WO2018207414A1

WO2018207414A1 - Sn-Zn-O-BASED OXIDE SINTERED BODY AND PRODUCTION METHOD THEREFOR

Info

Publication number: WO2018207414A1
Application number: PCT/JP2018/004072
Authority: WO
Inventors: 正和 ▲桑▼原; 茂生仁藤
Original assignee: 住友金属鉱山株式会社
Priority date: 2017-05-12
Filing date: 2018-02-06
Publication date: 2018-11-15
Also published as: JP6859841B2; JP2018193256A; CN110573474A; TW201900581A; TWI741154B; KR20200006534A

Abstract

Provided are an Sn-Zn-O-based oxide sintered body of high density and low resistance that can be used in such applications as barrier films and protective films, and a production method therefor. This Sn-Zn-O-based oxide sintered body has zinc (Zn) and tin (Sn) as components, and additionally contains at least germanium (Ge), tantalum (Ta), and gallium (Ga) as components, the metal atom number ratios being between 0.1 and 0.3 inclusive for Sn/(Zn+Sn), between 0.0005 and 0.01 inclusive for Ge/(Zn + Sn + Ge + Ta + Ga), between 0.0005 and 0.01 inclusive for Ta/(Zn + Sn + Ge + Ta + Ga), and between 0.001 and 0.1 inclusive for Ga/(Zn + Sn + Ge + Ta + Ga), the specific resistance thereof being between 5 Ω•cm and 12,000 Ω•cm inclusive, and the relative density thereof being 94% or greater.

Description

Sn-Zn-O-based oxide sintered body and method for producing the same

The present invention relates to a Sn—Zn—O-based oxide sintered material used as a sputtering target when a transparent conductive film applied to a solar cell, a liquid crystal surface element, a touch panel and the like is manufactured by a sputtering method such as direct current sputtering or high frequency sputtering. The present invention relates to a body and a manufacturing method thereof. This application claims priority based on Japanese Patent Application No. 2017-095982 filed on May 12, 2017 in Japan. This application is incorporated herein by reference. Incorporated.

A transparent conductive film having high conductivity and high transmittance in the visible light region is used for surface elements such as solar cells, liquid crystal display elements, organic electroluminescence and inorganic electroluminescence, electrodes for touch panels, etc. It is also used as various antifogging transparent heating elements such as automobile windows, heat ray reflective films for buildings, antistatic films, refrigerated showcases, protective films and the like.

Examples of the transparent conductive film include tin oxide (SnO ₂ ) containing antimony or fluorine as a dopant, zinc oxide (ZnO) containing aluminum or gallium as a dopant, and indium oxide (In ₂ O ₃ ) containing tin as a dopant. Are known. In particular, an indium oxide (In ₂ O ₃ ) film containing tin as a dopant, that is, an In—Sn—O-based film is called an ITO (Indium tin oxide) film, and a low resistance film can be easily obtained. Widely used.

As a method for producing the transparent conductive film, sputtering methods such as direct current sputtering and high frequency sputtering are often used. The sputtering method is an effective method when film formation of a material having a low vapor pressure or precise film thickness control is required, and since the operation is very simple, it is widely used industrially.

In order to produce the transparent conductive film, conventionally, indium oxide-based materials such as ITO have been widely used. However, since indium metal is a rare metal on the earth and has toxicity, there are concerns about adverse effects on the environment and the human body, and non-indium materials are required.

As the non-indium material, as described above, a zinc oxide (ZnO) material containing aluminum or gallium as a dopant and a tin oxide (SnO ₂ ) material containing antimony or fluorine as a dopant are known. . And although the transparent conductive film of the said zinc oxide (ZnO) type | system | group material is manufactured industrially by sputtering method, it has faults, such as being poor in chemical resistance (alkali resistance, acid resistance). On the other hand, although the transparent conductive film made of tin oxide (SnO ₂ ) is excellent in chemical resistance, it is difficult to produce a high-density and durable tin oxide-based sintered target. It has the disadvantages that are difficult to manufacture by the process.

Therefore, as a material for improving these drawbacks, a sintered body mainly composed of zinc oxide and tin oxide has been proposed. For example, Patent Literature 1 does not contain a tin oxide crystal phase or a tin oxide crystal phase in which zinc is dissolved, and is composed of a zinc oxide phase and a zinc stannate compound phase, or a zinc stannate compound phase. A Zn—Sn—O-based oxide sintered body comprising:

Patent Document 2 discloses that the integrated intensity of the (222) plane and the (400) plane in the Zn ₂ SnO ₄ phase by X-ray diffraction using CuKα rays with an average crystal grain size of 4.5 μm or less is I _{(222 ) And} I ₍₄₀₀₎ , the sintered body having an orientation degree represented by I ₍₂₂₂₎ / [I ₍₂₂₂₎ + I ₍₄₀₀₎ ] of 0.52 or more, which is larger than the standard (0.44). Is described. Further, in Patent Document 2, as a method for producing a sintered body having the above-mentioned characteristics, the sintered body production process is performed under the conditions of 800 ° C. to 1400 ° C. in an atmosphere containing oxygen in a firing furnace. And a method of cooling the inside of the firing furnace to an inert atmosphere such as Ar gas after holding at the maximum firing temperature is also described.

JP 2007-277075 A JP 2013-036073 A

However, in these methods, a Sn—Zn—O-based oxide sintered body mainly composed of Zn and Sn can obtain a sintered body strength that can withstand the mechanical strength, but has sufficient density and conductivity. It was difficult to obtain and was not satisfactory as a characteristic required for sputtering film formation at a mass production site. In other words, in the normal pressure sintering method, problems remain in terms of increasing the density and conductivity of the sintered body.

An Sn—Zn—O-based oxide sintered body containing Zn and Sn as main components is a material that is difficult to have both high density and low resistance, and is high even if the compounding ratio of Sn and Zn is changed. It is difficult to produce an oxide sintered body excellent in density and conductivity. In the sintered body density, although there is a slight increase or decrease in density depending on the blending ratio, the conductivity exhibits a very high specific resistance value of 1 × 10 ⁶ Ω · cm or more, and the conductivity is poor.

In the production of a Sn—Zn—O-based oxide sintered body containing Zn and Sn as main components, a compound called Zn ₂ SnO ₄ starts to be generated around 1100 ° C., and the volatilization of Zn begins after the temperature exceeds 1400 ° C. From about 1450 ° C., the volatilization of Zn becomes remarkable. When firing at a high temperature to increase the density of the Sn—Zn—O-based oxide sintered body, the volatilization of Zn proceeds, so that grain boundary diffusion and bonding between grains weaken, and a high-density oxide sintered body can be obtained. I can't.

Regarding conductivity, since Zn ₂ SnO ₄ , ZnO, and SnO ₂ are substances having poor conductivity, even if the compounding ratio is adjusted to adjust the amount of compound phase and ZnO, SnO ₂ Cannot be improved significantly.

The specific resistance value of a conventionally used ITO sintered body is 2 to 3 × 10 ⁻⁴ Ω · cm, and it is suitable as a transparent conductive film for liquid crystals, solar cells, etc. by sputtering this sintered body as a target. It is used for. On the other hand, although it is inferior to ITO in recent years, it can also be used for applications such as a barrier film such as a gas barrier film and a water vapor barrier film, and a protective film that protects against scratches and impacts, and has a specific resistance of 10 Ω · cm. There is a demand to achieve about × 10 ⁴ Ω · cm. Therefore, a Sn—Zn—O-based oxide sintered body suitable for these conditions is demanded.

