KR20210010451A - Laminated film and Ag alloy sputtering target - Google Patents

Abstract

As a laminated film 10 comprising an Ag alloy film 11 and a transparent conductive oxide film 12 laminated on one or both sides of the Ag alloy film 11, the Ag alloy film 11 contains 5.0 Ge It contains in the range of atomic% or more and 13.0 atomic% or less, the remainder is a composition of Ag and unavoidable impurities, and the film thickness of the Ag alloy film 11 is within the range of 3 nm or more and 10 nm or less.

Description

Laminated film and Ag alloy sputtering target

The present invention relates to, for example, a laminated film that can be used as a transparent conductive wiring film or transparent electrode such as a display or a touch panel, and an Ag alloy sputtering target used when forming an Ag alloy film constituting the laminated film.

This application claims priority based on Japanese Patent Application No. 2018-095293 filed in Japan on May 17, 2018, and Japanese Patent Application No. 2019-090548 filed in Japan on May 13, 2019, I use the content here.

For example, in a liquid crystal display, an organic EL display, a touch panel, etc., as a wiring, as shown in Patent Documents 1 to 3, a laminated film made of a laminated structure of a transparent conductive oxide film and an Ag film made of Ag or an Ag alloy is Is being applied. This laminated film is required to have high transmittance of light in the visible region and low electrical resistance.

Further, in the case of forming an Ag film made of Ag or an Ag alloy on a glass substrate or the like, a sputtering method using a sputtering target made of Ag or an Ag alloy is widely used, as disclosed in Patent Document 4, for example.

Japanese Laid-Open Patent Publication No. Hei 09-291356 (A) Japanese Patent Laid-Open Publication No. Hei 10-239697 (A) Japanese Patent Application Publication No. 2016-040411 (A) Japanese Laid-Open Patent Publication No. 2016-164305 (A)

However, in recent years, in a display or a touch panel, miniaturization of wires and electrodes is further progressing, and the length of wires and electrodes becomes longer due to a large screen, and conventionally used as a transparent conductive wiring film or a transparent electrode. There is a demand for a laminated film having a lower electrical resistance and excellent transmittance in a visible light region. That is, excellent electrical properties and optical properties are required for this laminated film.

Here, in a laminated film having a laminated structure of a transparent conductive oxide film and an Ag film made of Ag or an Ag alloy, in order to further improve the transmittance, it is necessary to decrease the thickness of the Ag film made of Ag or an Ag alloy. .

However, when the Ag film is merely made thin, there is a problem that the Ag film becomes a discontinuous film because Ag tends to aggregate, and the electrical resistance increases. In addition, there is a problem that the transmittance is rather reduced due to aggregation of Ag.

In particular, when the film thickness is 10 nm or less, Ag aggregates and the Ag film tends to become a discontinuous film, and a laminate film having excellent electrical and optical properties could not be obtained.

In addition, at the time of mass production, film formation may be performed while residual gas (water vapor, etc.) is contained in the film forming apparatus. When the Ag film is formed in an atmosphere containing water vapor, the aggregation of Ag is promoted on the surface of the Ag film by water vapor, and there is a fear that the Ag film cannot be stably formed.

The present invention has been made in view of the above circumstances, and has an Ag alloy film having a thin film thickness of, for example, 10 nm or less, has excellent electrical properties and optical properties, and is particularly suitable for a transparent conductive wiring film or a transparent electrode. , And an Ag alloy sputtering target used when forming an Ag alloy film constituting this laminated film is provided.

In order to solve the above problems, the laminated film of one aspect of the present invention (hereinafter referred to as the ``laminated film of the present invention'') is provided with an Ag alloy film and a transparent conductive oxide film laminated on one or both surfaces of the Ag alloy film. As a laminated film, the Ag alloy film contains Ge in the range of 5.0 atomic% or more and 13.0 atomic% or less, the balance is made of Ag and unavoidable impurities, and the thickness of the Ag alloy film is 3 nm or more and 10 nm. It is characterized by being within the following range.

According to the laminated film of the present invention, since the Ag alloy film contains Ge in the range of 5.0 atomic% or more and 13.0 atomic% or less, and the remainder is composed of Ag and unavoidable impurities, diffusion of Ag is suppressed by Ge. Thus, even when the Ag alloy film has a thin thickness of 3 nm or more and 10 nm or less, aggregation of Ag can be suppressed, and the Ag alloy film can be suppressed from becoming a discontinuous film. In addition, even when the film is formed in an atmosphere containing water vapor, aggregation of Ag on the surface of the Ag film can be suppressed, and even when the film is formed in a mass-production apparatus with insufficient exhaust capacity, the Ag alloy film can be suppressed from becoming a discontinuous film. have.

Further, since the Ag alloy film has a thickness of 3 nm or more, electrical properties can be ensured. Further, since the Ag alloy film has a thickness of 10 nm or less, optical properties can be ensured.

Accordingly, it is possible to provide a laminated film that is excellent in electrical properties and optical properties, and is particularly suitable for a transparent conductive wiring film or a transparent electrode.

Here, in the laminated film of the present invention, the Ag alloy film further contains any one or two or more elements selected from In, Zn, and Sn, and any one selected from In, Zn, and Sn, or The atomic ratio (In+Zn+Sn)/(Ge) of the total content (In+Zn+Sn) of two or more types and the content of Ge (Ge) may be in the range of 0.05 or more and 0.50 or less.

In this case, it contains In, Zn, and Sn, which are elements having an effect of suppressing the diffusion and movement of Ag atoms like Ge, and the atomic ratio of the total content of In, Zn and Sn (In+Zn+Sn) and the content of Ge (Ge) Since (In+Zn+Sn)/(Ge) is 0.05 or more, even when the thickness of the Ag alloy film is formed as thin as 3 nm or more and 10 nm or less, aggregation of Ag can be further suppressed, preventing the Ag alloy film from becoming a discontinuous film. Can be suppressed.

Further, since the atomic ratio (In+Zn+Sn)/(Ge) in the Ag alloy film is limited to 0.50 or less, deterioration in environmental resistance and water vapor resistance caused by In, Zn, and Sn can be suppressed.

In addition, in the laminated film of the present invention, the Ag alloy film further contains any one or two or more elements selected from Pd, Au, Pt, and any one selected from Pd, Au, Pt, or The atomic ratio (Pd+Au+Pt)/(Ge) of the total content of two or more (Pd+Au+Pt) and the Ge content (Ge) is 0.01 or more, and any one or two selected from In, Zn, Sn, Pd, Au, and Pt The atomic ratio (In+Zn+Sn+Pd+Au+Pt)/(Ge) of the above total content (In+Zn+Sn+Pd+Au+Pt) and the Ge content (Ge) may be in the range of 0.50 or less.

In this case, the Ag alloy film contains Pd, Au, Pt, which are elements having an effect of improving environmental resistance, and the total content of any one or two or more selected from Pd, Au, Pt (Pd+Au+Pt) and Since the atomic ratio (Pd+Au+Pt)/(Ge) of the Ge content (Ge) is 0.01 or more, the environmental resistance of the Ag alloy film can be sufficiently improved.

In addition, in the Ag alloy film, the atomic ratio (In+Zn+Sn+Pd+Au+Pt)/(Ge) of the total content (In+Zn+Sn+Pd+Au+Pt) and the Ge content (Ge) selected from In, Zn, Sn, Pd, Au, Pt ) Is limited to 0.50 or less, it is possible to suppress the deterioration of water vapor resistance caused by Pd, Au, and Pt.

