KR20180129655A - Oxide target material and manufacturing method thereof - Google Patents

Abstract

Provided are an oxide target material and a manufacturing method thereof, which can form a ZTO thin film forming a channel layer of a TFT driving a high precision display or the like to restrict instability of threshold voltage. The whole metal component comprises: 20.0-50.0 atom% of Sn; and the remainder consisting of Zn and inevitable impurities. In an area of 10000 μm^2, an area rate of ZnO is less than or equal to 10.5 area%, and in the whole metal component, the sum of at least one of Al, Ga, Mo and W is 0.005-4.000 atom%.

Description

TECHNICAL FIELD [0001] The present invention relates to an oxide target material and an oxide target material,

The present invention relates to an oxide target material used for forming an oxide semiconductor layer of a thin film transistor that drives, for example, a liquid crystal display, an organic EL display or the like, and a method for manufacturing the oxide target material.

2. Description of the Related Art In a display device such as a liquid crystal display or an organic EL display driven by a thin film transistor (hereinafter referred to as " TFT "), an amorphous silicon film or a crystalline silicon film is used as a channel layer of a TFT. Along with the demand for high definition display, oxide semiconductors have attracted attention as a material used for a channel layer of a TFT. For example, an oxide semiconductor film containing In, Ga, Zn, O (oxygen) (hereinafter referred to as "I-G-Z-O thin film") has excellent TFT characteristics and is put to practical use. In and Ga contained in the thin film of the I-G-Z-O are scarce and expensive metals designated in Japan as rare metal stocks.

Therefore, a Zn-Sn-O-based oxide semiconductor film (hereinafter referred to as a "ZTO thin film") has attracted attention as an oxide semiconductor film containing no In or Ga contained in the I-G-Z-O thin film. The ZTO thin film is formed by a sputtering method using a target. The sputtering method is a method in which an ion, an atom or a cluster is collided with a target surface, and the surface of the material is shaved (or spun) to deposit a component constituting the substance on the surface of a substrate or the like.

Here, since the ZTO thin film is a thin film containing oxygen, the so-called reactive sputtering method in which the film is formed in an atmosphere containing oxygen is used in the sputtering method. This reactive sputtering method is a method of sputtering in an atmosphere of a mixed gas composed of an argon gas and an oxygen gas and sputtering while reacting ions, atoms or clusters with oxygen to form an oxide thin film.

The target material used in this reactive sputtering method is a target material containing a ZTO-based oxide sintered body having a composition approximate to that of the ZTO thin film. Such a target material is applied to the DC sputtering method from the viewpoint of productivity and is required to be used at high power in order to improve the deposition rate. Patent Document 1 proposes a sintered body for a target material capable of suppressing the occurrence of arcing and improving the deposition rate even in high-power sputtering by not containing crystalline phase of tin oxide (SnO ₂ ), which causes arcing, in the structure .

Japanese Patent Application Laid-Open No. 2007-277075

According to the study of the present inventor, a ZTO thin film is formed by a sputtering method using the sintered body in which the crystal phase of SnO ₂ is suppressed as disclosed in the above-mentioned Patent Document 1, and a TFT is formed, It has been confirmed that there is a case where the threshold voltage is shifted in the minus direction when exposed to a bias application state (Negative Bias under Illumination Stress (NBIS)).

If the problem of instability of the threshold voltage occurs, there arises a problem that it becomes difficult to obtain a driving element for a high-precision display.

An object of the present invention is to provide an oxide target material for forming a ZTO thin film constituting a channel layer of a TFT for driving a high-precision display or the like in which the instability of threshold voltage is suppressed, and a manufacturing method thereof.

As a result of studying the above problems, the present inventors have found that the instability of the threshold voltage can be suppressed by setting the area ratio of the ZnO phase per unit area of the oxide target material within a predetermined range.

That is, the oxide target material of the present invention contains Sn in an amount of 20.0 atom% to 50.0 atom% based on the entire metal component, the balance of Zn and inevitable impurities, the area ratio of ZnO phase in an area of 10000 탆 ² Is not more than 10.5% by area.

The oxide target of the present invention preferably contains at least 0.005 atom% to 4.000 atom% of at least one of Al, Ga, Mo, and W relative to the entire metal component.

