nm or less, preferably 400 nm or less, more preferably 300 nm or less.

(Thickness ratio of the third layer (Ag alloy film))
The thickness ratio of the third layer (Ag alloy film) to the 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, if the ratio of the third layer (Ag alloy film) becomes too high, the above-mentioned etching rate control effect by the first layer (Al alloy film) cannot be obtained sufficiently, and the amount of etching during wet etching increases, resulting in high accuracy. Fine processing becomes difficult. 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.

In order to express the effect of controlling the etching rate of the first layer (Al alloy film), the film thickness ratio of the first layer (Al alloy film) is preferably 29% or more, more preferably 40% or more. More preferably, it is 45% or more.

(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. However, in order to exhibit good reflectance, wiring resistance, and fine workability while increasing the thickness of the electrode, 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 preferable that at least one selected from the group comprises at least one selected from the group consisting 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 of the (1-A) group and the (1-B) group may be used alone, or all (two groups) may be used in combination. Moreover, the element which comprises each group can be used individually or in combination with arbitrary 2 or more types. The same applies to the sputtering target described later.

In addition, the content of each group is a single content when it is included alone, and is a total amount when it includes a plurality of elements. The same applies to the second layer (Al alloy oxide film or nitride film) and the third layer (Ag alloy film).

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

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

(1-A) 0.05 to 1.0 atomic percent of rare earth elements
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 exhibit such an effect, the rare earth element content 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 higher the content of the rare earth element, the better. However, if the content is too large, the rare earth element becomes a residue after etching, and the leakage current increases or the transmittance of the glass substrate decreases. There is. Therefore, the content is preferably 1.0 atomic% or less, more preferably 0.8 atomic% or less, and still more 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, the content of 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, More preferably, it is 0.15 atomic% or more. From the viewpoint of suppressing the coarsening, it is preferable that the contents of Ti, Ta, W, and Nb are large. However, if the content is too large, a residue is generated in the same manner as the rare earth element, resulting in an increase in leakage current and a decrease in transmittance. May occur. Therefore, the content is preferably 0.7 atomic percent or less, more preferably 0.5 atomic percent or less, and still more preferably 0.4 atomic percent or less. Among these, preferred elements are Ti and Ta.

The component composition of the preferred 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 (Al alloy oxide film or nitride film))
The alloy element added to the second layer (the oxide film or nitride film of the Al alloy) is not particularly limited, and it is possible to adopt the component composition of the Al alloy film that has been conventionally used. The component composition of the second layer and the first layer (Al alloy) may be the same or different. However, the second layer contains the same alloy elements as the first layer (Al alloy) in a predetermined range in order to exhibit good reflectivity, contact resistance, and fine workability while increasing the thickness of the electrode. It is desirable to do.

That is, the alloy element added to the second layer (Al alloy) is preferably [(1-A) 0.05 to 1.0 atomic% of rare earth element; and / or (1-B) Ti, Ta, And at least one selected from the group consisting of 0.05 and 0.7 atomic%]. The preferable range of the content of each alloy element is also the same as that of the first layer (Al alloy film). As described above, any one of the groups (1-A) and (1-B) may be used alone, or two groups may be used in combination. The elements constituting each group are as follows: Single or arbitrary 2 or more types can be used together. The same applies to the sputtering target described later. The composition ratio of the alloy elements of the second layer (Al alloy oxide film or nitride film) may be the same as or different from that of the first layer (Al alloy film). However, it is preferable that the composition ratio of the second layer is the same as that of the first layer (Al alloy film) from the viewpoint of film formation ease and manufacturing cost. The second layer (the oxide film or nitride film of the Al alloy) is only required to exhibit the effect of preventing Al diffusion. Depending on the film thickness, all the Al alloys in the second layer are not oxidized or nitrided. Also good. Preferably, the second layer is made of an oxide (eg, Al oxide and / or additive alloy oxide) or nitride (eg, Al nitride and / or additive alloy nitride) of the first layer. It is desirable to be configured.

In relation to the above effect, as a more preferable embodiment, when the total of Al and alloy elements is 100%, preferably 90 atomic% or more, more preferably 95 atomic% or more is adjusted to be Al. Is desirable.

The metal element constituting the oxide or nitride of the second layer is preferably the additive element, and the balance is Al and 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 the conventionally used component composition of the Ag alloy film can be adopted. However, in order to exhibit good reflectivity, wiring resistance, and fine workability while increasing the thickness of the electrode, 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) 0.05 to 1.0 atomic% of Bi and / or Cu; C) 0.1 to 1.5 atomic% of at least one selected from the group consisting of Pd, Pt, and Au; and (2-D) 0.1 to 1.5 atomic% of Zn and / or In] 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. In addition, the elements constituting each group may be used alone or in combination of two or more, and the content of each group is a single content or a total amount as described above. The same applies to the sputtering target described later.

In relation to the above effects (particularly reflectance), as a more preferred embodiment, the Ag alloy is adjusted so that 98 atomic% or more and 99.98 atomic% or less of the Ag alloy become Ag.

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

(2-A) 0.05 to 1.0 atomic% of rare earth elements
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 effects, the rare earth element content is preferably 0.05 atomic% or more, more preferably 0.1 atomic% or more, and still more preferably 0.15 atomic% or more. From the viewpoint of improving the above effect, the higher the content of the rare earth element, the better. However, if the content is too high, the reflectance may be lowered. Therefore, the content 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.

(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 exhibit such an effect, the content of mBi 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, the higher the Bi and Cu contents, the better. However, if the content is too large, the reflectance may be lowered. The content of 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, the content of 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 Is 0.2 atomic% or more. From the viewpoint of improving the above effect, the higher the content of Pd, Pt, and Au, the better. However, if the content is too large, the reflectance may be lowered. Therefore, the content is preferably 1.5 atomic percent or less, more preferably 1.0 atomic percent or less, and still 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 exert such an effect, the content of 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 better that the contents of Zn and In are larger. However, if the content is too large, the reflectance may be lowered. Therefore, the content is preferably 1.5 atomic percent or less, more preferably 1.3 atomic percent or less, and even more preferably 1.1 atomic percent or less. Among these, a preferable element is Zn.

