WO2010058533A1 - ZnO-SnO2-In2O3 BASED SINTERED OXIDE AND AMORPHOUS TRANSPARENT CONDUCTIVE FILM - Google Patents

Abstract

A process for producing a sintered oxide, which comprises the following steps (a) to (d): (a) mixing raw material compound powders respectively containing Zn, Sn and In together to prepare a mixture; (b) molding the mixture to prepare a molded product; (c) sintering the molded product at a temperature equal to or higher than 1000˚C and lower than 1300˚C for 0 hour or longer; and (d) further sintering the sintered molded product at a temperature equal to or higher than 1300˚C and lower than 1500˚C for 2 hours or longer.

Description

ZnO—SnO2-In2O3 oxide sintered body and amorphous transparent conductive film

The present invention relates to an oxide sintered body, a sputtering target, an amorphous transparent conductive film, and a substrate with an amorphous transparent conductive film.

The transparent conductive film has both high visible light transmittance and high conductivity, such as a liquid crystal display element, a transparent electrode for a display element such as a plasma light emitting element, a transparent electrode for a solar cell, a heat ray reflective film for automotive or architectural glass, and a CRT charging. Widely used as a transparent heating element for anti-fogging, such as a prevention film or a refrigerated showcase.

As the transparent conductive film, an ITO (tin-doped indium oxide) film is mainly used because a low-resistance film can be easily obtained. In particular, an ITO film is widely used as an electrode for a display element. In addition to the ITO film, a zinc oxide-based transparent conductive film that can be manufactured at low cost and a tin oxide-based transparent conductive film that can be manufactured at low cost and have high chemical resistance are known.

As a problem of the conventional transparent conductive film, for example, in the case of an ITO film, indium which is a main component thereof is expensive, it cannot be manufactured at a low cost.
Moreover, about the zinc oxide type transparent conductive film, the chemical resistance with respect to an acid, an alkali, etc. is low, and it was difficult to apply a zinc oxide type transparent conductive film to industrial products, such as a display element.

The tin oxide-based transparent conductive film has extremely excellent chemical resistance as compared with the ITO film and the zinc oxide-based transparent conductive film. However, a tin oxide transparent conductive film is formed by an industrial manufacturing method, for example, by a spray method or a CVD method. However, it is difficult to form a uniform film thickness, and at the time of film formation, chlorine, hydrogen chloride, etc. There was a problem of environmental pollution due to these exhaust gases (or effluents).
Further, since the tin oxide-based transparent conductive film is crystalline, there is a problem that the scratch resistance is low. This is presumably because fine irregularities formed during crystal growth are present on the surface of the film.

As a method for forming a transparent conductive film with a large area, a sputtering method that is easy to obtain a uniform thin film and has little environmental pollution is suitable. Sputtering methods are roughly classified into a high frequency (RF) sputtering method using a high frequency power source and a direct current (DC) sputtering method using a direct current power source.
The RF sputtering method is excellent in that an electrically insulating material can be used as a target. However, a high-frequency power source is expensive and complicated in structure, and is not suitable for film formation over a large area. On the other hand, in the DC sputtering method, the target that can be used is limited to a target made of a highly conductive material, but it is easy to operate because a DC power source with a simple device structure is used. The method is preferred.

Patent Document 1 _discloses a sputtering target composed of an In ₂ O 3, ZnO and SnO _2. This sputtering target discloses a transparent electrode material containing a hexagonal layered compound represented by In ₂ O ₃ (ZnO) _m and having excellent etching characteristics. However, Patent Document 1 proposes to precipitate an In ₂ O ₃ (ZnO) _m phase for the purpose of reducing the bulk resistance, but the specific resistance of the In ₂ O ₃ (ZnO) _m crystal is not so small. For this reason, the resistance of the sintered body may not decrease.
Moreover, in the manufacturing method disclosed in Patent Document 1, since the In ₂ O ₃ phase in which both Zn and Sn are dissolved cannot be precipitated in the target, the bulk resistance may not be sufficiently lowered.

Patent Document 2 discloses a sputtering target made of In ₂ O ₃ , ZnO and SnO _2, but Patent Document 2 is a disclosure relating to an optical information recording medium, and is a specific example used as a transparent electrode material and a transparent semiconductor material. There is no description.
Moreover, in the manufacturing method disclosed in Patent Document 2, since the In ₂ O ₃ phase in which both Zn and Sn are dissolved cannot be precipitated in the target, the bulk resistance may not be sufficiently lowered.

Patent Document 3 discloses a target of tin phase and a zinc stannate compound phase oxidation _(Zn 2 SnO _4).

JP 2000-256059 A JP 2005-154820 A JP 2007-314364 A

An object of the present invention is to provide an amorphous zinc oxide-tin oxide-based transparent conductive film with indium saving and low bulk resistance.
An object of the present invention is to provide a sintered body capable of forming the amorphous zinc oxide-tin oxide transparent conductive film and a method for producing the same.

According to the present invention, the following method for producing an oxide sintered body and the like are provided.
1. (A) preparing a mixture by mixing raw material compound powders containing Zn, Sn and In;
(B) forming the mixture to prepare a molded body;
(C) a step of sintering the molded body at 1000 ° C. or higher and lower than 1300 ° C. for 0 hour or longer; and (d) a step of further sintering the sintered molded body at 1300 ° C. or higher and lower than 1500 ° C. for 2 hours or longer. And manufacturing method of oxide sintered body.
The oxide sintered compact manufactured by the manufacturing method of 2.1.
3. Contains indium, zinc and tin,
An oxide sintered body containing an indium oxide phase in which zinc and tin are dissolved.
4). 4. The oxide sintered body according to 3, wherein the atomic ratio of zinc, tin and indium satisfies the following relational expression.
0.01 ≦ Zn / (Zn + Sn + In) ≦ 0.80
0.10 ≦ Sn / (Zn + Sn + In) ≦ 0.98
0.01 ≦ In / (Zn + Sn + In) ≦ 0.50
5). 5. The oxide sintered body according to 4, wherein the atomic ratio of zinc, tin and indium satisfies the following relational expression (1).
Relational expression (1):
0.01 ≦ Zn / (Zn + Sn + In) ≦ 0.15
0.80 ≦ Sn / (Zn + Sn + In) ≦ 0.98
0.01 ≦ In / (Zn + Sn + In) ≦ 0.15
6). 5. The oxide sintered body according to 4, wherein the atomic ratio of zinc, tin and indium satisfies the following relational expression (2).
Relational expression (2):
0.01 ≦ Zn / (Zn + Sn + In) ≦ 0.68
0.30 ≦ Sn / (Zn + Sn + In) ≦ 0.50
0.01 ≦ In / (Zn + Sn + In) ≦ 0.50
7). 5. The oxide sintered body according to 4, wherein the atomic ratio of zinc, tin and indium satisfies the following relational expression (3).
Relational expression (3):
0.50 ≦ Zn / (Zn + Sn + In) ≦ 0.80
0.10 ≦ Sn / (Zn + Sn + In) ≦ 0.49
0.01 ≦ In / (Zn + Sn + In) ≦ 0.40
8). 4. The oxide sintered body according to 3, containing a bixbite In ₂ O ₃ phase and a corundum In ₂ O ₃ phase.
9. _4. The oxide sintered body according to 3, comprising a spinel Zn ₂ SnO ₄ phase and a corundum In ₂ O ₃ phase.
10. The oxide sintered body according to 8 or 9, wherein an atomic ratio of Zn, Sn, and In satisfies the following formula.
0.26 <Zn / (Zn + Sn + In) ≦ 0.70
0.05 <Sn / (Zn + Sn + In) ≦ 0.49
0.01 ≦ In / (Zn + Sn + In) <0.25
11. The oxide sintered body according to any one of 3 to 10, which contains one or more elements selected from Mg, Al, Ga, Si, Ti, Ge, and Ln in an oxide equivalent weight of 0.1 to 10% by weight.
12 The oxide sintered body according to any one of 3 to 11, which contains one or more elements selected from niobium, tantalum, molybdenum, tungsten, and ammotine.
13. 13. One or more metal elements selected from the group consisting of Group 3 elements, Group 4 elements and Group 5 elements excluding actinides in the long-period periodic table, or any one of 3 to 12 containing gallium oxide Oxide sintered body.
14. A sputtering target comprising the oxide sintered body according to any one of 1 to 13.
An amorphous transparent conductive film formed using the sputtering target according to 15.14.
A substrate with an amorphous transparent conductive film on which the amorphous transparent conductive film according to 16.15 is formed.