The oxide target of the present invention is obtained by mixing ZnO powder and SnO ₂ powder with pure water and a dispersant such that the total amount of Sn is 20.0 atomic percent to 50.0 atomic percent and the remainder is Zn and inevitable impurities, , A step of drying the slurry to prepare a granulated powder, and calcining the granulated powder to obtain a calcined powder containing Zn ₂ SnO ₄ and ZnO; a step of wet-crushing the calcined powder; A sintering step of sintering the oxide sintered body to obtain an oxide sintered body; polishing the surface to be the erosion surface of the oxide sintered body to obtain a sintered body having a surface of 10000 m ² And a polishing step of obtaining an oxide target material having an area ratio of ZnO phase occupying in an area of 10.5% or less by area.

In the polishing step, it is preferable to polish a surface to be an erosion surface while checking the lightness L ^* and chromaticity b ^* .

According to the present invention, a ZTO thin film suppressing the instability of the threshold voltage can be obtained. By suppressing the instability of the threshold voltage, it is a technology useful for forming a channel layer of a TFT in a manufacturing process of a high-precision large-size liquid crystal display, an organic EL display, and the like.

Fig. 1 is a reflection electron image of a scanning electron microscope of an oxide target material of Inventive Example 1. Fig.
2 is a reflection electron image of a scanning electron microscope of an oxide target material of the second embodiment of the present invention.
3 is a reflection electron image of a scanning electron microscope of an oxide target material of a comparative example.
4 is a schematic view of a TFT structure.
5 is a reflection electron image of a scanning electron microscope in visual field 1 of Example 3 of the present invention.
6 is a reflection electron image of a scanning electron microscope in the field of view 2 of Example 3 of the present invention.
7 is a reflection electron image of a scanning electron microscope in visual field 3 of Example 3 of the present invention.
8 is a reflection electron image of a scanning electron microscope in visual field 1 of Example 4 of the present invention.
Fig. 9 is a reflection electron image of a scanning electron microscope in the field of view 2 of Example 4 of the present invention. Fig.
10 is a reflection electron image of a scanning electron microscope in visual field 3 of Example 4 of the present invention.
11 is a reflection electron image of a scanning electron microscope in visual field 1 of Example 5. Fig.
12 is a reflection electron image of a scanning electron microscope in the field of view 2 of the present invention 5. Fig.
Fig. 13 is a reflection electron image of a scanning electron microscope in visual field 3 of Inventive Example 5. Fig.
Fig. 14 is a reflection electron image of a scanning electron microscope in visual field 1 of Inventive Example 6. Fig.
15 is a reflection electron image of a scanning electron microscope in the field of view 2 of Example 6 of the present invention.
16 is a reflection electron image of a scanning electron microscope in the visual field 3 of Example 6 of the present invention.
Fig. 17 is a reflection electron image of a scanning electron microscope in visual field 1 of Example 7 of the present invention. Fig.
18 is a reflection electron image of the scanning electron microscope in the field of view 2 of the present invention.
19 is a reflection electron image of the scanning electron microscope in the visual field 3 of the present invention 7. Fig.

The oxide target material of the present invention is characterized in that the area ratio of the ZnO phase occupied per unit area, that is, in the area of 10000 占 퐉 ² , on the surface to be the erosion surface is 10.5% or less. Thus, the oxide target material of the present invention can form a uniform ZTO thin film, and it is possible to suppress the instability of the threshold voltage in the TFT. Further, from the reasons similar to those of the above, the area ratio on the ZnO coating is preferably 10.3% or less of the area 10000㎛ ^2, more preferably not more than 10.2 area%.

Here, the area ratio of the ZnO phase in the present invention is such that the Zn ₂ SnO ₄ phase and the ZnO phase are photographed at high contrast on the reflected electron by a scanning electron microscope in an arbitrary field of view of the erosion surface of the oxide target material, Can be measured using image analysis software (for example, "Scandium" manufactured by OLYMPUS SOFT IMAGING SOLUTIONS GMBH).

Further, in order to improve the etching property when the channel layer is formed in a desired pattern, the area ratio of the ZnO phase is preferably 2.0 area% or more per 10000 mu m ² area, more preferably 5.0 area% or more.

The oxide target material of the present invention has a composition containing Sn in an amount of 20.0 atom% to 50.0 atom% based on the entire metal component, and the balance of Zn and inevitable impurities.