As the component composition of the preferred third layer (Ag alloy film) containing the alloy elements of the groups (2-A) to (2-D), Ag-0.3 atomic% Bi-0.5 atomic% Nd is used. Illustrated.

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. .05-0.7 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, it is not necessary for one sputtering target to contain all the elements corresponding to the component composition of the first layer (Al alloy film). Simultaneous sputtering (co-sputtering) of a sputtering target containing a predetermined amount of an element is also useful for forming a first layer (Al alloy film) having a desired component composition.

As a method for producing the Al alloy sputtering target, a vacuum melting method or a powder sintering method may be mentioned. In particular, the production by the vacuum melting method is desirable because the uniformity of the composition and structure within the target surface can be ensured.

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-(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 (A1 alloy oxide film or nitride film))
As a method for forming the second layer (the oxide film or nitride film of the Al alloy film) constituting the electrode, for example, an oxygen (or nitrogen) -added sputtering method or an inert gas atmosphere such as Ar (excluding nitrogen) And a method of forming an oxide film (or nitride film) by oxygen (or nitrogen) plasma treatment or the like after the Al alloy film is formed by the sputtering method.

The component composition of the Al alloy constituting the second layer (Al alloy oxide film or nitride film) is not particularly limited, and may be the same as or different from the first layer (Al alloy film). . For example, an Al alloy sputtering target containing a predetermined amount of the elements corresponding to the above (1-A) and (1-B) may be used. From the viewpoint of manufacturing cost reduction, after the first layer (Al alloy film) is formed by the sputtering method, the second layer is subsequently formed using the Al alloy sputtering target used for forming the first layer (Al alloy film). It is preferable to form. At that time, when using an oxygen (or nitrogen) -added sputtering method, sputtering is performed with an atmosphere containing oxygen (or nitrogen) (for example, oxygen gas or nitrogen gas is added to an inert gas such as argon gas at about 10%). Thus, the second layer (Al alloy oxide film or nitride film) can be formed. When plasma processing is used, after the Al alloy film is formed, high frequency plasma is applied in an oxygen gas (or nitrogen gas) atmosphere to oxidize (or nitride) the surface of the Al alloy film. (Al alloy oxide film or nitride film) can be formed. Various known methods can be employed as such plasma treatment.

The film forming conditions in the oxygen (or nitrogen) added sputtering method are not particularly limited. However, in order to form an Al alloy oxide film or nitride film having the above-mentioned effects, it is preferable to employ the following conditions, for example.
(Oxygen-added sputtering conditions)
-Substrate temperature: Room temperature to 150 ° C
Atmospheric gas: Inert gas such as Ar + oxygen-containing gas such as O ₂ Gas flow ratio: O2-containing gas such as O ₂ / (Inert gas such as Ar + oxygen-containing gas such as O ₂ ) = 0.05- 0.5
-Gas pressure during film formation: 1.0 to 5.0 mTorr
・ Sputtering power: 100-2000W
-Ultimate vacuum: 1 x ^10-5 Torr or less (nitrogen-added sputtering conditions)
-Substrate temperature: Room temperature to 150 ° C
Atmosphere gas: Inert gas such as Ar + nitrogen-containing gas such as N ₂ Gas flow ratio: Nitrogen-containing gas such as N ₂ / (Inert gas such as Ar + Nitrogen-containing gas such as N ₂ ) = 0.05 0.5
-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 method for forming the third layer (Ag alloy film) constituting the electrode, various film forming methods can be employed as in the case of the first layer (Al alloy film). However, for the same reason as the first layer (Al alloy film), it is desirable to form the third layer (Ag alloy film) using a sputtering target by a sputtering method.

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) rare earth element is 0.05 to 1.0 atomic%; (2-B) Cu is 0.05 to 1.0 atomic%, and / or Bi is 0.25 to 5.0 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 atomic%], an Ag alloy sputtering target containing at least one selected from the group consisting of

Basically, if an Ag alloy sputtering target containing these elements and 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) can be formed. 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. It is preferable to make it contain. Corresponding to the Bi content in the film, the Bi content is preferably 0.25 atomic% or more, more preferably 0.35 atomic% or more, and further preferably 0.5 atomic% or more. Is 5.0 atomic% or less, more preferably 3.5 atomic% or less, still more preferably 2.5 atomic% or less.

It is not necessary for one sputtering target to contain all the elements corresponding to the component composition of the third layer (Ag alloy film). Simultaneous sputtering (co-sputtering) of a sputtering target containing a predetermined amount of an element is also useful for forming a third layer (Ag alloy film) having a desired component composition.

When the second layer (A1 alloy oxide film or nitride film) is formed by the sputtering method, the third layer (Ag alloy film) may be formed subsequently by the sputtering method.

In addition, the shape of the Al alloy sputtering target and the Ag alloy sputtering target may be any shape (square plate shape, circular plate shape, donut plate shape, cylindrical shape, etc.) depending on the shape and structure of the sputtering apparatus. Includes processed products.

As described above, the first layer (Al alloy film), the second layer (Al alloy oxide film or nitride film), and the third layer (Ag alloy film) constituting the laminated film, which is a characteristic part of the present invention. explained. Hereinafter, a display device or an input using a laminated film including the first layer (Al alloy film), the second layer (Al alloy oxide film or nitride film), and the third layer (Ag alloy film) will be described. The structure of the organic EL element in which the electrode used in the apparatus is used as the reflective anode electrode of the organic EL will be described.

However, the present invention is not 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.