Accordingly, an object of the present invention is to provide a high-density, low-resistance Sn—Zn—O-based oxide sintered body that can be used for applications such as a barrier film and a protective film, and a method for manufacturing the same. There is.

In order to solve the above-mentioned problems, the present inventors include Sn as an atomic ratio Sn / (Sn + Zn) in a ratio of 0.1 to 0.3 and include Ge, Ta, and Ga as additive elements. By containing the three types at a predetermined ratio, Sn-Zn-O having a specific resistance value of about 10 Ω · cm to × 10 ⁴ Ω · cm and high density suitable for applications such as a barrier film and a protective film. The present invention has been completed by finding that a sintered oxide of a system oxide can be obtained.

That is, one embodiment of the present invention is a Sn—Zn—O-based oxide sintered body including zinc (Zn) and tin (Sn) as components, and further includes at least germanium (Ge) and tantalum (Ta). , And gallium (Ga) as a component, the metal atomic ratio is Sn / (Zn + Sn) is 0.1 or more and 0.3 or less, Ge / (Zn + Sn + Ge + Ta + Ga) is 0.0005 or more and 0.01 or less, Ta / ( Zn + Sn + Ge + Ta + Ga) is 0.0005 or more and 0.01 or less, Ga / (Zn + Sn + Ge + Ta + Ga) is 0.001 or more and 0.1 or less, specific resistance is 5Ω · cm or more and 12000Ω · cm or less, and relative density is 94% or more.

According to one embodiment of the present invention, germanium (Ge), tantalum (Ta), and gallium (Ga) are added at a ratio such that Sn / (Zn + Sn) is 0.1 or more and 0.3 or less. By using these three types, it can be used for applications such as a barrier film and a protective film, and a high-density and low-resistance Sn—Zn—O-based oxide sintered body can be obtained.

At this time, in one embodiment of the present invention, the metal atom number ratio is Sn / (Zn + Sn) is 0.16 to 0.23, the specific resistance is 5 Ω · cm to 110 Ω · cm, and the relative density is 98%. It can be said that it is above.

Thus, by further limiting Sn / (Zn + Sn), it is possible to realize a Sn—Zn—O-based oxide sintered body with higher density and lower resistance.

Further, in one embodiment of the present invention, in the Sn—Zn—O-based oxide sintered body, the ZnO phase of the wurtzite crystal structure is 5 to 70% of the whole (in this specification, “to” is equal to or more than the lower limit). The same applies below), or the Zn ₂ SnO ₄ phase having a spinel crystal structure may be constituted by 30 to 95% of the whole.

By setting the metal atom number ratio as in one embodiment of the present invention, a Sn—Zn—O-based oxide sintered body having the above crystal structure is obtained.

Another aspect of the present invention is a method for producing a Sn—Zn—O-based oxide sintered body having zinc (Zn) and tin (Sn) as components, the oxide powder of zinc, the oxidation of tin A granulating step of mixing a product powder and an oxide powder containing an additive element to produce a granulated powder, a molding step of pressing the granulated powder to obtain a compact, and firing the compact And a firing step of obtaining an oxide sintered body, wherein the additive element is at least germanium (Ge), tantalum (Ta), and gallium (Ga), and the metal atom number ratio is Sn / ( Zn + Sn) is 0.1 to 0.3, Ge / (Zn + Sn + Ge + Ta + Ga) is 0.0005 to 0.01, Ta / (Zn + Sn + Ge + Ta + Ga) is 0.0005 to 0.01, Ga / (Zn + Sn + Ge + Ta + Ga) There mixed oxide powder of the zinc so that 0.001 to 0.1, the oxide powder of the tin, and an oxide powder containing the additive element.

According to another aspect of the present invention, germanium (Ge), tantalum (Ta), and gallium (Ga) are added at a ratio such that Sn / (Zn + Sn) is 0.1 or more and 0.3 or less. 3) are mixed at a predetermined ratio to produce a Sn-Zn-O-based oxide sintered body that can be used for applications such as a barrier film and a protective film, and has high density and low resistance. Can do.

At this time, in another aspect of the present invention, in the firing step, the temperature is raised from 1300 ° C. to 1400 ° C. in a firing furnace atmosphere in the atmosphere at a rate of temperature rise of 0.3 to 1.0 ° C./min. The molded body is preferably fired under conditions of 15 hours or more and 25 hours or less.

By firing the molded body under the above conditions, a Sn-Zn-O-based oxide sintered body with higher density and lower resistance can be manufactured.

According to the present invention, it can be used for applications such as a barrier film and a protective film, and a high-density and low-resistance Sn—Zn—O-based oxide sintered body can be obtained.

FIG. 1 is a process diagram showing an outline of a process in a method for producing a Sn—Zn—O-based oxide sintered body according to an embodiment of the present invention.

Hereinafter, the Sn—Zn—O-based oxide sintered body and the manufacturing method thereof according to the present invention will be described in the following order with reference to the drawings. In addition, this invention is not limited to the following examples, In the range which does not deviate from the summary of this invention, it can change arbitrarily.
1. 1. Sn—Zn—O-based oxide sintered body 2. Manufacturing method of Sn—Zn—O-based oxide sintered body 2-1. Granulation step 2-2. Molding process 2-3. Firing process

<1. Sn—Zn—O-based oxide sintered body>
First, the Sn—Zn—O-based oxide sintered body of the present invention will be described. The Sn—Zn—O-based oxide sintered body according to one embodiment of the present invention includes Sn in an atomic ratio Sn / (Sn + Zn) in a ratio of 0.1 to 0.3, and includes the first additive element. Ge is included in a ratio of 0.0005 or more and 0.01 or less as an atomic ratio Ge / (Sn + Zn + Ge + Ta + Ga) with respect to the total amount of all metal elements, and the second additive element Ta is included in an atomic ratio Ta / (with respect to the total amount of all metal elements. Sn + Zn + Ge + Ta + Ga) is contained in a ratio of 0.0005 or more and 0.01 or less, and the third additive element Ga is an atomic ratio to the total amount of all metal elements Ga / (Sn + Zn + Ge + Ta + Ga) in a ratio of 0.001 or more and 0.1 or less. contains. Such a Sn—Zn—O-based oxide sintered body according to an embodiment of the present invention has a specific resistance of 5 Ω · cm to 12000 Ω · cm and a relative density of 94% or more.

The tin oxide and zinc oxide, which are the main raw materials of the Sn—Zn—O-based oxide sintered body according to one embodiment of the present invention, contain only a tin zinc oxide compound or a mixed powder of tin oxide and zinc oxide. The raw material powder contains Sn in an atomic ratio Sn / (Sn + Zn) at a ratio of 0.1 to 0.3.

Depending on the Sn content, there is a difference in the crystal structure of the sintered body after sintering. When Sn is contained in the atomic ratio Sn / (Sn + Zn) at a ratio of 0.1 to 0.3, the main component is a ZnO phase having a wurtzite crystal structure and a Zn ₂ SnO ₄ phase having a spinel crystal structure. . When contained in a ratio of more than 0.3 and 0.9 or less, the main component is a Zn ₂ SnO ₄ phase having a spinel crystal structure and a SnO ₂ phase having a rutile crystal structure. As the main component of the SnO ₂ phase having a rutile crystal structure increases, the resistance value increases. Further, the transmittance is also lowered.

The atomic ratio Sn / (Sn + Zn) is more preferably 0.16 or more and 0.23 or less. Within this range, a desired resistance value is obtained, and the density is more preferably 98% or more.

