KR101921827B1 - Sintered body, sputtering target and method of manufacturing the same - Google Patents

Abstract

[PROBLEMS] To provide a sintered body, a sputtering target and a manufacturing method thereof capable of effectively suppressing unevenness of volume resistivity on the surface and inside of the sintered body with the IZO target.
[MEANS FOR SOLVING PROBLEMS] The sintered body of the present invention is a sintered body of an oxide consisting of In, Zn and O, and has a volume resistivity (Rs) at a depth of 1 mm in the thickness direction from the surface of the sintered body, The absolute value of the ratio (Rs-Rd) / Rd obtained by dividing the difference in the volume resistivity Rd at the 4 mm depth position by the volume resistivity Rd at the 4 mm depth position is 20% or less as a percentage.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a sintered body, a sputtering target,

The present invention relates to a sputtering target such as a sintered body made of In, Zn or O and a sintered body for forming a transparent conductive film, which is also called IZO target, and a method for producing the sputtering target. Particularly, And to provide a technique that can contribute to the present invention.

The sputtering target can be used for manufacturing a film electrode such as a liquid crystal display (LCD) mounted on a PC or a word processor, an electroluminescence (EL), various other display device electrodes, a touch panel, , A sputtering method for forming a transparent conductive film made of a metal composite oxide on a substrate for film formation such as glass or plastic.

ITO target is widely used as a transparent conductive film of this type because ITO (Indium Tin Oxide) film excellent in light transmittance and conductivity is mainstream and this ITO film made of In, Sn and O is produced.

However, since the ITO film is relatively low in moisture resistance and has the drawback that the electric resistance value increases due to moisture, an IZO (Indium Zinc Oxide) film composed of In, Zn, and O is used instead of the ITO film as the transparent conductive film And to use the IZO target to produce this IZO film.

However, in order to achieve a stable film formation, it is also important that the sputtering target is required to have high density and low resistance, and that the density and resistance thereof are uniform over the entire target.

Particularly, with respect to the resistance, when the bulk resistivity in the thickness direction of the target is irregular, the film characteristics change during sputtering. In sputtering targets formed by combining a plurality of pieces at the same time, irregularities in the volume resistivity between the pieces can easily occur. It hurts stability. Therefore, in the sputtering target, it is necessary to ensure the uniformity of the volume resistivity in the thickness direction. In the conventional IZO target, the volume resistivity in the thickness direction is not uniform, and thus a stable IZO film can not be formed.

Generally, the volume resistivity tends to be higher on the surface of the sintered body than in the sintered body constituting the sputtering target. Even if the volume resistivity of the sintered body becomes uneven in the thickness direction, the amount of grinding on the surface of the sintered body is increased to produce a sputtering target , It is considered that the uniformity of the volume resistivity can be secured to a certain degree. In this case, however, it is necessary to prepare the sintered body with a large thickness in accordance with the increase in the amount of grinding, , The yield of the product due to the increase in the amount of grinding may be lowered.

Regarding such a volume resistance, Patent Document 1 discloses that, in producing a sputtering target containing at least indium oxide and zinc oxide, after a sintering step, the sintered body obtained may be subjected to an optional step, It is preferable to carry out the reduction treatment in the step ".

Patent Document 2 discloses that the volume resistivity of the In-Sn-Zn-Al sputtering target with a high density and low resistance is preferably 10 m? Cm or less and that cracks are generated at a temperature drop after sintering at the time of manufacturing such a target And at the same time, the temperature decreasing rate is set to 10 ° C / min or less, further 5 ° C / min or less for the purpose of obtaining a predetermined crystal form.

Also, Patent Document 3 discloses a sputtering target having a volume resistivity difference of not more than 20% in a target thickness direction, though it is related to an ITO target instead of an IZO target. Patent Document 3 discloses that in order to reduce the difference in volume resistivity in the target thickness direction, mainly, the atmosphere at the time of temperature drop is set to an atmospheric atmosphere and the average cooling rate is set to 0.1 to 3.0 ° C / min. Further, it is suggested that the difference in the volume resistivity in the sintered body greatly correlates with the resistance difference of the thin film formed on the target.

Patent Document 1: Japanese Laid-Open Patent Publication No. 2011-68993 Patent Document 2: JP-A-2014-218706 Patent Document 3: International Publication No. 2014/156234

The above-mentioned Patent Document 1 does not disclose any method for reducing unevenness in the volume resistivity in the thickness direction, and even if the uniformization of the volume resistivity can be realized by performing the reduction treatment in a separate step after the sintering, It is undesirable from a production point of view in that it causes an increase in cost and an increase in the number of process steps.