Using the organic EL display shown in FIG. 8 as an example, the first layer (Al alloy film), the second layer (Al alloy oxide film or nitride film) and the third layer (Ag alloy film) of the present invention are used. An organic EL element including an electrode composed of a laminated film including a reflective electrode will be described. Below, the case where this organic EL element is applied to an organic EL display is demonstrated. However, the application of the organic EL element is not limited to the organic EL display, and various known configurations such as organic EL illumination can be adopted. 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. 8, a TFT 22 and a passivation film 23 are formed on a substrate 21, and a planarizing layer 24 is further formed thereon. A contact hole 25 is formed on the TFT 22. Via the contact hole 25, the source-drain electrode (not shown) of the TFT 22 and the first layer (Al alloy film) 26 constituting the reflective electrode according to the present invention are electrically connected.

Further, a second layer (Al alloy oxide film or nitride film) 27 is formed immediately above the first layer (Al alloy film) 26, and a third layer (Ag alloy film) 28 is formed immediately above. Has been. The first layer (Al alloy film) 26, the second layer (Al alloy oxide film or nitride film) 27, and the third layer (Ag alloy film) 28 can be formed by the method described above. .

Next, an organic layer 29 is formed on the third layer (Ag alloy film) 28. The organic layer 29 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 30 is formed on the organic layer 29. In the case of FIG. 8, the material constituting the cathode electrode 30 is not particularly limited and can be constituted by a conventionally used material.

In the organic EL display, light emitted from the organic light emitting layer in the organic layer 29 is efficiently reflected by the reflective anode electrodes 26 to 28 (particularly the third layer (Ag alloy film) 28) of the present invention. Excellent emission brightness can be achieved. The higher the reflectivity of the reflective electrode (first layer (Al alloy film) 26, second layer (Al alloy oxide film or nitride film) 27, third layer (Ag alloy film) 28), the better. In general, a reflectance of 90% or more, preferably 93% or more is required.

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

The electrodes of the display device of the present invention described above can be used as electrodes of various display devices (including input devices). Examples of applicable electrodes include a gate electrode for a thin film transistor and a source-drain electrode (source electrode, drain electrode) in the liquid crystal display (LDC) illustrated in FIG. 2 described with reference to the first invention, for example, illustrated in FIG. A gate electrode for a thin film transistor in an organic EL display (OELD), a source-drain electrode, for example, a cathode electrode in a field emission display (FED) illustrated in FIG. 4, and a gate electrode, for example, a fluorescent vacuum tube (VFD illustrated in FIG. 5) ), For example, an address electrode in the plasma display (PDP) illustrated in FIG. 6, for example, a back electrode in the inorganic EL display illustrated 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 having no display device such as a touch pad. Specifically, an input device for operating the device by combining the various display devices and the position input means and pressing a display on the screen, or a display device 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 (for example, various electrodes described above) of an input device that operates the above. As the position input means, various known operation principles such as a matrix switch, a resistance film method, a surface acoustic wave method, an infrared method, an electromagnetic induction method, and a capacitance method can be adopted.

[Second Embodiment]
Hereinafter, the second invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples as a matter of course, and appropriate modifications are made within a range that can meet the purpose described above and below. Of course, it is also possible to implement them, and they are all included in the technical scope of the present invention.

(Film formation)
Sputtering target (disk having a diameter of 4 inches) having the same component composition as the first layer (Al alloy film: the balance is Al and inevitable impurities) of the component composition shown in Tables 4 to 6B (all alloy component contents are atomic%) Type). And using this sputtering target, the 1st layer was formed into a film on the glass substrate (non-alkali glass, plate | board thickness 0.7mm, diameter 4 inches) on the following sputtering conditions with DC magnetron sputtering apparatus. Subsequently, using the sputtering target used for forming the first layer (Al alloy film) as it is, under the following sputtering conditions, the second layer (Al alloy oxide film or Al alloy film) is directly above the first layer (Al alloy film). Nitride film) was formed.

Subsequently, immediately above the second layer (Al alloy oxide film or nitride film), the same component as the third layer (Ag alloy film: the balance is Ag and inevitable impurities) having the composition shown in Tables 4 to 6B. A third film was formed under the following sputtering conditions using a sputtering target having a disk shape having a diameter of 4 inches to prepare a sample.

In addition, No. in Table 4 101 did not form the second layer (Al alloy film oxide film or nitride film). In Table 5, No. The first layer of 121 is a pure Al sputtering target. 201, no. A pure Ag sputtering target was used for the third layer of 233. The Bi content in the sputtering target when Bi was contained in the third layer (Ag alloy film) was set to 5 times the Bi content in the third layer (Ag alloy film). For example, No. 5 in Table 5. 121, a third layer (Ag alloy film) of Ag-0.1 atomic% Bi-1.0 atomic% Zn is formed using a sputtering target of Ag-0.5 atomic% Bi-1.0 atomic% Zn. Formed.

The composition of the first layer (Al alloy film) and the third layer (Ag alloy film) after film formation was confirmed by inductively coupled plasma (ICP) mass spectrometry. In the table, the contents in the “first layer” and “third layer” are both atomic%. The composition of the second layer (Al alloy oxide film or nitride film) is the same as that of the first layer (Al alloy film) because the same sputtering target as that of the first layer is used. I did not. Whether the second layer is formed of an Al alloy oxide film or nitride film was analyzed by XPS (X-Ray Spectroscopy, X-ray photoelectron spectroscopy). In the table, “oxide film” means an Al alloy oxide film having the same composition as the first layer Al alloy, and “nitride film” means an Al alloy having the same composition as the first layer Al alloy. This means the nitride film.