According to the present invention, it is possible to provide an amorphous zinc oxide-tin oxide based transparent conductive film that is indium-saving and has low bulk resistance.
According to the present invention, it is possible to provide a sintered body capable of forming the amorphous zinc oxide-tin oxide transparent conductive film and a method for producing the same.

2 is a chart showing an X-ray diffraction pattern of a sintered body obtained in Example 1. FIG. 3 is a chart showing an X-ray diffraction pattern of a sintered body obtained in Example 2. FIG. 6 is a chart showing an X-ray diffraction pattern of a sintered body obtained in Example 3. 6 is a chart showing an X-ray diffraction pattern of a sintered body obtained in Example 4. 6 is a chart showing an X-ray diffraction pattern of a sintered body obtained in Example 5. 6 is a chart showing an X-ray diffraction pattern of a sintered body obtained in Example 6. FIG. 6 is a chart showing an X-ray diffraction pattern of a sintered body obtained in Example 7. 6 is a chart showing an X-ray diffraction pattern of a sintered body obtained in Example 7. 6 is a chart showing an X-ray diffraction pattern of a sintered body obtained in Example 8. 10 is a chart showing an X-ray diffraction pattern of a sintered body obtained in Example 9. 14 is a chart showing an X-ray diffraction pattern of a sintered body obtained in Example 14. 6 is a chart showing an X-ray diffraction pattern of a sintered body obtained in Example 21. FIG.

The method for producing the oxide sintered body of the present invention comprises:
(A) preparing a mixture by mixing raw material compound powders containing Zn, Sn and In;
(B) forming the mixture to prepare a molded body;
(C) a step of sintering the molded body at 1000 ° C. or higher and lower than 1300 ° C. for 0 hour or longer; and (d) a step of further sintering the sintered molded body at 1300 ° C. or higher and lower than 1500 ° C. for 2 hours or longer. .

In the step of preparing a mixture by mixing raw material compound powders containing Zn, Sn, and In, as the raw material compound powder to be used, for example, an indium compound, a tin compound, a zinc compound, or the like can be used.
When the raw material compound powder is an indium compound, a tin compound and a zinc compound, the indium compound, tin compound and zinc compound to be used are preferably these oxides or compounds which become these oxides after sintering (oxide precursors). Body).

The indium oxide precursor, tin oxide precursor and zinc oxide precursor include sulfide, sulfate, nitrate, halide (chloride, bromide, etc.), carbonate, organic, indium, tin and zinc, respectively. Acid salts (acetate, propionate, naphthenate, etc.), alkoxides (methoxide, ethoxide, etc.), organometallic complexes (acetylacetonate, etc.) and the like can be mentioned.
Among these, nitrates, organic acid salts, alkoxides, or organometallic complexes are preferred because they can be completely thermally decomposed at low temperatures and do not leave impurities.
The raw material compound powder is most preferably indium oxide, tin oxide and zinc oxide.

At least one element selected from magnesium, aluminum, gallium, silicon, titanium, germanium, lanthanoid, titanium, niobium, tantalum, tungsten, molybdenum and antimony in raw material compound powder (for example, indium compound, tin compound and zinc compound) A compound containing, for example, an oxide may be further added. These compounds function as, for example, a sintering aid.

The purity of each raw material compound powder is usually 99.9% by mass (3N) or more, preferably 99.99% by mass (4N) or more, more preferably 99.995% by mass or more, particularly preferably 99.999% by mass ( 5N) or more. If the purity of each raw material is 99.9% by mass (3N) or more, the semiconductor characteristics are not deteriorated by impurities such as Fe, Ni, Cu, and the reliability can be sufficiently maintained.
In particular, when the content of Na in the raw material compound powder is less than 100 ppm, reliability can be improved when an amorphous transparent conductive film obtained from the manufactured oxide sintered body is used as a thin film transistor.

The average particle diameter of the raw material compound powder is preferably 0.1 μm or more and 20 μm or less from the viewpoints of powder handling and moldability. When the average particle diameter of the raw material oxide powder is more than 20 μm, the sinterability may be reduced, and a dense sintered body may not be obtained.

The mixing is preferably carried out by (i) a solution method (coprecipitation method) or (ii) a physical mixing method, and more preferably a physical mixing method from the viewpoint of cost reduction.
In the physical mixing method, the raw material compound powder is put in a mixer such as a ball mill, jet mill, pearl mill, or bead mill and mixed uniformly.

The mixing time is preferably 1 to 200 hours. If it is less than 1 hour, the elements to be dispersed may be insufficiently homogenized, and if it exceeds 200 hours, it may take too much time and productivity may be reduced. A particularly preferred mixing time is 10 to 120 hours.

The average particle diameter of the raw material compound powder mixture obtained by the above mixing is preferably 0.1 to 1.0 μm. If the average particle size is less than 0.1 μm, the powder tends to aggregate, handling is poor, and a dense sintered body may not be obtained. On the other hand, if the average particle diameter exceeds 1.0 μm, a dense sintered body may not be obtained.

The present invention may include a step of calcining the obtained mixture after the step of preparing the mixture by mixing raw material compound powders.
In the calcining step, the mixture obtained in the above step is calcined. By performing the calcination, it is easy to increase the density of the finally obtained sputtering target.

