TW201922672A - Oxide sintered article and sputtering target - Google Patents

Abstract

An oxide sintered article according to one aspect of the embodiment is an oxide sintered article containing tin oxide and gallium oxide, wherein the content of the gallium oxide is 20 mol% < Ga2O3 ≤ 90 mol%, the specific resistance is 1*10<SP>3</SP>[Omega].cm or less.

Description

   Oxide sintered body and sputtering target   

Embodiments disclosed in the present invention relate to an oxide sintered body and a sputtering target.

Conventionally, as a sputtering target formed into an oxide semiconductor thin film, a GTO (Gallium Tin Oxide) target (SnO ₂ ) and gallium oxide (Ga ₂ O ₃ ) is known ( For example, refer to Patent Document 1).

    [Prior technical literature]         [Patent Literature]    

Patent Document 1: Japanese Patent Laid-Open Publication No. 2013-40394

However, in the conventional GTO target, when the concentration of gallium oxide is higher than 20 mol%, there is a problem that the specific resistance of the target becomes large and sputtering using a DC (direct current) power supply cannot be performed (hereinafter, also referred to as DC sputtering) .

In view of the foregoing problems, an aspect of an embodiment is to provide an oxide sintered body for a GTO sputtering target that can perform DC sputtering even when the gallium oxide concentration is higher than 20 mol%.

The oxide sintered body according to one aspect of the embodiment is an oxide sintered body containing tin oxide and gallium oxide. The content of gallium oxide is 20mol% <Ga ₂ O ₃ ≦ 90mol%, and the specific resistance is 1 × 10 ³ Ω‧cm or less.

According to one aspect of the embodiment, an oxide sintered body for a GTO sputtering target can be provided, which can perform DC sputtering even when the gallium oxide concentration is higher than 20 mol%.

1‧‧‧ oxide sintered body

1a‧‧‧ Central

1b‧‧‧ Peripheral

FIG. 1 is a SEM observation photograph of the oxide sintered body of Example 4. FIG.

Fig. 2 is a schematic diagram showing a measurement point of a bulk resistance of an oxide sintered body.

Fig. 3 is an X-ray diffraction pattern of the oxide sintered bodies of Examples 4 to 8.

FIG. 4 is an X-ray diffraction pattern of the oxide sintered body of Comparative Example 1. FIG.

Hereinafter, embodiments of the oxide sintered body and the sputtering target disclosed in this case will be described with reference to the attached drawings. The present invention is not limited to the embodiments described below.

The oxide sintered body 1 (refer to FIG. 2) of the embodiment contains tin oxide and gallium oxide and can be used as a sputtering target. The oxide sintered body 1 according to the embodiment includes, for example, tin oxide, gallium oxide, and unavoidable impurities, and can be used as a GTO target. In addition, the GTO target of the embodiment may contain a small amount of other elements within a range that does not impair the advantageous effects of the embodiment.

The gallium oxide content of the oxide sintered body 1 of the embodiment is 20 mol% <Ga ₂ O ₃ ≦ 90 mol%, and the specific resistance is 1 × 10 ³ Ω · cm or less.

In the oxide sintered body 1 of the embodiment, the content of gallium oxide is preferably more than 20 mol% (typically 20.5 mol% or more) and 90 mol% or less. When the content of gallium oxide is 90 mol% or less, the benefit to Ga ₂ O ₃ having a larger specific resistance compared to SnO ₂ becomes smaller, so the specific resistance of the sputtering target becomes lower, which is preferable. From this viewpoint, the content of gallium oxide is preferably 85 mol% or less, more preferably 75 mol% or less, even more preferably 65 mol% or less, and still more preferably 50 mol% or less. In addition, when the content of gallium oxide is 50 mol% or less, the content of gallium oxide is preferably 45 mol% or less, and more preferably 40 mol% or less.

The specific resistance of the oxide sintered body 1 according to the embodiment is 1 × 10 ³ Ω · cm or less. Accordingly, when the oxide sintered body 1 is used as a sputtering target, it becomes possible to perform sputtering using an inexpensive DC power source, and the film formation rate can be increased.

The oxide sintered body 1 of the embodiment preferably has a specific resistance of 5 × 10 ² Ω · cm or less, and more preferably has a specific resistance of 1 × 10 ² Ω · cm or less.