When the Sn—Zn—O-based oxide sintered body is manufactured, as described above, Zn ₂ SnO ₄ compound starts to be generated from around 1100 ° C. during sintering, and Zn volatilization starts after exceeding 1400 ° C. From about 1450 ° C., the volatilization of Zn becomes remarkable. When firing at a high temperature to increase the density of the Sn—Zn—O-based oxide sintered body, the volatilization of Zn proceeds, so that grain boundary diffusion and bonding between grains weaken, and a high-density oxide sintered body can be obtained. I can't. On the other hand, regarding conductivity, Zn ₂ SnO ₄ , ZnO, and SnO ₂ are substances having poor conductivity. Therefore, even if the compounding ratio is adjusted to adjust the compound phase and the amount of ZnO, SnO ₂ Cannot be improved significantly.

(Additive elements)
Therefore, in the present invention, first to third additive elements are added to improve the conductivity. That is, by adding germanium (Ge) as the first additive element, tantalum (Ta) as the second additive element, and gallium (Ga) as the third additive element, high density and low resistance Sn—Zn—O based oxidation A sintered product can be obtained.

[First additive element]
For densification of the oxide sintered body, the effect of densification can be obtained by adding the first additive element Ge. The first additive element Ge promotes grain boundary diffusion, helps neck growth between grains, strengthens the bond between grains, and contributes to densification. Here, the atomic ratio Ge / (Sn + Zn + Ge + Ta + Ga) with respect to the total amount of all the metal elements of the first additive element Ge is set to 0.0005 or more and 0.01 or less because the atomic ratio Ge / (Sn + Zn + Ge + Ta + Ga) is 0.0005. This is because the effect of increasing the density does not appear when the ratio is less than (see Comparative Example 10). Even when the atomic ratio Ge / (Sn + Zn + Ge + Ta + Ga) exceeds 0.01, the effect of increasing the density does not appear (see Comparative Example 9). This is because another compound, for example, a compound of Zn ₂ Ge ₃ O ₈ is produced.

However, just adding the first additive element Ge increases the density of the oxide sintered body, but does not improve the conductivity.

[Second additive element]
The Sn—Zn—O-based oxide sintered body to which the first additive element Ge is added under the condition that Sn is contained in an atomic ratio Sn / (Sn + Zn) in a ratio of 0.1 to 0.3 is described above. As described above, although the density is improved, a problem remains in conductivity.

Therefore, the second additive element Ta is added. The addition of the second additive element Ta improves the conductivity while maintaining the high density of the oxide sintered body. The second additive element Ta is a pentavalent or higher element.

The amount to be added requires that the atomic ratio Ta / (Sn + Zn + Ge + Ta + Ga) of the second additive element Ta to the total amount of all metal elements be 0.0005 or more and 0.01 or less. When the atomic ratio Ta / (Sn + Zn + Ge + Ta + Ga) is less than 0.0005, the conductivity does not increase (see Comparative Example 12). On the other hand, if the atomic ratio Ta / (Sn + Zn + Ge + Ta + Ga) exceeds 0.01, the compound phase such as Ta ₂ O ₅ , ZnTa ₂ O _6, etc. is generated to deteriorate the conductivity. (See Comparative Example 11).

[Third additive element]
As described above, the conductivity is improved by the addition of the second additive element Ta. However, since Ta substitutes for Sn and SnO ₂ in the Zn ₂ SnO ₄ phase and dissolves, the resistance may not be able to obtain the desired conductivity.

Therefore, the third additive element Ga is added. Addition of the third additive element Ga is expected to improve conductivity with respect to Zn in the Zn, Zn ₂ SnO ₄ phase.

The amount to be added requires that the atomic ratio Ga / (Sn + Zn + Ge + Ta + Ga) of the third additive element Ga to the total amount of all metal elements be 0.001 or more and 0.1 or less. When the atomic ratio Ga / (Sn + Zn + Ge + Ta + Ga) is less than 0.001, the conductivity does not increase. (See Comparative Example 14). On the other hand, when the atomic ratio Ga / (Sn + Zn + Ge + Ta + Ga) exceeds 0.1, conductivity is deteriorated because another compound phase, for example, a compound phase such as Ga ₂ O ₃ is generated (Comparative Example). 13).

It can be used for applications such as a barrier film and a protective film, which is a feature of the Sn—Zn—O-based oxide sintered body according to one embodiment of the present invention, and has a high density (relative density of 94% or more). ) And low resistance (specific resistance is 5 Ω · cm or more and 12000 Ω · cm or less), an additive element may be further contained. Examples of further additive elements include Si, Ti, Bi, Ce, Al, Nb, W, and Mo.

(X-ray diffraction peak)
In the Sn—Zn—O-based oxide sintered body according to one embodiment of the present invention, when the atomic ratio Sn / (Sn + Zn) is 0.1 or more and 0.3 or less, the ZnO phase and spinel of the wurtzite crystal structure are obtained. A Zn ₂ SnO ₄ phase having a crystalline structure is a main component, and appropriate amounts of the first additive element Ge, the second additive element Ta, and the third additive element Ga are Zn, Zn ₂ SnO ₄ phase in the ZnO phase. Since Zn in the Zn or Sn, Sn in the SnO ₂ phase is substituted for solid solution, no other compound phase other than the ZnO phase of the wurtzite type crystal structure and the Zn ₂ SnO ₄ phase of the spinel type crystal structure is formed.

(Resistivity)
The specific resistance of the Sn—Zn—O-based oxide sintered body according to one embodiment of the present invention is 5 Ω · cm or more and 12000 Ω · cm or less. As described above, the specific resistance of the Sn—Zn—O oxide sintered body is a very high specific resistance value of 1 × 10 ⁶ Ω · cm or more. In the present invention, the specific resistance value is reduced by blending Ge, Ta, and Ga as the first to third additive elements.

The specific resistance value of a conventionally used ITO sintered body is 2 to 3 × 10 ⁻⁴ Ω · cm, and it is suitable as a transparent conductive film for liquid crystals, solar electrons, etc. by sputtering this sintered body as a target. It is used for. The transparent conductive film obtained by sputtering using the Sn—Zn—O-based oxide sintered body according to one embodiment of the present invention has a specific resistance of about 10Ω · cm to 1 × 10 ⁴ Ω · cm. Although it is inferior in conductivity to ITO, it can be used for applications such as a barrier film such as a gas barrier film and a water vapor barrier film, and a protective film for protecting from scratches and impacts. The oxide sintered body of Sn—Zn—O according to an embodiment of the present invention has a specific resistance suitable for sputtering of a film having a specific resistance of about 10 Ω · cm to 1 × 10 ⁴ Ω · cm.

The specific resistance value of the sputtering film is also affected by the film forming conditions during sputtering, particularly the oxygen concentration during sputtering. However, in consideration of productivity at the time of sputtering, film uniformity, and the like, it is preferable to match the specific resistance value of the film and the specific resistance value of the crystal.

Further, since the specific resistance value depends on the film formation rate during sputtering, it is preferable that the specific resistance value is small. Since the specific resistance of the Sn—Zn—O-based oxide sintered body according to one embodiment of the present invention is 5 Ω · cm or more and 12000 Ω · cm or less, the oxide sintered body is suitable for sputtering. When the specific resistance is less than 5 Ω · cm, the resistance value of the obtained film is low, so that there is a problem that leakage from nearby electrodes occurs. On the other hand, when the specific resistance value exceeds 12000 Ω · cm, it becomes difficult to discharge, which causes a problem because the film formation cannot be performed stably with respect to DC sputtering.

Furthermore, in one embodiment of the present invention, when the metal atom number ratio is Sn / (Zn + Sn) being 0.16 or more and 0.23 or less, the specific resistance value is in the range of 5 Ω · cm or more and 110 Ω · cm or less. (See Examples 1, 8, and 9). A specific resistance value of 5 Ω · cm or more and 110 Ω · cm is more preferable because the film formation rate is improved.

