JP2018199861A - Oxide target material and method for producing the same - Google Patents

Abstract

To provide an oxide target material that resolves instability of threshold voltage, and is for forming a ZTO thin film constituting a channel layer of a TFT that drives a high-definition display or the like, and a method of producing the same.SOLUTION: An oxide target material contains Sn of 20.0 atom%-50.0 atom% relative to the total content of metal components, with the balance being Zn and inevitable impurities. In the area of 10000 μm, the area ratio of a ZnO phase is 10.5 area% or less. Relative to the total content of metal components, more preferably, at least one of Al, Ga, Mo and W may be contained by 0.005 atom%-4.000 atom% in total.SELECTED DRAWING: Figure 1

Description

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

  Conventionally, 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 mainly used as a TFT channel layer. It is. With the demand for higher definition of displays, oxide semiconductors have attracted attention as materials used for TFT channel layers. For example, an oxide semiconductor film containing In, Ga, Zn, and O (oxygen) (hereinafter referred to as “IGZO thin film”) has been put into practical use as having excellent TFT characteristics. . In and Ga contained in the I-G-Z-O thin film are rare and expensive metals designated as rare metal stockpiling target steel types in Japan.

  Therefore, a Zn—Sn—O-based oxide semiconductor film (hereinafter referred to as “ZTO thin film”) is attracting attention as an oxide semiconductor film containing no In or Ga contained in the IGZO thin film. is there. The ZTO thin film is formed by sputtering using a target. In this sputtering method, ions, atoms, or clusters collide with the target surface, and the surface of the material is scraped (or skipped), thereby depositing components constituting the material on the surface of the substrate or the like. It is a method to do.

  Here, since the ZTO thin film is a thin film containing oxygen, a 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 argon gas and oxygen gas. Sputtering while reacting ions, atoms or clusters with oxygen makes it possible to form an oxide-based thin film. It is a technique of forming.

And the target material used for this reactive sputtering method uses the target material which consists of a ZTO type oxide sintered compact which has the component composition approximated to the component composition of the ZTO thin film. Such a target material is applied to the direct current sputtering method from the viewpoint of productivity, and is required to be used with high power in order to improve the film formation rate. In Patent Document 1, for a target material that does not contain a tin oxide (SnO ₂ ) crystal phase that causes arcing in the structure, the generation of arcing can be suppressed even in high-power sputtering, and the film formation rate can be improved. Sintered bodies have been proposed.

JP 2007-277075 A

According to the study of the present inventor, a ZTO thin film is formed by a sputtering method using a sintered body in which the crystal phase of SnO ₂ disclosed in Patent Document 1 described above is suppressed, and a TFT is formed. It was confirmed that when the TFT is exposed to a negative bias applied state under light irradiation (hereinafter referred to as NBIS :), the threshold voltage may be unstable in a negative direction.
When this threshold voltage instability problem occurs, it becomes difficult to obtain a driving element for a high-definition 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-definition display or the like, in which threshold voltage instability is suppressed, and a manufacturing method thereof. is there.

  As a result of examining the above problems, the present inventor has found that the instability of the threshold voltage can be suppressed by making the area ratio of the ZnO phase per unit area of the oxide target material within a predetermined range. Reached.

That is, the oxide target material of the present invention contains 20.0 atomic% to 50.0 atomic% of Sn with respect to the entire metal component, and the balance is made of Zn and inevitable impurities, and ZnO in an area of 10,000 μm ^2. The area ratio of the phase is 10.5 area% or less.
Moreover, it is preferable that the oxide target material of this invention contains 0.005 atomic%-4.0000 atomic% of 1 or more types in total among Al, Ga, Mo, and W with respect to the whole metal component.