It is preferable that the oxide sintered body 1 of the embodiment does not generate a gallium stannate compound (Ga ₄ SnO ₈ ) as much as possible. Although it has not been determined whether the formation of the gallium stannate compound (Ga ₄ SnO ₈ ) is a reason for lowering the specific resistance, it is believed that the reason is that the specific resistance of the gallium stannate compound (Ga ₄ SnO ₈ ) is higher.

From this viewpoint, in the X-ray diffraction measurement of the oxide sintered body 1 according to the embodiment, the gallium stannate compound (Ga ₄ SnO ₈ ) with respect to the spectrum peak of the (110) plane of the tin oxide (SnO ₂ ) phase. In contrast, the intensity of the spectral peak of the (111) plane is preferably 0.15 or less. That is, in the oxide sintered body 1 according to the embodiment, the ratio of the gallium stannate compound (Ga ₄ SnO ₈ ) phase to the tin oxide (SnO ₂ ) phase is preferably greater than that specified by the aforementioned spectral peak intensity ratio I. The established ratio is even smaller.

Thereby, an oxide sintered body 1 having a small specific resistance can be formed. Therefore, according to the embodiment, when this oxide sintered body 1 is used as a sputtering target, it becomes easy to perform DC sputtering.

In the oxide sintered body 1 according to the embodiment, the above-mentioned spectral peak intensity ratio I is preferably 0.10 or less, more preferably 0.05 or less, still more preferably 0.03 or less, and still more preferably 0.01 or less.

It is preferable that the oxide sintered body 1 of the embodiment has a relative density of 90% or more. Accordingly, when the oxide sintered body 1 is used as a sputtering target, the discharge state of DC sputtering can be stabilized. From this viewpoint, the relative density of the oxide sintered body 1 of the embodiment is more preferably 95% or more.

When the relative density is 90% or more, when the oxide sintered body 1 is used as a sputtering target, the voids in the sputtering target can be reduced, and it is easy to prevent intake of gas components in the atmosphere. In addition, it becomes difficult to generate abnormal discharges with the gap as a starting point, a phenomenon in which a sputtering target is cracked, and the like.

The oxide sintered body 1 according to the embodiment can be produced, for example, by the method described below. First, the raw material powder is mixed. Ga ₂ O ₃ powder and SnO ₂ powder were used as raw material powders. The average particle diameter of each raw material powder is preferably 2 μm or less. When the average particle diameter of each raw material powder is 2 μm or less, it becomes easy to obtain a high-density sintered body even if the sintering temperature is reduced. From this viewpoint, the average particle diameter of each raw material powder is more preferably 1.5 μm or less, and even more preferably 1 μm or less. Although the lower limit value of the average particle diameter of each raw material powder is not specified, it is preferably 0.1 μm or more from the viewpoint of preventing raw material aggregation. The average particle diameter of the raw material powder is a volume cumulative particle diameter D _{50 of 50} % by volume of the cumulative volume obtained by a laser diffraction scattering particle size distribution measurement method.

Various mixing methods can be used for mixing the raw material powder. For example, bead mills, sand mills, attritors (registered trademarks), and ball mills can be used. The obtained mixed powder can be sieved.

Next, the obtained mixed powder is sintered. The oxide sintered body 1 according to the embodiment is preferably sintered by a spark plasma sintering (Spark Plasma Sintering: SPS) method or a hot press (Hot Press: HP) method. When sintering is performed by the SPS method or the HP method, the mixed powder is filled into a sintering mold having a molding recess having a predetermined shape. Examples of the sintering mold can be made of graphite. If the sintering mold is filled with the mixed powder, it can be sintered by the SPS method or the HP method.

The oxide sintered body 1 of the embodiment is preferably sintered at a relatively low temperature of 1200 ° C or lower. By sintering at a low temperature of 1200 ° C or lower, the formation of a gallium stannate compound (Ga ₄ SnO ₈ ) can be suppressed, and the specific resistance of the oxide sintered body 1 can be reduced.

From this viewpoint, the sintering temperature of the embodiment is preferably 1100 ° C or lower, more preferably 1000 ° C or lower, and even more preferably 950 ° C or lower. From the viewpoint of sufficient sintering, the lower limit of the firing temperature is preferably 500 ° C or higher.