Patent Document 2 mentions that a low volume resistivity is preferable. However, no consideration is given to variations in the volume resistivity in the thickness direction, and the description of the temperature lowering process is for stabilizing the volume resistance no.

Since the patent document 3 relates to the ITO target that is not the IZO target, the proposed technique can not be applied to the IZO target as it is. Particularly, unlike the ITO target, the IZO target has a surface alteration layer on the surface of the sintered body, and the volume resistivity near the surface alteration layer is higher. In the IZO target, the proposed technique of the temperature lowering process , The unevenness of the volume resistivity could not be sufficiently reduced.

The object of the present invention is to solve such a problem of the prior art. The object of the present invention is to provide a sintered body, a sputtering target and a sputtering target which can effectively suppress unevenness of the volume resistivity on the surface and inside of the sintered body by the IZO target And a manufacturing method thereof.

In manufacturing the IZO target, oxygen sintering or air sintering, in which oxygen is introduced during the heating, is preferable in order to improve the density of the sintered body and realize excellent film characteristics when heating and sintering the molded body formed into a predetermined shape. As a result of intensive studies, it has been found that the oxygen deficiency in the vicinity of the surface of the sintered body decreases when the oxygen is introduced into the atmosphere even during the temperature drop, and thus the unevenness of the volume resistivity in the thickness direction of the sputtering target greatly differs.

Therefore, unlike the case of raising the temperature, the atmosphere at the time of lowering the temperature after sintering the molded body is nitrogen atmosphere or argon atmosphere to suppress reduction of oxygen deficiency in the vicinity of the surface of the sintered body, Can be suppressed, and a sputtering target having more uniform volume characteristics can be produced.

The sintered body of the present invention is a sintered body of an oxide consisting of In, Zn, and O. The volume resistivity (Rs) at a depth of 1 mm in the thickness direction on the surface of the sintered body and the volume resistivity The absolute value of the ratio (Rs-Rd) / Rd obtained by dividing the difference in the volume resistivity (Rd) at the depth position by the volume resistivity (Rd) at the depth position of 4 mm is 20% or less.

Here, the absolute value of the ratio (Rs-Rd) / Rd is preferably 15% or less, more preferably 10% or less, expressed as a percentage.

The sintered body may contain Zn / (In + Zn) at 7 at% (atomic%) to 20 at%, preferably 10 at% to 17 at%.

The sputtering target of the present invention is a sputtering target of an oxide consisting of In, Zn, and O. The sputtering target has a volume resistivity (Rf) at a depth of 0 mm in the thickness direction from the surface of the sputtering target, The absolute value of the ratio (Rf-Ra) / Ra obtained by dividing the difference from the volume resistivity (Ra) at a depth of 3 mm in the thickness direction by the volume resistivity (Ra) at the depth of 3 mm is 20% will be.

Here, the absolute value of the ratio (Rf-Ra) / Ra is preferably 15% or less, more preferably 10% or less, expressed as a percentage.

The sputtering target may contain Zn / (In + Zn) at 7 at% to 20 at%, preferably 10 at% to 17 at%.

A method for producing a sputtering target of the present invention includes mixing a powder raw material containing indium oxide powder and zinc oxide powder to form a mixture, heating and sintering the resulting mixture, and subjecting the temperature drop after heating and sintering the mixture to a nitrogen atmosphere Or in an argon atmosphere.

In this production method, the temperature drop rate at the temperature drop is preferably set at a rate exceeding 1 占 폚 / min, more preferably at a rate exceeding 3 占 폚 / min.

Further, in this manufacturing method, it is preferable that the heating and sintering of the molded body is carried out in the atmosphere or an oxygen atmosphere.

According to the present invention, since the difference in the volume resistivity between the surface and the inside of the sputtering target can be reduced, the change in the film characteristics at the time of sputtering is reduced and the formation of a stable thin film can be realized. In addition, since the amount of grinding on the surface of the final product required for manufacturing a sputtering target of stable quality is reduced, the yield of the material can be improved.

Hereinafter, embodiments of the present invention will be described in detail.

The sintered body of the first embodiment of the present invention is a sintered body composed of indium, zinc and oxygen, and has a volume resistivity (Rs) at a depth of 1 mm in the thickness direction from the surface of the sintered body, Is 20% or less when the absolute value of the ratio (Rs-Rd) / Rd obtained by dividing the difference in the volume resistivity Rd at the 4 mm depth position by the volume resistivity Rd at the 4 mm depth position is expressed as a percentage .