The oxide target material of the present invention contains 20.0 atomic% to 50.0 atomic% of Sn with respect to the entire metal component, and the ZnO powder and SnO ₂ so that the balance is Zn and inevitable impurities. The powder is mixed with pure water and a dispersant to form a slurry, and the slurry is dried to produce granulated powder. The granulated powder is calcined to obtain a calcined powder composed of Zn ₂ SnO ₄ and ZnO. A granulation step, a sintering step in which the calcined powder is crushed wet, a molded body is produced by casting, the molded body is degreased, and then fired in an air atmosphere to obtain an oxide sintered body. Polishing to obtain an oxide target material having a ZnO phase area ratio of 10.5 area% or less in an area of 10,000 μm ^{2 on} the surface to be an erosion surface by polishing the surface to be an erosion surface of the oxide sintered body Obtained by a manufacturing method having a process You can.
And in the said grinding | polishing process, it is preferable to grind | polish the surface used as an erosion surface, confirming the lightness L ^* and chromaticity b ^* .

  According to the present invention, a ZTO thin film in which instability of threshold voltage is suppressed can be obtained. By suppressing the instability of the threshold voltage, it becomes a useful technique for forming a TFT channel layer in a manufacturing process of a high-definition large-sized liquid crystal display or an organic EL display.

The reflection electron image of the scanning electron microscope of the oxide target material of Example 1 of the present invention. The reflection electron image of the scanning electron microscope of the oxide target material of the example 2 of this invention. The reflection electron image of the scanning electron microscope of the oxide target material of a comparative example. Schematic of TFT structure. The reflection electron image of the scanning electron microscope in the visual field 1 of the example 3 of this invention. The reflection electron image of the scanning electron microscope in the visual field 2 of Example 3 of this invention. The reflection electron image of the scanning electron microscope in the visual field 3 of the example 3 of this invention. The reflection electron image of the scanning electron microscope in the visual field 1 of the example 4 of this invention. The reflection electron image of the scanning electron microscope in the visual field 2 of the example 4 of this invention. The reflection electron image of the scanning electron microscope in the visual field 3 of the example 4 of this invention. The reflection electron image of the scanning electron microscope in the visual field 1 of the example 5 of this invention. The reflection electron image of the scanning electron microscope in the visual field 2 of Example 5 of this invention. The reflection electron image of the scanning electron microscope in the visual field 3 of the example 5 of this invention. The reflection electron image of the scanning electron microscope in the visual field 1 of the example 6 of this invention. The reflection electron image of the scanning electron microscope in the visual field 2 of Example 6 of this invention. The reflection electron image of the scanning electron microscope in the visual field 3 of Example 6 of this invention. The reflection electron image of the scanning electron microscope in the visual field 1 of the example 7 of this invention. The reflection electron image of the scanning electron microscope in the visual field 2 of Example 7 of this invention. The reflection electron image of the scanning electron microscope in the visual field 3 of Example 7 of this invention.

The oxide target material of the present invention is characterized in that the area ratio of the ZnO phase per unit area on the surface serving as the erosion surface, that is, the area of 10,000 μm ² is 10.5 area% or less. Thereby, the oxide target material of this invention can form a uniform ZTO thin film, and can suppress the instability of the threshold voltage in TFT. For the same reason as described above, the area ratio of the ZnO phase is preferably 10.3 area% or less and more preferably 10.2 area% or less per 10,000 μm ² area.
Here, the area ratio of the ZnO phase referred to in the present invention is a high-contrast image of the Zn ₂ SnO ₄ phase and the ZnO phase as reflected electron images by a scanning electron microscope in an arbitrary field of view on the erosion surface of the oxide target material. The image can be measured using image analysis software (for example, “Scandium” manufactured by OLYMPUS SOFT IMAGEING SOLUTIONS GMBH).
In order to improve the etching property when forming the channel layer with a desired pattern, the area ratio of the ZnO phase is preferably 2.0 area% or more per 10,000 μm ² area. More preferably, it is area% or more.