    [Example]    

[Example 1]

The average particle diameter (volume cumulative particle diameter D ₅₀₎ of 1μm powder of Ga ₂ O _3, and the average particle diameter (volume cumulative particle diameter D ₅₀₎ of the _powder SnO 0.5μm, so as to be Ga ₂ O _3: SnO ₂ = 21.1: Weighing in a manner of 78.9 (mol%). Next, a ball mill was used for 24 hours to obtain a mixed powder.

Next, the mixed powder was sieved with a sieve having a mesh size of 710 μm to obtain a mixed powder having an average particle diameter (volume cumulative particle diameter D ₅₀ ) of 0.8 μm.

Next, the sieved mixed powder was filled into a graphite sintered mold having an inner diameter of 120 mm. Then, the sintering mold filled with the mixed powder was sintered in a spark plasma sintering (SPS) apparatus to produce a sintered body. The sintering by the SPS device is performed in a vacuum (15 Pa or less), with a pressure of 20 MPa, a sintering temperature of 600 ° C, a heating rate of 20 ° C / min, a sintering temperature holding time of 30 minutes, and a natural furnace cooling for cooling. Way to proceed.

Next, the obtained sintered body was subjected to cutting processing to obtain an oxide sintered body 1 having a diameter of 101.6 mm and a thickness of 6 mm.

In addition, in the manufacturing method used in the examples, the ratio (mol%) of each oxide contained in the mixed powder of SnO ₂ powder and Ga ₂ O ₃ powder can be regarded as the content contained in the finally obtained oxide sintered body 1 Ratio of each oxide (mol%).

[Example 2]

By the same method as in Example 1, an oxide sintered body 1 was obtained. In Example 2, each raw material powder was weighed so that Ga ₂ O ₃ : SnO ₂ = 30.0: 70.0 (mol%) was obtained when the mixed powder was weighed.

[Example 3]

By the same method as in Example 1, an oxide sintered body 1 was obtained. In Example 3, each raw material powder was weighed so that Ga ₂ O ₃ : SnO ₂ = 35.0: 65.0 (mol%) was obtained when the mixed powder was weighed.

[Example 4]

The average particle diameter (volume cumulative particle diameter D ₅₀₎ of 1μm of Ga ₂ O ₃ powder with an average particle diameter (volume cumulative particle diameter D ₅₀₎ of the _powder SnO 0.5μm, so as to be Ga ₂ O _3: SnO ₂ = 21.1: 78.9 (mol%). Next, a ball mill was used for 24 hours to obtain a mixed powder.

Next, the mixed powder was sieved with a sieve having a mesh size of 710 μm to obtain a mixed powder having an average particle diameter (volume cumulative particle diameter D ₅₀ ) of 0.8 μm.

Next, the sieved mixed powder was filled into a graphite sintering mold having an inner diameter of 120 mm. Then, the sintering mold filled with the mixed powder was sintered in a hot press (HP) apparatus to produce a sintered body. The sintering by the HP device was performed in an argon gas environment at a pressure of 17 MPa, a sintering temperature of 920 ° C, a heating rate of 60 ° C / min, a holding time of the sintering temperature of 180 minutes, and cooling in a natural furnace cooling. .

Next, the obtained sintered body was subjected to cutting processing to obtain an oxide sintered body 1 having a diameter of 101.6 mm and a thickness of 6 mm.

[Example 5]

Using the same method as in Example 4, an oxide sintered body 1 was obtained. In Example 5, each raw material powder was weighed so that it became Ga ₂ O ₃ : SnO ₂ = 30.0: 70.0 (mol%) when the mixed powder was weighed.

[Example 6]

Using the same method as in Example 4, an oxide sintered body 1 was obtained. In Example 6, each raw material powder was weighed so that Ga ₂ o ₃ : SnO ₂ = 35.0: 65.0 (mol%) was obtained when the mixed powder was weighed.

[Example 7]

Using the same method as in Example 4, an oxide sintered body 1 was obtained. In Example 7, each raw material powder was weighed so that Ga ₂ O ₃ : SnO ₂ = 70.0: 30.0 (mol%) was obtained when the mixed powder was weighed.

[Example 8]

Using the same method as in Example 4, an oxide sintered body 1 was obtained. In Example 8, each raw material powder was weighed so that Ga ₂ O ₃ : SnO ₂ = 80.0: 20.0 (mol%) was obtained when the mixed powder was weighed.