In addition, in the laminated film of the present invention, the sheet resistance of the laminated film is 40 Ω/□ (Ω/sq.) or less, and the average value μ _R and the standard deviation σ _R of the sheet resistance measured at multiple points in the plane. It is preferable that the distribution of sheet resistance defined by D _R = (σ _R /μ _R ) × 100 is 20% or less.

In this case, since the sheet resistance of the laminated film is 40 Ω/□ or less, the electrical properties are sufficiently excellent. In addition, since the distribution D _R of the sheet resistance described above is 20% or less, properties such as sheet resistance are stable in the plane of the laminated film. That is, even when the thickness of the Ag alloy film is formed to be 3 nm or more and 10 nm or less, an Ag alloy film having a relatively uniform thickness is formed.

In addition, in the laminated film of the present invention, the transparent conductive oxide film contains any one or two or more selected from In oxide, Sn oxide, Zn oxide, Nb oxide, Ti oxide, Al oxide, and Ga oxide. It can be done.

In this case, since the transparent conductive oxide film laminated on the Ag alloy film contains any one or two or more selected from In oxide, Sn oxide, Zn oxide, Nb oxide, Ti oxide, Al oxide, and Ga oxide, The transparent conductive oxide film has excellent electrical properties and optical properties, and the optical properties and electrical properties of the entire laminated film can be improved.

In addition, in the laminated film of the present invention, the transparent conductive oxide film may have a refractive index at a wavelength of 550 nm of 1.9 or more and 2.4 or less, and a film thickness of 5 nm or more and 50 nm or less.

In this case, since the transparent conductive oxide film laminated on the Ag alloy film has a refractive index at a wavelength of 550 nm of 1.9 or more and 2.4 or less, and a film thickness of 5 nm or more and 50 nm or less, the transparent conductive oxide The transmittance of visible light in the film can be improved, and the transmittance of visible light in the entire laminated film can be sufficiently improved.

The Ag alloy sputtering target of the present invention contains Ge in the range of 5.0 atomic% or more and 13.0 atomic% or less, the balance is made of Ag and unavoidable impurities, and the average crystal grain size is 200 μm or less, and sputtering The distribution of the grain size defined by the mean value μ _GS of the grain size measured at multiple points on the plane and the standard deviation of grain size σ _GS D _GS = (σ _GS / μ _GS ) × 100 is 25% or less. I am doing it.

According to the Ag alloy sputtering target having this configuration, Ge is contained in the range of 5.0 atomic% or more and 13.0 atomic% or less, and the remainder is composed of Ag and unavoidable impurities. Therefore, in the formed Ag alloy film, Ag Diffusion is suppressed by Ge, and even when the Ag alloy film is formed as thin as 3 nm or more and 10 nm or less, aggregation of Ag can be suppressed, and an Ag alloy film with a relatively uniform film thickness can be formed. .

In addition, the average value of the grain size is 200 μm or less, and the distribution of grain size D _GS = (σ _GS / μ) defined by the average value μ _{GS of the} grain size measured at multiple points on the sputtering surface and the standard deviation σ _GS of the grain size _{Since GS} ) × 100 is 25% or less, the sputter rate becomes relatively constant over the entire sputtering surface, and an Ag alloy film having a thickness of 3 nm or more and 10 nm or less can be stably formed.

Here, in the Ag alloy sputtering target of the present invention, any one or two or more elements selected from In, Zn, and Sn are further contained, and any one or two or more elements selected from In, Zn, and Sn The atomic ratio (In+Zn+Sn)/(Ge) of the total content (In+Zn+Sn) and the Ge content (Ge) may be in the range of 0.05 or more and 0.50 or less.

In this case, since the atomic ratio (In+Zn+Sn)/(Ge) of the total content (In+Zn+Sn) selected from In, Zn, Sn and the total content (In+Zn+Sn) of Ge content (Ge) is 0.05 or more, 3 nm or more Even if it is a thin Ag alloy film of 10 nm or less, aggregation of Ag can be suppressed, and an Ag alloy film can be formed stably.

In addition, since the atomic ratio (In+Zn+Sn)/(Ge) is limited to 0.50 or less, deterioration in environmental resistance and water vapor resistance caused by In, Zn, and Sn can be suppressed, and even when a film is formed in an atmosphere containing water vapor , Ag aggregation can be suppressed.

In addition, in the Ag alloy sputtering target of the present invention, any one or two or more elements selected from Pd, Au, and Pt are further contained, and any one or two or more elements selected from Pd, Au, and Pt are contained. The atomic ratio (Pd+Au+Pt)/(Ge) of the total content (Pd+Au+Pt) and the Ge content (Ge) is 0.01 or more, and any one or two or more types selected from In, Zn, Sn, Pd, Au, and Pt The atomic ratio (In+Zn+Sn+Pd+Au+Pt)/(Ge) of (In+Zn+Sn+Pd+Au+Pt) and the Ge content (Ge) may be in the range of 0.50 or less.

In this case, since the atomic ratio (Pd+Au+Pt)/(Ge) of the total content (Pd+Au+Pt) and the Ge content (Ge) selected from Pd, Au, Pt is 0.01 or more, environmental resistance An excellent Ag alloy film can be formed.

In addition, the atomic ratio (In+Zn+Sn+Pd+Au+Pt)/(Ge) of the total content (In+Zn+Sn+Pd+Au+Pt) and Ge content (Ge) selected from In, Zn, Sn, Pd, Au, Pt is limited to 0.50 or less. Therefore, deterioration in water vapor resistance caused by Pd, Au, and Pt can be suppressed, and even when a film is formed in an atmosphere containing water vapor, aggregation of Ag can be suppressed.

According to the present invention, for example, a laminated film having an Ag alloy film having a thin film thickness of 10 nm or less, excellent in electrical and optical properties, and particularly suitable for a transparent conductive wiring film or transparent electrode, and Ag constituting the laminated film It becomes possible to provide an Ag alloy sputtering target used when forming an alloy film.

1 is an explanatory cross-sectional view of a laminated film according to an embodiment of the present invention.
2A is an image showing the result of observing the distribution state of Ag in the Ag alloy film.
2B is an image showing the result of observing the distribution state of Ge in the Ag alloy film.
3 is an explanatory diagram showing a measurement position of sheet resistance in the plane of a laminated film according to an embodiment of the present invention.
4 is an explanatory view showing a measurement position of a crystal grain size on a sputtering surface of an Ag alloy sputtering target according to an embodiment of the present invention.
5 is an explanatory cross-sectional view of a laminated film according to another embodiment of the present invention.
6 is an explanatory cross-sectional view of a laminated film according to another embodiment of the present invention.
7 is an explanatory cross-sectional view of a laminated film according to another embodiment of the present invention.
8 is an explanatory view showing a measurement position of a crystal grain size of a sputtered surface in a disk-shaped sputtering target.
9A is an explanatory view showing a measurement position of a crystal grain size as viewed from a direction parallel to an axis among sputtering surfaces in a cylindrical sputtering target.
9B is an explanatory view showing a measurement position of a crystal grain size as viewed from a direction perpendicular to an axis among sputtering surfaces in a cylindrical sputtering target.

Hereinafter, a laminated film and an Ag alloy sputtering target according to an embodiment of the present invention will be described.

The laminated film 10 according to the present embodiment is used as a transparent conductive wiring film or transparent electrode of various displays and touch panels.

<Laminated film>

As shown in FIG. 1, the laminated film 10 of the present embodiment is formed on one side of a substrate 1 made of glass or the like, and on both sides of the Ag alloy film 11. Each of the formed transparent conductive oxide films 12 is provided.