The sputtering target according to the first embodiment of the present invention is a sputtering target comprising a sintered body made of indium, zinc and oxygen. The sputtering target has a position at a depth of 0 mm in the thickness direction (i.e., the surface position of the sputtering target) (Rf) obtained by dividing the difference between the volume resistivity (Rf) of the sputtering target and the volume resistivity (Ra) at a position 3 mm deep in the thickness direction on the surface of the sputtering target by the volume resistivity -Ra) / Ra is expressed as a percentage and is 20% or less.

(Furtherance)

The sintered body constituting the sputtering target is composed of In, Zn and O, and includes, for example, an amorphous oxide represented by the general formula In ₂ O ₃ (ZnO) _m . Here, m in the general formula is an integer, and the value of m may take a value within the range of 3 to 20.

Zinc may be contained in an amount of 7 at% to 20 at% represented by the atomic ratio Zn / (In + Zn) of zinc, and may be typically 10 at% to 17 at%. The amount of zinc can be appropriately changed depending on the conductivity of the desired film.

The contents of line segments such as In and Zn can be measured by fluorescent X-ray analysis (XRF).

The sintered body may contain, in addition to In and Zn, other elements insofar as the characteristics of the present invention are not impaired. For example, when at least one element among Fe, Al, Si, Cu, and Pb is contained, the content of each element may be 100 wt ppm (weight ppm) or less, and at least one of Sn and Zr , The content of each of these elements may be set to 1000 wtppm or less.

(Volume resistivity)

In the embodiment of the sintered body, the volume resistivity (Rs) at the surface (1 mm depth position) exposed by grinding 1 mm in the thickness direction on the surface of the sintered body obtained after the temperature is lowered by heating and sintering and the surface (Rs-1) obtained by dividing the difference in volume resistivity (Rd) at the exposed surface (4 mm depth position) by 4 mm in the thickness direction by the volume resistivity (Rd) at the target surface at the depth of 4 mm, Rd) / Rd is expressed as a percentage to be 20% or less.

If the ratio (Rs-Rd) / Rd exceeds 20%, stable film formation can not be performed due to a change in film characteristics during sputtering when a sintered body is used for a sputtering target. Therefore, for use in a sputtering target, Is required. As a result, in order to produce a sputtering target having a predetermined thickness, it is necessary to prepare a sintered body having a large thickness in anticipation of the grinding amount in advance. In this case, there is a fear of lowering the density at the center position in the thickness direction, Resulting in a decrease in the material yield.

Therefore, from this viewpoint, the ratio (Rs-Rd) / Rd is more preferably 15% or less, and particularly preferably 10% or less.

In the embodiment of the sputtering target, the volume resistivity (Rf) at the surface (0 mm depth position) of the sputtering target obtained by polishing the sintered body and the surface resistivity (Rf) at 3 mm in the thickness direction on the surface of the sputtering target It is preferable that the absolute value of the ratio (Rf-Ra) / Ra obtained by dividing the difference in the volume resistivity (Ra) at the depth of 3 mm by the volume resistivity (Ra) at the depth of 3 mm is not more than 20% .

Accordingly, stable film formation can be realized at the time of sputtering. In other words, when the ratio exceeds 20%, the film characteristics are not changed because the film characteristics are changed in accordance with the decrease in thickness during sputtering.

The ratio (Rf-Ra) / Ra is preferably 15% or less, and more preferably 10% or less.

The measurement of the volume resistivity described above in the sintered body or the sputtering target can be carried out on a surface finishing with a grinding thickness of 0.2 mm by a grinding fine grinding material of # 400 grain size specified in JIS R6001 (1998).

The above-mentioned volume resistivity can be measured based on the four-needle method described in JIS R1637. More specifically, the measurement planes of the sintered body and the sputtering target were measured at five points in total of four corners and a central area divided into nine equal parts by 3x3 in the longitudinal direction and the lateral direction, and the average value To the volume resistivity referred to in the present invention. The measurement point may be, for example, the center of each area.

(Crystal grain size)

The crystal grain size Ds in the texture of the surface ground by 1 mm from the surface and the surface ground by 4 mm from the surface (for example, the surface at the center position in the thickness direction) by the resistance difference in the thickness direction as described above, The difference of the grain size Dd in the grain boundary can be 20% or less. The size of the crystal grains is selected by observing any four points at the 5 mm edge of the center of the target surface. From the x300 image of the SEM image, the size of the crystal grains is obtained as an average value according to the code method. The difference between the crystal grains is obtained by comparing the grinding surface with the grinding surface of 1 mm from the surface and the grinding surface of 4 mm from the surface (for example, the surface of the thickness center position), and the relative difference (Ds-Dd) / Dd The value is taken as the difference in crystal grain size.