(First layer: Al alloy sputtering conditions)
・ Substrate temperature: room temperature ・ Ar gas flow rate: 30 sccm
Ar gas pressure: 2 mTorr
・ Sputtering power: 260W
Ultimate vacuum: 3 × 10 ⁻⁶ Torr

(Second layer: oxygen-added sputtering conditions)
・ Substrate temperature: room temperature ・ Ar gas flow rate: 27 sccm
・ O ₂ gas flow rate: 3 sccm
Ar gas pressure: 2 mTorr
Ultimate vacuum: 3 × 10 ⁻⁶ Torr
・ Sputtering power: 260W

(Second layer: Nitrogen-added sputtering conditions)
・ Substrate temperature: room temperature ・ Ar gas flow rate: 27 sccm
・ N ₂ gas flow rate: 3 sccm
Ar gas pressure: 2 mTorr
・ Sputtering power: 260W
Ultimate 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
Ultimate vacuum: 3 × 10 ⁻⁶ Torr

(Measuring method of film thickness)
The thicknesses of the first layer (Al alloy film), the second layer (Al alloy oxide film or nitride film), and the third layer (Ag alloy film) are measured with a stylus step meter (manufactured by KLA-Tencor, (Alpha-step). A total of three film thicknesses were measured 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). The thicknesses of the first layer (Al alloy film), the second layer (Al alloy oxide film or nitride film), and the third layer (Ag alloy film) were summed to obtain the thickness of the laminated film (Table "Total"). The film thickness ratio of the third layer was calculated from the total film thickness (“Ag alloy film thickness ratio” in the table).

(Processability evaluation)
A 10 μm wide line-and-space resist pattern was formed on the prepared sample (laminated film), and the etching processability was evaluated. Specifically, the laminated film is immersed in a mixed acid etching solution (phosphoric acid: nitric acid: acetic acid: water = 50: 0.2: 30: 19.8) after heating to 40 ° C., etching completion time + 20 seconds (over) Etching was performed during the etching time. Side etching was evaluated by observing the wiring pattern dimensions after etching with an optical microscope (1000 times magnification), measuring the wiring dimensions, and visually confirming the presence or absence of residues. In this example, evaluation was made according to the following criteria, and ◎ or ○ was determined to be acceptable (good etching property) and x was determined to be unacceptable (“fine workability” in the table).
◎: 9 μm or more and no residue ○: 8 μm or more and less than 9 μm and no residue ×: Less than 8 μm or with residue

(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 D65 light source having a wavelength of 380 to 780 nm based on JIS R 3106 (manufactured by JASCO Corporation: visible Measurement was performed using an ultraviolet spectrophotometer “V-570”. Specifically, the reflectance was determined as follows from the reflected light intensity (measured value) of the prepared sample with respect to the reflected light intensity of the reference mirror.
“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 ◯ and Δ were determined to be acceptable and × was determined to be unacceptable.
○: 93% or more △: 90% or more, less than 93% ×: less than 90%

(Contact resistance)
The laminated film wiring of the first layer (Al alloy film) and the second layer (Al alloy oxide film or nitride film) having a width of 10 μm and the single layer wiring of the third layer (Ag alloy film) are crossed. A simple Kelvin pattern was formed and the contact resistance was measured. In this example, evaluation was made according to the following criteria, and ◎, ○, and △ were determined to be acceptable, and × was determined to be unacceptable.
◎: 10 kΩ or less ○: 10 kΩ or more to 1 MΩ or less △: 1 MΩ or more to 100 MΩ or less ×: 100 MΩ or more

Tables 4 to 6B show the test results.

Table 4 shows the reflectivity by changing the film thicknesses of the first layer (Al alloy film), the second layer (Al alloy oxide film or nitride film) and the third layer (Ag alloy film). It is the result of investigating the influence on micro workability and contact resistance. Table 4 shows the following.

No. 101 is an example in which the second layer (Al alloy oxide film or nitride film) was not formed, and the reflectance was low.

No. In No. 105, since the film thickness of the second layer (Al alloy oxide film or nitride film) was too thick, desired fine workability and contact resistance could not be obtained.

No. 102 and no. 109, no. 103 and No. 110, no. 104 and no. 111, no. 106 and no. 112, no. 107 and no. 113, no. 108 and No. Reference numeral 114 is an example in which the thickness of each layer is the same, and the configuration of the second layer is different depending on whether it is an Al alloy oxide film or a nitride film. In any case, good reflectance, fine workability, and contact resistance were obtained.

Especially No. 106, 112 (30 nm) and No. 107 and 113 (200 nm) are examples in which the film thickness of the first layer (Al alloy film) was changed, and all showed good reflectance, fine workability, and contact resistance.

From the above results, in order to improve the reflectance, the second layer (Al alloy oxide film or nitride film) is provided with an appropriate film thickness, and the thickness of the third layer (Ag alloy film) is increased. Proved to be effective.

Table 5 shows the composition of the second layer (Al alloy oxide film or nitride film) and the third layer (Ag alloy film), the film thickness, and the film thickness ratio, and the composition of the first layer (Al alloy). This is a result of examining the influence of these on reflectivity, fine workability, and contact resistance. Table 5 shows the following.

No. 121 is an example in which pure Al is the first layer. In this example, both contact resistance and fine workability were good, but the reflectance was low.

No. Nos. 122 to 124, 126 to 128, 130, 131, and 133 are examples in which the preferred alloying elements of the present invention were added at appropriate contents, and the reflectivity, fine workability, and contact resistance were good.

Especially No. 133 is an example in which a plurality of preferable alloying elements of the present invention are added in an appropriate content, and reflectivity, fine workability, and contact resistance are good.

No. 125, 129, and 132 are examples in which the alloy element content is excessive. Residue of the alloy component was confirmed in the first layer (Al alloy film) after etching, and the fine workability was poor.

Tables 6A and 6B show the results of examining the influence of these on the reflectance, fine workability, and contact resistance by appropriately changing the component composition of the third layer (Ag alloy film). Tables 6A and 6B show the following.

No. 201 and No. 233 is an example in which pure Ag is the third layer. In these examples, fine workability and contact resistance were good, but the reflectivity was low.

