KR20210019126A - Oxide thin film, and oxide sintered body for sputtering target for producing oxide thin film - Google Patents

Abstract

It is an oxide thin film made of Nb, Mo, O, and the content ratio (atomic ratio) of Nb and Mo is 0.1≤Nb/(Nb+Mo)≤0.8, and the content ratio (atomic ratio) of O and metal (Nb+Mo) is An oxide thin film characterized in that 1.5<O/(Nb+Mo)<2.0. In addition, it is an oxide sintered body composed of Nb, Mo, and O, and the content ratio (atomic ratio) of Nb and Mo is 0.1≦Nb/(Nb+Mo)≦0.8, and the content ratio of O and metal (Nb+Mo) (atomic ratio) ) Is 1.5<O/(Nb+Mo)<2.1, the relationship between the XRD peak intensity I _MoO2 and the background intensity I _BG attributable to the (-111) plane on MoO ₂ satisfies I _MoO2 /I _BG >3 Oxide sintered body made into. The present invention is an oxide thin film having excellent properties such that it has low reflectance and transmittance, has excellent light absorption ability, is dissolved in an etching solution, is easy to process, has high weather resistance, and is less likely to change over time, and is suitable for forming the thin film. It is an object to provide an oxide sintered body for sputtering targets.

Description

Oxide thin film and oxide sintered body for sputtering target for producing the thin film {OXIDE THIN FILM, AND OXIDE SINTERED BODY FOR SPUTTERING TARGET FOR PRODUCING OXIDE THIN FILM}

The present invention relates to an oxide thin film having light absorbing ability and an oxide sintered body for a sputtering target for producing the thin film.

In liquid crystal displays, plasma displays, organic EL displays, touch panels, solar cells, and the like, a transparent conductive film made of ITO (indium tin oxide) is used as a wiring member. Since ITO has excellent transmittance to visible light and has a low resistivity in oxides, it is an excellent material as a wiring member. However, when the display or panel is made into a large area, there is a problem that resistance is high and that it cannot cope with the large area.

In this respect, instead of the ITO film, it has been studied to use a metal thin film having a low resistivity as a wiring member. However, when used as a wiring member, there has been a problem that the metal thin film reflects visible light, thereby reducing the visibility of a display or panel. On the other hand, it has been studied to form a film capable of absorbing reflected light in the vicinity of the metal thin film, to suppress reflection of light by the metal thin film, and to improve visibility.

Regarding the film for reducing reflection of light, for example, in Patent Document 1, as a film for reducing the metallic luster of the wiring pattern of the touch panel screen, it contains any one of Cu and Fe, and any one of Ni and Mn. It is disclosed to use an oxide film. In addition, Patent Document 2 discloses forming a blackening layer containing oxygen, copper, nickel, and molybdenum together with a wiring layer composed of copper foil or the like.

Patent Documents 3 to 5 disclose a light absorbing layer composed of two layers in which a metal as an absorbing component is dispersed in an oxide matrix with respect to a light absorbing layer for use of solar heat or a black matrix layer of a liquid crystal display. . In addition, those having a luminous transmittance of less than 1% and a luminous reflectance of less than 6% in a wavelength range of 380 to 780 nm are described in which the thickness of the entire layer is in the range of 180 to 455 nm.

In addition, a phase shift type photomask is known as an application requiring light transmittance, reflectance, and film thickness. The phase shift type photomask is used for the purpose of improving the resolution by utilizing interference of light. The phase shift type photomask film is required to have a specific film thickness, a specific transmittance (about several%), and a low reflectance depending on the laser wavelength to be used. In addition, even in decorative applications, there is a demand for a film that reduces reflection of light.

In addition, Patent Document 6 discloses a thin film for a black matrix in which the Nb content is 1 to 35% by weight and the remainder is substantially Mo, and a part or all of the thin film is one or two or more of oxides, nitrides and carbides. It is described that exists as a compound. However, in Patent Document 6, there is no specific disclosure about the content ratio of oxygen or the like, and it is not known at all what degree of reflectance or transmittance is obtained.