In the calcination step, the mixture is usually heat treated at 500 to 1200 ° C. for 1 to 100 hours.
Furthermore, it is preferable to grind the calcined mixture before the subsequent molding step. The calcined mixture can be pulverized using a bead mill, ball mill, roll mill, pearl mill, jet mill or the like.

The mixture of the raw material compound powder can be formed by a known method such as pressure forming or cold isostatic pressing.
Specifically, the mixture can be molded by mold molding, cast molding, injection molding, or the like, but press molding is preferable in order to obtain a sintered body having a high sintered density.
In the case of the said shaping | molding, you may use shaping | molding adjuvants, such as PVA (polyvinyl alcohol), MC (methylcellulose), a polywax, oleic acid.

For the press molding, a known molding method such as a cold press method or a hot press method can be used, preferably CIP (cold isostatic pressure).
For example, a mixture of the obtained raw material compound powders is filled in a mold and pressure-molded with a cold press machine. This pressure molding is performed, for example, at normal temperature (25 ° C.), usually at a pressure of 100 to 100,000 kg / cm ² , preferably at a pressure of 500 to 10,000 kg / cm ² . Further, in the temperature profile, it is preferable that the temperature increase rate up to 1000 ° C. is 30 ° C./hour or more, and the temperature decrease rate during cooling is 30 ° C./hour or more.

An oxide sintered body is produced by sintering a molded body of a mixture of raw material compound powders. Sintering after molding can be performed by atmospheric pressure firing, HIP (hot isostatic pressure) firing or the like.
In the present invention, since both of In ₂ O ₃ phase and zinc and tin bixbyite structure both of zinc and tin in solid solution causes the precipitation of In ₂ O ₃ phase of the corundum structure solid solution, the following two steps Includes sintering process (first stage sintering and second stage sintering).

The sintering temperature of the first stage sintering may be equal to or higher than the temperature at which the zinc compound, the indium compound, and the tin compound react to form a bixbite In ₂ O ₃ phase in which both zinc and tin are solid-solved, It is 1000 degreeC or more and less than 1300 degreeC. When the sintering temperature of the first stage sintering is 1300 ° C. or higher, the amount of precipitation of the In ₂ O ₃ phase is small, and the bulk resistance of the obtained sintered body may not be lowered.
The sintering time of the first stage sintering is usually 0 hours or more, preferably 0.1 to 10 hours, more preferably 1 to 5 hours. The upper limit of the sintering time of the first stage sintering is not particularly limited, but is, for example, 20 hours.
In the sintering process of the first stage sintering, the reaction of indium oxide with zinc and tin proceeds, and an In ₂ O ₃ phase in which both zinc and tin are dissolved can be generated.

In order to prevent the obtained sintered body from warping or cracking, it is preferable that the temperature is slowly raised in multiple stages until the above-mentioned sintering temperature is reached in the first stage sintering. The temperature rising rate is preferably 1.0 ° C./min or less, more preferably 0.5 ° C./min.

The sintering temperature of the second stage sintering is that the zinc compound, the indium compound and the tin compound react, the bixbite In ₂ O ₃ phase in which both zinc and tin are in solid solution, and both zinc and tin are in solid solution. The temperature may be higher than the temperature at which the corundum In ₂ O ₃ phase is generated, and it is 1300 ° C. or higher and lower than 1500 ° C., preferably 1350 ° C. to 1450 ° C.
When the sintering temperature of the second stage sintering is less than 1300 ° C., zinc and tin do not form a solid solution in the In ₂ O ₃ phase, so that the bulk resistance may not decrease. On the other hand, when the sintering temperature of the second stage sintering is 1500 ° C. or higher, zinc oxide may be sublimated to cause a composition shift.

The sintering time of the second stage sintering is 2 hours or more. The preferred sintering time for the second stage sintering is 2 to 30 hours, although it depends on the sintering temperature. The upper limit of the sintering time of the second stage sintering is not particularly limited, but is, for example, 100 hours.
The second-stage sintering can be transferred by further raising the temperature after finishing the first-stage sintering.

The first stage sintering and the second stage sintering may be performed in an oxidizing atmosphere, and examples of the oxidizing atmosphere include an atmosphere in which air or oxygen gas is introduced. In addition, it can also sinter under oxygen pressurization. In order to prevent sublimation of zinc oxide and tin oxide, it is preferable to carry out under oxygen inflow and oxygen pressurization.
The first stage sintering and the second stage sintering are preferably performed in an oxygen gas atmosphere. By sintering in an oxygen gas atmosphere, the density of the obtained oxide sintered body can be increased, and abnormal discharge during sputtering of the oxide sintered body can be suppressed. The oxygen gas atmosphere is preferably an atmosphere having an oxygen concentration of 10 to 100 vol%.
The first stage sintering and the second stage sintering can be performed under atmospheric pressure or under pressure. The pressure is, for example, 98,000 to 1,000,000 Pa, preferably 100,000 to 500,000 Pa.

In the present invention, by performing the above-described sintering (first-stage sintering and second-stage sintering), both Bixbite In ₂ O ₃ phase in which both zinc and tin are dissolved, and both zinc and tin An oxide sintered body containing a corundum In ₂ O ₃ phase in which is dissolved. When the oxide sintered body includes an In ₂ O ₃ phase in which both zinc and tin are dissolved, the bulk resistance can be lowered.

The method for producing an oxide sintered body of the present invention may include a reduction step.
The reduction step is an optional step performed to reduce the sintered body obtained in the above-described sintering step and to uniformize the bulk specific resistance of the sintered body as a whole.

Examples of the reduction method that can be applied in the reduction step include a method of circulating a reducing gas, a method of baking in a vacuum, and a method of baking in an inert gas.
As the reducing gas, for example, hydrogen, methane, carbon monoxide, a mixed gas of these gas and oxygen, or the like can be used.
As the inert gas, nitrogen, argon, a mixed gas of these gases and oxygen, or the like can be used.

The temperature of the reduction treatment is usually 100 to 1200 ° C., preferably 300 to 1100 ° C. The reduction treatment time is usually 0.01 to 5 hours, preferably 0.5 to 1 hour.
The pressure of the reducing gas or inert gas is, for example, 9.8 to 1000 KPa, preferably 98 to 500 KPa. In the case of firing in vacuum, the vacuum specifically refers to about 10 ⁻¹ to 10 ⁻⁸ Pa, preferably about 10 ⁻² to 10 ⁻⁵ Pa, and the residual gas is argon, nitrogen, or the like.

The oxide sintered body of the present invention contains zinc, tin, and indium, and includes an indium oxide phase in which zinc and tin are dissolved.
When the oxide sintered body includes an indium oxide phase in which zinc and tin are dissolved, bulk resistance can be reduced.