[Comparative Example 1]

The average particle diameter (volume cumulative particle diameter D ₅₀₎ of 1μm of Ga ₂ O ₃ powder with an average particle diameter (volume cumulative particle diameter D ₅₀₎ of the _powder SnO 0.5μm, so as to be Ga ₂ O _3: SnO ₂ = 30.0: 70.0 (mol%). Next, use a ball mill to mix for 24 hours to obtain a mixed powder.

Next, the mixed powder was sieved with a sieve having a mesh size of 710 μm to obtain a mixed powder having an average particle diameter (volume cumulative particle diameter D ₅₀ ) of 0.8 μm.

Next, to the obtained mixed powder, 6% by mass of the mixed powder was added to polyvinyl alcohol diluted to 4% by mass, and the polyvinyl alcohol and the powder were thoroughly mixed using a mortar. Then, the obtained powder was temporarily pressed under the condition of 200 kg / cm ² , and the obtained temporarily formed body was pulverized in a mortar to obtain a pulverized powder. Next, the obtained pulverized powder was filled into a mold for pressing, and formed at a pressing pressure of 1 t / cm ² in 60 seconds to obtain a molded body.

Next, the obtained formed body was placed in a sintering furnace, and 1 L / hour of oxygen was flowed in the furnace. The oxygen flow gas environment was used as the sintering gas environment. Sintering was performed at a holding time of 1500 ° C. and a sintering temperature of 540 minutes (9 hours). Thereafter, the obtained sintered body was cooled at a temperature reduction rate of 100 ° C / hour.

Next, the cooled sintered body was cut to obtain an oxide sintered body 1 having a diameter of 101.6 mm and a thickness of 6 mm.

[Comparative Example 2]

Using the same method as in Example 4, an oxide sintered body 1 was obtained. In Comparative Example 2, each raw material powder was weighed so that Ga ₂ O ₃ : SnO ₂ = 95.0: 5.0 (mol%) was obtained when the mixed powder was weighed.

Next, the relative density of the oxide sintered bodies 1 of Examples 1 to 8 and Comparative Examples 1 and 2 obtained as described above was measured. This relative density was measured according to the Archimedes method.

Specifically, the air mass of the oxide sintered body 1 is divided by the volume (the mass of the sintered body in water / the specific gravity of water at the measurement temperature), and the value of the percentage relative to the theoretical density ρ (g / cm ³ ) is taken as the value Relative density (unit:%).

The theoretical density ρ (g / cm ³ ) is calculated from the mass% and the density of the raw material powder used in the production of the oxide sintered body 1. Specifically, it is calculated by the following expression.

_{ρ = {(C 1/100} ) / ρ 1 + (C 2/100) / ρ 2} -1

In addition, C ₁ and C ₂ and ρ ₁ and ρ ₂ in the above formulas respectively represent the following values.

‧C ₁ : mass% of SnO ₂ powder used in the production of oxide sintered body 1

‧Ρ ₁ : Density of SnO ₂ (6.95g / cm ³ )

‧C ₂ : mass% of Ga ₂ O ₃ powder used in the production of oxide sintered body 1

‧Ρ ₂ : Density of Ga ₂ O ₃ (5.95g / cm ³ )

Next, the surfaces of the oxide sintered bodies 1 of Examples 1 to 8 obtained as described above were observed using a scanning electron microscope (SEM: Scanning Electron Microscope), and details of each phase of the observed surface were investigated. The observation results are shown below.

FIG. 1 is a SEM observation photograph of the oxide sintered body 1 of Example 4. FIG. As shown in FIG. 1, it was found that the oxide sintered bodies 1 of Examples 1 to 8 were dispersed in a tin oxide (SnO ₂ ) phase having a light color, and a gallium oxide (Ga ₂ O ₃ ) phase having a deep color was dispersed. Further, in the SEM observation, the oxide sintered body 1 of Examples 1 to 8 did not observe a gallium stannate compound (Ga ₄ SnO ₈ ) phase, which is a compound of tin oxide and gallium oxide.

Next, the oxide sintered bodies 1 obtained in Examples 1 to 8 and Comparative Examples 1 and 2 were measured for the concentration of Zr impurities contained in the oxide sintered bodies 1 respectively. Specifically, the measurement was performed by an acid decomposition ICP-OES method using an ICP emission spectroscopic analyzer 720 ICP-OES manufactured by Agilent Technologies. As a result, the Zr concentration of all the oxide sintered bodies 1 did not reach 50 ppm.