The oxide target of the present invention can suppress the ZnO phase to be coarsened or the plurality of ZnO phases to be connected by setting the amount of Sn to 20.0 atomic% or more. For the same reason as described above, the amount of Sn is preferably 25.0 atomic% or more, more preferably 29.0 atomic% or more.

In addition, the oxide target of the present invention can improve the etching property when a channel layer is formed in a desired pattern by setting the amount of Sn to 50.0 atomic% or less. For the same reason as described above, the amount of Sn is preferably 40.0 atomic percent or less, more preferably 35.0 atomic percent or less.

The oxide target of the present invention can improve the etching property when a channel layer is formed in a desired pattern by setting the amount of Zn to 50.0 atomic% or more. For the same reason as described above, the Zn content is preferably 60.0 atomic% or more, more preferably 65.0 atomic% or more.

In addition, the oxide target of the present invention can suppress the ZnO phase to be coarsened or the plurality of ZnO phases to be connected by setting the amount of Zn to 80.0 atomic% or less. For the same reason as described above, the amount of Zn is preferably 75.0 atomic percent or less, and more preferably 71.0 atomic percent or less.

The oxide target material of the present invention contains 0.005 atom% to 4.000 atom% of a total of at least one of Sn and Zn described above by at least one of Al, Ga, Mo, and W relative to the entire metal component Preferably in the range of < RTI ID = 0.0 > These elements are useful elements for controlling the mobility of carriers and suppressing photo deterioration.

In the oxide target material of the present invention, it is more preferable that the total amount of these elements is 0.050 atomic% or more, more preferably 0.100 atomic% or more. Further, the oxide target of the present invention more preferably contains 3.000 at% or less of these elements in total, more preferably 2.000 at% or less.

Hereinafter, a method for producing the oxide target material of the present invention will be described.

In the method for producing an oxide target material of the present invention, ZnO powder and SnO ₂ powder are mixed with pure water in an amount of 20.0 atomic% to 50.0 atomic% of Sn relative to the entire metal component, and the remainder is Zn and inevitable impurities, And a dispersant to prepare a slurry. After drying the slurry, a granulated powder is prepared, and the granulated powder is calcined to prepare a calcined powder containing Zn ₂ SnO ₄ and ZnO.

The calcining temperature of the granulated powder for preparing the calcined powder is preferably set to 1000 ° C to 1200 ° C. The calcination temperature is preferable in that it can sufficiently proceed the reaction, ZnO powder and SnO ₂ powder, by more than 1000 ℃, more preferably more than 1050 ℃.

Further, the calcination temperature is below 1200 ℃, can be suppressed with an excessive reaction of the ZnO powder and the SnO ₂ powder, and can maintain a powder particle size suitable for sintering that 0.5㎛ to 1.5㎛, this dense oxide target by And it is more preferable that the temperature is 1120 DEG C or less.

The holding time at the calcination temperature is preferably in the range of 1 hour to 10 hours. The holding time at the calcination temperature is preferably 1 hour or more, because it can accelerate the reaction between the ZnO powder and the SnO ₂ powder, and more preferably 2 hours or more.

The holding time at the calcining temperature is preferably 10 hours or less in that sintering of the ZnO powder and the SnO ₂ powder can be suppressed, more preferably 7 hours or less.

In the method for producing an oxide target material according to the present invention, in the calcination step, the calcined powder obtained in the above-mentioned granulation step is wet-cracked, and then a formed body is formed by injection molding, followed by degreasing and firing in an air atmosphere to obtain an oxide sintered body .

The firing temperature in the air atmosphere is preferably set at 1300 ° C to 1450 ° C. The sintering temperature is preferably 1300 占 폚 or higher because sintering can be promoted and a dense oxide target material can be obtained. For the same reason as above, the firing temperature is more preferably 1350 DEG C or more.

The firing temperature is preferably 1450 占 폚 or less in that the void generated by evaporation of ZnO can be suppressed and a high-density oxide target material can be obtained. For the same reason as described above, the firing temperature is more preferably 1420 DEG C or lower.

The holding time at the firing temperature is preferably 4 hours or more in that densification due to firing can be promoted. For the same reason as described above, the holding time at the firing temperature is more preferably 8 hours or more.

If the holding time at the firing temperature exceeds 15 hours, the growth of the ZnO phase is promoted, making it difficult to reduce the area ratio of the ZnO phase per unit area. Therefore, in order to obtain the oxide target material of the present invention, the holding time at the firing temperature is preferably 15 hours or less. For the same reason as described above, the holding time at the firing temperature is more preferably 12 hours or less.