Japanese Patent Publication No. 2016-160448 Japanese Patent Publication No. 2017-41115 Japanese Patent Publication No. 2016-504484 Japanese Patent Publication No. 2016-502592 Japanese Patent Publication No. 2016-522317 Japanese Patent Publication No. 2000-214308

An object of the present invention is to provide an oxide thin film suitable for preventing reflection of light and having a light absorbing ability having both good workability by etching and weather resistance, and an oxide sintered body for a sputtering target suitable for forming the oxide thin film.

The oxide thin film according to the embodiment of the present invention is an oxide thin film made of Nb, Mo, O (oxygen), and the content ratio (atomic ratio) of Nb and Mo is 0.1≦Nb/(Nb+Mo)≦0.8, and O and The gist is that the content ratio (atomic ratio) of the metal (Nb+Mo) is 1.5<O/(Nb+Mo)<2.0.

In addition, the oxide sintered body according to the embodiment of the present invention is made of Nb, Mo, O (oxygen), and the content ratio (atomic ratio) of Nb and Mo is 0.1≦Nb/(Nb+Mo)≦0.8, and O and The content ratio (atomic ratio) of metal (Nb+Mo) is 1.5<O/(Nb+Mo)<2.1, XRD peak intensity I _MoO2 and background intensity I _BG attributable to the (-111) plane of MoO ₂ I have a gist of satisfying I _MoO2 /I _BG >3.

Advantageous Effects of Invention According to the present invention, it is possible to obtain an oxide thin film having good workability by etching and weather resistance, and having a light absorption ability suitable for preventing reflection of light. Further, it is possible to obtain an oxide sintered body for a sputtering target suitable for forming the oxide thin film.

1 is an explanatory diagram of the reflectance (film side reflectance) of light incident from the thin film side.
Fig. 2 is an explanatory diagram of reflectance (substrate side reflectance) of light incident from the glass substrate side.

It is also conceivable to use a metal film as the light absorbing film. However, in this case, light absorption is high and the transmittance can be reduced, but metal reflection peculiar to the metal occurs, making it difficult to reduce the reflectance. It is also conceivable to form an oxide film on the metal film, but the manufacturing process increases, resulting in lowering the production efficiency. On the other hand, it is conceivable to use an oxide film as the light absorbing film. In this case, since metal reflection does not occur, surface reflection is suppressed. However, since the light absorption property is lower than that of the metal film, the transmittance increases, the reflected light from the lower metal electrode or the like is remarkable, and the visibility may be deteriorated.

From this point of view, among oxides, NbO ₂ or MoO ₂ is a material that has a relatively low transmittance of visible light and a low reflectance, and is considered useful as a light absorbing film. However, in the case of the NbO ₂ film alone, there is a problem in that the change over time is small and the weather resistance is excellent, while it is difficult to dissolve in an etching solution other than hydrogen fluoride (HF), and processing by etching is difficult. On the other hand, in the case of the MoO ₂ film alone, it is possible to process by etching even in a hydrogen peroxide (H ₂ O ₂ )-based etching solution used for metal wiring, but there is a problem that weather resistance is inferior.

In this respect, the oxide thin film according to the embodiment of the present invention has good weather resistance, but contains NbO _{2 which} is difficult to process by etching, and MoO ₂ which can be processed by etching, but has difficulty in weather resistance, in a specific ratio. Is to do. That is, the oxide thin film according to the embodiment of the present invention is made of Nb, Mo, O (oxygen), and the content ratio (atomic ratio) of Nb and Mo is 0.1≦Nb/(Nb+Mo)≦0.8, and O and It is characterized in that the content ratio (atomic ratio) of the metal (Nb+Mo) is 1.5<O/(Nb+Mo)<2.0.