Next, the specific resistance (bulk resistance) of each of the oxide sintered bodies 1 of Examples 1 to 8 and Comparative Examples 1 and 2 obtained as described above was measured.

Specifically, Mitsubishi Chemical Corporation's LORESTA (registered trademark) HP MCP-T410 (probe type ESP with 4 probes in-line) was used, and the probe was pressed against the surface of the oxide sintered body 1 after processing, and AUTO Measurements were performed in RANGE mode. As shown in FIG. 2, the measurement points are uniformly provided in the central portion 1 a of the oxide sintered body 1, and in four places in the outer peripheral portion 1 b, for a total of five points. The average value of each measured value is taken as the oxide sintering. Body resistance of body 1. FIG. 2 is a schematic diagram showing a measurement place of the bulk resistance of the oxide sintered body 1. FIG.

As a result, the specific resistance (bulk resistance) of any of Examples 1 to 8 was 1 × 10 ³ Ω · cm or less, and the specific resistance was measurable. In contrast, Comparative Example 1 became an insulator (ie, , Specific resistance is greater than 1 × 10 ⁷ Ω · cm), it is impossible to measure specific resistance (bulk resistance). The specific resistance of Comparative Example 2 was 2.4 × 10 ³ Ω · cm, which was higher than that of Examples 1 to 8. It is believed that this is because the proportion of tin oxide that bears conductivity is reduced, and it becomes difficult to form a conductive path in the target.

Next, the sputtering targets of Examples 1 to 8 and Comparative Examples 1 and 2 were prepared from the oxide sintered bodies 1 of Examples 1 to 8 and Comparative Examples 1 and 2 obtained as described above. This sputtering target is produced by using indium, which is a low-melting point solder, as a bonding material, and bonding the obtained oxide sintered body 1 to a copper base material.

Next, using the prepared sputtering targets of Examples 1 to 8 and Comparative Examples 1 and 2, a sputtering using a DC power source was attempted under the following conditions, and it was evaluated whether DC sputtering can be performed from the manufactured sputtering targets.

‧Film forming device: DC magnetron sputtering device

‧Exhaust system: cryopump, rotary pump

‧Sputtering power: 150W (1.85W / cm ² )

‧Available vacuum degree: 1.0 × 10 ^-4 Pa

‧Sputtering pressure: 0.4Pa

‧Oxygen partial pressure: O ₂ 2.0%

In addition, the evaluation criteria for the availability of DC sputtering are as follows.

A (Good): DC sputtering can be performed well

B (OK): DC sputtering can be performed

C (impossible): DC sputtering cannot be performed

Here, Table 1 shows the manufacturing conditions of the oxide sintered body 1 and the evaluation results regarding various characteristics of the oxide sintered body 1 for the above-mentioned Examples 1 to 8 and Comparative Examples 1 and 2.

By using the SPS method or the HP method, Examples 1 to 8 sintered at a lower temperature below 1200 ° C were compared with Comparative Example 1 which was sintered at a temperature higher than 1200 ° C. It was found that by sintering at a lower temperature, The specific resistance is reduced to 1 × 10 ³ Ω‧cm or less.

By comparing Examples 1 to 8 in which the content of gallium oxide is 90 mol% or less and Comparative Example 2 in which the content of gallium oxide is 95 mol% or more, it is known that by setting the content of gallium oxide to 90 mol% or less, the ratio can be changed. The resistance is reduced below 1 × 10 ³ Ω‧cm.

Then, than by the resistance of 1 × 10 ³ Ω‧cm the following embodiments of Examples 1 to 8 were compared with a specific resistance not less than 1 × 10 ³ Ω‧cm of Comparative Examples 1 and 2, so that the specific resistance by It is reduced to 1 × 10 ³ Ω‧cm or less, and a sputtering target capable of DC sputtering can be realized.

In addition, by setting the relative density to 90% or more, the discharge state of DC sputtering can be stabilized. Further, by comparing Examples 4 to 8 with a relative density of less than 95% and Examples 1 to 3 with a relative density of 95% or more, it is known that the DC sputtering can be performed by the relative density of 95% or more. The discharge state is more stable.