In the present invention, it is preferable that the oxide sintered body obtained in the sintering step is subjected to a reduction heat treatment in a non-oxidizing atmosphere to lower the electric resistivity of the oxide sintered body to enable the ZTO thin film to be formed by DC sputtering. The electrical resistivity of the oxide sintered body is related to the density of oxygen defects in the oxide sintered body. For this reason, the reduction heat treatment is preferably performed at 1300 DEG C or higher in that the oxygen defect density can be increased and the electrical resistivity can be lowered. For the same reason as above, the reduction heat treatment is more preferably performed at 1350 占 폚 or higher.

Further, the reduction heat treatment is preferably performed at a temperature of 1450 占 폚 or lower in that evaporation of ZnO can be suppressed and coarsening of ZnO can be suppressed. For the same reason as described above, the reduction heat treatment is more preferably performed at 1420 占 폚 or lower.

The holding time of the reduction heat treatment is preferably 3 hours or longer. Thereby, the oxygen deficiency state in the oxide sintered body can be made uniform. For the same reason as described above, the holding time of the reduction heat treatment is more preferably 4 hours or more.

The holding time of the reduction heat treatment is preferably 15 hours or less. As a result, the evaporation of ZnO and the coarsening of ZnO can be suppressed. For the same reason as described above, the holding time of the reduction heat treatment is more preferably 10 hours or less.

The oxide target material of the present invention is characterized in that, in the polishing step, the area ratio of the ZnO phase occupying in the area of 10000 占 퐉 ² on the surface which becomes the erosion surface of the oxide-sintered body obtained in the above- And polishing the surface to be the erosion surface of the sintered body. Here, in order to make the area ratio of the ZnO phase 10.5% or less, it is possible to actually observe the structure of the surface which becomes the erosion surface of the oxide-sintered body to calculate the area ratio of the ZnO phase, and to perform the calculation and polishing alternately .

In order to make the area ratio of the ZnO phase to 10.5 area% or less, it is preferable that the lightness L ^* and the chromaticity b ^* defined in JIS Z8781-4: 2013 on the surface which actually becomes the erosion surface of the oxide- ^* it is possible also by carrying a 60.3 or less, b ^* is L ^* and b ^* measurement, a shift of the measurement and the grinding to be equal to or less than -0.3. L ^* and b ^* can be measured using, for example, a spectroscopic colorimeter (CM2500d) manufactured by Konica Minolta K.K.

≪ Example 1 >

First, a ZnO powder having an average particle diameter (D50 of cumulative particle size distribution) of 0.70 占 퐉 and an average particle size (D50 of cumulative particle size distribution) of 30.0 atomic% of Sn and the balance of Zn and inevitable impurities SnO ₂ powder having a particle diameter of 1.85 μm was weighed and placed in a stirring vessel containing a predetermined amount of pure water and a dispersing agent, followed by mixing to obtain a slurry. After drying and assembly, this slurry, 1090 ℃, calcined for 4 hours to obtain a calcined powder containing Zn ₂ SnO ₄ and ZnO. The calcined powder was adjusted in particle size so that the average particle size (D50 of the cumulative particle size distribution) became 1 占 퐉 by wet cracking.

Then, the calcined powder was subjected to wet-cracking, and three molded bodies each having a thickness of 10 mm and a diameter of 125 mm were obtained by injection molding.

Subsequently, one of the obtained compacts was fired at 1400 DEG C for 10 hours in an atmospheric environment, followed by a reduction heat treatment at 1400 DEG C for 4 hours in a nitrogen atmosphere, thereby obtaining an oxide sintered body. Then, the surface of the oxide-sintered body be in the oxide machining carried out with a thickness of 5mm × 50mm in diameter in the sintered body, and eroded surface, the area ratio on the ZnO in the area of the 10000㎛ ² to be equal to or less than 10.5 area%, specifically L ^* and b ^* were measured so that L ^* was 60.3 or less and b ^* was -0.3 or less, and this measurement and polishing were carried out alternately to obtain an oxide target material of Inventive Example 1. [ The measurement of L ^* and b ^* was performed using a spectroscopic colorimeter (CM2500d) manufactured by Konica Minolta Corporation.