The oxide target material of the present invention contains 20.0 atomic% to 50.0 atomic% of Sn with respect to the entire metal component, and the balance is composed of Zn and inevitable impurities.
And the oxide target material of this invention can suppress that a ZnO phase coarsens or a several ZnO phase connects by making Sn amount into 20.0 atomic% or more. For the same reason as described above, the Sn content is preferably 25.0 atomic% or more, and more preferably 29.0 atomic% or more.
Moreover, the oxide target material of this invention can improve the etching property when forming a channel layer with a desired pattern by making Sn amount into 50.0 atomic% or less. For the same reason as described above, the Sn content is preferably 40.0 atomic% or less, and more preferably 35.0 atomic% or less.
And the oxide target material of this invention can improve the etching property when forming a channel layer by a desired pattern by making Zn amount into 50.0 atomic% or more. For the same reason as described above, the Zn content is preferably 60.0 atomic% or more, and more preferably 65.0 atomic% or more.
Moreover, the oxide target material of this invention can suppress that a ZnO phase coarsens or a several ZnO phase connects by making Zn amount into 80.0 atomic% or less. For the same reason as described above, the Zn content is preferably 75.0 atomic% or less, and more preferably 71.0 atomic% or less.
In the oxide target material of the present invention, a total of 0.005 part of one or more of the above-described Sn and Zn is contained in one or more of Al, Ga, Mo, and W with respect to the entire metal component. Substitution is preferably performed within a range of atomic% to 4.0000 atomic%. These elements are useful for controlling carrier mobility and suppressing photodegradation.
And it is more preferable that the oxide target material of this invention contains these elements 0.050 atomic% or more in total, and it is further more preferable to contain 0.100 atomic% or more. Further, the oxide target material of the present invention preferably contains these elements in total of 3.000 atomic% or less, and more preferably 2.000 atomic% or less.

Below, the manufacturing method of the oxide target material of this invention is demonstrated.
In the method for producing an oxide target material of the present invention, in the granulation step, Sn is contained in an amount of 20.0 atomic% to 50.0 atomic% with respect to the entire metal component, with the balance being Zn and inevitable impurities. ZnO powder and SnO ₂ powder were mixed with pure water and a dispersant to form a slurry. After drying the slurry, granulated powder was prepared, and the granulated powder was calcined to obtain Zn ₂ SnO ₄ and ZnO. A calcined powder consisting of
The calcining temperature of the granulated powder for producing the calcined powder is preferably set to 1000 ° C to 1200 ° C. The calcination temperature is preferably 1000 ° C. or more, and is preferably in a point that the reaction between the ZnO powder and the SnO ₂ powder can sufficiently proceed, and more preferably 1050 ° C. or more.
Further, by setting the calcining temperature to 1200 ° C. or less, excessive reaction between the ZnO powder and the SnO ₂ powder can be suppressed, and a powder particle size suitable for firing of 0.5 μm to 1.5 μm can be maintained. This is preferable in that a dense oxide target material can be obtained, and 1120 ° C. or lower is more preferable.
The holding time at the calcining temperature is preferably in the range of 1 hour to 10 hours. The holding time at the calcination temperature is preferably 1 hour or longer, and is preferably from the point that the reaction between the ZnO powder and the SnO ₂ powder can be promoted, and more preferably 2 hours or longer.
In addition, the holding time at the calcining temperature is preferably 10 hours or less, so that sintering of the ZnO powder and the SnO ₂ powder can be suppressed, and more preferably 7 hours or less.