(Relative density)
The relative density of the Sn—Zn—O-based oxide sintered body according to an embodiment of the present invention is 94% or more. As shown in Patent Document 1, in an oxide sintered body of Sn—Zn—O blended at a ratio of 0.23 or more and 0.5 or less as an atomic ratio Sn / (Sn + Zn), the relative density is as measured at the time of sintering. Due to volatilization of Zn, it was not possible to obtain a crystal having a high relative density. In this invention, a relative density can be improved by mix | blending a predetermined amount with the additive element mentioned above.

In addition, the said relative density can be improved to 98% or more by making metal atom number ratio Sn / (Zn + Sn) 0.16 or more and 0.23 or less. When the relative density is 98% or more, the target strength is improved, the film formation rate during sputtering is improved, and at the same time, the outgas resulting from the target is reduced, thereby enabling stable film formation.

<2. Method for producing Sn—Zn—O-based oxide sintered body>
Next, a method for producing the Sn—Zn—O-based oxide sintered body of the present invention will be described. One embodiment of the present invention is a method for producing a Sn—Zn—O-based oxide sintered body having zinc (Zn) and tin (Sn) as components, which includes zinc oxide powder and tin oxide powder. , And an oxide powder containing an additive element to produce a granulated powder S1, a molding process S2 to obtain a compact by pressing the granulated powder, and firing the compact And firing step S3 to obtain an oxide sintered body. For example, the Sn—Zn—O-based oxide sintered body according to one embodiment of the present invention includes a first additive element in a raw material powder containing only a tin zinc oxide compound or a mixed powder of tin oxide and zinc oxide. Germanium oxide, tantalum oxide of the second additive element, gallium oxide of the third additive element are blended at a predetermined ratio, granulated, and the granulated powder is molded by a cold hydrostatic press or the like, and the molding is performed. The body is fired in a firing furnace to obtain a sintered body. Hereinafter, each process will be described individually.

(2-1. Granulation process)
First, in the granulation step S1, a main raw material is prepared. The tin oxide and zinc oxide used as the main raw material are a raw material powder containing only a tin zinc oxide compound or a mixed powder of tin oxide and zinc oxide, and Sn is 0.1 or more and 0.0 in terms of the atomic ratio Sn / (Sn + Zn). It is contained at a ratio of 3 or less. The main raw material is preferably a mixed powder of tin oxide and zinc oxide because the blending ratio can be easily adjusted. For example, this raw material powder is SnO ₂ powder and ZnO powder. Also, an oxide containing the third additive element from the first additive element is prepared, and added to the main material to prepare. For example, GeO ₂ powder as the first additive element Ge, Ta ₂ O ₅ powder as the second additive element Ta, and Ga ₂ O ₃ powder as the third additive element Ga are prepared and added to the main raw material.

In the granulation step S1, the metal atom ratio is such that Sn / (Zn + Sn) is 0.1 or more and 0.3 or less, Ge / (Zn + Sn + Ge + Ta + Ga) is 0.0005 or more and 0.01 or less, and Ta / (Zn + Sn + Ge + Ta + Ga) is 0. A zinc oxide powder, a tin oxide powder, and an oxide powder containing an additive element are mixed so that 0005 to 0.01 and Ga / (Zn + Sn + Ge + Ta + Ga) is 0.001 to 0.1. Thus, the ratio of Sn / (Zn + Sn) is 0.1 or more and 0.3 or less and, as described above, germanium (Ge), tantalum (Ta), and gallium (Ga) as additive elements. By mixing the three kinds at a predetermined ratio, it can be used for applications such as a barrier film and a protective film, and a high-density and low-resistance Sn—Zn—O-based oxide sintered body can be produced. .

Next, the prepared raw material powder is mixed with pure water or ultrapure water, an organic binder, a dispersant, and an antifoaming agent in a mixing tank so that the raw material powder concentration becomes a predetermined concentration. Then, the raw material powder is wet pulverized using a bead mill apparatus or the like into which hard ZrO ₂ balls are charged, and then mixed and stirred to obtain a slurry. A granulated powder can be obtained by spraying and drying the obtained slurry with a spray dryer or the like.

(2-2. Molding process)
The molding step S2 is a step of obtaining a molded body by pressure molding the granulated powder obtained in the granulation step S1. In the molding step S2, pressure molding is performed at a pressure of about 294 MPa (3.0 ton / cm ² ), for example, in order to remove pores between the particles of the granulated powder. Although there is no particular limitation on the method of pressure molding, for example, a cold isostatic press (CIP: Cold Isostatic) capable of filling the granulated powder obtained in the granulation step S1 into a rubber mold and applying a high pressure. Press) is preferred.

(2-3. Firing step)
The firing step S3 is a step of obtaining a sintered body by firing the molded body obtained in the molding step S2 at a predetermined temperature and a predetermined time at a predetermined temperature increase rate in the baking furnace. The firing step S3 is performed, for example, in an atmosphere in a firing furnace in the air. The method for producing a Sn—Zn—O-based oxide sintered body according to an embodiment of the present invention is also characterized by these firing conditions, and will be described in detail below.

[Raising rate]
The molded body is preferably fired at a rate of temperature increase from 700 ° C. to a predetermined sintering temperature in the sintering furnace at a rate of 0.3 to 1.0 ° C./min. This is because there is an effect of promoting diffusion of ZnO, SnO ₂ and Zn ₂ SnO ₄ compound, improving sinterability and improving conductivity. Further, by such a heating rate in the high temperature region, there is also the effect of suppressing the volatilization of the ZnO and _Zn 2 SnO _4.

In the method for producing a Sn—Zn—O-based oxide sintered body according to an embodiment of the present invention, SnO ₂ may exist during sintering (relatively low temperature range), but Sn / ( Zn + Sn) is also 0.1 or more and 0.3 or less, the temperature sintering of the specified ends, SnO ₂ phase is no longer, the diffraction peak of SnO ₂ phase by X-ray diffraction analysis will not be measured.

When the heating rate in the sintering furnace is less than 0.3 ° C./min, the diffusion of the compound declines. On the other hand, when the temperature exceeds 1.0 ° C./min, the temperature rise rate is high, so that the compound formation is incomplete and a dense sintered body cannot be produced. (See Comparative Examples 3 and 4)

[Sintering temperature]
The sintering temperature is preferably 1300 ° C. or higher and 1400 ° C. or lower. When the sintering temperature is less than 1300 ° C. (see Comparative Example 5), the temperature is too low and the grain boundary diffusion of the sintering in the ZnO, SnO ₂ , Zn ₂ SnO ₄ compound does not proceed. On the other hand, even when the temperature exceeds 1400 ° C. (see Comparative Example 6), grain boundary diffusion is promoted and sintering proceeds, but volatilization of the Zn component cannot be suppressed, leaving large voids inside the sintered body. It will end up.

[Retention time]
The holding time is preferably 15 hours or more and 25 hours or less. When the time is less than 15 hours, sintering is incomplete, resulting in a sintered body with large distortion and warpage, and grain boundary diffusion does not proceed and sintering does not proceed. As a result, a dense sintered body cannot be produced (see Comparative Example 7). On the other hand, when it exceeds 25 hours, the volatilization of ZnO and Zn ₂ SnO ₄ increases, resulting in a decrease in density, deterioration in work efficiency, and high cost (see Comparative Example 8).