The Ag alloy film 11 contains Ge in the range of 5.0 atomic% or more and 13.0 atomic% or less, and the balance is composed of Ag and unavoidable impurities.

In addition, the Ag alloy film 11 further contains any one or two or more elements selected from In, Zn, and Sn, and the total content of any one or two or more elements selected from In, Zn, and Sn The atomic ratio (In+Zn+Sn)/(Ge) of (In+Zn+Sn) and the Ge content (Ge) may be in the range of 0.05 or more and 0.50 or less.

In addition, the Ag alloy film 11 further contains any one or two or more elements selected from Pd, Au, and Pt, and the total content of any one or two or more elements selected from Pd, Au, and Pt The atomic ratio (Pd+Au+Pt)/(Ge) of (Pd+Au+Pt) and Ge content (Ge) is 0.01 or more, and the total content of any one or two or more selected from In, Zn, Sn, Pd, Au, Pt (In+Zn+Sn+Pd+Au+Pt) ) And the atomic ratio of the Ge content (Ge) (In+Zn+Sn+Pd+Au+Pt)/(Ge) may be in the range of 0.50 or less.

And the film thickness of this Ag alloy film 11 is in the range of 3 nm or more and 10 nm or less.

The transparent conductive oxide film 12 is composed of, for example, a transparent conductive oxide containing one or two or more selected from In oxide, Sn oxide, Zn oxide, Nb oxide, Ti oxide, Al oxide, and Ga oxide. Has been. Specifically, In-Sn oxide (ITO), Al-Zn oxide (AZO), In-Zn oxide (IZO), Zn-Sn oxide (ZTO), Zn-Sn-Al oxide (AZTO), Ga-Zn oxide (GZO), Zn-Y oxide (ZYO), Ga-Zn-Y oxide (GZYO), and the like.

In addition, the thickness of the transparent conductive oxide film 12 is preferably in a range of 5 nm or more and 50 nm or less, for example. In addition, it is preferable that the transparent conductive oxide film 12 has a refractive index at a wavelength of 550 nm of 1.9 or more and 2.4 or less.

And in the laminated film 10 which is this embodiment, the sheet resistance is 40 Ω/□ or less.

In addition, the distribution of sheet resistance defined by the average value μ _R of sheet resistance measured at multiple points in the plane of the laminated film 10 and the standard deviation σ _R D _R = (σ _R / μ _R ) × 100 is 20% or less. It is made into.

In addition, in the laminated film 10 of the present embodiment, the average transmittance at a wavelength of 380 nm to 780 nm is 85% or more.

Here, in the laminated film 10 of the present embodiment, the component composition of the Ag alloy film 11, the sheet resistance and average transmittance of the laminated film 10, the refractive index and the film thickness of the transparent conductive oxide film 12, The reasons specified as described above will be described.

(Ge)

Ge is segregated on the surface (interface) of the Ag alloy film 11 as shown in FIGS. 2A and 2B, for example. Thereby, it has an effect of suppressing the diffusion and movement of Ag atoms and suppressing Ag aggregation in the Ag alloy film 11. Further, since Ge particularly suppresses diffusion of Ag elements on the surface of the Ag alloy film 11, aggregation of Ag is suppressed even when the film is formed in the presence of water vapor. In addition, FIGS. 2A and 2B show the results of performing energy dispersive X-ray analysis (EDS) on Ge of the Ag alloy film 11 with a spherical aberration correction scanning transmission electron microscope (Cs-STEM), (a) Denotes Ag distribution 11Ag, and (b) denotes Ge distribution 11Ge. From these Figs. 2A and 2B, it is confirmed that Ge is segregated on the surface (interface) of the Ag alloy film 11.

Here, when the Ge content is less than 5.0 atomic%, there is a fear that the above-described effects cannot be exhibited. On the other hand, when the Ge content exceeds 13.0 atomic%, the solubility limit of Ge to Ag is exceeded, and therefore it becomes difficult to produce an Ag alloy sputtering target used for film formation.

From the above point, in the present embodiment, the Ge content in the Ag alloy film 11 is set within the range of 5.0 atomic% or more and 13.0 atomic% or less.

In addition, in order to suppress the diffusion movement of Ag atoms and further suppress Ag aggregation in the Ag alloy film 11, it is preferable that the Ge content in the Ag alloy film 11 be 7.0 atomic% or more. It is more preferable to set it as 9.0 atomic% or more.

On the other hand, in order to more stably produce the Ag alloy sputtering target used for film formation, the Ge content in the Ag alloy film 11 is preferably 12.0 atomic% or less, and furthermore 11.0 atomic% or less. desirable.

(Any one or two or more elements selected from In, Zn, Sn)

Elements such as In, Zn, and Sn described above have an effect of suppressing aggregation of Ag in the Ag alloy film 11 like Ge. Therefore, you may add these In, Zn, and Sn suitably.

Here, by setting the atomic ratio (In+Zn+Sn)/(Ge) of the total content (In+Zn+Sn) of any one or two or more selected from In, Zn and Sn to the Ge content (Ge) to 0.05 or more, In, Zn, Sn It becomes possible to sufficiently exhibit the above-described action and effect by the addition of. On the other hand, by setting the atomic ratio (In+Zn+Sn)/(Ge) to 0.50 or less, it is possible to suppress deterioration of water vapor resistance and environmental resistance caused by In, Zn, and Sn.

From the above point of view, in the present embodiment, when the Ag alloy film 11 contains any one or two or more elements selected from In, Zn, and Sn, the atomic ratio (In+Zn+Sn)/(Ge ) Is set within the range of 0.05 or more and 0.50 or less.

In addition, in order to further suppress Ag aggregation by In, Zn, and Sn, the atomic ratio (In+Zn+Sn)/(Ge) is preferably set to 0.10 or more, and more preferably 0.15 or more.

On the other hand, in order to further suppress deterioration of water vapor resistance and environmental resistance caused by In, Zn, and Sn, the atomic ratio (In+Zn+Sn)/(Ge) is preferably set to 0.40 or less, and more preferably 0.30 or less.

In addition, when any one or two or more elements selected from In, Zn, and Sn described above are contained as impurities, the atomic ratio (In+Zn+Sn)/(Ge) may be less than 0.05.

(Any one or two or more elements selected from Pd, Au, Pt)

Elements such as Pd, Au, and Pt described above have an effect of improving the environmental resistance (resistance to a hot and humid environment) of the Ag alloy film 11. So, when the environmental resistance of the Ag alloy film 11 is required, it is preferable to add it appropriately.

Here, by making the atomic ratio (Pd+Au+Pt)/(Ge) of the total content (Pd+Au+Pt) and the content of Ge (Ge) selected from Pd, Au, Pt to be 0.01 or more, Pd, Au, Pt It becomes possible to sufficiently exhibit the above-described action and effect by the addition of. On the other hand, by making the atomic ratio (In+Zn+Sn+Pd+Au+Pt)/(Ge) of the total content (In+Zn+Sn+Pd+Au+Pt) selected from In, Zn, Sn, Pd, Au, and Pt to be 0.50 or less. , Pd, Au, it is possible to suppress the deterioration of water vapor resistance caused by Pt.

From the above point of view, in the present embodiment, when the Ag alloy film 11 contains any one or two or more elements selected from Pd, Au, Pt, the atomic ratio (Pd+Au+Pt)/(Ge ) Is set to 0.01 or more, and the atomic ratio (In+Zn+Sn+Pd+Au+Pt)/(Ge) is set to 0.50 or less.