In the oxide sintered body of the present invention, tin is preferably partly present in solid solution in the In ₂ O ₃ phase together with zinc, and the remaining portion is SnO ₂ phase and / or Zn ₂ SnO ₄ phase. And does not contain other tin-containing phases (eg SnO phase).

In the oxide sintered body of the present invention, zinc is preferably partly dissolved in the In ₂ O ₃ phase together with tin, and the remaining part as ZnO phase and / or Zn ₂ SnO ₄ phase. Preferably it is present.

In the oxide sintered body of the present invention, it is preferable that indium exists as a bixbite phase and / or corundum phase of indium oxide, and further exists in a state where tin and zinc are further dissolved. This indium oxide phase imparts conductivity to the oxide sintered body.

Each phase such as an indium oxide phase in which zinc and tin in the oxide sintered body are dissolved can be confirmed by X-ray diffraction. For example, the SnO ₂ phase has a main peak near a diffraction angle of 26 degrees, In ₄ Sn ₃ O ₄ that is a composite oxide has a main peak near 30 degrees, and Zn ₂ SnO ₄ has a main peak near 34 degrees. When any of the peaks has a solid solution substitution, the position of the main peak may be shifted.

The shift in the position of the main peak indicates a change in the lattice constant, and in the corundum structure, usually a = 5.45 or less, c = 14.45 or less, preferably a = 5.44 or less, c = 14.42 or less, and more Preferably, a = 5.42 or less and c = 14.41 or less. If a = 5.45 or less and c = 14.45 or less, the resistance of indium oxide can be lowered by solid solution of zinc and tin.
In the bixbyite structure, a is usually 10.10 or less, preferably 10.07 or less, and more preferably 10.05 or less. If a = 10.10 or less, the resistance of indium oxide can be lowered by solid solution of zinc and tin.
The presence of such an indium oxide phase in which zinc and tin are dissolved can lower the bulk resistance of the sintered body.

In addition, when the main peaks overlap, it is possible to calculate the main peak from other peaks. Specifically, the main peak can be obtained by calculating back the peak intensities other than the main peak using the intensity ratio data published in ICDD (International Center for Diffraction Data).

As the indium content of the oxide sintered body increases, the specific resistance of the thin film obtained from the oxide sintered body tends to decrease. Similarly, the specific resistance of the thin film tends to decrease as the content of tin in the oxide sintered body increases. Since the effect of lowering the specific resistance of the thin film is higher with indium than with tin, the resistance of the thin film can be controlled by using the characteristics of indium and tin.
In the oxide sintered body of the present invention, the atomic ratio of zinc, tin and indium preferably satisfies the following relational expression.
0.01 ≦ Zn / (Zn + Sn + In) ≦ 0.80
0.10 ≦ Sn / (Zn + Sn + In) ≦ 0.98
0.01 ≦ In / (Zn + Sn + In) ≦ 0.50

When In / (Zn + Sn + In) is more than 0.50, the manufacturing cost may increase. On the other hand, if In / (Zn + Sn + In) is less than 0.01, the effect of reducing the bulk resistance of the sintered body obtained by the indium oxide phase may not be exhibited.
When Sn / (Zn + Sn + In) is less than 0.10, unreacted zinc oxide tends to remain in the sintered body, and thus zinc may be scattered during sintering.
It is preferable that Zn / (Zn + Sn + In) is 0.80 or less because there is an effect of stabilizing the amorphous state of the obtained thin film. On the other hand, if Zn / (Zn + Sn + In) is more than 0.80, the presence of a zinc oxide phase in the sintered body causes the sintered body to warp due to a difference in thermal expansion from other phases, during cooling or during processing. There is a risk of cracking.

The atomic ratio of zinc, tin and indium in the oxide sintered body of the present invention preferably satisfies the following relational expression.
0.01 ≦ Zn / (Zn + Sn + In) ≦ 0.65
0.20 ≦ Sn / (Zn + Sn + In) ≦ 0.98
0.01 ≦ In / (Zn + Sn + In) ≦ 0.50
More preferably, the following relational expression is satisfied.
0.05 ≦ Zn / (Zn + Sn + In) ≦ 0.65
0.20 ≦ Sn / (Zn + Sn + In) ≦ 0.94
0.01 ≦ In / (Zn + Sn + In) ≦ 0.45
More preferably, the following relational expression is satisfied.
0.05 ≦ Zn / (Zn + Sn + In) ≦ 0.60
0.20 ≦ Sn / (Zn + Sn + In) ≦ 0.90
0.05 ≦ In / (Zn + Sn + In) ≦ 0.40

The atomic ratio of zinc, tin and indium in the oxide sintered body of the present invention particularly preferably satisfies any of the following relational expressions (1) to (3).
Relational expression (1):
0.01 ≦ Zn / (Zn + Sn + In) ≦ 0.15
0.80 ≦ Sn / (Zn + Sn + In) ≦ 0.98
0.01 ≦ In / (Zn + Sn + In) ≦ 0.15
When the oxide sintered body satisfies the relational expression (1), a transparent conductive film excellent in chemical resistance can be obtained from the oxide sintered body.

Relational expression (2):
0.01 ≦ Zn / (Zn + Sn + In) ≦ 0.68
0.30 ≦ Sn / (Zn + Sn + In) ≦ 0.50
0.01 ≦ In / (Zn + Sn + In) ≦ 0.50
When the oxide sintered body satisfies the relational expression (2), the thin film obtained from the oxide sintered body can be etched with an aqueous oxalic acid solution without dissolving in a mixed acid composed of phosphoric acid, nitric acid, acetic acid, and the like. Therefore, a transparent conductive film that can be easily patterned can be obtained.

Relational expression (3):
0.50 ≦ Zn / (Zn + Sn + In) ≦ 0.80
0.10 ≦ Sn / (Zn + Sn + In) ≦ 0.49
0.01 ≦ In / (Zn + Sn + In) ≦ 0.40
When the oxide sintered body satisfies the relational expression (3), carrier control is possible, and a semiconductor film can be formed.

The oxide sintered body of the present invention preferably further contains 0 to 10 wt% of one or more elements selected from Mg, Al, Ga, Si, Ti, Ge and Ln in terms of oxide weight.
In the present invention, “weight in terms of oxide” means, for example, the weight when the oxide sintered body contains magnesium element (Mg) and the magnesium element is magnesium oxide (MgO). Moreover, containing 1% or more of elements selected from Mg, Al, Ga, Si, Ti, Ge, and Ln in terms of oxide weight means that the oxide sintered body does not contain these elements.

One or more elements selected from Mg, Al, Ga, Si, Ti, Ge and Ln can promote the sintering and control the density of the oxide sintered body. Moreover, when the oxide sintered body contains the above element, oxygen in the thin film obtained from the oxide sintered body can be fixed, and the resistance of the thin film can be stabilized.
When the oxide equivalent weight of one or more elements selected from Mg, Al, Ga, Si, Ti, Ge and Ln is more than 10% by weight, the bulk resistance of the oxide sintered body may be increased.