The Sn—Zn—O-based oxide sintered body according to an embodiment of the present invention containing Zn and Sn as main components obtained under such conditions has improved conductivity. Film formation is possible. Moreover, since a special manufacturing method is not used, it can be applied to a cylindrical target.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

Example 1
In Example 1, SnO ₂ powder, ZnO powder, GeO ₂ powder as the first additive element Ge, Ta ₂ O ₅ powder as the second additive element Ta, and Ga ₂ O ₃ powder as the third additive element Ga Prepared.

Next, SnO ₂ powder and ZnO powder are prepared so that the atomic ratio Sn / (Sn + Zn) of Sn and Zn is 0.2, and the atomic ratio Ge / (Sn + Zn + Ge + Ta + Ga) of the first additive element Ge is 0.004, the atomic ratio Ta / (Sn + Zn + Ge + Ta + Ga) of the second additive element Ta is 0.002, and the atomic ratio Ga / ((Sn + Zn + Ge + Ta + Ga) of the third additive element Ga is 0.02. GeO ₂ powder, Ta ₂ O ₅ powder, and Ga ₂ O ₃ powder were prepared.

Then, the prepared raw material powder and pure water or ultrapure water, an organic binder, a dispersing agent, and an antifoaming agent were mixed in a mixing tank so that the raw material powder concentration was 55 to 65% by mass. Next, using a bead mill apparatus (manufactured by Ashizawa Finetech Co., Ltd., LMZ type) charged with hard ZrO ₂ balls, wet grinding is performed until the average particle size of the raw material powder becomes 1 μm or less, and then 10 hours. The mixture was stirred as above to obtain a slurry. In addition, a laser diffraction particle size distribution measuring device (manufactured by Shimadzu Corporation, SALD-2200) was used to measure the average particle size of the raw material powder.

The obtained slurry was sprayed and dried with a spray dryer (Okawara Koki Co., Ltd., ODL-20 type) to obtain granulated powder.

Next, the obtained granulated powder is filled into a rubber mold and molded by applying a pressure of 294 MPa (3 ton / cm ² ) with a cold isostatic press, and the resulting molded body having a diameter of about 250 mm is fired at normal pressure. The furnace was charged and air was introduced into the sintering furnace up to 700 ° C. After confirming that the temperature in the firing furnace reached 700 ° C., oxygen was introduced, the temperature was raised to 1350 ° C., and held at 1350 ° C. for 20 hours. The temperature rising rate at this time was set to 0.7 ° C./min.

After completion of the holding time, introduction of oxygen was stopped and cooling was performed to obtain a Sn—Zn—O-based oxide sintered body according to Example 1.

Next, the Sn—Zn—O-based oxide sintered body according to Example 1 was processed to a diameter of 200 mm and a thickness of 5 mm using a surface grinder and a grinding center.

When the density of this processed body was measured by the Archimedes method, the relative density was 99.0%. The specific resistance was measured by a 4-probe method and found to be 5.5 Ω · cm.

Moreover, a part of this processed body was cut and powdered by mortar grinding. As a result of analyzing this powder with an X-ray diffractometer [X'Pert-PRO (manufactured by PANalytical)] using CuKα rays, the Zn ₂ SnO ₄ phase of the spinel crystal structure was 66%, and the wurtzite crystal structure The ZnO phase was diffracted to 34% of the total, and the diffraction peaks of the other compound phases were not measured. These results are shown in Table 1.

(Example 2)
In Example 2, the Sn—Zn—O-based oxidation according to Example 2 was performed in the same manner as in Example 1 except that the compound was prepared in such a ratio that the Sn / Zn atomic ratio Sn / (Sn + Zn) was 0.1. A sintered product was obtained. As in Example 1, X-ray diffraction analysis of the powder revealed that the wurtzite ZnO phase was 70% and the Zn ₂ SnO ₄ phase having a spinel crystal structure was diffracted to 30%. The diffraction peaks of other other compound phases were not measured. The relative density was 96.0% and the specific resistance value was 1780 Ω · cm. These results are shown in Table 1.

(Example 3)
In Example 3, the Sn—Zn—O-based oxidation according to Example 3 was performed in the same manner as in Example 1 except that the compound was prepared in such a ratio that the Sn / Zn atomic number ratio Sn / (Sn + Zn) was 0.3. A sintered product was obtained. As in Example 1, X-ray diffraction analysis of the powder revealed that the wurtzite ZnO phase was diffracted to 5% and the spinel crystal structure Zn ₂ SnO ₄ phase to 95%. The diffraction peaks of other other compound phases were not measured. The relative density was 95.5% and the specific resistance value was 7100 Ω · cm. These results are shown in Table 1.

Example 4
In Example 4, the compound was prepared at a ratio where the Sn / Zn atomic number ratio Sn / (Sn + Zn) was 0.1, and the first additive element Ge atomic ratio Ge / (Sn + Zn + Ge + Ta + Ga) was 0.0005, GeO ₂ powder, Ta so that the atomic ratio Ta / (Sn + Zn + Ge + Ta + Ga) of the second additive element Ta is 0.0005 and the atomic ratio Ga / (Sn + Zn + Ge + Ta + Ga) of the third additive element Ga is 0.001. _A Sn—Zn—O-based oxide sintered body according to Example 4 was obtained in the same manner as in Example 1 except that ₂ O ₅ powder and Ga ₂ O ₃ powder were prepared. As in Example 2, the wurtzite ZnO phase was diffracted to 70%, and the spinel crystal structure Zn ₂ SnO ₄ phase was diffracted to 30%. The diffraction peaks of other other compound phases were not measured. The relative density was 95.0% and the specific resistance value was 5300 Ω · cm. These results are shown in Table 1.

(Example 5)
In Example 5, the compound was prepared at a ratio where the Sn / Zn atomic ratio Sn / (Sn + Zn) was 0.1, and the first additive element Ge atomic ratio Ge / (Sn + Zn + Ge + Ta + Ga) was 0.01. The GeO ₂ powder, Ta so that the atomic ratio Ta / (Sn + Zn + Ge + Ta + Ga) of the second additive element Ta is 0.01 and the atomic ratio Ga / (Sn + Zn + Ge + Ta + Ga) of the third additive element Ga is 0.1. _A Sn—Zn—O-based oxide sintered body according to Example 5 was obtained in the same manner as in Example 1 except that ₂ O ₅ powder and Ga ₂ O ₃ powder were prepared. As in Example 2, the wurtzite ZnO phase was diffracted to 70%, and the spinel crystal structure Zn ₂ SnO ₄ phase was diffracted to 30%. The diffraction peaks of other other compound phases were not measured. The relative density was 96.0% and the specific resistance value was 980 Ω · cm. These results are shown in Table 1.

(Example 6)
In Example 6, preparation was performed at a ratio such that the Sn / Zn atomic ratio Sn / (Sn + Zn) was 0.3, and the first additive element Ge atomic ratio Ge / (Sn + Zn + Ge + Ta + Ga) was 0.0005, GeO ₂ powder, Ta so that the atomic ratio Ta / (Sn + Zn + Ge + Ta + Ga) of the second additive element Ta is 0.0005 and the atomic ratio Ga / (Sn + Zn + Ge + Ta + Ga) of the third additive element Ga is 0.001. _A Sn—Zn—O-based oxide sintered body according to Example 6 was obtained in the same manner as in Example 1 except that ₂ O ₅ powder and Ga ₂ O ₃ powder were prepared. As in Example 3, the wurtzite ZnO phase was diffracted to 5% and the Zn ₂ SnO ₄ phase having a spinel crystal structure was diffracted to 95%. The diffraction peaks of other other compound phases were not measured. The relative density was 94.7% and the specific resistance value was 10000 Ω · cm. These results are shown in Table 1.