The average crystal grain size of the sintered body constituting the sputtering target may be, for example, 1.0 탆 to 5.0 탆, and preferably 2.0 탆 to 3.0 탆. The crystal grain size can be measured by cutting a part of the obtained sintered body, polishing the cut surface by mirror polishing, and observing the SEM image.

(density)

The relative density of the sintered body and the sputtering target may be 95% or more, preferably 98% or more.

Particularly, according to the present invention, unevenness in the volume resistivity in the thickness direction is reduced, and the amount of polishing when the sputtering target is produced by the sintered body can be reduced, so that the density at the center position in the thickness direction can also be increased. In other words, if the degree of unevenness of the volume resistivity in the thickness direction is large, it is necessary to prepare a sintered body having a large thickness in advance in anticipation of increasing the polishing amount of the sintered body when the sputtering target is manufactured. In this case, Heat is not sufficiently transferred to the vicinity of the center in the thickness direction at the time of heat sintering and the density at the center position in the thickness direction of the obtained sintered body or sputtering target is lowered.

The relative density is calculated from the theoretical density calculated by the density of the raw material powder and the density of the sintered body measured by the Archimedes method by the equation of relative density = (density measured by Archimedes method) / (theoretical density) x 100 can do. The theoretical density of IZO 10.7% is 7.00 g / cm3.

(Manufacturing method)

The sintered body and the sputtering target as described above can be produced, for example, by the method described below.

First, for example, a powder raw material containing at least an indium oxide powder and a zinc oxide powder is mixed together with a molding binder as required.

Then, the mixed raw powder material is filled in a metal mold and pressure-formed to produce a molded body having a predetermined shape. Here, for example, a pressure of 400 to 1000 kgf / cm 2 can be applied for 1 minute to 3 minutes.

The formed body is sintered in a sintering furnace, for example, by heating to a temperature of 1350 to 1500 ° C. The holding time of the heating temperature may be from 1 hour to 100 hours, preferably from 5 hours to 30 hours. This heating and sintering is preferably carried out in an atmosphere of atmosphere such as air or an oxygen atmosphere because the sputtering target having high density and excellent film characteristics can be obtained.

It is important to cool the temperature drop after the heating and sintering in a nitrogen atmosphere or an argon atmosphere instead of an atmosphere or an oxygen atmosphere. By making the atmosphere of nitrogen, it is possible to suppress the reduction of the oxygen deficiency in the vicinity of the surface of the sintered body, and to suppress the unevenness of the volume resistance in the thickness direction of the sintered body to the above-described degree. In other words, when this temperature drop is performed in an atmospheric atmosphere or an oxygen atmosphere, the oxygen deficiency near the surface decreases, and the volume resistance in the thickness direction largely fluctuates, resulting in non-uniformity.

Further, in order to obtain an effect of suppressing the decrease in oxygen deficiency, the temperature lowering rate after the heat sintering is preferably set at a rate exceeding 1 占 폚 / min, more preferably at a rate exceeding 3 占 폚 / min, Particularly preferably at a rate exceeding 5 DEG C / min. Accordingly, the unevenness of the volume resistivity in the thickness direction of the sintered body is further suppressed, so that a sintered body having a more uniform volume resistivity can be manufactured.

The temperature drop can be carried out, for example, by introducing cold air whose temperature has been adjusted into a sintering furnace, preferably nitrogen / argon.

The atmosphere / temperature drop rate is preferably in a range of at least 1400 ° C to 1000 ° C at a temperature drop, and less than 1000 ° C may be a natural temperature drop. This is because the temperature drop rate and the temperature dropping atmosphere in the IZO target greatly affect the volume characteristics thereof, especially in the high temperature region.

One surface of the sintered body obtained after the temperature drop is ground by a known method such as mechanical grinding or chemical grinding at a thickness of, for example, 1% to 20%, preferably 1% to 10% A sputtering target can be manufactured. This grinding amount can be specifically set to, for example, 0.1 mm to 2.0 mm, preferably 0.1 mm to 1.0 mm in the thickness direction of the sintered body. However, the amount of grinding at the time of manufacturing the sputtering target is not limited to this range, but may be any amount. This grinding can be carried out by using a fine grinding abrasive for abrasive # 80 specified in JIS R6001 (1998).