In addition, in order to further improve the environmental resistance (resistance to a hot and humid environment) of the Ag alloy film 11, the atomic ratio (Pd+Au+Pt)/(Ge) is preferably set to 0.02 or more, and more preferably 0.05 or more. .

On the other hand, in order to further suppress the deterioration of water vapor resistance caused by Pd, Au, and Pt, the atomic ratio (In+Zn+Sn+Pd+Au+Pt)/(Ge) is preferably set to 0.40 or less, and more preferably 0.30 or less.

In addition, when any one or two or more elements selected from Pd, Au, and Pt described above are contained as impurities, the atomic ratio (Pd+Au+Pt)/(Ge) may be less than 0.01.

In addition, even when In, Zn, and Sn are not intentionally added and contained at an impurity level, the atomic ratio (In+Zn+Sn+Pd+Au+Pt)/(Ge) may be defined as described above.

(The film thickness of the Ag alloy film 11)

In the laminated film 10, the transmittance can be improved by reducing the thickness of the Ag alloy film 11.

Here, when the film thickness of the Ag alloy film 11 is less than 3 nm, the Ag alloy film 11 becomes an island shape and becomes discontinuous, and the electrical resistance is significantly increased. Further, since a uniform film is not formed, the transmittance is also significantly lowered. On the other hand, when the film thickness of the Ag alloy film 11 exceeds 10 nm, there is a fear that the transmittance may become insufficient.

From the above point of view, in this embodiment, the film thickness of the Ag alloy film 11 is set within the range of 3 nm or more and 10 nm or less.

In addition, the thickness of the Ag alloy film 11 is preferably 4 nm or more, and more preferably 5 nm or more. On the other hand, the thickness of the Ag alloy film 11 is preferably 8 nm or less, and more preferably 7 nm or less.

(Sheet resistance)

In this embodiment, since the sheet resistance of the laminated film 10 is 40 Ω/square or less, it has excellent electrical properties and is particularly suitable as a transparent conductive wiring film and a transparent electrode.

And the distribution D _R = (σ _R /μ _R ) × 100 of sheet resistance defined by the average value μ _R of sheet resistance measured at a plurality of points in the plane and the standard deviation σ _R is 20% or less. In addition, in this embodiment, as shown in FIG. 3, in the plane of the laminated film 10, the intersection 1 where diagonal lines intersect and the corners 2, 3, (4), ( a measurement of the sheet resistance in each of 5 of 5), and calculates an average value μ and standard deviation σ _{R R R} D and the distribution of the sheet resistance. In addition, the corner portions 2, 3, 4, and 5 were in the range within 10% of the total length of the diagonal line from the corner portion toward the inside.

Since the distribution D _R of the sheet resistance calculated in this way is 20% or less, the Ag alloy film 11 does not become a discontinuous film, and is formed with a relatively uniform film thickness.

Moreover, the sheet resistance of the laminated film 10 is preferably 30 Ω/□ or less, and more preferably 25 Ω/□ or less.

Moreover, it is preferable that it is 18% or less, and, as for the distribution D _R of sheet resistance, it is more preferable that it is 15% or less.

(Average transmittance)

In this embodiment, since the average transmittance of the laminated film 10 at a wavelength of 380 nm to 780 nm is 85% or more, it is excellent in optical properties and is particularly suitable as a transparent conductive wiring film and a transparent electrode.

In addition, the average transmittance of the laminated film 10 at a wavelength of 380 nm to 780 nm is preferably 88% or more, and more preferably 90% or more.

(Refractive index and film thickness of the transparent conductive oxide film 12)

In this embodiment, the refractive index of the transparent conductive oxide film 12 at a wavelength of 550 nm is within the range of 1.9 or more and 2.4 or less, and the film thickness of the transparent conductive oxide film 12 is within the range of 5 nm or more and 50 nm or less. If so, the transmittance of visible light in the transparent conductive oxide film 12 can be improved. This makes it possible to improve the optical properties of the laminated film 10 as a whole.

Further, the refractive index of the transparent conductive oxide film 12 at a wavelength of 550 nm is preferably 2.0 or more, and preferably 2.2 or less. Further, the thickness of the transparent conductive oxide film 12 is preferably 10 nm or more, and preferably 40 nm or less.

<Ag alloy sputtering target>

Next, the Ag alloy sputtering target 20 which is this embodiment is demonstrated. This Ag alloy sputtering target 20 is used to form the Ag alloy film 11 constituting the laminated film 10 according to the present embodiment described above.

In addition, in the Ag alloy sputtering target 20 according to the present embodiment, when forming a film on a relatively large substrate 1, the area of the sputtering surface is preferably 0.25 m 2 or more.

The Ag alloy sputtering target 20 according to the present embodiment contains Ge in the range of 5.0 atomic% or more and 13.0 atomic% or less, and the remainder has a composition of Ag and unavoidable impurities.

In addition, the Ag alloy sputtering target 20 further contains any one or two or more elements selected from In, Zn, and Sn, and any one or two or more types selected from In, Zn and Sn The atomic ratio (In+Zn+Sn)/(Ge) of the content (In+Zn+Sn) and the Ge content (Ge) may be in the range of 0.05 or more and 0.50 or less.

In addition, the Ag alloy sputtering target 20 further contains any one or two or more elements selected from Pd, Au, Pt, and any one or two or more types selected from Pd, Au, Pt The atomic ratio (Pd+Au+Pt)/(Ge) of the content (Pd+Au+Pt) and the Ge content (Ge) is 0.01 or more, and the total content of any one or two or more selected from In, Zn, Sn, Pd, Au, Pt ( The atomic ratio (In+Zn+Sn+Pd+Au+Pt)/(Ge) of In+Zn+Sn+Pd+Au+Pt) and the Ge content (Ge) may be in the range of 0.50 or less.

In addition, the Ag alloy sputtering target 20 has an average crystal grain size of 200 µm or less, and a grain size defined by the average value μ _{GS of the} grain size measured at multiple points on the sputtering surface and the standard deviation σ _GS of the grain size. Distribution D _GS = (σ _GS / μ _GS ) × 100 is 25% or less.

Here, in the Ag alloy sputtering target 20 according to the present embodiment, the reason for specifying the component composition and the crystal grain size as described above will be described.

(Ingredient composition)

In the Ag alloy sputtering target 20 according to the present embodiment, since the above-described Ag alloy film 11 is formed into a film, it is set according to the composition of the Ag alloy film 11 according to the present embodiment described above.

Therefore, the Ag alloy sputtering target 20 according to the present embodiment has a Ge content of 5.0 atomic% or more and 13.0 atomic% or less.

Moreover, it is preferable to set it as 7.0 atomic% or more, and, as for the content of Ge in the Ag alloy sputtering target 20, it is more preferable to set it as 9.0 atomic% or more. On the other hand, the content of Ge in the Ag alloy sputtering target 20 is preferably 12.0 atomic% or less, and more preferably 11.0 atomic% or less.

In addition, in the case of containing In, Zn, Sn, which has the effect of suppressing the diffusion of Ag like Ge, the total content of any one or two or more selected from In, Zn and Sn (In+Zn+Sn) and the content of Ge ( It is preferable to make the atomic ratio (In+Zn+Sn)/(Ge) of Ge) within the range of 0.05 or more and 0.50 or less.

Moreover, it is preferable to set it as 0.10 or more, and, as for the atomic ratio (In+Zn+Sn)/(Ge), it is more preferable to set it as 0.15 or more. On the other hand, the atomic ratio (In+Zn+Sn)/(Ge) is preferably 0.40 or less, and more preferably 0.30 or less.