In the method for producing an oxide target material of the present invention, in the firing step, the calcined powder obtained in the above granulation step is wet pulverized, then a molded body is produced by casting, degreased, and in an air atmosphere. Firing to obtain an oxide sintered body.
The firing temperature in the air atmosphere is preferably set to 1300 ° C to 1450 ° C. The firing temperature is preferably 1300 ° C. or higher because sintering can be promoted and a dense oxide target material can be obtained. For the same reason as described above, the firing temperature is more preferably 1350 ° C. or higher.
In addition, the firing temperature is preferably 1450 ° C. or less, in that vacancies 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 set to 1420 ° C. or lower.
The holding time at the firing temperature is preferably 4 hours or more, from the viewpoint that densification by firing can be promoted. For the same reason as described above, the holding time at the firing temperature is more preferably 8 hours or longer.
If the holding time at the firing temperature exceeds 15 hours, the growth of the ZnO phase is promoted, and it becomes difficult to reduce the area ratio of the ZnO phase per unit area. For this reason, in order to obtain the oxide target material of this invention, it is preferable to make holding time in a calcination temperature into 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, the oxide sintered body obtained in the above firing step is subjected to a reduction heat treatment in a non-oxidizing atmosphere, thereby reducing the electrical resistivity of the oxide sintered body and forming a ZTO thin film by direct current sputtering. Is preferable in that it becomes possible. The electrical resistivity of the oxide sintered body is related to the oxygen deficiency density in the oxide sintered body. For this reason, it is preferable that the reduction heat treatment is performed at 1300 ° C. or higher because the oxygen deficiency density can be increased and the electrical resistivity can be lowered. For the same reason as described above, the reduction heat treatment is more preferably performed at 1350 ° C. or higher.
Further, the reduction heat treatment is preferably performed at 1450 ° C. or less in that it can suppress the evaporation of ZnO and also suppress the coarsening of the ZnO phase. For the same reason as described above, the reduction heat treatment is more preferably performed at 1420 ° C. or lower.
The holding time for the reduction heat treatment is preferably 3 hours or longer. Thereby, the oxygen deficient state in the oxide sintered body can be made uniform. And, for the same reason as described above, it is more preferable that the holding time of the reduction heat treatment is 4 hours or longer.
Further, the holding time of the reduction heat treatment is preferably 15 hours or less. Thereby, suppression of evaporation of ZnO and coarsening of the ZnO phase can be suppressed. And, 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 has a ZnO phase area ratio of 10.5 area in the area of 10,000 μm ^{2 in} the surface serving as the erosion surface of the oxide sintered body obtained in the firing step in the polishing step. % Or less, it can be obtained by polishing the surface to be the erosion surface of the oxide sintered body. Here, in order to reduce the area ratio of the ZnO phase to 10.5 area% or less, the structure of the surface that becomes the erosion surface of the oxide sintered body is actually observed to calculate the area ratio of the ZnO phase, Calculation and polishing can be performed alternately.
In order to make the area ratio of the ZnO phase 10.5 area% or less, the lightness L ^* and chromaticity defined by JIS Z8781-4: 2013 on the surface that actually becomes the erosion surface of the oxide sintered body Using b ^* as an index, L ^* and b ^* may be measured so that L ^* is 60.3 or less and b ^* is −0.3 or less, and the measurement and polishing are alternately performed. L ^* and b ^* can be measured using, for example, a spectrocolorimeter (CM2500d) manufactured by Konica Minolta.

First, a ZnO powder having an average particle size (D50 of cumulative particle size distribution) of 0.70 μm and an average particle size so that Sn is 30.0 atomic% with respect to the entire metal component, and the balance is Zn and inevitable impurities. SnO ₂ powder having a cumulative particle size distribution (D50) of 1.85 μm was weighed, put into a stirring vessel containing a predetermined amount of pure water and a dispersant, and then mixed to obtain a slurry. The slurry was dried and granulated and then calcined at 1090 ° C. for 4 hours to obtain a calcined powder composed of Zn ₂ SnO ₄ and ZnO. The calcined powder was adjusted in particle size by wet crushing so that the average particle size (D50 of cumulative particle size distribution) was 1 μm.
And after carrying out wet crushing of said calcined powder, three compacts 10 mm in thickness x 125 mm in diameter were obtained by casting.

Next, one of the obtained compacts was fired at 1400 ° C. for 10 hours in an air atmosphere, and then subjected to a reduction heat treatment at 1400 ° C. for 4 hours in a nitrogen atmosphere to obtain an oxide sintered body. Obtained. Then, the oxide sintered body is machined to have a thickness of 5 mm × a diameter of 50 mm. The surface of the oxide sintered body serving as an erosion surface has a ZnO phase area ratio of 10.5 in an area of 10,000 μm ^2. L ^* and b ^* are measured so that L ^* is 60.3 or less and b ^* is −0.3 or less so that the area% or less, and this measurement and polishing are alternately performed. Then, an oxide target material to be Inventive Example 1 was obtained. The measurement of L ^* and b ^* was performed using a spectrocolorimeter (CM2500d) manufactured by Konica Minolta.

Further, another piece of the obtained molded body was fired in an air atmosphere at 1400 ° C. for 10 hours, and then subjected to a reduction heat treatment at 1400 ° C. for 4 hours in a nitrogen atmosphere to obtain an oxide sintered body. Got. Then, the oxide sintered body is machined to have a thickness of 5 mm × a diameter of 50 mm. The surface of the oxide sintered body serving as an erosion surface has a ZnO phase area ratio of 10.5 in an area of 10,000 μm ^2. L ^* and b ^* are measured so that L ^* is 60.3 or less and b ^* is −0.3 or less so that the area% or less, and this measurement and polishing are alternately performed. Then, an oxide target material to be Inventive Example 2 was obtained.