In this embodiment, since the unevenness of the volume resistivity in the thickness direction is small as described above, the required amount of grinding is reduced. Accordingly, the material yield can be improved.

[ Example ]

Next, the sputtering target according to the present invention is started and its performance is confirmed. It should be understood, however, that the description herein is for the purpose of illustration only and is not intended to be limiting.

The indium oxide powder and the zinc oxide powder were mixed and pulverized so as to have the respective compositions shown in Table 1, and this was put into a mold and a pressure of 800 kgf / cm 2 was applied for 1 minute to obtain a molded article. The formed body was heated to 1400 캜 in an electric furnace, held for 10 hours, sintered, and then cooled down.

Here, the temperature drop after the heat sintering was carried out in the nitrogen atmosphere in Examples 1 to 7, while in the atmosphere in Comparative Examples 1 to 5. In Examples 1 to 7 and Comparative Examples 1 to 5, as shown in Table 1, the temperature during heating and sintering, the holding atmosphere and the temperature drop rate were changed. The rate of temperature decrease shown in Table 1 is the rate when it is between 1400 ° C and 1000 ° C and the temperature drops naturally after the temperature drops to less than 1000 ° C.

The thus obtained sintered body was manually cut using a # 80 abrasive powder for fine grinding by 1 mm in the thickness direction on the surface of the sintered body to produce a sputtering target. Further, the surface of the sintered body is ground to a final extent of about 5 mm by the same polishing method, and the volume resistivity is measured at each depth position in the middle by using a resistivity meter (model number: Σ-5 +) manufactured by NPS Co., The volume resistivity Rs at a depth of 1 mm from the surface, the volume resistivity Rd at a depth of 4 mm from the surface of the sintered body, and the volume resistivity Rb of the surface of the sintered body were measured. Prior to measuring each volume resistivity, the measuring surface was ground with a hand of 0.2 mm thick with # 400 abrasive powder sandpaper and finished. Using these, the ratio (Rs-Rd) / Rd × 100 of the difference between Rs and Rd (Rb-Rd) / Rd × 100 of the difference between Rb and Rd was calculated. The results are shown in Table 1.

Further, in this embodiment, the volume resistivity Rs at a depth of 1 mm from the surface of the sintered body becomes equal to the volume resistivity Rf at a position of 0 mm depth from the surface of the sputtering target, and at a depth of 4 mm from the surface of the sintered body Is equal to the volume resistivity (Ra) at a depth of 3 mm from the surface of the sputtering target.

In Table 1, " maximum value (%) of difference ratio " is calculated by calculating the ratio of the maximum and minimum difference of the volume resistances measured at each depth position to the depth position of about 5 mm. Quot; refers to the amount of grinding when the volume resistivity ratio based on the volume resistivity at the depth of 4 mm of the grinding surface is 20% from the surface toward the deep side.

The crystal grains in Example 1 were measured to be 2.45 mu m in a 1 mm ground plane and 2.59 mu m in a 4 mm ground plane from the surface of the sintered body, and the absolute value of the relative difference (Ds-Dd) / Dd was 5.4%.

[Table 1]

As shown in Table 1, in all of Examples 1 to 7 in which the temperature lowering atmosphere was nitrogen, the volume resistivity (Rs) at a depth of 1 mm of the sintered body, regardless of oxygen or atmospheric temperature, And the difference in the volume resistivity (Rd) at the depth of 4 mm between the sintered body and the sintered body was 20% or less. Thus, reduction in volume resistivity and suppression of unevenness were realized.

Particularly, in Examples 3 and 6 in which the temperature was lowered at a high speed exceeding 5 占 폚 / min, reduction in volume resistivity and suppression of unevenness could be realized.

On the other hand, in Comparative Examples 1 to 5, the volume resistivity (Rs) at a depth of 1 mm of the sintered body and the volume at a depth of 4 mm of the sintered body due to the fact that the temperature was lowered in an atmospheric environment after the molded body was heated and sintered The ratio of the difference in resistivity (Rd) exceeded 20%, and the volume resistivity became uneven.

From the above, it has been found that according to the present invention, the unevenness of the volume resistivity on the surface and inside of the sintered body can be effectively suppressed.