The oxide sintered body of the present invention preferably contains one or more elements selected from niobium, tantalum, molybdenum, tungsten and antimony.
When the oxide sintered body of the present invention contains the above pentavalent element or more, these elements are contained in the oxide sintered body, for example, substituted by solid solution in the SnO ₂ phase or Zn ₂ SnO ₄ phase. Thus, carrier electrons can be increased, and the resistance of the oxide sintered body can be further reduced.

The content of one or more elements selected from niobium, tantalum, molybdenum, tungsten, and antimony is preferably 0.01 to in terms of oxide weight relative to the total weight in terms of oxide weight of each of tin, indium, and zinc. 5% by weight.
When the content of one or more elements selected from niobium, tantalum, molybdenum, tungsten, and antimony is more than 5% by weight in terms of oxide, the resistance of the oxide sintered body increases and the resulting thin film may be colored. There is. On the other hand, when the content of one or more elements selected from niobium, tantalum, molybdenum, tungsten and antimony is less than 0.01% by weight in terms of oxide, the above-mentioned desired effect may not be obtained.

The oxide of niobium is Nb ₂ O ₅ , the oxide of tantalum is Ta ₂ O ₅ , the oxide of molybdenum is MoO ₃ , the oxide of tungsten is WO ₃ , and the oxide of ammotine Is Sb ₂ O ₅ .

The oxide sintered body of the present invention is preferably one or more metal elements selected from the group consisting of Group 3 elements, Group 4 elements and Group 5 elements excluding actinoids in the long-period periodic table (hereinafter simply referred to as simply “group elements”). 3) or a gallium oxide.
When the oxide sintered body contains a metal element of Group 3 to 5 or gallium oxide, the bond of the compound in the sintered body can be strengthened to increase the strength of the sintered body, and the transmittance of the obtained thin film The electrical characteristics can be stabilized by improving the resistance and fixing the oxygen in the thin film.

The group 3 to 5 metal element is preferably contained as an oxide in the oxide sintered body.
The oxide content of the group 3-5 metal element is preferably an oxide equivalent weight of each of at least one element selected from tin, zinc, indium, and Mg, Al, Ga, Si, Ti, Ge, and Ln. The total weight is 0 to 10% by weight.
When the content of the oxide of a metal element belonging to Group 3 to Group 5 exceeds 10% by weight, the specific resistance of the obtained thin film may be increased.

Examples of Group 3 elements excluding actinides include Sc, Y and lanthanoids (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu). From the viewpoint of relatively low cost and high chemical resistance, Y, La, Ce, Yb and Gd are preferred.
As oxides of Group 3 elements excluding actinides, Sc ₂ O ₃ , Y ₂ O ₃ , La ₂ O ₃ , CeO ₂ , Pr ₆ O ₁₁ , Nd ₂ O ₃ , Pm ₂ O ₃ , Sm ₂ O ₃ Eu ₂ O ₃ , Gd ₂ O ₃ , Tb ₄ O ₇ , Dy ₂ O ₃ , Ho ₂ O ₃ , Er ₂ O ₃ , Tm ₂ O ₃ , Yb ₂ O ₃ and Lu ₂ O ₃ .

Examples of Group 4 elements include Ti, Zr, and Hf, and Ti and Zr are preferable from the viewpoint of being relatively inexpensive and having high chemical resistance.
Examples of Group 4 element oxides include TiO ₂ , ZrO _2, and HfO ₂ .

Examples of the Group 5 element include V, Nb and Ta, and Nb and Ta are preferable from the viewpoint of being relatively inexpensive and having high chemical resistance.
Examples of Group 5 element oxides include V ₂ O ₅ , Nb ₂ O ₅ and Ta ₂ O ₅ .

The crystal particles in the oxide sintered body of the present invention including the above-described oxides preferably have an average particle size of 20 μm or less. When the average particle diameter of the crystal particles exceeds 20 μm, abnormal discharge may occur when the oxide sintered body is used as a sputtering target.

The oxide sintered body of the present invention is selected from zinc, tin, indium, and optionally (1) Mg, Al, Ga, Si, Ti, Ge, and Ln, as long as an indium oxide phase in which zinc and tin are dissolved is included. (2) one or more elements selected from niobium, tantalum, molybdenum, tungsten and antimony, and (3) group 3 elements, group 4 elements and groups excluding actinides in the long-period periodic table It may consist essentially of one or more metal elements or gallium oxide selected from the group consisting of Group 5 elements, or may consist solely of these components. “Substantially” means that the oxide sintered body is composed of zinc oxide, tin oxide, indium oxide and optionally (1) to (3), and does not impair the effects of the present invention in addition to these components. It can include other components in the range.

The oxide sintered body of the present invention can be used as a sputtering target by performing processing such as polishing. Specifically, the sintered body is ground by, for example, a surface grinder so that the surface roughness Ra is 5 μm or less. Further, the sputter surface of the target may be mirror-finished so that the average surface roughness Ra is 1000 angstroms or less. For this mirror finishing (polishing), a known polishing technique such as mechanical polishing, chemical polishing, mechanochemical polishing (a combination of mechanical polishing and chemical polishing) can be used. For example, polishing to # 2000 or more with a fixed abrasive polisher (polishing liquid: water) or lapping with loose abrasive lapping (abrasive: SiC paste, etc.), and then lapping by changing the abrasive to diamond paste Can be obtained by: Such a polishing method is not particularly limited.

The sputtering target of the present invention contains at least Zn, Sn and In, and is a sputtering target made of an oxide sintered body containing a bixbite In ₂ O ₃ phase and a corundum In ₂ O ₃ phase, or at least Zn, Sn and In And a sputtering target made of an oxide sintered body containing a spinel structure Zn ₂ SnO ₄ phase and a corundum In ₂ O ₃ phase. This sputtering target has a low bulk resistance and is suitable for manufacturing a semiconductor film.

In the above sputtering target, the atomic ratio of Zn, Sn, and In preferably satisfies the following formula.
0.26 <Zn / (Zn + Sn + In) ≦ 0.70
0.05 <Sn / (Zn + Sn + In) ≦ 0.49
0.01 ≦ In / (Zn + Sn + In) <0.25
In particular, it is preferable to satisfy the following formula.
0.30 <Zn / (Zn + Sn + In) ≦ 0.49
0.20 <Sn / (Zn + Sn + In) ≦ 0.49
0.10 ≦ In / (Zn + Sn + In) <0.25

Within the above range, a sputtering target composed of an oxide sintered body including a bixbite In ₂ O ₃ phase and a corundum In ₂ O ₃ phase, or at least Zn, Sn, In, and a spinel structure Zn ₂ SnO ₄ phase It is easy to produce a sputtering target made of an oxide sintered body containing a corundum In ₂ O ₃ phase. In addition, a favorable thin film transistor can be easily formed by forming a semiconductor film.