The oxide thin film according to the embodiment of the present invention satisfying the composition range 0.1≦Nb/(Nb+Mo)≦0.8 has desired optical properties, film resistance, and amorphous properties. On the other hand, when Nb/(Nb+Mo) is less than 0.1, desired weatherability cannot be obtained, and when Nb/(Nb+Mo) is more than 0.8, desired workability by etching cannot be obtained. Preferably, the content ratio of Nb and Mo is 0.1<Nb/(Nb+Mo)<0.5. Further, when the content ratio O/(Nb+Mo) of O and metal (Nb+Mo) is 1.5 or less, the reflectance increases, and when it is 2.0 or more, the transmittance increases, and desired optical properties cannot be obtained. Therefore, it is set as the above composition range.

In addition, the oxide thin film according to the embodiment of the present invention has an average reflectance of 30% or less for incident light in the visible region (wavelength: 380 to 780 nm) when a thin film having a film thickness of 100 ± 10 nm is formed on a glass substrate. It is desirable. Here, the "average" reflectance is obtained by measuring the reflectance of the above-described wavelength range every 5 nm, and calculating the average value.

The reflectance includes the reflectance of light incident from the thin film side as shown in Fig. 1 (film side reflectance) and the reflectance of light incident from the glass substrate side as shown in Fig. 2 (substrate side reflectance). In, reflectance means only the film side reflectance. In addition, the reflected light includes specular reflected light and diffusely reflected light, and in the present disclosure, it refers to a relative total light reflectance obtained by combining the specularly reflected light and diffusely reflected light.

In addition, in the oxide thin film according to the embodiment of the present invention, when a thin film having a film thickness of 100 ± 10 nm is formed on a glass substrate, the average transmittance to incident light in the visible region (wavelength: 380 to 780 nm) is 20 It is preferable that it is% or less. Here, the "average" transmittance is obtained by measuring the transmittance of the wavelength region every 5 nm and calculating the average value.

With this level of reflectance and transmittance, light reflected from metal wirings (copper foil, etc.) inside the display or panel can be sufficiently absorbed, and a decrease in visibility can be suppressed. In addition, it is possible to satisfy the low reflectance required for a phase shift type photomask application.

By the way, the transmittance is related to the film thickness of the oxide thin film, and generally, the transmittance decreases as the film thickness increases. As described above, in the embodiment of the present invention, the transmittance when the thickness of the oxide thin film is 100 nm ± 10 nm or more is specified, but the value of ± 10 nm is that it is practically difficult to form a film accurately at 100 nm. This is considered, and even if the film thickness fluctuates by ±10 nm (ie, 90 to 110 nm), in theory, the fluctuation width of the transmittance is within ±1.3%. The oxide thin film according to the embodiment of the present invention satisfies an average transmittance of 20% or less even when the fluctuation width of the transmittance is considered.

In addition, it is preferable that the oxide thin film according to the embodiment of the present invention has a surface resistivity of 1.0×10 ⁵ Ω/sq or less. The oxide thin film functioning as the light absorbing film is laminated adjacent to the metal wiring in order to suppress light reflection by the metal wiring, but when the resistivity of the oxide thin film is high, sufficient current does not flow through the metal wiring. Therefore, it is preferable that the surface resistivity of the oxide thin film is within the above-described range.

In addition, it is preferable that the oxide thin film according to the embodiment of the present invention is excellent in weather resistance, and has an average transmittance and an average reflectance change rate of 30% or less in the visible light region (wavelength: 380 to 780 nm) before and after the constant temperature and humidity test. Further, it is preferable that the rate of change of the surface resistivity before and after the constant temperature and humidity test is 30% or less.

Here, in the constant temperature and humidity test according to the present disclosure, the oxide thin film sample formed on the substrate is left to stand in room A (temperature 40°C-90% humidity) and room B (temperature 85°C-85% humidity), and 120 Transmittance, reflectance, and surface resistivity were measured after the lapse of time, after 500 hours, and after 1000 hours, and the rate of change was investigated in comparison with each measured value immediately after film formation.