No. Examples 202 to 204 are examples in which preferable alloy elements of the present invention are added in an appropriate content. If the alloy element content is within a predetermined range, desirable results can be obtained in terms of reflectance, fine workability, and contact resistance (No. 202 to 204). However, as the alloy element content increased, the reflectance tended to decrease (the reflectance when the Nd content was 0.2 atomic% was good (◯), but 1.0 atomic% (If yes, it was acceptable (△)).

No. 205 is an example in which the content of the alloy element is excessive, and the reflectance is lowered (impossible (x)).

The same trend is 207-No. 210 (No. 210 is an example with a high Bi content and a low reflectance). 211-No. 214 (No. 214 is an example in which the Pd content is high and the reflectance is poor). 217-No. 220 (No. 220 is an example in which the Zn content is large and the reflectance is poor). 221-No. No. 224 (No. 224 is an example in which the In content is large and the reflectance is poor). No. 234 to Table 6B. 237 (No. 237 is an example in which the Nd content is high and the reflectance is poor), 239-No. 242 (No. 242 is an example in which the Bi content is large and the reflectance is poor), 243-No. No. 246 (No. 246 is an example in which the Pd content is high and the reflectance is poor). 249-No. 252 (No. 252 is an example in which the Zn content is high and the reflectance is poor), No. 252. 253-No. 256 (No. 256 is also an example in which the In content is large and the reflectance is poor). Thereby, when the content of the alloy element contained in the third layer (Ag alloy film) is excessively increased, it is understood that the reflectance is adversely affected.

No. 206, 215, 216, 247, and 248 are examples in which the preferred alloying elements of the present invention were added in an appropriate content, and all had good reflectivity, fine workability, and contact resistance.

No. 225 to 232, No. Nos. 257 to 264 are examples in which a plurality of preferable alloy elements of the present invention were added in appropriate contents, and the reflectance, fine workability, and contact resistance were good.

[Third invention]
Hereinafter, the third invention will be described in detail.

The inventors of the present invention have made extensive studies to solve the above problems. As a result, the present inventors, in order from the substrate side, the electrodes used in the display device or the input device, the first layer made of Al alloy and (a) Mo, Mo alloy, Ti, A second layer comprising: at least one selected from the group consisting of Ti alloy, Ta, W, and Nb; and / or (b) a conductive oxide containing In oxide and / or Zn oxide; A laminated film including a third layer made of an Ag alloy formed above the second layer (the first layer, the second layer, and the third layer may be in direct contact with each other, or may not be in direct contact with each other). The present invention has been completed by finding that the film thickness of the electrode and the film thickness of each layer constituting the electrode may be appropriately controlled.

The background to the third 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 multilayer film with Al that has excellent conductivity and has excellent properties in adhesion to a base layer (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 suppression of wiring resistance. Therefore, in the conventional technique disclosed in Patent Document 1, since the thickness of the target anode is as thin as about 100 to 300 nm, 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 stable high reflectance. 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 is difficult to ensure a high reflectance because it does not have a sufficient reflectance.

As a result of investigations by the present inventors, ensuring a good wiring resistance and high reflectance even when the electrode is thickened while ensuring good adhesion, the first layer provided on the substrate side is made of pure Al ( Alternatively, it is difficult to form with an Al oxide or an Al intermetallic compound, and it has been found useful to use an Al alloy film.

Further investigations have shown that the high temperature in the process of manufacturing thin film transistors and organic EL devices, such as the formation of transparent oxide conductive films such as ITO and insulating films, simply by laminating Al alloy films and Ag alloy films. 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.

About the effect by formation of the said intermediate | middle layer, the present inventors are the reflective electrode which laminated | stacked the 1st layer (Al alloy film), the 2nd layer (diffusion prevention film), and the 3rd layer (Ag alloy film) in this order. (Laminated film) was produced. And as a result of examining reflectance and wiring resistance, the following knowledge was obtained from Table 7 of the postscript Example.

First, No. in Table 7 When the second layer (diffusion prevention film) was not provided as in 301, it was found that Al diffusion could not be prevented, and the reflectance of the reflective electrode and the wiring resistance deteriorated.

On the other hand, No. As in 302 to 304, when the thickness of the second layer (diffusion prevention film) was appropriately controlled, a sufficient diffusion prevention effect was exhibited, and good reflectance and wiring resistance were obtained.

However, no. As in 305, when the thickness of the second layer (diffusion prevention film) is too thick, the wiring resistance is deteriorated.

Such a tendency was the same even when the component composition of the second layer (diffusion prevention film) was different (Nos. 309 to 328).

No. Since the component composition of the second layer (diffusion prevention film) of 329 to 331 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 reflectivity and wiring resistance.

In addition, although the following results are not described in Table 7, it has been found that the reflectance decreases as the thickness of the third layer (Ag alloy film) decreases. 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 reflectivity at the third layer (Ag alloy film) is reduced. At the same time, the reflectance of the first layer (Al alloy film) and the second layer (diffusion prevention film) with respect to the transmitted light is considered to be lower than that of the third layer (Ag alloy film).

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), the third layer (Ag alloy film) ), The ratio of the thickness of the third layer (Ag alloy film) to the total thickness of the laminated film must be appropriately controlled within a predetermined thickness range. It was.

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 8).

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 8 Reference numeral 351 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. Reference numerals 352 to 354 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. 355 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.

No. The tendency as shown in 351 to 355 was the same even when the component composition of the second layer (diffusion prevention film) was different (Mo, Ti, ITO) (No. 359 to 363, No. 367 to 371). .

Although not shown in the table, the first layer was excellent in adhesion to the substrate regardless of the component composition, and did not peel 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. It has been found that the wiring resistance may deteriorate. Therefore, it is preferable to control appropriately the addition amount of an alloy element.