The amorphous transparent conductive film of the present invention can be formed by sputtering a sputtering target comprising the oxide sintered body of the present invention.
Since the oxide sintered body of the present invention has high conductivity, a DC sputtering method having a high film formation rate can be applied when a sputtering target is used.
In addition to the DC sputtering method described above, any sputtering method such as a magnetron sputtering method, an RF sputtering method, an AC sputtering method, a pulsed DC sputtering method, or an opposed sputtering method can be applied to the sputtering target comprising the oxide sintered body of the present invention. Sputtering without abnormal discharge is possible.

Sputtering is preferably performed in an oxidizing atmosphere into which an oxygen atom-containing gas (oxidizing gas) such as O ₂ , H ₂ O, CO, or CO ₂ is introduced. It is possible to suppress the generation of impurities that hinder electrical conductivity and permeability of the conductive film obtained by performing sputtering in an oxidizing atmosphere.

The concentration of the oxidizing gas may be appropriately adjusted depending on the desired film conductivity, light transmittance, and the like. This adjustment can be performed by, for example, the substrate temperature, the sputtering pressure, or the like.

As a sputtering gas, from the viewpoint of easily controlling the composition of the gas, preferably with Ar-O ₂ based gas or Ar-CO ₂ based gas, more preferably Ar-O ₂ based gas controllability particularly excellent.

By using an Ar—O ₂ gas, a transparent and low resistance film can be obtained. The O ₂ concentration is preferably 0.2 to 50% by volume.
When the O ₂ concentration is less than 0.2% by volume, the resulting film may be colored yellow and the resistance of the film may be increased. On the other hand, when the O ₂ concentration is more than 50% by volume, the deposition cost of the thin film at the time of sputtering becomes slow, which may increase the production cost.
Further, when the O ₂ concentration is 10% by volume or more and the obtained film has a carrier concentration of 10 ¹⁵ to 10 ¹⁸ cm ⁻³ by heat treatment, it can be used as a semiconductor.

The pressure in the sputtering apparatus (the pressure in the chamber) is preferably 10 ⁻⁶ to 10 ⁻³ Pa.
When the pressure in the chamber exceeds 10 ⁻³ Pa, it is affected by residual moisture remaining in the vacuum, so that resistance control may be difficult. On the other hand, when the pressure in the chamber is less than 10 ⁻⁶ Pa, it takes time for evacuation, which may deteriorate productivity.

The power density during sputtering (the value obtained by dividing the input power by the area of the target surface) is preferably 1 to 10 W / cm ² .
When the current density is less than 1 W / cm ² , the discharge may not be stable. On the other hand, when the current density exceeds 10 W / cm ² , there is a possibility that the target may break due to the heat generated.

The sputtering pressure is preferably 0.01 to 20 Pa.
If the sputtering pressure is less than 0.01 Pa, the discharge may not be stable. On the other hand, when the sputtering pressure is higher than 20 Pa, the sputtering discharge may not be stable, and the sputtering gas itself may be taken into the conductive film to deteriorate the film characteristics.

Examples of the substrate on which the amorphous transparent conductive film of the present invention is formed include glass, ceramics, plastics, and metals.
The substrate temperature during film formation is not particularly limited, but is preferably 300 ° C. or less from the viewpoint of easily obtaining an amorphous film. The substrate temperature may be about room temperature when no intentional heating is performed. Also,

After the film formation, oxygen introduced during sputtering is not fixed in the film, and thus the substrate is preferably post-heated (heat treatment). This heat treatment is preferably carried out at 150 to 350 ° C., preferably 200 to 300 ° C. in the air, nitrogen or vacuum. By performing heat treatment at 200 ° C. to 300 ° C., deterioration of the conductive film can be prevented, and the resistance of the conductive film can be reduced and the transmittance can be improved.
When the heat treatment is less than 150 ° C., oxygen in the thin film is gradually discharged and the conductive film may be deteriorated. On the other hand, when the heat treatment exceeds 350 ° C., the resistance of the conductive film may increase.

The geometric film thickness (hereinafter simply referred to as film thickness) of the amorphous transparent conductive film of the present invention is preferably 2 nm to 5 μm, more preferably 2 nm to 300 nm.
When the film thickness of the amorphous transparent conductive film is more than 5 μm, the film formation time becomes long and the cost may increase. On the other hand, when the film thickness of the amorphous transparent conductive film is less than 2 nm, the specific resistance of the amorphous transparent conductive film may be increased.

In addition, the composition of the amorphous transparent conductive film of the present invention generally matches the composition of the sputtering target used.

The amorphous transparent conductive film of the present invention obtained using the sputtering target comprising the oxide sintered body of the present invention has a specific resistance of 5000 μΩcm or less and a visible light region transmittance of 78% or more. it can.
The specific resistance of the amorphous transparent conductive film can be controlled by the In ₂ O ₃ content.

Hereinafter, examples of the present invention will be described in detail, but the present invention is not limited to the following examples unless it exceeds the gist.

Example 1
[Production of sintered oxide]
PVA (polyvinyl alcohol) as a granulating agent and ion-exchanged water as a solvent, ZnO powder, SnO ₂ powder and In ₂ O ₃ powder (ZnO powder: SnO ₂ powder: In ₂ O ₃ powder = 5: 90: 5 (weight ratio)) was put into a bead mill and mixed for 24 hours to obtain a slurry. The obtained slurry was dried by a spray drying apparatus at 100 ° C. to obtain a dry powder (average particle size 1.5 μm). The obtained mixed and dried powder was filled into a rubber mold, and pressure-molded at 2600 kg / cm ² with a CIP device to prepare a molded body. The prepared compact is desolvated at 400 ° C., and air is introduced at a flow rate of 500 ml / min, and the first stage sintering is performed at a sintering temperature of 1100 ° C., atmospheric pressure, holding time of 2 hours, and then further increased. The second stage of sintering was performed at a sintering temperature of 1300 ° C., atmospheric pressure, and holding time of 10 hours to produce a sintered body.

The bulk resistance of the obtained sintered body was evaluated. The results are shown in Table 1.
The bulk resistance was measured by a 4-terminal method by cutting a 3 × 3 × 30 mm prism sample.

The composition of the sintered body in Table 1 is calculated from the weighed value of each raw material powder. The composition of the obtained sintered body was measured by ICP method (inductively coupled plasma emission spectroscopy). It was confirmed that the composition coincided with the composition calculated from the weighed value.
The average particle size of the dry powder was measured with a Microtrac particle size measuring device (manufactured by Nikkiso Co., Ltd.).