In addition, in the embodiment of the present invention, the thickness of the oxide thin film is preferably 20 to 2000 nm. If the film thickness is less than 20 nm, the light absorbing ability may decrease. On the other hand, if the film thickness exceeds 2000 nm, the film formation takes more time than necessary, which is not preferable. However, since the film thickness is finally determined by the device design, it is not limited to this film thickness as long as the light absorption ability can be secured.

In addition, it is preferable that the oxide thin film according to the embodiment of the present invention is amorphous (amorphous). Since the amorphous film has a smaller film stress than the crystallized film, film peeling or cracking at the time of lamination is less likely to occur. Therefore, it is particularly suitable for use in flexible devices.

Next, an oxide sintered body according to an embodiment of the present invention will be described in detail.

The oxide sintered body according to the embodiment of the present invention is made of Nb, Mo, O (oxygen), and the content ratio (atomic ratio) of Nb and Mo is 0.1≦Nb/(Nb+Mo)≦0.8, and O and metal ( The content ratio (atomic ratio) of Nb+Mo) is 1.5<O/(Nb+Mo)<2.1, the relationship between the XRD peak intensity I _MoO2 and the background intensity I _BG attributable to the (-111) plane on MoO ₂ , It is characterized by satisfying I _MoO2 /I _BG >3. An oxide sintered body having such characteristics can be used as a sputtering target.

The oxide sintered body according to the embodiment of the present invention satisfying the above composition ranges 0.1≦Nb/(Nb+Mo)≦0.8 and 1.5<O/(Nb+Mo)<2.1 is a sputtered thin film having desired optical properties. , Membrane resistance, and amorphous properties. In the oxide sintered body, when the content ratio of O and metal (Nb+Mo) is 1.5<O/(Nb+Mo)<2.1, in the thin film formed by sputtering using the oxide sintered body (sputtering target), during sputtering, Even when oxygen introduction is not performed, the content ratio of O and metal (Nb+Mo) is in the range of 1.5<O/(Nb+Mo)<2.0, and desired film properties are obtained.

And the oxide-sintered body of the embodiment of the present invention, MoO ₂ (-111) XRD peak intensity I _MoO2 attributable to the surface on, but that the relationship between the background intensity _BG I, satisfying the I _MoO2 / I _BG> 3, the When the XRD peak intensity ratio I _MoO2 /I _BG > 3 is satisfied, most of the molybdenum (Mo) in the sintered body is present as MoO ₂ , and when such an oxide sintered body is used, desired optical properties in the sputtered thin film Is obtained.

In addition, it is preferable that the relative density of the oxide sintered body according to the embodiment of the present invention is 80% or more. If the relative density is 80% or more, it can withstand practical use as a sputtering target. More preferably, it is 85% or more.

In addition, it is preferable that the oxide sintered body according to the embodiment of the present invention has a bulk resistivity of 100 mΩ·cm or less. Due to the decrease in bulk resistivity, film formation by DC sputtering becomes possible. Compared to RF sputtering, DC sputtering has a faster film formation speed and has excellent sputtering efficiency, and thus throughput can be improved. Moreover, although RF sputtering may be performed depending on the manufacturing conditions, there is an improvement in the film forming speed also in that case.

The oxide sintered body according to the embodiment of the present invention can be produced, for example, as follows.

The raw material powder of NbO ₂ powder and MoO ₂ powder is weighed and mixed so as to obtain a desired composition. It is preferable to use a raw material powder having a purity of 99.9% or more and a particle diameter (D50) of 0.5 to 10 µm. As a mixing method, it is preferable to use a ball mill or the like to pulverize and mix. As the raw material powder, it is also conceivable to use Nb ₂ O ₅ powder and Mo powder, but Nb ₂ O ₅ and Mo have a large difference in sintering temperature, making it difficult to increase density.

Next, the mixed powder is subjected to hot pressing (uniaxial pressure sintering) in an Ar atmosphere of 1100°C or more and 1200°C or less, a pressing force of 250 MPa or more for 5 to 10 hours. Thereby, an oxide sintered body made of Nb, Mo, and O having a relative density of 80% or more can be obtained. Further, the obtained oxide sintered body can be cut and polished to be processed into a sputtering target.