In addition, in order to improve the environmental resistance of the formed Ag alloy film 11, in the case of containing Pd, Au, Pt, the total content of any one or two or more selected from Pd, Au, Pt (Pd+Au+Pt) and The atomic ratio (Pd+Au+Pt)/(Ge) of the Ge content (Ge) is 0.01 or more, and the total content of any one or two or more selected from In, Zn, Sn, Pd, Au, Pt (In+Zn+Sn+Pd+Au+Pt) and Ge It is preferable to make the atomic ratio (In+Zn+Sn+Pd+Au+Pt)/(Ge) of the content (Ge) within the range of 0.50 or less.

Further, the atomic ratio (Pd+Au+Pt)/(Ge) is preferably 0.02 or more, and more preferably 0.05 or more. On the other hand, the atomic ratio (In+Zn+Sn+Pd+Au+Pt)/(Ge) is preferably 0.40 or less, and more preferably 0.30 or less.

(Crystal grain size)

In the Ag alloy sputtering target 20 according to the present embodiment, by setting the average value of the crystal grain size to 200 µm or less, it is possible to suppress the surface roughness of the sputtered surface from becoming rough even when sputtering proceeds. Thereby, occurrence of abnormal discharge during sputtering is suppressed, and sputtering film formation can be stably performed.

And, by making the distribution of the grain size D _GS = (σ _GS / μ _GS ) × 100 defined by the average value μ _GS of the grain size measured at multiple points on the sputtering surface and the standard deviation σ _GS of the grain size, × 100 to 25% or less. , The sputter rate is relatively constant over the entire sputtering surface, and the Ag alloy film 11 having a film thickness of 3 nm or more and 10 nm or less can be stably formed.

Further, the average value of the grain size of the Ag alloy sputtering target 20 is preferably 180 µm or less, and more preferably 150 µm or less.

Moreover, it is preferable that it is 20% or less, and, as for distribution D _GS of the crystal grain size, it is more preferable that it is 15% or less.

In addition, in this embodiment, as shown in FIG. 4, in the sputtering surface of the Ag alloy sputtering target 20, the intersection (1) where the diagonals intersect and the corners (2), (3), ( The crystal grain size was measured at the five points of 4) and (5), and the average value μ _GS of the crystal grain size, the standard deviation σ _GS, and the distribution D _GS were calculated. In addition, the corner portions 2, 3, 4, and 5 were in the range within 10% of the total length of the diagonal line from the corner portion toward the inside.

As described above, since the distribution D _GS of the crystal grain size on the sputtered surface is suppressed to 25% or less, the Ag alloy film 11 having a uniform film thickness can be formed.

<Method of manufacturing Ag alloy sputtering target>

Next, the manufacturing method of the Ag alloy sputtering target 20 which is this embodiment is demonstrated.

First, an Ag raw material having a purity of 99.9 mass% or higher, a Ge raw material having a purity of 99.9 mass% or higher, and an In raw material, Zn raw material, Sn raw material, Pd raw material, Au raw material, and Pt raw material having a purity of 99.9 mass% or higher are prepared as needed. .

Next, using a melting furnace, the Ag raw material is dissolved in a high vacuum or in an inert gas atmosphere, and a predetermined amount of Ge raw material in the obtained molten Ag metal, an In raw material, Zn raw material, Sn raw material, Pd raw material, Au raw material, Pt raw material is added. Thereafter, it is dissolved under high vacuum or in an inert gas atmosphere to prepare an Ag alloy ingot having a predetermined composition.

Here, it is preferable that the Ag raw material is dissolved in a high vacuum once inside the melting furnace, and then carried out in an atmosphere substituted with Ar, and after the dissolution, an auxiliary raw material is added in an Ar atmosphere.

In addition, a master alloy containing Ge, (In, Zn, Sn, Pd, Au, Pt) may be used as a raw material.

Subsequently, the obtained ingot is forged and rolled. Rolling is performed by hot rolling or cold rolling.

In the case of using hot rolling, it is preferable to perform heat treatment under conditions of holding at a temperature of 600°C or more and 700°C or less for 1 hour or more and 10 hours or less as a homogenization heat treatment step before the start of rolling. If it is less than 600°C, homogenization may be insufficient, and if it exceeds 700°C, a liquid phase may appear in the ingot, and the target may be softened and dissolved. In addition, if the heat treatment time is less than 1 hour, homogenization may be insufficient, and if it exceeds 10 hours, there is a concern that sub-materials in Ag may be internally oxidized.

Hot rolling is performed after the homogenization heat treatment step, but the temperature at the end of rolling is preferably 400° C. or more and 700° C. or less, and in some cases, intermediate annealing is preferably performed.

In rolling, it is preferable that the cumulative reduction ratio is 70% or more, and it is preferable that the reduction ratio of at least the last one pass of rolling is 20% or more. If the reduction ratio is less than 20%, the crystal grain size is not sufficiently refined, and the internal crystal grain size is also insufficiently uniform. In addition, in relation to the capability of the rolling mill, a reduction ratio of 50% or more per pass is not practical.

After rolling, heat treatment is performed in order to homogenize the crystal structure of the target material and remove work hardening. The heat treatment temperature is preferably carried out under conditions of holding for 1 hour or more and 5 hours or less in the range of 600°C or more and 700°C or less. If it is less than 600°C, the effect of removing work hardening is not sufficient, and if it exceeds 700°C, there is a concern that crystal grains become coarse or a liquid phase appears, causing the target to dissolve and soften. In addition, if the heat treatment time is less than 1 hour, uniformization becomes insufficient. After heat treatment, it is rapidly cooled by air cooling or water cooling.

By the above-described process, the Ag alloy sputtering target 20 according to the present embodiment is manufactured.

<Method of manufacturing a laminated film>

Next, the manufacturing method of the laminated film 10 which is this embodiment is demonstrated.

First, a transparent conductive oxide film 12 is formed on the surface of a substrate 1 made of glass or the like. In this embodiment, a film is formed using the sputtering target made of the above-described transparent conductive oxide. In addition, it is preferable to appropriately select and use DC (direct current) sputter, RF (high frequency) sputter, MF (medium frequency) sputter, AC (alternating current) sputter, etc. in consideration of the conductivity of the sputtering target.

Then, on the formed transparent conductive oxide film 12, the Ag alloy film 11 is formed using the Ag alloy sputtering target 20 according to the present embodiment described above. At this time, sputtering conditions are appropriately adjusted so that the thickness of the Ag alloy film 11 is in the range of 3 nm or more and 10 nm or less.

In addition, at the time of sputtering, the sputtering rate is measured by measuring the film thickness when the film is formed for a certain period of time with a step difference measuring system (DEKTAK-XT), and the film formation time is adjusted from the value to obtain the desired film thickness.

In addition, since the film thickness of the Ag alloy film 11 is very thin, 10 nm or less, it is preferable from the viewpoint of film thickness control to make the sputtering rate as slow as possible, so it is preferable to set the sputtering power as low as possible. .

On the Ag alloy film 11 formed as described above, the transparent conductive oxide film 12 is formed by using the sputtering target made of the above-described transparent conductive oxide.

In this way, the laminated film 10 according to the present embodiment is formed.