Claims (26)

Wherein a volume resistivity Rs at a depth of 1 mm from the surface of the sintered body containing Zn / (In + Zn) in an amount of 7 at% to 20 at% as a sintered body of an oxide consisting of In, Zn, The absolute value of the ratio (Rs-Rd) / Rd obtained by dividing the difference in the volume resistivity Rd at the 4 mm depth position in the thickness direction by the volume resistivity Rd at the 4 mm depth position is expressed as a percentage Wherein the sintered body is 20% or less. The method according to claim 1,
Wherein an absolute value of the ratio (Rs-Rd) / Rd is expressed as a percentage of 15% or less. The method according to claim 1,
Wherein the absolute value of the ratio (Rs-Rd) / Rd is 10% or less as a percentage. 4. The method according to any one of claims 1 to 3,
Zn / (In + Zn) of 10 at% to 17 at%. 4. The method according to any one of claims 1 to 3,
The difference between the grain size (Ds) on the surface of 1 mm in the thickness direction from the surface of the sintered body and the grain size (Dd) on the surface grinded 4 mm in the thickness direction from the surface of the sintered body was 4 mm Wherein the absolute value of the ratio (Ds-Dd) / Dd divided by the grain size (Dd) in the plane is 20% or less as a percentage. 4. The method according to any one of claims 1 to 3,
Wherein the sintered body contains an amorphous oxide represented by the general formula In ₂ O ₃ (ZnO) _m (3? _M ? 20). 4. The method according to any one of claims 1 to 3,
Wherein the sintered body further contains at least one element selected from the group consisting of Fe, Al, Si, Cu and Pb in an amount of not more than 100 wtppm and at least one element selected from Sn and Zr in an amount of not more than 1000 wtppm. 4. The method according to any one of claims 1 to 3,
And an average crystal grain size of 1.0 占 퐉 to 5.0 占 퐉. 4. The method according to any one of claims 1 to 3,
A sintered body having a relative density of 95% or more. A sputtering target of an oxide consisting of In, Zn and O, wherein the sputtering target contains Zn / (In + Zn) in an amount of 7 at% to 20 at%, a volume resistivity Rf at a position 0 mm deep in the thickness direction on the surface of the sputtering target, The absolute value of the ratio (Rf-Ra) / Ra obtained by dividing the difference in volume resistivity (Ra) at a depth of 3 mm from the surface of the sputtering target by the volume resistivity (Ra) at the depth of 3 mm And a sputtering target expressed as a percentage of 20% or less. 11. The method of claim 10,
Wherein the absolute value of the ratio (Rf-Ra) / Ra is 15% or less, expressed as a percentage. 11. The method of claim 10,
Wherein the absolute value of the ratio (Rf-Ra) / Ra is 10% or less, expressed as a percentage. 13. The method according to any one of claims 10 to 12,
Wherein the sputtering target contains Zn / (In + Zn) at 10 at% to 17 at%. 13. The method according to any one of claims 10 to 12,
Wherein the sputtering target comprises an amorphous oxide represented by the general formula In ₂ O ₃ (ZnO) _m (3? _M ? 20). 13. The method according to any one of claims 10 to 12,
Wherein the sputtering target further contains at least one element selected from the group consisting of Fe, Al, Si, Cu and Pb in an amount of not more than 100 wtppm and at least one element selected from Sn and Zr in an amount of not more than 1000 wtppm. 13. The method according to any one of claims 10 to 12,
A sputtering target having an average crystal grain size of 1.0 탆 to 5.0 탆. 13. The method according to any one of claims 10 to 12,
A sputtering target having a relative density of 95% or more. Wherein the temperature drop after the heating and sintering of the formed body is carried out in a nitrogen atmosphere or an argon atmosphere, and a step of mixing the powdery material containing Zn / (In + Zn) in a range of 7 at% to 20 at% is produced by the sputtering method. 19. The method of claim 18,
Wherein the temperature drop rate at the temperature drop is set to a rate exceeding 1 占 폚 / min. 19. The method of claim 18,
Wherein the temperature drop rate at the time of the temperature drop is set to a rate exceeding 3 占 폚 / min. 21. The method according to any one of claims 18 to 20,
Wherein the heating and sintering of the formed body is carried out in an atmosphere or an oxygen atmosphere. 21. The method according to any one of claims 18 to 20,
Wherein a pressure of 400 to 1000 kgf / cm < 2 > is applied for 1 minute to 3 minutes when the powder raw materials are mixed and molded. 21. The method according to any one of claims 18 to 20,
Wherein the molded body is heated at a temperature of 1350 ° C to 1500 ° C for 1 hour to 100 hours when the molded body is heated and sintered. delete delete delete