The obtained sintered body was analyzed by X-ray diffraction. FIG. 1 is an X-ray diffraction chart of the sintered body.
From Figure 1, it was found that SnO ₂ phase, _In 2 _{O 3} phase of _In 2 _{O 3} and bixbyite structure of corundum structure are precipitated, respectively. Further, peak shifts of In ₂ O _{3 having} a corundum structure and an In ₂ O ₃ phase having a bixbite structure occur, and the lattice constants of the corundum structure are a = 5.43, c = 14.41, In the bite structure, a = 10.03, and it was found that Zn and Sn were dissolved in the In ₂ O ₃ phase and the lattice constant was changed.

The measurement conditions for the X-ray diffraction measurement (XRD) are as follows.
Equipment: Ultimate-III manufactured by Rigaku Corporation
X-ray: Cu-Kα ray (wavelength 1.5406mm, monochromatized with graphite monochromator)
Output: 40kV-40mA
2θ-θ reflection method, continuous scan (1.0 ° / min)
Sampling interval: 0.02 °
Slit DS, SS: 2/3 °, RS: 0.6 mm

[Deposition of amorphous transparent conductive film]
The manufactured sintered body was cut into dimensions of 2 inches in diameter and 5 mm in thickness to produce a sputtering target. The sputtering target was attached to a magnetron sputtering apparatus and sputtered to form a thin film having a thickness of about 100 nm on the substrate. This thin film was further heat-treated at 250 ° C. for 1 hour in the atmosphere.
Abnormal discharge was not confirmed during the sputtering.

The sputtering was performed under the following conditions.
Magnetron sputtering system: ULVAC MPS6000
Input power: DC100W
Introduced gas: Ar—O ₂ mixed gas (Ar + O ₂ is 100 vol%, O ₂ is 10 vol%, total flow rate is 32 sccm)
Pressure: 0.2Pa
Substrate: non-alkali glass substrate (Corning 1737)
Substrate temperature: No heating

When the obtained thin film was subjected to X-ray diffraction measurement as in the case of the sintered body, the obtained X-ray diffraction pattern was flat, and it was confirmed that the obtained thin film was amorphous.
When the composition of the thin film was measured by ICP emission analysis, it was confirmed that it was the same as the composition of the target used.
Further, the specific resistance and transmittance (wavelength 550 nm) of the obtained thin film were evaluated. The results are shown in Table 2.

Examples 2 to 20 and Comparative Examples 1 to 5
The raw material oxide powder shown in Table 1 was used, and the production conditions of the sintered body (sintering temperature and holding time of the first stage sintering and the second stage sintering) were performed under the conditions shown in Table 1. A sintered body was produced and evaluated in the same manner as in Example 1, and a thin film was formed and evaluated. The evaluation results of the sintered body are shown in Table 1, and the evaluation results of the thin film are shown in Table 2.
In addition, although film formation was attempted using the targets of Comparative Examples 1 to 5, a thin film could not be formed because DC sputtering discharge could not be performed or discharge could not be maintained.

The X-ray diffraction charts of the sintered bodies of Examples 2 to 9 and Example 14 are respectively FIGS. 2 to 11 (for example, the X-ray diffraction chart of the sintered body of Example 2 is FIG. The X-ray diffraction chart of the sintered body is FIG. 11).
The X-ray diffraction chart of Example 7 is shown in FIGS. 7 and 8 are X-ray diffraction charts of the sintered body of Example 7 except that the scale of the vertical axis is different.

In Table 1 above, in the column of “Precipitated phase”, the confirmed substance is set to “◯”. Further, in the case of In ₂ O ₃ phase with In ₂ O ₃ phase and / or corundum structures with bixbyite structure is confirmed, if the further solid solution of Zn and Sn was confirmed, the column of "solid solution" Was marked as “◯”.

Example 21
[Production of sintered oxide]
PVA (polyvinyl alcohol) as a granulating agent and ion-exchanged water as a solvent, ZnO powder, SnO ₂ powder and In ₂ O ₃ powder (ZnO powder: SnO ₂ powder: In ₂ O ₃ powder = 27.0: 49.9: 23.1 (weight ratio)) was charged into a bead mill and mixed for 24 hours to obtain a slurry. The obtained slurry was dried by a spray drying apparatus at 100 ° C. to obtain a dry powder (average particle size 1.5 μm).
The obtained mixed and dried powder was filled into a rubber mold and pressure-molded at 2600 kg / cm ² with a CIP device to obtain a molded body. The molded body was desolvated at 400 ° C. and heated at 1 ° C./min, and then the first stage sintering was performed at a sintering temperature of 1100 ° C. and a holding time of 0.5 hours, and then further 1.5 ° C. / The temperature was raised in minutes, and the second stage sintering was performed at a sintering temperature of 1450 ° C. and a holding time of 8 hours to produce a sintered body. Sintering was performed in an oxygen atmosphere. The obtained sintered body having a thickness of 9 mm was ground to obtain a sintered body for a sputtering target having a thickness of 5 mm.
The bulk resistance was evaluated about the obtained sintered compact for sputtering targets. The bulk resistance was measured by a four-terminal method by cutting a 3 × 3 × 30 mm prism sample. The bulk resistance was 26.3 mΩcm.
The composition of the sintered body was calculated from the weighed value of each raw material powder. The composition of the obtained sintered body was measured by the ICP method (inductively coupled plasma emission spectroscopy). As a result, In: Zn: Sn = 20:40:40 (atomic ratio).
The average particle size of the dry powder was measured with a Microtrac particle size measuring device (manufactured by Nikkiso Co., Ltd.).
Similarly to Example 1, the obtained sintered body for a sputtering target was analyzed by X-ray diffraction. FIG. 12 is an X-ray diffraction chart of the sintered body.
From FIG. 12, it was found that a SnO ₂ phase having a rutile structure, a Zn ₂ SnO ₄ layer having a spinel structure, and an In ₂ O ₃ phase having a corundum structure were precipitated. Further, a peak shift of the In ₂ O ₃ phase having a corundum structure occurs, the lattice constants are a = 5.36, c = 14.34, and Zn and Sn are In ₂ O ₃ phases having a corundum structure. It was found that the lattice constant changed due to solid solution.

Experimental example 1
The amorphous transparent conductive films formed in Examples 1 and 4 were each immersed in a 10% nitric acid solution for 5 minutes, and then the electrical characteristics (specific resistance) were evaluated again with Loresta (manufactured by Mitsubishi Yuka). There was no change in the electrical characteristics of the immersed amorphous transparent conductive films of Examples 1 and 4.

Experimental example 2
The amorphous transparent conductive films formed in Examples 7 and 10 were each immersed in a PAN nitric acid solution (aluminum etching solution, manufactured by Kanto Chemical Co., Inc.) for 5 minutes, and the film thickness and electrical characteristics (resistivity) were again measured. evaluated. There was no change in the film thickness and electrical characteristics of the amorphous transparent conductive films of Examples 7 and 10 immersed.
The amorphous transparent conductive films formed in Examples 7 and 10 were each immersed in an oxalic acid aqueous solution for 1.5 minutes, and then the film thickness was evaluated. There was no change in the film thickness of the amorphous transparent conductive films of Examples 7 and 10 immersed.