In the laminated film 10 of the present embodiment having the configuration as described above, it has an Ag alloy film 11 containing Ge in the range of 5.0 atomic% or more and 13.0 atomic% or less, and the Ag alloy film 11 Since the film thickness is in the range of 3 nm or more and 10 nm or less, diffusion of Ag is suppressed by Ge, and the Ag alloy film 11 does not become island-like, resulting in a relatively uniform film thickness. Further, even when the film is formed in an atmosphere containing water vapor, aggregation of Ag can be suppressed, and even when mass-produced, the Ag alloy film 11 can be suppressed from becoming a discontinuous film. As a result, sheet resistance and transmittance are improved.

Specifically, the sheet resistance of the laminated film 10 is 40 Ω/□ or less, and the average transmittance at a wavelength of 380 nm to 780 nm of the laminated film is 85% or more, and electrical properties and optical properties are great.

In addition, in the laminated film 10 of the present embodiment, the distribution of sheet resistance D _R = (σ _R / μ _R ) defined by the average value μ _R of sheet resistance measured at multiple points in the plane and the standard deviation σ _R Since × 100 is 20% or less, the properties are stable in the plane of the laminated film 10, and even if the film thickness is 3 nm or more and 10 nm or less, the Ag alloy film 11 with a relatively uniform film thickness is formed. .

In addition, in the laminated film 10 of the present embodiment, the Ag alloy film 11 further contains any one or two or more elements selected from In, Zn, and Sn, and In, Zn, Sn When the atomic ratio (In+Zn+Sn)/(Ge) of any one or two or more total content (In+Zn+Sn) and Ge content (Ge) selected from is within the range of 0.05 or more and 0.50 or less, In, Zn, and Sn As a result, Ag aggregation can be further suppressed, and the Ag alloy film can be suppressed from becoming a discontinuous film. In addition, deterioration in environmental resistance and water vapor resistance caused by In, Zn, and Sn can be suppressed.

In addition, in the laminated film 10 of the present embodiment, the Ag alloy film 11 further contains any one or two or more elements selected from Pd, Pt, and Au, and Pd, Au, Pt The atomic ratio (Pd+Au+Pt)/(Ge) of the total content (Pd+Au+Pt) and the Ge content (Ge) selected from is 0.01 or more, and is selected from In, Zn, Sn, Pd, Au, Pt. When the atomic ratio (In+Zn+Sn+Pd+Au+Pt)/(Ge) of any one or two or more of the total content (In+Zn+Sn+Pd+Au+Pt) and the Ge content (Ge) is within the range of 0.50 or less, the electrical properties of the laminated film 10 and It is possible to further improve the environmental resistance of the laminated film 10 while securing the optical properties.

In addition, in the laminated film 10 of this embodiment, the transparent conductive oxide film 12 is any one selected from In oxide, Sn oxide, Zn oxide, Nb oxide, Ti oxide, Al oxide, and Ga oxide, or Since the structure contains two or more types, the transparent conductive oxide film 12 has excellent electrical properties and optical properties, and the optical properties and electrical properties of the laminated film 10 as a whole can be improved.

In addition, in the Ag alloy sputtering target 20 according to the present embodiment, Ge is contained in the range of 5.0 atomic% or more and 13.0 atomic% or less, and the remainder is composed of Ag and unavoidable impurities. ), the diffusion of Ag is suppressed by these elements, and even when the thickness of the Ag alloy film 11 is formed to be 3 nm or more and 10 nm or less, aggregation of Ag can be suppressed. It becomes possible to form the Ag alloy film 11 of a uniform film thickness.

In addition, in the Ag alloy sputtering target 20 according to the present embodiment, the average value of the grain size is 200 μm or less, and the average value μ _{GS of the} grain size measured at multiple points on the sputtering surface and the standard deviation σ _GS of the grain size are determined. Since the defined crystal grain size distribution D _GS = (σ _GS / μ _GS ) × 100 is 25% or less, the sputter rate is relatively constant over the entire sputtering surface, and the Ag alloy film with a thickness of 3 nm or more and 10 nm or less (11) Can form a film stably.

In addition, the Ag alloy sputtering target 20 according to the present embodiment further contains any one or two or more elements selected from In, Zn, and Sn, and any one selected from In, Zn, and Sn, or When the atomic ratio (In+Zn+Sn)/(Ge) of the total content of two or more (In+Zn+Sn) and the Ge content (Ge) is in the range of 0.05 or more and 0.50 or less, a thin Ag alloy film of 3 nm or more and 10 nm or less ( Even if it is 11), aggregation of Ag can be suppressed, and the Ag alloy film 11 can be formed stably. Further, deterioration in environmental resistance and water vapor resistance caused by In, Zn, and Sn can be suppressed, and aggregation of Ag can be suppressed even when a film is formed in an atmosphere containing water vapor.

In addition, the Ag alloy sputtering target 20 of this embodiment further contains any one or two or more elements selected from Pd, Au, Pt, and any one selected from Pd, Au, Pt, or The atomic ratio (Pd+Au+Pt)/(Ge) of the total content of two or more (Pd+Au+Pt) and the Ge content (Ge) is 0.01 or more, and any one or two selected from In, Zn, Sn, Pd, Au, and Pt When the atomic ratio (In+Zn+Sn+Pd+Au+Pt)/(Ge) of the above total content (In+Zn+Sn+Pd+Au+Pt) and Ge content (Ge) is within the range of 0.50 or less, the electrical properties and optical properties of the formed Ag alloy film 11 are secured. As it remains, the environmental resistance of the Ag alloy film 11 can be further improved.

As mentioned above, although the embodiment of this invention was demonstrated, this invention is not limited to this, It can change suitably within the range which does not deviate from the technical idea of the invention.

For example, in the present embodiment, it has been described that a laminated film is formed on a glass substrate, but the present invention is not limited thereto, and a laminated film according to the present embodiment may be formed on a resin substrate or a resin film.

In addition, in this embodiment, as shown in FIG. 1, as shown in FIG. 1, one layer of Ag alloy film 11 is formed, and the transparent conductive oxide film 12 is formed on both surfaces of this Ag alloy film 11. Although described as a laminated film, it is not limited to this, for example, as shown in FIG. 5, two layers of the Ag alloy film 11 are formed, and a transparent conductive oxide film ( 12) The laminated film 110 of the five-layer structure may be a laminated film in which three or more Ag alloy films are formed, and transparent dielectric films are formed on both surfaces of each Ag alloy film.

Further, as shown in FIG. 6, even if it is a laminated film 210 in which an Ag alloy film 11 is formed on the substrate 1 and a transparent conductive oxide film 12 is formed on the Ag alloy film 11 do.

Further, as shown in FIG. 7, a laminated film 310 in which a transparent conductive oxide film 12 is formed on a substrate 1 and an Ag alloy film 11 is formed on the transparent conductive oxide film 12 May be.

That is, a laminated film in which the transparent conductive oxide film 12 is formed only on one side of the Ag alloy film 11 may be used.

In addition, in the present embodiment, the transparent conductive oxide film 12 was described as being formed by using a sputtering target made of oxide, but the present invention is not limited thereto, and the metals (In, Sn, Zn, Nb, You may form a film by carrying out reactive sputtering in an oxygen atmosphere using a sputtering target made of Ti, Al, Ga).

In addition, in the present embodiment, the sputtering surface has been described as having a rectangular shape, but the sputtering surface is not limited to this, and the sputtering surface may be circular or a cylindrical sputtering target that becomes a cylindrical surface.

In addition, in the sputtering target in which the sputtering surface has a circular shape, as shown in FIG. 8, the center 1 of the circle and two outer peripheral portions 2 on a straight line that are orthogonal to each other while passing through the center of the circle, It is preferable to measure the crystal grain size at five points of (3), (4) and (5). In addition, the outer circumferential portions (2), (3), (4), and (5) were within 10% of the diameter from the outer circumferential edge toward the inside.