The oxide thin film according to the embodiment of the present invention can be produced, for example, as follows.

An NbO ₂ sputtering target and a MoO ₂ sputtering target are installed in a sputtering device, sputtering is performed simultaneously, and a mixed film of NbO ₂ and MoO ₂ is formed on the substrate. At this time, the film composition can be changed by changing the respective sputtering power during sputtering.

Alternatively, a sputtering target produced by the above-described method is installed in a sputtering apparatus, sputtering is performed, and a mixed film of NbO ₂ and MoO ₂ is formed on the substrate. At this time, the composition of the sputtering target does not become completely the same as the composition of the film, but a composition approximates it. Since the composition of the target and the composition of the film have a relationship, it becomes possible to grasp the composition of the target capable of obtaining a desired film composition by presenting conditions. Further, the amount of oxygen in the film can also be adjusted by adjusting the flow rate of oxygen introduced during sputtering.

<film formation conditions>

Sputter device: ANELVA SPL-500

Substrate temperature: room temperature (substrate no heating)

Film formation atmosphere: Ar or Ar+O ₂

Gas pressure: 0.2 to 2.0 Pa

Gas flow: 50-100 sccm

Power: 100 to 1000W (DC, RF)

Substrate: Corning Eagle XG (φ4㎜×0.7㎜)

The evaluation methods of the oxide thin film and the oxide sintered body according to the embodiment of the present invention are as follows, including examples and comparative examples.

(About transmittance and reflectance)

Apparatus: SHIMADZU spectrophotometer UV-2450

Measurement sample:

A sample formed to a film thickness of 100±10 nm on a glass substrate having a thickness of 0.7 mm, and an unfilmed glass substrate

How to measure:

(Reflectance) Relative total light reflectance using an integrating sphere (reference sample; mirror mirror).

The reflectance (film side reflectance) of light incident from the thin film side includes not only the reflectance from the thin film surface, but also the reflectance from the glass substrate (surface) at the interface with the thin film, and the reflectance from the back surface of the glass substrate.

In the reflectance of light incident from the glass substrate side (substrate side reflectance),

It includes the reflectance from the surface of the glass substrate and the reflectance from the thin film at the interface of the glass substrate.

(Transmittance) Relative transmittance using a glass substrate as a reference sample.

(About the composition of the film)

Device: JEOL manufactured JXA-8500F

Method: Electron Beam Microanalyzer (EPMA)

Acceleration voltage: 5 to 10 keV

Irradiation current: 1.0×10 ^-8 ∼1.0∼10 ^-9 A

Probe diameter 10㎛, 5 points, no adhesion of dust, no visible substrate surface,

A smooth film-forming part was selected, point analysis was performed, and their average composition was calculated.

(About the surface resistance of the film)

Apparatus: Resistivity measuring instrument manufactured by NPS Σ-5+

Method: DC 4-probe method

(About the amorphous nature of the film)

It was judged by the presence or absence of a diffraction peak by X-ray diffraction of the film-forming sample. When the diffraction peak due to the film material is not observed by measurement under the following conditions, it is judged as an amorphous film. Here, that the diffraction peak does not exist, when the maximum peak intensity at 2θ = 10° to 60° is I _max , and the average peak intensity at 2θ = 20° to 25° is I _BG , I _max / I _It means the case of _BG <5. In addition, in the table, as a criterion for the determination of amorphous property, the case where I _max /I _BG <5 was satisfied was set to ○, and the case not satisfied was set to ×.

Apparatus: Smart Lab manufactured by Rigaku Corporation

District: Cu-Kα line

Tube voltage: 40kV

Current: 30㎃

Measurement method: 2θ-θ reflection method

Scan speed: 20°/min

Sampling interval: 0.02°

Measurement range: 10° to 60°

Measurement sample: Film formation sample on glass substrate (Eagle XG) (film thickness 100 nm or more)

(About film thickness measurement)

Dektak8 manufactured by Veeco, a stylus type step meter

Way; The film thickness is measured from the step difference between the film-forming surface and the non-film-forming surface of the formed glass substrate.