Furthermore, the present inventors also investigated the relationship between the third layer (Ag alloy film) and the above characteristics by adding various alloy elements as in the first layer (Al alloy film). As a result, it is found that, among the alloy elements, when rare earth elements, Bi, Cu, Pd, Pt, Au, In, and Zn are added to the third layer, it is suitable for improving the reflectance and the wiring resistance. (See Tables 9A, 9B, and 9C). Moreover, when adding these alloy elements, there existed preferable content in relation to a reflectance and wiring resistance.

No. in Table 9A 401 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. Reference numerals 402 to 404 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. 405 is an example in which the alloy element content 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.

No. The tendency as shown in 401 to 405 was the same even when the type of alloy element of the third layer was different (No. 407 to 410, etc.) or when the component composition of the second layer (diffusion prevention layer) was different. (Table 9B, Table 9C).

From the experimental results shown in Tables 7, 8, 9A, 9B, and 9C, 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.

(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 And a third layer made of a formed Ag alloy.

In the laminated film of the present invention, 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 three-layer structure is also a preferred embodiment.

The laminated film of the present invention is not limited to this, and may include an arbitrary layer (fourth layer). Therefore, any fourth layer (of any component composition) between the first layer (Al alloy film), the second layer (diffusion prevention film), the second layer (diffusion prevention film) and the third layer (Ag alloy film). Film) may be formed. As a 4th layer, the well-known adhesive improvement film etc. which contribute to adhesive improvement are illustrated.

(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 film thickness exceeds 800 nm, the coverage of the upper layer film (passivation film or the like) is deteriorated, resulting in problems such as faults. 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.

If the film thickness of the first layer (Al alloy film) is 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) or the third layer (Ag alloy film). Good. 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 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 nm or less.

(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 film 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, thereby increasing the wiring resistance. Therefore, the thickness of the second layer needs to be 50 nm or less, 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 high reflectance, the film thickness of the third layer needs to be 60 nm or more, preferably 90 nm or more, 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 manufacturing cost increases as the amount of Ag used increases. Therefore, the film thickness of the third layer needs to be 480 nm or less, preferably 400 nm or less, more preferably 300 nm or less.

(Thickness ratio of the third layer)
The thickness ratio of the third layer (Ag alloy film) to the 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 of the (1-A) group and the (1-B) group may be used alone, or all (two groups) may be used in combination. Moreover, the element which comprises each group can be used individually or in combination with arbitrary 2 or more types. The same applies to the sputtering target described later.

In addition, the content of each group is a single content when it is included alone, and is a total amount when it includes a plurality of elements. The same applies to the second layer (diffusion prevention film) and the third layer (Ag alloy film).

In relation to the above effect, the Al alloy is preferably adjusted so that 90 atomic% or more, more preferably 95 atomic% or more is Al.

(1-A) 0.05 to 1.0 atomic percent of rare earth elements
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 effects, the rare earth element content 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 higher the content of the rare earth element, the better. However, if the content is too large, the reflectivity may be lowered or the electrical resistivity may be deteriorated. Therefore, the content is preferably 1.0 atomic% or less, more preferably 0.8 atomic% or less, and still more preferably 0.6 atomic% or less.

(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, the content of 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, More preferably, it is 0.15 atomic% or more. From the viewpoint of suppressing the coarsening, the larger the content of Ti, Ta, W, and Nb, the better. However, if the content is too large, the reflectance may decrease or the electrical resistivity may deteriorate. Therefore, the content is preferably 0.7 atomic percent or less, more preferably 0.5 atomic percent or less, and still more preferably 0.4 atomic percent or less. Among these, preferred elements are Ti and Ta.

(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.

Desirable component composition of the second layer is exemplified by Mo. Examples of preferable alloy components of the Mo alloy and Ti alloy constituting the second layer include Mo—Nb alloy, Mo—Ta alloy, and Mo—Ti alloy.

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

The metal element constituting the second layer is preferably the above element, and the balance is 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 the conventionally used component composition of the Ag alloy film can be adopted. However, in order to exhibit good reflectance and electrical resistivity, it is preferable to contain the following alloy elements in a predetermined range.

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

(2-A) 0.05 to 1.0 atomic% of rare earth elements
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 effects, the rare earth element content 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 reflectance may be lowered. Therefore, the content 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.

The rare earth element means a lanthanoid element, Sc, Y as in the first layer. 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 effects, the Bi and / or Cu content 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 preferably has a content of 1.0 atomic% or less, more preferably 0.7 atomic% or less, and still more preferably 0.5 atomic% 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, the content of 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 Is 0.2 atomic% 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. Therefore, the content is preferably 1.5 atomic percent or less, more preferably 1.0 atomic percent or less, and still 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 exert such an effect, the content of 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 contents of Zn and In are large. However, if the content is too large, the reflectivity may be decreased. Therefore, the content is preferably 1.5 atomic% or less, more preferably 1 .3 atomic% or less, more preferably 1.1 atomic% or less. A preferred element is Zn.

However, it is not necessary for the sputtering target to contain all the elements corresponding to the component composition of the first layer (Al alloy film) in one sputtering target. Simultaneous sputtering (co-sputtering) of a sputtering target containing a predetermined amount of element is also useful for forming the first layer (Al alloy film) having a desired component composition.

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).

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), if a sputtering target having the component composition corresponding to the above (a) and (b) constituting the second layer (diffusion prevention film) is used, there is a risk of composition deviation or the like. 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.

(Method for forming third layer (Ag alloy film))
As a method for forming the third layer (Ag alloy film) constituting the electrode, various film forming methods can be adopted as in the case of the first layer (Al alloy film). However, for the same reason as the first layer (Al alloy film), it is desirable to form the third layer (Ag alloy film) using a sputtering target by a sputtering method.

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, Bi is an element that is easily scattered during the film formation process and is easily concentrated in the vicinity of the film surface. For this reason, it is preferable to contain approximately five times Bi in the sputtering target with respect to the amount of Bi in the third layer (Ag alloy film). 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 5.0. Atomic% or less, More preferably, it is 3.5 atomic% or less, More preferably, it is 2.5 atomic% or less.