In addition, in the cylindrical sputtering target in which the sputtering surface becomes a cylindrical surface, as shown in Figs. 9A and 9B, (1), (2), ( It is preferable to measure the crystal grain size at 4 points of 3) and (4).

Example

Hereinafter, the results of a confirmation experiment conducted to confirm the effectiveness of the present invention will be described.

An Ag raw material having a purity of 99.9 mass% or more is prepared, the Ag raw material is dissolved in a vacuum atmosphere, and replaced with Ar gas, and then contains Ge and In, Zn, Sn, Pd, Au, and Pt having a purity of 99.9 mass% or more. Sub-materials were added, and a molten Ag alloy having a predetermined composition was dissolved. Then, this molten Ag alloy was cast to produce an Ag alloy ingot.

(Ingredient composition)

A sample for analysis was taken from the obtained Ag alloy ingot, and the component composition was measured by ICP emission spectrometry. This measurement result is shown in Table 1 as a component composition of an Ag alloy sputtering target.

The obtained Ag alloy ingot was subjected to a homogenization treatment under the conditions of 650°C x 2 hours. After performing this homogenization treatment, hot rolling was performed. The rolling end temperature was set to 500°C, and the cumulative reduction ratio was set to 80%. Moreover, the reduction ratio of the final pass of rolling was made into 20 %.

After hot rolling, heat treatment was performed under the conditions of 650°C x 1 hour. After the heat treatment, it was rapidly cooled by water cooling.

In addition, in Comparative Example 6, the cumulative reduction ratio of rolling was set to 80%, and the heat treatment conditions after rolling were set to 800°C x 1 hour.

In addition, in Comparative Example 7, the cumulative reduction ratio of rolling was set to 40%, and the heat treatment conditions after rolling were set to 650°C x 1 hour.

By the above, a plate member having a length of 2000 mm, a width of 200 mm, and a thickness of 8 mm was obtained.

(Crystal grain size)

In the obtained plate material, the average value and distribution of the crystal grain size on the sputtered surface were measured as follows.

A measurement sample was taken from the position shown in FIG. 4, and after polishing with the sputtered surface of each measurement sample as an observation surface, etching treatment was performed.

Next, the observation surface was etched by using a mixed solution of an aqueous hydrogen peroxide solution and an aqueous ammonia solution as an etching solution, and immersing the etching solution at room temperature for 1 to 2 seconds.

The observation surface after etching was observed with an optical microscope, and a structure photograph was obtained. Using this structure photograph, particle diameter measurement was performed by the cutting method based on international standard ASTM E-112, ASTM particle size number G was calculated, and the average particle diameter corresponding to ASTM particle size number G was calculated|required. At this time, twins were excluded from the measurement. For one measurement sample, it was measured in 3 visual fields, and the average value was made into the crystal grain size of the said measurement sample. Further, observation was conducted by appropriately selecting an observation magnification according to the size of the crystal grain size.

Average value of each 5 places crystal grain size as a whole from the plate member 5 which is average of the diameter obtained from the measurement sample was calculated in the _GS μ and standard deviation σ _GS. And distribution D _GS = (σ _GS /μ _GS ) x 100 (%) was calculated using the average value μ _GS of these crystal grain sizes and the standard deviation sigma _GS . The measurement results are shown in Table 1 as the grain size of the Ag alloy sputtering target.

Next, an Ag alloy sputtering target having a predetermined dimension (126 mm × 178 mm × thickness 6 mm) was produced by cutting and machining the above-described plate material.

Using the Ag alloy sputtering target described above, a laminate film was formed in the following manner.

First, a 10 cm x 30 cm glass substrate (EAGLEXG manufactured by Corning) was prepared as a substrate.

Further, as a sputtering target for forming a transparent conductive oxide film, a sputtering target having the following composition was prepared.

ITO: In ₂ O ₃ -10 mass% SnO ₂

IZO: In ₂ O ₃ -10 mass% ZnO

TiO _x : TiO ₂

NbO _x : Nb ₂ O ₅

Here, the refractive index at a wavelength of 550 nm of the transparent conductive oxide film formed by the above-described sputtering target is as follows.

ITO membrane: 2.1

IZO membrane: 2.0

TiO _x membrane: 2.4

NbO _x membrane: 2.4

The above-described sputtering target and Ag alloy sputtering target were soldered to a backing plate made of oxygen-free copper, and this was attached to a sputtering device. In this embodiment, a magnetron DC sputtering device was used. In addition, in this embodiment, a substrate transfer sputtering device was used.

And sputtering was performed under the following conditions, a transparent conductive oxide film and an Ag alloy film were formed on a substrate, and the laminated film which has a layer structure shown in Table 2 was obtained. Further, after film formation, heat treatment was performed at 230° C. for 15 minutes in air using an infrared imaging furnace.

Film formation start vacuum degree: 1.0 × 10 ^-4 Pa or less

Sputter gas: high purity argon

Sputter gas pressure in the chamber: 0.4 Pa

DC power: 100 W

(Composition of Ag alloy film)

Further, separately from the laminated film, an Ag alloy film was formed on a substrate to a thickness of 1000 nm, and the component composition was measured by ICP emission spectroscopy. Thereby, it was confirmed that the component composition of the Ag alloy film is the same as that of the Ag alloy sputtering target.

(Measurement of film thickness)

In the case of forming a film by sputtering, the sputtering rate is measured by measuring the film thickness when the film is formed for a certain period of time with a level difference measuring system (DEKTAK-XT), and the film forming time is adjusted based on the value, and the film is formed so as to reach the target thickness. Further, since the Ag alloy film has a very thin film thickness of 10 nm or less, it is preferable to make the sputtering rate as slow as possible for the film thickness control.

The actual laminated film was confirmed by observing the cross section of the laminated film with a transmission electron microscope (TEM), and it was confirmed that the film thickness as the desired value was formed. For sample preparation for TEM observation, for example, a cross section polisher (CP) or a focused ion beam (FIB) can be used.

And, for the laminated film obtained as described above, sheet resistance, transmittance, environmental resistance, and water vapor resistance were evaluated as follows. Table 3 shows the evaluation results.

(Sheet resistance)

The sheet resistance of the laminated film was measured by a four-probe method using a resistance meter Loresta GP manufactured by Mitsubishi Chemical.

In addition, a substrate piece was collected from each point shown in FIG. 3 of a 10 cm × 30 cm glass substrate, and sheet resistance was evaluated, and the average value μ _{R in} the 5-point measurement of the sheet resistance and the 5-point measurement of the sheet resistance The standard deviation σ _{R in} was measured, and the distribution of sheet resistance D _R = (σ _R /μ _R ) x 100 (%) was calculated. Table 3 shows the evaluation results.

(Transmittance)

The transmittance of the laminated film was measured using a spectrophotometer (U-4100 manufactured by Hitachi High-Technologies Corporation). In Table 3, the average value of the transmittance at a wavelength of 380 nm to 780 nm is described.

In addition, at the time of measurement, since the measurement base line was measured with a glass substrate, the values listed in the table were taken as the relative transmittance when the transmittance of the substrate was 100.

(Environmental resistance)

The laminated film was held for 250 hours in an environment of 85°C and 85% humidity as a constant temperature and humidity test, and the sheet resistance of the film after the test was measured, and the rate of change before and after the test was evaluated.