Further, another obtained sheet was fired at 1400 ° C. for 10 hours in an air atmosphere, and then subjected to a reduction heat treatment at 1400 ° C. for 4 hours in a nitrogen atmosphere at a normal pressure to sinter oxide. Got the body. Then, the oxide sintered body is machined to have a thickness of 5 mm × a diameter of 50 mm. The surface of the oxide sintered body serving as an erosion surface has a ZnO phase area ratio of 10.5 in an area of 10,000 μm ^2. L ^* and b ^* are measured so that L ^* exceeds 60.3, and specifically, L ^* exceeds 60.3 and b ^* exceeds −0.3, and this measurement and polishing are performed alternately. The oxide target material used as a comparative example was obtained.

The reflected electron images of the scanning electron microscope of the surface used as the erosion surface of the oxide target material of this invention example 1, this invention example 2, and the comparative example obtained above are shown in FIGS. In the reflection electron image of the scanning electron microscope, any vertical: 94.6μm × Horizontal: 130.6μm (area: 12355μm ²⁾ of the field of view to observe the one visual field as the 10000 ^2, present in the field of view The area of the ZnO phase was measured. Here, the measurement is performed by taking a reflected electron image of the Zn ₂ SnO ₄ phase and the ZnO phase with high contrast using a scanning electron microscope, and using the image analysis software (“Scandium” manufactured by OLYMPUS SOFT IMAGES SOLITIONS GMBH). The ZnO phase area ratio was obtained. The results are shown in Table 1. For reference, the values of L ^* and b ^* at arbitrary positions on the surface serving as the erosion surface of each oxide target material are also shown.
From the results of Table 1, it was confirmed that the oxide target material of the present invention had an area ratio of ZnO phase in an area of 10,000 μm ² of 10.5 area% or less.
On the other hand, in the oxide target material of the comparative example, the area ratio of the ZnO phase in the area of 10,000 μm ² exceeded 10.5 area%, and was outside the scope of the present invention.

Next, in order to confirm the influence of the ZTO thin film on the TFT characteristics, a simple TFT shown in FIG. 4 was produced and evaluated.
First, a Mo metal thin film to be the gate electrode 2 was formed on the glass substrate 1. Thereafter, a gate pattern mask was formed with a photoresist. Etching was performed through this mask to form a gate electrode 2 having a thickness of 70 nm. Thereafter, a SiO ₂ film to be the gate insulating film 3 was formed to a thickness of 100 nm on the entire surface. And the channel layer 4 of thickness 30nm was formed by sputtering using each oxide target material produced above.
Next, a photoresist layer to be a channel pattern later was formed on the channel layer 4. Here, in order to process the channel region, a mask was formed by drawing, exposing and developing a channel pattern on the photoresist layer. Then, etching was performed using this mask to form a channel region.
Further, a Mo metal thin film to be the source electrode 5 and the drain electrode 6 was formed with a thickness of 140 nm and etched using the photoresist as a mask to form the source electrode 5 and the drain electrode 6. And it covered with the protective film and produced the simple TFT.

Reliability evaluation by NBIS was performed using each simple TFT produced above. NBIS (gate voltage Vg = -15V, drain voltage Vd = 0V, illuminance = 1000lx) was applied at room temperature (25 ° C) for 0 to 1000 seconds, and the threshold voltage (Vth) after 1000 seconds was compared with that before the test. The difference was calculated as ΔVth. 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 with the oxide target material of the present invention had a ΔVth of less than −10.0 V and the stability was ensured.
On the other hand, the simple TFT in which the ZTO thin film is formed of the oxide target material of the comparative example has ΔVth lower than −10.0 V, and is not suitable as a TFT.