(About workability by film etching)

As the etching solution, a hydrogen peroxide (H ₂ O ₂ )-based chemical solution was used. Etching determination was made as (circle) a case in which the etching rate is fast, △ for a slow case, and × as a case where it hardly melts.

(About the composition of the sintered body)

Device: SPS3500DD manufactured by SII

Method: ICP-OES (high frequency inductively coupled plasma luminescence assay)

(About the relative density of the sintered body)

The dimensional density is calculated by measuring the size (using a vernier caliper) and the weight of the sintered body, and from the dimensional density and the theoretical density of the sintered body, relative density (%) = dimensional density/theoretical density x 100 is calculated.

The theoretical density is calculated from the mixing ratio of each oxide and each theoretical density.

When the weight of NbO ₂ is a (wt%) and the weight of MoO ₂ is b (wt%),

Theoretical density = 100/(a/5.90+b/6.44)

Theoretical density of NbO ₂ : 5.90 g/cm 3, Theoretical density of MoO ₂ : 6.44 g/cm 3

(About XRD analysis of sintered body)

Apparatus: Smart Lab manufactured by Rigaku Corporation

District: Cu-Kα line

Tube voltage: 40kV

Current: 30㎃

Measurement method: 2θ-θ reflection method

Scan speed: 20°/min

Sampling interval: 0.02°

Measurement range: 10° to 60°

Sample measurement location: sputtered surface

In addition, the XRD peak I _MoO2 attributable to the (-111) plane on MoO ₂ is defined below.

I _MoO2 =I _MoO2´ /I _MoO2-BG

I _MoO2' : XRD peak intensity in the range of 25.5°≤2θ≤26.5°

I _MoO2-BG : XRD average intensity in the range of 19.5°≦2θ<20.5°.

(About bulk resistivity of sintered body)

Apparatus: Resistivity measuring instrument manufactured by NPS Σ-5+

Method: DC 4 probe method

[Example]

Hereinafter, it demonstrates based on an Example and a comparative example. In addition, this embodiment is an example only, and is not limited at all by this example. That is, the present invention is to be limited only by the claims, and includes various modifications other than the embodiments included in the present invention.

(Examples 1-1 to 1-6, Comparative Examples 1-1 to 1-2)

NbO ₂ target (φ 6 inch) and MoO ₂ target (φ 6 inch) were installed on a sputtering device (ANELVA SPL-500), and a mixed film of NbO ₂ and MoO ₂ was formed on a glass substrate (Eagle XG, φ 4 inch) by simultaneous sputtering. I did. Film formation conditions were as described above, and as shown in Table 1, the power of each target during sputtering was changed to produce a film having the composition shown in Table 1. In addition, in Comparative Example 1-1, only the MoO ₂ target was sputtered to form a MoO ₂ film, and in Comparative Example 1-2, only the NbO ₂ target was sputtered to form an NbO ₂ film. Thereafter, for each oxide thin film whose composition was respectively changed, the transmittance, the surface reflectance, the back surface reflectance, and the surface resistivity were measured immediately after film formation (room temperature), and further investigated for etching property. The results are shown in Table 1.

As shown in Table 1, all of the oxide thin films (Examples 1-1 to 1-6) satisfying the content ratio (atomic ratio) of Nb and Mo to 0.1≦Nb/(Nb+Mo)≦0.8 were The average transmittance and the average reflectance were low, exhibiting excellent light absorption capability, low film resistance, excellent etching processability, and exhibiting amorphous properties. Examples 1-1 to 1-5 exhibited particularly fast etching rates.

Next, in order to investigate weather resistance, each oxide thin film formed on the substrate under each condition was left to stand in room A (temperature 40°C-90% humidity) and room B (temperature 85°C-85% humidity), Changes in transmittance, surface reflectance, back surface reflectance, and surface resistance after the lapse of 12 hours, 500 hours, and 1000 hours were investigated. The results are shown in Table 2.