Of course, as with 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.

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

As described above, 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.

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.

Using the organic EL display shown in FIG. 9 as an example, the organic EL display 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. Below, the case where this organic EL element is applied to an organic EL display will be described. However, the application of this organic EL element is not limited to the organic EL display, and various known configurations such as organic EL lighting are used. Can be adopted. 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. 9, a TFT 32 and a passivation film 33 are formed on a substrate 31, and a planarization layer 34 is further formed thereon. A contact hole 35 is formed on the TFT 32. Via the contact hole 5, the source-drain electrode (not shown) of the TFT 32 and the first layer (Al alloy film) 36 constituting the reflective electrode according to the present invention are electrically connected.

Further, a second layer (diffusion prevention film) 37 is formed immediately above the first layer (Al alloy film) 36, and a third layer (Ag alloy film) 38 is formed immediately above. The first layer (Al alloy film) 36, the second layer (diffusion prevention film) 37, and the third layer (Ag alloy film) 38 can be formed by the method described above.

Next, an organic layer 39 is formed on the third layer (Ag alloy film) 38. The organic layer 39 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 40 is formed on the organic layer 39. In the case of FIG. 9, the material constituting the cathode electrode 40 is not particularly limited, and can be constituted by a conventionally used material.

In the organic EL display, light emitted from the organic light emitting layer in the organic layer 39 is efficiently reflected by the reflective anode electrodes 36 to 38 (particularly, the third layer (Ag alloy film) 38) of the present invention. Excellent light emission luminance can be realized. The reflectivity of the reflective electrode (first layer (Al alloy film) 36, second layer (diffusion prevention film) 37, third layer (Ag alloy film) 38) is better as it is higher, generally 90% or more, Preferably, a reflectance of 93% or more is required.

In addition, it is preferable that the reflective anode electrode has higher hole injection characteristics into the organic layer 39.

[Third embodiment]
Hereinafter, the third invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples as a matter of course, and appropriate modifications are made within a range that can meet the purpose described above and below. Of course, it is also possible to implement them, and they are all included in the technical scope of the present invention.

(Film formation)
Sputtering target (disk having a diameter of 4 inches) having the same component composition as the first layer (Al alloy film: balance is Al and inevitable impurities) of the component composition shown in Tables 7 to 9C (all alloy component contents are atomic%) Mold). Using this sputtering target, a first layer was formed on a glass substrate (non-alkali glass, plate thickness 0.7 mm, diameter 4 inches) under the following sputtering conditions using a DC magnetron sputtering apparatus.

Subsequently, a sputtering target (a disk type having a diameter of 4 inches) having the same component composition as the second layer (diffusion prevention film: including inevitable impurities in addition to the predetermined component) having the component composition shown in Tables 7 to 9C was prepared. Using this sputtering target, a second layer was formed directly on the first layer (Al alloy film) under the following sputtering conditions using the same sputtering apparatus as the first layer.

Subsequently, a sputtering target (disk shape with a diameter of 4 inches) having the same component as the third layer (Ag alloy film: the balance is Ag and inevitable impurities) having the component composition shown in Tables 7 to 9C is used under the following sputtering conditions. A third layer was formed immediately above the second layer (diffusion prevention film) to prepare each sample.

In addition, No. in Table 7 In 301, the second layer (diffusion prevention film) was not formed. In Table 8, No. For the first layer of 351, 359, 367, a pure Al sputtering target was used. 401, No. of Table 9B. 433, No. in Table 9C. For the third layer 465, a pure Ag sputtering target was used. The Bi content in the sputtering target when Bi was contained in the third layer (Ag alloy film) was set to be 5 times the Bi content in the third layer (Ag alloy film). For example, No. in Table 8 In No. 351, a third layer (Ag alloy film) of Ag-0.1 atomic% Bi-1.0 atomic% Zn is formed using a sputtering target of Ag-0.5 atomic% Bi-1.0 atomic% Zn. Is formed.

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
Ultimate 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
Ultimate 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
Ultimate 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
Ultimate vacuum: 3 × 10 ⁻⁶ Torr

(Measuring method of film thickness)
The film thicknesses of the first layer (Al alloy film), the second layer (diffusion prevention film) and the third layer (Ag alloy film) are measured with a stylus step meter (manufactured by KLA-Tencor, Alpha-step). did. A total of three film thicknesses were measured 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). The film thickness of the first layer (Al alloy film), the film thickness of the second layer (diffusion prevention film), and the film thickness of 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) using light having a wavelength of 380 to 780 nm with a D65 light source based on JIS R 3106. : Visible / ultraviolet spectrophotometer “V-570”). Specifically, the reflectance was determined as follows from the reflected light intensity (measured value) of the prepared sample with respect to the reflected light intensity of the reference mirror.
“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 and “×” was determined to be unacceptable.
○: 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, 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) is not provided (No. 301 in Table 7) are compared. 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. Etching was performed for completion time +20 seconds (overetching time).

(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.

Tables 7 to 9 show the test results.

Table 7 changes 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, These are the results of examining the influence of these on the reflectance and wiring resistance. Table 7 shows the following.

No. 301 is an example in which the second layer (diffusion prevention film) was not formed, and the reflectance and wiring resistance were also poor.

No. In 305, 312, and 324, since the second layer (diffusion prevention film) was too thick, a desired wiring resistance could not be obtained.

No. Reference numerals 329 to 331 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. 302 to 304, 306 to 311, 313 to 323, and 325 to 328 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 8 shows the results of examining the influence of the component composition of the first layer on the reflectance and wiring resistance by appropriately changing the component composition of the first layer (Al alloy). Table 8 shows the following.

No. 351, 359, and 367 are examples in which pure Al is used for the first layer. In these examples, the wiring resistance was good, but the reflectance was low.

No. 355, 363, and 371 are examples in which the content of the alloy element is excessive, and the wiring resistance deteriorated.