(Change rate) = (Sheet resistance after test-Sheet resistance before test)/(Sheet resistance before test) × 100 (%)

(Water vapor tolerance)

When forming a laminated film, water vapor (H ₂ O) was introduced into Ar gas so that the partial pressure ratio was 4%. Then, about the formed laminated film, sheet resistance and transmittance were measured as described above. Table 3 shows the measurement results.

In Comparative Example 101, an Ag alloy film was formed using the Ag alloy sputtering target of Comparative Example 1, where the Ge content was 3.0 atomic% and lower than the range of the present invention, and the environmental resistance was insufficient, and the water vapor resistance was also insufficient.

In Comparative Example 102, an Ag alloy film was formed using the Ag alloy sputtering target of Comparative Example 3 whose atomic ratio (In+Zn+Sn)/(Ge) was 1.14, which was larger than the scope of the present invention, and the environmental resistance was insufficient, and the water vapor resistance. Also was insufficient.

In Comparative Examples 103 and 104, an Ag alloy film was formed using the Ag alloy sputtering targets of Comparative Examples 4 and 5 whose atomic ratios (In+Zn+Sn+Pd+Au+Pt)/(Ge) were 1.14 and 0.71, respectively, which were larger than the scope of the present invention, Water vapor tolerance was insufficient.

In Comparative Example 105, an Ag alloy film was formed using the Ag alloy sputtering target of Comparative Example 6 having an average crystal grain size μ _GS of 289 μm larger than the range of the present invention, and the distribution of sheet resistance D _R was large, and An Ag alloy film with uniform properties could not be formed.

In Comparative Example 106, an Ag alloy film was formed using the Ag alloy sputtering target of Comparative Example 7 having an average crystal grain size μ _GS of 241 μm and a distribution D _GS of 40% than the range of the present invention, and the distribution of sheet resistance D _The Ag alloy film having a large _R and uniform in-plane characteristics could not be formed.

In Comparative Example 107, an Ag alloy film having a thickness of 2 nm was formed by using the Ag alloy sputtering target of Comparative Example 2 in which the Ge content was 15.0 atomic%, which was greater than the range of the present invention, and the sheet resistance was high, and the electrical properties were It was insufficient.

In Comparative Example 108, an Ag alloy film having a thickness of 10 nm was formed by using the Ag alloy sputtering target of Comparative Example 2 with a Ge content of 15.0 atomic% greater than the scope of the present invention, and the transmittance was low and the optical properties were insufficient. I did.

In contrast, in the laminated films of Inventive Examples 101 to 127 in which an Ag alloy film having a film thickness of 3 nm or more and 10 nm or less was formed using the Ag alloy sputtering target of Examples 1 to 18, the sheet resistance of the laminated film was 32 Ω. It was confirmed that the transmittance of the laminated film was 86.5% or more while being equal to or less than /□, and excellent electrical properties and optical properties. In addition, it was confirmed that the rate of change in sheet resistance after the constant temperature and humidity test was relatively small, and that the environmental resistance was excellent.

Moreover, even when water vapor was introduced during film formation, it was confirmed that the sheet resistance and transmittance were excellent, and that the water vapor resistance was excellent.

Further, it was confirmed that the distribution of the sheet resistance measured at a plurality of points in the plane was 20% or less, and that an Ag alloy film having a uniform film thickness was formed.

In addition, in Inventive Example 121, a transparent conductive oxide film was formed on a substrate, and an Ag alloy film was formed on one side of the transparent conductive oxide film to form a two-layered laminated film, and in Inventive Example 122, Ag alloy A transparent conductive oxide film was formed on one side of the film, but the same effect was observed respectively.

In view of the above, according to the examples of the present invention, for example, the thickness of the Ag alloy film is 10 nm or less, excellent in electrical properties and optical properties, and particularly suitable for a transparent conductive wiring film or a transparent electrode, and It was confirmed that an Ag alloy sputtering target used when forming the Ag alloy film constituting this laminated film can be provided.

10, 110, 210, 310: laminated film
11: Ag alloy film
11AG: Distribution of Ag
11Ge: Ge distribution
12: transparent conductive oxide film
20: Ag alloy sputtering target

Claims (9)

A laminated film comprising an Ag alloy film and a transparent conductive oxide film laminated on one or both sides of the Ag alloy film,
The Ag alloy film contains Ge in a range of 5.0 atomic% or more and 13.0 atomic% or less, and the balance is made of Ag and unavoidable impurities,
A laminated film, wherein the Ag alloy film has a thickness of 3 nm or more and 10 nm or less. The method of claim 1,
The Ag alloy film further contains any one or two or more elements selected from In, Zn and Sn, and the total content of any one or two or more elements selected from In, Zn, and Sn (In+Zn+Sn) and Ge A laminated film, wherein the atomic ratio (In+Zn+Sn)/(Ge) of the content (Ge) of is in a range of 0.05 or more and 0.50 or less. The method according to claim 1 or 2,
The Ag alloy film further contains any one or two or more elements selected from Pd, Au, Pt, and the total content (Pd+Au+Pt) of any one or two or more selected from Pd, Au, Pt and Ge The atomic ratio (Pd+Au+Pt)/(Ge) of the content (Ge) is 0.01 or more, and the total content of any one or two or more selected from In, Zn, Sn, Pd, Au, and Pt (In+Zn+Sn+Pd+Au+Pt) and the content of Ge A laminated film, characterized in that the atomic ratio of (Ge) (In+Zn+Sn+Pd+Au+Pt)/(Ge) is in a range of 0.50 or less. The method according to any one of claims 1 to 3,
While the sheet resistance of the laminated film becomes 40 Ω/□ or less, the distribution of sheet resistance defined by the average value μ _R of the sheet resistance measured at multiple points in the plane and the standard deviation σ _R D _R = (σ _R / μ A laminated film, wherein _R ) x 100 is 20% or less. The method according to any one of claims 1 to 4,
The transparent conductive oxide film contains any one or two or more selected from In oxide, Sn oxide, Zn oxide, Nb oxide, Ti oxide, Al oxide, and Ga oxide. The method according to any one of claims 1 to 5,
The transparent conductive oxide film has a refractive index at a wavelength of 550 nm of 1.9 or more and 2.4 or less, and a film thickness of 5 nm or more and 50 nm or less. Ge is contained in the range of 5.0 atomic% or more and 13.0 atomic% or less, and the balance is made of Ag and unavoidable impurities,
In addition, the average value of the crystal grain size is 200 μm or less,
The distribution of the grain size defined by the average value μ _GS of the grain size measured at multiple points on the sputtering surface and the standard deviation σ _GS of the grain size D _GS = (σ _GS / μ _GS ) × 100 is 25% or less. Ag alloy sputtering target characterized by. The method of claim 7,
In addition, it contains any one or two or more elements selected from In, Zn, and Sn, and the total content (In+Zn+Sn) and Ge content (Ge) An Ag alloy sputtering target characterized in that the atomic ratio of (In+Zn+Sn)/(Ge) is in a range of 0.05 or more and 0.50 or less. The method according to claim 7 or 8,
In addition, it contains any one or two or more elements selected from Pd, Au, Pt, and the total content (Pd+Au+Pt) and Ge content (Ge) The atomic ratio of (Pd+Au+Pt)/(Ge) is 0.01 or more, and the total content (In+Zn+Sn+Pd+Au+Pt) and Ge content (Ge) of any one or more selected from In, Zn, Sn, Pd, Au, Pt. An Ag alloy sputtering target, characterized in that the boiling ratio (In+Zn+Sn+Pd+Au+Pt)/(Ge) is within a range of 0.50 or less.

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