As shown in Table 2, the oxide thin films (Examples 1-2 to 1-5) had a change in transmittance, reflectance, and surface resistance with time (change rate) of 30% or less, and were excellent in weather resistance.

On the other hand, the oxide thin film containing only Mo (Comparative Example 1-1) was inferior in weather resistance, and the transmittance and the like remarkably increased with the passage of time. In addition, the oxide thin film containing only Nb (Comparative Example 1-3) was hardly dissolved in the etching solution.

(Examples 2-1 to 2-4, Comparative Example 2-1)

As raw material powders, NbO ₂ powder and MoO ₂ powder having a purity of 99.9% or more and a particle diameter of 0.5 to ₁₀ μm were prepared, and these powders were weighed so as to have a predetermined ratio shown in Table 3, and mixed and pulverized by a ball mill. Implemented. Next, the obtained mixed powder was hot press-sintered in an argon atmosphere at a sintering temperature of 1200°C and a surface pressure of 250 kgf/cm 2 to prepare an oxide sintered body. In addition, all of them were mixed, pulverized and sintered under the same conditions, except that only the weighing ratio was adjusted.

Table 3 shows the evaluation results of the obtained oxide sintered body. As shown in Table 3, which embodiment examples the XRD peak intensity I relationship between _MoO2 and the background intensity _BG I attributable to plane (-111) on the MoO ₂ satisfy the _MoO2 I / I _BG> 3, also a relative density of 80 % Or more, and the bulk resistivity was 100 mΩcm or less. On the other hand, for Comparative Example 2-1, and the XRD peak intensity ratio of 1.7 on the MoO _2, MoO ₂ is disappeared.

Next, the oxide sintered body obtained in Examples and Comparative Examples was processed into a sputtering target, and sputtering was formed using the target. Table 3 shows the optical properties of the obtained sputtering film. All of the films formed by sputtering using the oxide sintered body obtained in Examples had low average transmittance and average reflectance, and exhibited excellent light absorption ability.

The oxide thin film according to the embodiment of the present invention has excellent characteristics such as low transmittance and reflectance, excellent light absorption ability, and further processing by etching, high weather resistance, and less likely to change over time. In addition, since the oxide sintered body according to the embodiment of the present invention has high density, it can be used as a sputtering target. The oxide thin film according to the embodiment of the present invention is a light absorbing film that prevents reflection of light by metal wiring used in a liquid crystal display, a plasma display, an organic EL display, a touch panel, a solar cell, etc. Very useful as an application.

Claims (9)

It is an oxide thin film made of Nb, Mo, O, and the content ratio (atomic ratio) of Nb and Mo is 0.1≤Nb/(Nb+Mo)≤0.8, and the content ratio (atomic ratio) of O and metal (Nb+Mo) is An oxide thin film characterized in that 1.5<O/(Nb+Mo)<2.0. The method of claim 1,
An oxide thin film characterized by having an average reflectance of 30% or less in a visible light region (wavelength: 380 to 780 nm). The method according to claim 1 or 2,
An oxide thin film having an average transmittance of 20% or less in a visible light region (wavelength: 380 to 780 nm). The method according to claim 1 or 2,
An oxide thin film having a surface resistivity of 1.0×10 ⁵ Ω/sq or less. The method according to claim 1 or 2,
An oxide thin film characterized in that the rate of change in the average reflectance in the visible light region (wavelength: 380 to 780 nm) before and after the constant temperature and humidity test is 30% or less. The method according to claim 1 or 2,
An oxide thin film characterized in that the rate of change in the average transmittance in the visible region (wavelength: 380 to 780 nm) before and after the constant temperature and humidity test is 30% or less. The method according to claim 1 or 2,
An oxide thin film characterized in that the rate of change of the surface resistivity before and after the constant temperature and humidity test is 30% or less. The method according to claim 1 or 2,
An oxide thin film having a film thickness of 20 to 2000 nm. The method according to claim 1 or 2,
Oxide thin film, characterized in that the amorphous.

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