(Example 7)
In Example 7, the compound was prepared so that the Sn / Zn atomic number ratio Sn / (Sn + Zn) was 0.3, and the first additive element Ge atomic ratio Ge / (Sn + Zn + Ge + Ta + Ga) was 0.01. The GeO ₂ powder, Ta so that the atomic ratio Ta / (Sn + Zn + Ge + Ta + Ga) of the second additive element Ta is 0.01 and the atomic ratio Ga / (Sn + Zn + Ge + Ta + Ga) of the third additive element Ga is 0.1. _A Sn—Zn—O-based oxide sintered body according to Example 7 was obtained in the same manner as in Example 1 except that ₂ O ₅ powder and Ga ₂ O ₃ powder were prepared. As in Example 3, the wurtzite ZnO phase was diffracted to 5% and the Zn ₂ SnO ₄ phase having a spinel crystal structure was diffracted to 95%. The diffraction peaks of other other compound phases were not measured. The relative density was 95.0% and the specific resistance value was 9500 Ω · cm. These results are shown in Table 1.

(Example 8)
Example 8 was carried out in the same manner as in Example 1 except that the atomic ratio Sn / (Sn + Zn) of Sn and Zn was prepared at a ratio of 0.16, and the sintering holding temperature was 1300 ° C. A Sn—Zn—O-based oxide sintered body according to Example 8 was obtained. As in Example 1, X-ray diffraction analysis of the powder revealed that the Zn ₂ SnO ₄ phase having a spinel crystal structure was diffracted to 54%, and the ZnO phase having a wurtzite crystal structure was diffracted to 46% of the total. The diffraction peak of another compound phase of was not measured. The relative density was 98.0%, and the specific resistance value was 60 Ω · cm. These results are shown in Table 1.

Example 9
Example 9 was carried out in the same manner as in Example 1 except that the atomic ratio Sn / (Sn + Zn) between Sn and Zn was prepared at a ratio of 0.23, and the sintering holding temperature was 1400 ° C. A Sn—Zn—O-based oxide sintered body according to Example 9 was obtained. As in Example 1, X-ray diffraction analysis of the powder revealed that the Zn ₂ SnO ₄ phase having a spinel crystal structure was diffracted to 74%, and the ZnO phase having a wurtzite crystal structure was diffracted to 26% of the total. The diffraction peak of another compound phase of was not measured. The relative density was 98.5% and the specific resistance value was 105 Ω · cm. These results are shown in Table 1.

(Example 10)
In Example 10, the compound was prepared at a ratio such that the Sn / Zn atomic ratio Sn / (Sn + Zn) was 0.3, and the first additive element Ge atomic ratio Ge / (Sn + Zn + Ge + Ta + Ga) was 0.0005, GeO ₂ powder, Ta so that the atomic ratio Ta / (Sn + Zn + Ge + Ta + Ga) of the second additive element Ta is 0.0005 and the atomic ratio Ga / (Sn + Zn + Ge + Ta + Ga) of the third additive element Ga is 0.001. _The Sn—Zn—O-based oxide sintered body according to Example 10 was prepared in the same manner as in Example 1 except that ₂ O ₅ powder and Ga ₂ O ₃ powder were prepared and the sintering holding time was 15 hours. Obtained. As in Example 6, the wurtzite ZnO phase was diffracted to 5% and the Zn ₂ SnO ₄ phase having a spinel crystal structure was diffracted to 95%. The diffraction peaks of other other compound phases were not measured. The relative density was 94.0% and the specific resistance value was 12000 Ω · cm. These results are shown in Table 1.

(Example 11)
In Example 11, the compound was prepared at a ratio such that the Sn / Zn atomic number ratio Sn / (Sn + Zn) was 0.3, and the first additive element Ge atomic ratio Ge / (Sn + Zn + Ge + Ta + Ga) was 0.01. The GeO ₂ powder, Ta so that the atomic ratio Ta / (Sn + Zn + Ge + Ta + Ga) of the second additive element Ta is 0.01 and the atomic ratio Ga / (Sn + Zn + Ge + Ta + Ga) of the third additive element Ga is 0.1. _The Sn—Zn—O-based oxide sintered body according to Example 11 was prepared in the same manner as in Example 1 except that ₂ O ₅ powder and Ga ₂ O ₃ powder were mixed and the sintering holding time was 25 hours. Obtained. As in Example 3, the wurtzite ZnO phase was diffracted to 5% and the Zn ₂ SnO ₄ phase having a spinel crystal structure was diffracted to 95%. The diffraction peaks of other other compound phases were not measured. The relative density was 95.5% and the specific resistance value was 10500 Ω · cm. These results are shown in Table 1.

(Example 12)
In Example 12, the compound was prepared at a ratio where the Sn / Zn atomic number ratio Sn / (Sn + Zn) was 0.1, and the first additive element Ge atomic ratio Ge / (Sn + Zn + Ge + Ta + Ga) was 0.01. The GeO ₂ powder, Ta so that the atomic ratio Ta / (Sn + Zn + Ge + Ta + Ga) of the second additive element Ta is 0.01 and the atomic ratio Ga / (Sn + Zn + Ge + Ta + Ga) of the third additive element Ga is 0.1. Sn—Zn—O-based oxide according to Example 12 except that ₂ O ₅ powder and Ga ₂ O ₃ powder were prepared and the rate of temperature increase was 0.3 ° C./min. A sintered body was obtained. As in Example 2, the wurtzite ZnO phase was diffracted to 70%, and the spinel crystal structure Zn ₂ SnO ₄ phase was diffracted to 30%. The diffraction peaks of other other compound phases were not measured. The relative density was 95.0% and the specific resistance value was 1320 Ω · cm. These results are shown in Table 1.

(Example 13)
In Example 13, the compound was prepared so that the Sn / Zn atomic number ratio Sn / (Sn + Zn) was 0.1, and the first additive element Ge atomic ratio Ge / (Sn + Zn + Ge + Ta + Ga) was 0.0005, GeO ₂ powder, Ta so that the atomic ratio Ta / (Sn + Zn + Ge + Ta + Ga) of the second additive element Ta is 0.0005 and the atomic ratio Ga / (Sn + Zn + Ge + Ta + Ga) of the third additive element Ga is 0.001. Sn—Zn—O-based oxide according to Example 13 in the same manner as in Example 1 except that ₂ O ₅ powder and Ga ₂ O ₃ powder were prepared and the rate of temperature increase was 1.0 ° C./min. A sintered body was obtained. As in Example 2, the wurtzite ZnO phase was diffracted to 70%, and the spinel crystal structure Zn ₂ SnO ₄ phase was diffracted to 30%. The diffraction peaks of other other compound phases were not measured. The relative density was 94.5% and the specific resistance value was 6800 Ω · cm. These results are shown in Table 1.

(Comparative Example 1)
In Comparative Example 1, the Sn—Zn—O-based oxide firing according to Comparative Example 1 was performed in the same manner as in Example 1 except that the compound was prepared at a ratio where the atomic ratio Sn / (Sn + Zn) of Sn and Zn was 0.05. A ligature was obtained. The Sn—Zn—O-based oxide sintered body according to Comparative Example 1 was subjected to X-ray diffraction analysis in the same manner as in Example 1. As a result, the wurtzite-type ZnO phase was 90% and the spinel-type Zn ₂ SnO ₄ crystal structure was obtained. The phase was diffracted as 10%. The diffraction peaks of other other compound phases were not measured. Further, when the relative density and the specific resistance value were measured, the relative density was 93.0%, and the specific resistance value was 3510 Ω · cm. That is, it was confirmed that the relative density was 94% or more, and the specific resistance of 5 Ω · cm to 12000 Ω · cm could not be achieved. The results are shown in Table 2.