No. 352 to 354, 356 to 358, 360 to 362, 364 to 366, 368 to 370, and 372 to 374 are examples that satisfy all of the component composition and other requirements of the first layer of the present invention, and have good wiring resistance. And the reflectance was obtained.

Tables 9A, 9B, and 9C show the results of examining the influence on the reflectance and wiring resistance by appropriately changing the component composition of the third layer (Ag alloy film). Tables 9A, 9B, and 9C show the following.

No. 401, 433, and 465 are examples in which a pure Ag film is the third layer. In these examples, the wiring resistance was good, but the reflectance was low.

No. 405, 410, 414, 420, 424, 437, 442, 446, 452, 456, 469, 474, 478, 484, and 488 are examples in which the alloy element content is excessive, and the reflectivity decreased.

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

Note that No. in Table 9A. Nos. 401 to 432 are examples in which pure Mo is used for the second layer. Nos. 433 to 464 are examples in which a pure Ti film is used for the second layer. Reference numerals 465 to 496 are examples in which an ITO film is used for the second layer. In addition, although the component composition of the third layer (Ag alloy) is also changed, 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. I knew it was possible.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims. This application is a Japanese patent application filed on November 21, 2012 (Japanese Patent Application No. 2012-255360), a Japanese patent application filed on December 12, 2012 (Japanese Patent Application No. 2012-271802), and a Japanese patent application filed on December 12, 2012 This is based on a patent application (Japanese Patent Application No. 2012-271803), the contents of which are incorporated herein by reference.

1, 21, 31

Substrate

2, 32 TFT
3, 33

Passivation films

4, 34 Flattening

layers

5, 35 Contact holes 6, 36 First layer (Al alloy film)
7 Second layer (Ag alloy film)
9, 29, 39

Organic layer

10, 30, 40 Cathode electrode 27 Second layer (Al alloy oxide film or nitride film)
28, 38 3rd layer (Ag alloy film)
37 Second layer (diffusion prevention film)

Claims

An electrode used for a display device or an input device,
The electrode has a laminated film including a first layer containing an Al alloy formed on the substrate side and a second layer containing an Ag alloy formed above the first layer,
The film thickness of the electrode is 100 nm or more and 800 nm or less, the film thickness of the second layer is 60 nm or more and 480 nm or less, and the film thickness ratio of the second layer in the film thickness of the electrode is 10% or more and 70%. The film thickness ratio of the first layer in the film thickness of the electrode is 30% or more,
The Al alloy is an alloy element,
(1-A) 0.05 atom% or more and 1.0 atom% or less of the rare earth element,
(1-B) at least one selected from the group consisting of Si, Cu, and Ge is 0.5 atomic% or more and 1.5 atomic% or less, and
(1-C) at least one selected from the group consisting of Ti, Ta, W, and Nb is 0.05 atomic% or more and 0.7 atomic% or less,
An electrode comprising at least one selected from the group consisting of:
The electrode according to claim 1, wherein the Ag alloy contains 98 atomic percent or more and 99.98 atomic percent or less of Ag.
The Ag alloy is an alloy element,
(2-A) 0.05 to 1.0 atomic% of the rare earth element,
(2-B) Bi and / or Cu is 0.05 atomic% or more and 1.0 atomic% or less,
(2-C) at least one selected from the group consisting of Pd, Pt and Au is 0.1 atomic% or more and 1.5 atomic% or less, and (2-D) Zn and / or In is 0.1 atomic% 1.5 atomic% or less,
The electrode according to claim 1, comprising at least one selected from the group consisting of:
4. The electrode according to claim 3, wherein the rare earth element (1-A) or (2-A) is at least one selected from the group consisting of Nd, La, Gd, and Ce.
The electrode has a third layer containing an oxide of Al alloy or a nitride of Al alloy between the first layer and the second layer, and the thickness of the third layer is 1 nm or more and 10 nm. The electrode according to claim 1, wherein:
The Al alloy of the third layer is an alloy element,
(3-A) 0.05 atomic% to 1.0 atomic% of rare earth elements, or (3-B) 0.05 atomic% of at least one selected from the group consisting of Ti, Ta, W, and Nb 0.7 atomic% or less,
The electrode according to claim 5, comprising:
The electrode is between the first layer and the second layer,
(A) at least one selected from the group consisting of Mo, Mo alloy, Ti, Ti alloy, Ta, W, Nb, or
(B) having a fourth layer containing a conductive oxide containing at least one of In oxide and Zn oxide;
The electrode according to claim 1, wherein the film thickness of the fourth layer is 3 nm or more and 50 nm or less.
The electrode according to claim 7, wherein the conductive oxide of the fourth layer is ITO (indium tin oxide) or IZO (indium zinc oxide).
An Al alloy sputtering target used for forming the electrode according to claim 1,
(1-A) 0.05 atom% or more and 1.0 atom% or less of the rare earth element,
(1-B) at least one selected from the group consisting of Si, Cu, and Ge is 0.5 atomic% or more and 1.5 atomic% or less, and
(1-C) at least one selected from the group consisting of Ti, Ta, W, and Nb is 0.05 atomic% or more and 0.7 atomic% or less,
An Al alloy sputtering target for forming an electrode, comprising at least one selected from the group consisting of:
The sputtering target according to claim 9, 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 3,
(2-A) 0.05 to 1.0 atomic% of the rare earth element,
(2-B) Cu is 0.05 atomic% or more and 1.0 atomic% or less, and / or Bi is 0.25 atomic% or more and 5.0 atomic% or less,
(2-C) at least one selected from the group consisting of Pd, Pt and Au is 0.1 atomic% or more and 1.5 atomic% or less, and
(2-D) Zn and / or In is 0.1 atomic% or more and 1.5 atomic% or less,
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 11, wherein the rare earth element is at least one selected from the group consisting of Nd, La, Gd, and Ce.