Further, another piece of the obtained molded body was fired at 1400 DEG C for 10 hours in an atmospheric atmosphere, and then subjected to reduction heat treatment at normal pressure in a nitrogen atmosphere at 1400 DEG C for 4 hours to obtain an oxide sintered body. Then, the surface of the oxide-sintered body be in the oxide machining carried out with a thickness of 5mm × 50mm in diameter in the sintered body, and eroded surface, the area ratio on the ZnO in the area of the 10000㎛ ² to be equal to or less than 10.5 area%, specifically L ^* and b ^* were measured so that L ^* was 60.3 or less and b ^* was -0.3 or less, and this measurement and polishing were carried out alternately to obtain an oxide target material of Inventive Example 2. [

Further, another piece of the obtained molded body was fired at 1400 DEG C for 10 hours in an atmospheric atmosphere, and then subjected to reduction heat treatment at normal pressure in a nitrogen atmosphere at 1400 DEG C for 4 hours to obtain an oxide sintered body. The oxide-sintered body was machined to have a thickness of 5 mm and a diameter of 50 mm, and the surface of the oxide-sintered body to be an erosion surface was so designed that the area ratio of the ZnO phase in an area of 10000 占 퐉 ² exceeded 10.5 area% the L ^* is greater than 60.3, and b ^* is -0.3 so that the excess and measuring the L ^* and b ^*, subjected to the measurement and grinding alternately, to obtain a target material to be an oxide in the comparative example.

1 to 3 show reflection electron images of a scanning electron microscope of a surface to be an erosion surface of the oxide target material of Inventive Example 1, Inventive Example 2 and Comparative Example obtained above. On the reflected electrons of the scanning electron microscope, any vertical: 94.6㎛ × width: 130.6㎛ (area: 12355㎛ ²⁾ of the field of view, and the first field of view to be observed in 10000㎛ ^2, an area on the ZnO present in the field of view Were measured. Here, the measurement was made by taking a Zn ₂ SnO ₄ phase and a ZnO phase on a reflected electron image at high contrast by a scanning electron microscope and then analyzing the image using image analysis software ("Scandium" manufactured by OLYMPUS SOFT IMAGING SOLUTIONS GMBH) , And the area ratio of ZnO phase was obtained. The results are shown in Table 1. For reference, the values of L ^* and b ^* at arbitrary positions on the surface to be etched surfaces of the respective oxide target materials are also shown.

From the results shown in Table 1, it was confirmed that the oxide target of the present invention had an area ratio of ZnO phase of 10.5 area% or less at an area of 10000 占 퐉 ² .

On the other hand, the oxide target of the comparative example had an area ratio of ZnO phase exceeding 10.5 area% at an area of 10000 占 퐉 ² and was outside the scope of the present invention.

Then, in order to confirm the influence of the ZTO thin film on the TFT characteristics, the simple TFT shown in Fig. 4 was fabricated and evaluated.

First, on the glass substrate 1, a metal thin film of Mo to be the gate electrode 2 was formed. Thereafter, a mask of a gate pattern was formed with a photoresist. The gate electrode 2 having a thickness of 70 nm was formed by etching through this mask. Thereafter, an SiO ₂ film serving as the gate insulating film 3 was formed to have a thickness of 100 nm on the entire surface. Then, a channel layer 4 having a thickness of 30 nm was formed by sputtering using each oxide target produced above.

Subsequently, on the channel layer 4, a photoresist layer to be a channel pattern was formed subsequently. Here, in order to process the channel region, a channel pattern was drawn on the photoresist layer, exposed and developed to form a mask. Then, etching was performed using this mask to form a channel region.

A metal thin film of Mo to be the source electrode 5 and the drain electrode 6 was formed to a thickness of 140 nm and etched using the photoresist as a mask to form a source electrode 5 and a drain electrode 6 . Then, a simple TFT was fabricated by covering with a protective film.

Reliability evaluation by NBIS was performed using each of the simple TFTs prepared above. The threshold voltage (Vth) after the lapse of 1000 seconds was compared with that before the test, and the NBIS (gate voltage Vg = -15 V, drain voltage Vd = 0 V, And the difference was calculated as? Vth. The results are shown in Table 2.

As a result, it was confirmed that the simple TFT in which the ZTO thin film was formed of the oxide target material of the present invention was a TFT having? Vth of less than -10.0 V and ensuring stability.

On the other hand, the simple TFT having the ZTO thin film formed of the oxide target of the comparative example had a? Vth of less than -10.0 V and was unsuitable as a TFT.