Experimental example 3
An oxide semiconductor thin film having a thickness of 50 nm was formed on the thermal oxide film of a hard-doped Si substrate with a 300 nm-thick thermal oxide film using the oxide sintered body produced in Example 16, and a gold electrode was formed. A semiconductor element having a channel length of 200 μm and a channel width of 500 μm was manufactured. The manufactured semiconductor element was evaluated for TFT characteristics using a semiconductor characteristic evaluation apparatus 4200-SCS (manufactured by Keithley Instruments Co., Ltd.). As a result, it was confirmed that the manufactured semiconductor element had good TFT characteristics.

Experimental Example 4
A semiconductor element was produced and evaluated in the same manner as in Experimental Example 3 except that the oxide sintered body produced in Example 17 was used instead of the oxide sintered body produced in Example 16. As a result, it was confirmed that the manufactured semiconductor element had good TFT characteristics.

Experimental Example 5
A semiconductor element was produced using the sputtering target made of the oxide sintered body produced in Example 21.
On the thermal oxide film of a hard-doped Si substrate with a 100 nm thick thermal oxide film, an oxide semiconductor thin film having a thickness of 50 nm is formed using the target prepared in Example 21, and the channel length having a gold electrode: A semiconductor element having a thickness of 200 μm and a channel width of 500 μm was produced. About the produced semiconductor element, when the TFT characteristic was evaluated using the semiconductor characteristic evaluation apparatus, it confirmed that it had a favorable TFT characteristic.

Experimental Example 6
The sputtering target made of the oxide sintered body produced in Example 21 was used. A thin film transistor was manufactured.
After forming a transparent conductive film made of 100 nm of Mo on a glass substrate, a gate electrode was formed by photolithography. A gate insulating film was formed by laminating 200 nm of SiO ₂ by PECVD.
An oxide film was formed over the gate insulating film using the sputtering target of Example 21, a semiconductor layer with a thickness of 25 nm was formed by photolithography, and heat treatment was performed at 250 ° C. for 1 hour. After forming the SiO ₂ protective film as an etching stopper layer, Ti / Al / Ti source / drain electrodes were formed.
Heat treatment was performed at 300 ° C. for 30 minutes. When the TFT characteristics were evaluated using a semiconductor characteristic evaluation apparatus, a favorable transistor having a mobility of 25 cm ² / Vs, an on / off ratio of 10 ⁹ or more, an S value of 0.12 V / decae, and Vth 0.2 V was obtained.

Since the amorphous transparent conductive film of the present invention is amorphous, it has no surface irregularities and is smooth, and can be suitably used as a transparent electrode for touch panels and flat panel displays. In particular, since the amorphous transparent conductive film of the present invention can provide a transparent film without heating the substrate, it is suitable for an antistatic film having a protective film function such as a plastic film or a touch panel produced on plastic. It can be suitably used as a transparent electrode film.
The substrate with an amorphous transparent conductive film of the present invention can be suitably used as a display element, a transparent surface heater, or an antistatic article.

Although several embodiments and / or examples of the present invention have been described in detail above, those skilled in the art will appreciate that these exemplary embodiments and / or embodiments are substantially without departing from the novel teachings and advantages of the present invention. It is easy to make many changes to the embodiment. Accordingly, many of these modifications are within the scope of the present invention.
The entire contents of the documents described in this specification are incorporated herein by reference.

Claims (16)

(A) preparing a mixture by mixing raw material compound powders containing Zn, Sn and In;
(B) forming the mixture to prepare a molded body;
(C) a step of sintering the molded body at 1000 ° C. or higher and lower than 1300 ° C. for 0 hour or longer; and (d) a step of further sintering the sintered molded body at 1300 ° C. or higher and lower than 1500 ° C. for 2 hours or longer. And manufacturing method of oxide sintered body. An oxide sintered body produced by the production method according to claim 1. Contains indium, zinc and tin,
An oxide sintered body containing an indium oxide phase in which zinc and tin are dissolved. The oxide sintered body according to claim 3, wherein an atomic ratio of zinc, tin and indium satisfies the following relational expression.
0.01 ≦ Zn / (Zn + Sn + In) ≦ 0.80
0.10 ≦ Sn / (Zn + Sn + In) ≦ 0.98
0.01 ≦ In / (Zn + Sn + In) ≦ 0.50 The oxide sintered body according to claim 4, wherein an atomic ratio of zinc, tin and indium satisfies the following relational expression (1).
Relational expression (1):
0.01 ≦ Zn / (Zn + Sn + In) ≦ 0.15
0.80 ≦ Sn / (Zn + Sn + In) ≦ 0.98
0.01 ≦ In / (Zn + Sn + In) ≦ 0.15 The oxide sintered body according to claim 4, wherein an atomic ratio of zinc, tin and indium satisfies the following relational expression (2).
Relational expression (2):
0.01 ≦ Zn / (Zn + Sn + In) ≦ 0.68
0.30 ≦ Sn / (Zn + Sn + In) ≦ 0.50
0.01 ≦ In / (Zn + Sn + In) ≦ 0.50 The oxide sintered body according to claim 4, wherein an atomic ratio of zinc, tin and indium satisfies the following relational expression (3).
Relational expression (3):
0.50 ≦ Zn / (Zn + Sn + In) ≦ 0.80
0.10 ≦ Sn / (Zn + Sn + In) ≦ 0.49
0.01 ≦ In / (Zn + Sn + In) ≦ 0.40 The oxide sintered compact according to claim _3, comprising a bixbite In ₂ O ₃ phase and a corundum In ₂ O ₃ phase. The oxide sintered body according to claim _3, comprising a spinel Zn ₂ SnO ₄ phase and a corundum In ₂ O ₃ phase. The oxide sintered body according to claim 8 or 9, wherein an atomic ratio of Zn, Sn, and In satisfies the following formula.
0.26 <Zn / (Zn + Sn + In) ≦ 0.70
0.05 <Sn / (Zn + Sn + In) ≦ 0.49
0.01 ≦ In / (Zn + Sn + In) <0.25 The oxide sintered body according to any one of claims 3 to 10, comprising 0.1 to 10 wt% of one or more elements selected from Mg, Al, Ga, Si, Ti, Ge and Ln in terms of oxide weight. body. The oxide sintered body according to any one of claims 3 to 11, comprising one or more elements selected from niobium, tantalum, molybdenum, tungsten, and ammotine. 13. One or more metal elements selected from the group consisting of Group 3 elements, Group 4 elements and Group 5 elements excluding actinides in the long-period periodic table, or gallium oxide. The oxide sintered body described. A sputtering target comprising the oxide sintered body according to any one of claims 2 to 13. An amorphous transparent conductive film formed using the sputtering target according to claim 14. A substrate with an amorphous transparent conductive film on which the amorphous transparent conductive film according to claim 15 is formed.

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