(Comparative Example 2)
In Comparative Example 2, the Sn—Zn—O-based oxide firing according to Comparative Example 2 was performed in the same manner as in Example 1 except that the compound was prepared at a ratio such that the Sn / Zn atomic ratio Sn / (Sn + Zn) was 0.40. A ligature was obtained. The Sn—Zn—O-based oxide sintered body according to Comparative Example 2 was subjected to X-ray diffraction analysis as in Example 1. As a result, the wurtzite type ZnO phase was 0%, the rutile type SnO ₂ phase was 14%, and The Zn ₂ SnO ₄ phase having a spinel crystal structure was diffracted to 86%. The diffraction peaks of other other compound phases were not measured. Moreover, when the relative density and specific resistance value were measured, the relative density was 89.0% and the specific resistance value was 597000 Ω · cm. That is, it was confirmed that the relative density was 94% or more and the specific resistance of 5Ω · cm or more and 12000Ω · cm or less could not be achieved. The results are shown in Table 2.

(Comparative Example 3)
In Comparative Example 3, a Sn—Zn—O-based oxide sintered body according to Comparative Example 3 was obtained in the same manner as in Example 1 except that the rate of temperature increase was 0.2 ° C./min. The Sn—Zn—O-based oxide sintered body according to Comparative Example 3 was subjected to X-ray diffraction analysis in the same manner as in Example 1. As a result, it was found that the wurtzite type ZnO phase was 34% and the spinel type crystal structure Zn ₂ SnO _4. The phase was diffracted to 66%. The diffraction peaks of other other compound phases were not measured. Further, when the relative density and the specific resistance value were measured, the relative density was 90.0% and the specific resistance value was 15000 Ω · cm. That is, it was confirmed that a relative density of 94% or more and a specific resistance of 5 Ω · cm to 12000 Ω · cm cannot be achieved. The results are shown in Table 2.

(Comparative Example 4)
In Comparative Example 4, a Sn—Zn—O-based oxide sintered body according to Comparative Example 4 was obtained in the same manner as in Example 1 except that the temperature rising rate was 1.2 ° C./min. The Sn—Zn—O-based oxide sintered body according to Comparative Example 4 was subjected to X-ray diffraction analysis in the same manner as in Example 1. As a result, the wurtzite type ZnO phase was 34% and the spinel type crystal structure Zn ₂ SnO _4. The phase was diffracted to 66%. The diffraction peaks of other other compound phases were not measured. Further, when the relative density and the specific resistance value were measured, the relative density was 92.0% and the specific resistance value was 12,500 Ω · cm. That is, it was confirmed that a relative density of 94% or more and a specific resistance of 5Ω · cm or more and 12000Ω · cm or less could not be achieved. The results are shown in Table 2.

(Comparative Example 5)
In Comparative Example 5, a Sn—Zn—O-based oxide sintered body according to Comparative Example 5 was obtained in the same manner as in Example 1 except that the sintering temperature was 1280 ° C. The Sn—Zn—O-based oxide sintered body according to Comparative Example 5 was subjected to X-ray diffraction analysis in the same manner as in Example 1. As a result, it was found that the wurtzite type ZnO phase was 34% and the spinel type crystal structure Zn ₂ SnO _4. The phase was diffracted to 66%. The diffraction peaks of other other compound phases were not measured. Further, when the relative density and the specific resistance value were measured, the relative density was 91.0% and the specific resistance value was 14000 Ω · cm. That is, it was confirmed that a relative density of 94% or more and a specific resistance of 5Ω · cm or more and 12000Ω · cm or less could not be achieved. The results are shown in Table 2.

(Comparative Example 6)
In Comparative Example 6, a Sn—Zn—O-based oxide sintered body according to Comparative Example 6 was obtained in the same manner as in Example 1 except that the sintering temperature was 1430 ° C. The Sn—Zn—O-based oxide sintered body according to Comparative Example 6 was subjected to X-ray diffraction analysis in the same manner as in Example 1. As a result, it was found that the wurtzite type ZnO phase was 34% and the spinel type crystal structure Zn ₂ SnO _4. The phase was diffracted to 66%. The diffraction peaks of other other compound phases were not measured. Further, when the relative density and the specific resistance value were measured, the relative density was 93.0%, and the specific resistance value was 12,500 Ω · cm. That is, it was confirmed that a relative density of 94% or more and a specific resistance of 5Ω · cm or more and 12000Ω · cm or less could not be achieved. The results are shown in Table 2.

(Comparative Example 7)
In Comparative Example 7, a Sn—Zn—O-based oxide sintered body according to Comparative Example 7 was obtained in the same manner as in Example 1 except that the sintering holding time at 1350 ° C. was 10 hours. The Sn—Zn—O-based oxide sintered body according to Comparative Example 7 was subjected to X-ray diffraction analysis in the same manner as in Example 1. As a result, it was found that the wurtzite type ZnO phase was 34% and the spinel type crystal structure Zn ₂ SnO _4. The phase was diffracted to 66%. The diffraction peaks of other other compound phases were not measured. Further, when the relative density and the specific resistance value were measured, the relative density was 90.0% and the specific resistance value was 13500 Ω · cm. That is, it was confirmed that a relative density of 94% or more and a specific resistance of 5Ω · cm or more and 12000Ω · cm or less could not be achieved. The results are shown in Table 2.

(Comparative Example 8)
In Comparative Example 8, a Sn—Zn—O-based oxide sintered body according to Comparative Example 8 was obtained in the same manner as in Example 1 except that the sintering holding time at 1350 ° C. was 30 hours. The Sn—Zn—O-based oxide sintered body according to Comparative Example 8 was subjected to X-ray diffraction analysis in the same manner as in Example 1. As a result, it was found that the wurtzite type ZnO phase was 34% and the spinel type crystal structure Zn ₂ SnO _4. The phase was diffracted to 66%. The diffraction peaks of other other compound phases were not measured. Further, when the relative density and specific resistance value were measured, ZnO and Zn ₂ SnO ₄ were volatilized, the relative density was 93.0%, and the specific resistance value was 13000 Ω · cm. That is, it was confirmed that a relative density of 94% or more and a specific resistance of 5Ω · cm or more and 12000Ω · cm or less could not be achieved. The results are shown in Table 2.

(Comparative Example 9)
In Comparative Example 9, a Sn—Zn—O-based oxide sintered body according to Comparative Example 9 was obtained in the same manner as in Example 1 except that Ge / (Sn + Zn + Ge + Ta + Ga) was prepared at a ratio of 0.03. . The Sn—Zn—O-based oxide sintered body according to Comparative Example 9 was subjected to X-ray diffraction analysis in the same manner as in Example 1. As a result, it was found that the wurtzite type ZnO phase was 34% and the spinel type crystal structure Zn ₂ SnO _4. The phase was diffracted to 66%. The diffraction peaks of other other compound phases were not measured. Further, when the relative density and the specific resistance value were measured, the relative density was 93.0%, and the specific resistance value was 8500 Ω · cm. That is, it was confirmed that a relative density of 94% or more cannot be achieved. The results are shown in Table 2.

(Comparative Example 10)
In Comparative Example 10, a Sn—Zn—O-based oxide sintered body according to Comparative Example 10 was obtained in the same manner as in Example 1 except that Ge / (Sn + Zn + Ge + Ta + Ga) was prepared at a ratio of 0.0001. . The Sn—Zn—O-based oxide sintered body according to Comparative Example 10 was subjected to X-ray diffraction analysis in the same manner as in Example 1. As a result, the wurtzite type ZnO phase was 34% and the spinel type crystal structure Zn ₂ SnO _4. The phase was diffracted to 66%. The diffraction peaks of other other compound phases were not measured. Further, when the relative density and the specific resistance value were measured, the relative density was 91.0% and the specific resistance value was 9800 Ω · cm. That is, it was confirmed that a relative density of 94% or more cannot be achieved. The results are shown in Table 2.