First, ZnO powder having an average particle diameter (D50 of cumulative particle size distribution) of 0.70 μm and an average particle diameter so that Sn is 33.3 atomic% with respect to the entire metal component, and the balance is Zn and inevitable impurities. SnO ₂ powder having a cumulative particle size distribution (D50) of 1.85 μm was weighed, put into a stirring vessel containing a predetermined amount of pure water and a dispersant, and then mixed to obtain a slurry. The slurry was dried and granulated and then calcined at 1090 ° C. for 4 hours to obtain a calcined powder composed of Zn ₂ SnO ₄ and ZnO. The calcined powder is ZnO powder having an average particle diameter (D50 of cumulative particle size distribution) of 0.70 μm so that Sn is 29.5 to 31.0 atomic% and Al is 0.132 atomic% during wet crushing. After adding Al ₂ O ₃ powder having an average particle size (D50 of cumulative particle size distribution) of 0.1 to 0.4 μm, the total average particle size (D50 of cumulative particle size distribution) is 0.7 μm to 1. The particle size was adjusted to 0 μm.
After wet pulverizing the calcined powder, five molded bodies having a thickness of 10 mm, a width of 235 mm, and a length of 310 mm were obtained by casting.

Next, the obtained molded body was fired in an air atmosphere at 1400 ° C. for 10 hours, and then subjected to a reduction heat treatment at 1400 ° C. for 4 hours in a nitrogen atmosphere to obtain an oxide sintered body. Then, this oxide sintered body is machined to have a thickness of 5 mm × a diameter of 50 mm, and in a reflected electron image of a scanning electron microscope, arbitrary length: 94.6 μm × width: 130.6 μm (area: 12355 μm) Among the three visual fields of ² ), a visual field of 10,000 μm ² in each visual field was observed, and the area of the ZnO phase existing in the visual field was measured. And the oxide target material used as this invention example 3-this invention example 7 was obtained by performing this measurement and grinding | polishing alternately.
Here, the measurement is performed by taking a reflected electron image of the Zn ₂ SnO ₄ phase and the ZnO phase with high contrast using a scanning electron microscope, and using the image analysis software (“Scandium” manufactured by OLYMPUS SOFT IMAGES SOLITIONS GMBH). Using, the area ratio of the ZnO phase of each visual field and the average value of three visual fields were obtained. The results are shown in Table 3.

The reflected electron images of the scanning electron microscope of the visual field 1 to the visual field 3 in the surface used as the erosion surface of the oxide target material of this invention example 3-this invention example 7 obtained above are shown in FIGS.
From the results of Table 3 and FIGS. 5 to 19, it was confirmed that the oxide target material of the present invention had an area ratio of ZnO phase of 10.5 area% or less in an area of 10,000 μm ² .

1. 1. Glass substrate 2. Gate electrode Gate insulating film 4. Channel layer 5. Source electrode 6. Drain electrode

Claims (4)

The area ratio of the ZnO phase occupying 10,000 μm ^{2 on} the surface of the erosion surface, containing 20.0 atomic percent to 50.0 atomic percent of Sn with respect to the entire metal component, the balance being Zn and inevitable impurities. Is 10.5 area% or less, The oxide target material characterized by the above-mentioned.   2. The oxide target material according to claim 1, comprising 0.005 atomic% to 4.000 atomic% in total of at least one of Al, Ga, Mo, and W with respect to the entire metal component. . ZnO powder and SnO ₂ powder are mixed with pure water and a dispersant so that Sn is contained in 20.0 atomic% to 50.0 atomic% with respect to the whole metal component, and the balance is Zn and inevitable impurities. A granulation step of obtaining a calcined powder composed of Zn ₂ SnO ₄ and ZnO by slurrying, producing the granulated powder by drying the slurry, and calcining the granulated powder;
After wet crushing the calcined powder, a molded body is produced by casting, and after degreasing the molded body, a sintering step of firing in an air atmosphere to obtain an oxide sintered body,
Polishing step of polishing the surface that becomes the erosion surface of the oxide sintered body to obtain an oxide target material in which the area ratio of the ZnO phase in the area of 10000 μm ² in the surface that becomes the erosion surface is 10.5 area% or less The manufacturing method of the oxide target material which has these. 4. The method for producing an oxide target material according to claim 3, wherein in the polishing step, a surface that becomes an erosion surface is polished while confirming lightness L ^* and chromaticity b ^* . 5.