≪ Example 2 >

First, a ZnO powder having an average particle diameter (D50 of cumulative particle size distribution) of 0.70 占 퐉 and an average particle size (D50 of cumulative particle size distribution) of 33.3 atomic% of Sn and an inevitable impurity of Sn SnO ₂ powder having a particle diameter of 1.85 μm was weighed and placed in a stirring vessel containing a predetermined amount of pure water and a dispersing agent, followed by mixing to obtain a slurry. After drying and assembly, this slurry, 1090 ℃, calcined for 4 hours to obtain a calcined powder containing Zn ₂ SnO ₄ and ZnO. The calcined powder had a mean particle size (D50 of the cumulative particle size distribution) of ZnO powder having an average particle diameter (D50 of the cumulative particle size distribution) of 0.70 탆 and a mean particle size (D50 of the cumulative particle size distribution) of 29.5 to 31.0 atomic% Al ₂ O ₃ powder of 0.1 to 0.4 탆 was added, and then the particle size was adjusted so that the total average particle size (D50 of the cumulative particle size distribution) was 0.7 탆 to 1.0 탆.

The calcined powder was wet-laid and then subjected to injection molding to obtain five molded articles each having a thickness of 10 mm, a width of 235 mm and a length of 310 mm.

Subsequently, the obtained molded body was fired at 1400 DEG C for 10 hours in an air atmosphere, and then subjected to reduction heat treatment at 1400 DEG C for 4 hours in a nitrogen atmosphere at normal pressure to obtain an oxide sintered body. This oxide-sintered body was machined to have a thickness of 5 mm and a diameter of 50 mm. On the reflection electron of a scanning electron microscope, in the three fields of arbitrary length: 94.6 占 퐉 占 width: 130.6 占 퐉 (area: 12355 占 퐉 ² ) With each field of view 10000 μm ² And the area of the ZnO phase present in the field of view was measured. Then, this measurement and polishing were carried out alternately to obtain an oxide target material of Inventive Example 3 to Inventive Example 7.

Here, the measurement was made by taking a Zn ₂ SnO ₄ phase and a ZnO phase on a reflected electron image at high contrast by a scanning electron microscope and then analyzing the image using image analysis software ("Scandium" manufactured by OLYMPUS SOFT IMAGING SOLUTIONS GMBH) , The area ratio of the ZnO phase of each field and the average value of the three fields of view were obtained. The results are shown in Table 3.

5 to 19 show the reflected electron images of the scanning electron microscope of Scanning field 1 to Scanning field 3 on the surface of the oxide target material of the present invention of the present invention 3 obtained as described above as the erosion surface.

Table 3 and from the results of Figs. 5 to 19, the area percent on the oxide ZnO in the target material, the 10000㎛ area ² of the present invention was confirmed to be less than 10.5 area%.

1: glass substrate
2: gate electrode
3: Gate insulating film
4: channel layer
5: source electrode
6: drain electrode

Claims (4)

The area ratio of the ZnO phase occupying an area of 10000 占 퐉 ² in a surface containing Sn of 20.0 atomic% to 50.0 atomic%, the remainder containing Zn and inevitable impurities, Area% or less. The oxide target according to any one of claims 1 to 4, which contains at least 0.005 atom% to 4.000 atom% of at least one of Al, Ga, Mo and W relative to the entire metal component. ZnO powder and SnO ₂ powder are mixed with pure water and a dispersing agent to make a slurry containing Sn at 20.0 atomic% to 50.0 atomic% with respect to the whole metal component and the balance of Zn and inevitable impurities to form a slurry, A granulation step of preparing a powder and calcining the granulated powder to obtain a calcined powder containing Zn ₂ SnO ₄ and ZnO,
A sintering step of wet-cracking the calcined powder, preparing a compact by injection molding, degreasing the compact, and firing in an air atmosphere to obtain an oxide sintered compact;
By polishing a surface where the erosion surface of the oxide-sintered body, the abrasive to obtain the area ratio is 10.5 area% or less oxide target material on the ZnO occupied in the area of the 10000㎛ ² of the surface on which the surface erosion process
Of the oxide target material. 4. The method of manufacturing an oxide target material according to claim 3, wherein in the polishing step, the surface to be the erosion surface is polished while confirming the lightness L ^* and chromaticity b ^* .

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