(Comparative Example 11)
In Comparative Example 11, a Sn—Zn—O-based oxide sintered body according to Comparative Example 11 was obtained in the same manner as in Example 1 except that Ta / (Sn + Zn + Ge + Ta + Ga) was prepared at a ratio of 0.03. . The Sn—Zn—O-based oxide sintered body according to Comparative Example 11 was subjected to X-ray diffraction analysis in the same manner as in Example 1. As a result, it was found that the wurtzite type ZnO phase was 34% and the spinel type crystal structure Zn ₂ SnO _4. The phase was diffracted to 66%. The diffraction peaks of other other compound phases were not measured. Further, when the relative density and the specific resistance value were measured, the relative density was 97.0% and the specific resistance value was 16000 Ω · cm. That is, it was confirmed that a specific resistance of 5 Ω · cm or more and 12000 Ω · cm or less could not be achieved. The results are shown in Table 2.

(Comparative Example 12)
In Comparative Example 12, a Sn—Zn—O-based oxide sintered body according to Comparative Example 12 was obtained in the same manner as in Example 1 except that Ta / (Sn + Zn + Ge + Ta + Ga) was prepared at a ratio of 0.0001. . The Sn—Zn—O-based oxide sintered body according to Comparative Example 12 was subjected to X-ray diffraction analysis in the same manner as in Example 1. As a result, it was found that the wurtzite type ZnO phase was 34% and the spinel type crystal structure Zn ₂ SnO _4. The phase was diffracted to 66%. The diffraction peaks of other other compound phases were not measured. Further, when the relative density and the specific resistance value were measured, the relative density was 96.7% and the specific resistance value was 25000 Ω · cm. That is, it was confirmed that a specific resistance of 5 Ω · cm or more and 12000 Ω · cm or less could not be achieved. The results are shown in Table 2.

(Comparative Example 13)
In Comparative Example 13, a Sn—Zn—O-based oxide sintered body according to Comparative Example 13 was obtained in the same manner as in Example 1 except that Ga / (Sn + Zn + Ge + Ta + Ga) was prepared at a ratio of 0.2. . The Sn—Zn—O-based oxide sintered body according to Comparative Example 13 was subjected to X-ray diffraction analysis in the same manner as in Example 1. As a result, it was found that the wurtzite type ZnO phase was 34% and the spinel type crystal structure Zn ₂ SnO _4. The phase was diffracted to 66%. The diffraction peaks of other other compound phases were not measured. Further, when the relative density and the specific resistance value were measured, the relative density was 97.3% and the specific resistance value was 14800 Ω · cm. That is, it was confirmed that a specific resistance of 5 Ω · cm or more and 12000 Ω · cm or less could not be achieved. The results are shown in Table 2.

(Comparative Example 14)
In Comparative Example 14, a Sn—Zn—O-based oxide sintered body according to Comparative Example 14 was obtained in the same manner as in Example 1 except that Ga / (Sn + Zn + Ge + Ta + Ga) was mixed at a ratio of 0.0008. . The Sn—Zn—O-based oxide sintered body according to Comparative Example 14 was subjected to X-ray diffraction analysis in the same manner as in Example 1. As a result, the wurtzite type ZnO phase was 34% and the spinel type crystal structure Zn ₂ SnO _4. The phase was diffracted to 66%. The diffraction peaks of other other compound phases were not measured. Further, when the relative density and the specific resistance value were measured, the relative density was 97.0% and the specific resistance value was 22000 Ω · cm. That is, it was confirmed that a specific resistance of 5 Ω · cm or more and 12000 Ω · cm or less could not be achieved. The results are shown in Table 2.

Although one embodiment and each example of the present invention have been described in detail as described above, it will be understood by those skilled in the art that many modifications that do not substantially depart from the novel matters and effects of the present invention are possible. It will be easy to understand. Therefore, all such modifications are included in the scope of the present invention.

For example, a term described together with a different term having a broader meaning or the same meaning at least once in the specification or the drawings can be replaced with the different term in any part of the specification or the drawings. Further, the configuration of the Sn—Zn—O-based oxide sintered body and the manufacturing method thereof is not limited to that described in the embodiment and the examples of the present invention, and various modifications can be made.

Claims

A Sn—Zn—O-based oxide sintered body having zinc (Zn) and tin (Sn) as components,
Furthermore, at least germanium (Ge), tantalum (Ta), and gallium (Ga) are contained as components,
The metal atom ratio is
Sn / (Zn + Sn) is 0.1 or more and 0.3 or less,
Ge / (Zn + Sn + Ge + Ta + Ga) is 0.0005 or more and 0.01 or less,
Ta / (Zn + Sn + Ge + Ta + Ga) is 0.0005 or more and 0.01 or less,
Sn / Zn—O-based oxide having Ga / (Zn + Sn + Ge + Ta + Ga) of 0.001 or more and 0.1 or less, a specific resistance of 5 Ω · cm or more and 12000 Ω · cm or less, and a relative density of 94% or more Sintered body.
The metal atom number ratio is Sn / (Zn + Sn) of 0.16 or more and 0.23 or less,
2. The Sn—Zn—O-based oxide sintered body according to claim 1, wherein the specific resistance is 5 Ω · cm or more and 110 Ω · cm or less, and the relative density is 98% or more.
In the Sn—Zn—O-based oxide sintered body,
The Sn-Zn according to claim 1, wherein the ZnO phase of the wurtzite type crystal structure is comprised in the range of 5 to 70% of the whole, or the Zn 2 SnO 4 phase of the spinel type crystal structure is comprised of 30 to 95% of the whole. -O-based oxide sintered body.
In the Sn—Zn—O-based oxide sintered body,
3. The Sn—Zn according to claim 2, wherein the ZnO phase of the wurtzite type crystal structure is comprised in the range of 5 to 70% of the whole, or the Zn 2 SnO 4 phase of the spinel type crystal structure is comprised in the range of 30 to 95% of the whole. -O-based oxide sintered body.
A method for producing a Sn—Zn—O-based oxide sintered body having zinc (Zn) and tin (Sn) as components,
A granulation step of preparing a granulated powder by mixing an oxide powder of zinc, an oxide powder of tin, and an oxide powder containing an additive element;
A molding step of pressing the granulated powder to obtain a molded body; and
Firing the molded body to obtain an oxide sintered body,
The additive element is at least germanium (Ge), tantalum (Ta), and gallium (Ga),
The metal atom ratio is
Sn / (Zn + Sn) is 0.1 or more and 0.3 or less,
Ge / (Zn + Sn + Ge + Ta + Ga) is 0.0005 or more and 0.01 or less,
Ta / (Zn + Sn + Ge + Ta + Ga) is 0.0005 or more and 0.01 or less,
The zinc oxide powder, the tin oxide powder, and the oxide powder containing the additive element are mixed so that Ga / (Zn + Sn + Ge + Ta + Ga) is 0.001 or more and 0.1 or less. A method for producing a Sn—Zn—O-based oxide sintered body.
In the firing step, the temperature is raised from 1300 ° C. to 1400 ° C. at a temperature rising rate of 0.3 to 1.0 ° C./min in an atmosphere in a firing furnace in the atmosphere, 6. The method for producing a Sn—Zn—O-based oxide sintered body according to claim 5, wherein the compact is fired.