Next, the oxide sintered bodies 1 obtained in Examples 1 to 8 and Comparative Examples 1 and 2 were measured for X-ray diffraction (XRD) to obtain X-ray diffraction patterns. Then, the structures of the oxide sintered bodies 1 of Examples 1 to 8 and Comparative Examples 1 and 2 were identified from the obtained X-ray diffraction patterns.

Specific measurement conditions are shown below.

‧Device: SmartLab (manufactured by Rigaku Co., Ltd.)

‧Line source: CuKα line

‧ Tube voltage: 40kV

‧ Tube current: 30mA

‧Scan speed: 5deg / min

‧Step: 0.02deg

‧Scanning range: 2θ = 20 degrees to 80 degrees

Fig. 3 is an X-ray diffraction pattern of the oxide sintered body 1 of Examples 4 to 8. In addition, in Fig. 3, the X-ray diffraction pattern also shows the positions of spectral peaks that appear due to various planes existing in each oxide.

As shown in FIG. 3, the X-ray diffraction patterns of Examples 4 to 8 show a spectral peak derived from a tin oxide (SnO ₂ ) phase and a spectral peak derived from a gallium oxide (Ga ₂ O ₃ ) phase. On the other hand, the X-ray diffraction patterns of Examples 4 to 8 hardly showed spectral peaks due to the gallium stannate compound (Ga ₄ SnO ₈ ) phase.

Here, based on the X-ray diffraction patterns of Examples 4 to 8 shown in FIG. 3, a gallium stannate compound (Ga ₄ SnO) with respect to the peak intensity of the (110) plane of the tin oxide (SnO ₂ ) phase was identified. ₈ ) The spectral peak intensity ratio I of the spectral peak intensity of the (111) plane of the phase.

Further, as shown in FIG. 3, tin oxide (SnO ₂₎ phase of the spectrum (110) plane peak of a tin-based oxide (SnO ₂₎ relative to the main peak, is the diffraction angle (2 [Theta]) at 26.58 ° appears at the Spectrum peak. Further, the compound stannate, gallium (Ga ₄ SnO ₈₎ relative to the (111) plane peak of stannate, gallium-based compound (Ga ₄ SnO ₈₎ relative to the main peak, is the diffraction angle (2 [Theta]) at 34.81 ° appears at The peak of the spectrum.

As a result, the spectral peak intensity ratio I in Example 4 was 0.03, the spectral peak intensity ratio I in Example 5 was 0.03, the spectral peak intensity ratio I in Example 6 was 0.04, and the spectral peak in Example 7 was The intensity ratio I was 0.09, and the peak intensity ratio I of Example 8 was 0.13. Although not shown in FIG. 3, the spectral peak intensity ratio I in Example 1 is 0.01, the spectral peak intensity ratio I in Example 2 is 0.01, and the spectral peak intensity ratio I in Example 3 is 0.01.

FIG. 4 is an X-ray diffraction pattern of the oxide sintered body 1 of Comparative Example 1. FIG. In addition, Fig. 4 also shows the positions of the spectral peaks appearing in the X-ray diffraction pattern due to various planes existing in each oxide in the same manner as in Fig. 3.

As shown in FIG. 4, the X-ray diffraction pattern of Comparative Example 1 shows a peak due to a tin oxide (SnO ₂ ) phase and a peak due to a gallium stannate compound (Ga ₄ SnO ₈ ) phase.

Here, based on the X-ray diffraction pattern of Comparative Example 1 shown in FIG. 4, a gallium stannate compound (Ga ₄ SnO ₈ ) with respect to the peak intensity of the (110) plane of the tin oxide (SnO ₂ ) phase is identified. The phase peak intensity ratio I of the phase peak intensity of the (111) plane. As a result, the spectral peak intensity ratio I of Comparative Example 1 was 0.16. Although not shown in FIG. 4, the peak intensity ratio I of Comparative Example 2 was 0.21.

By using the SPS method or the HP method, Examples 1 to 6 sintered at a lower temperature below 1200 ° C and Comparative Example 1 sintered at a temperature higher than 1200 ° C are compared. By sintering at a lower temperature, the The peak intensity of the spectrum is lower than I to below 0.05. That is, in the embodiment, generation of a gallium stannate compound (Ga ₄ SnO ₈ ) phase can be suppressed by sintering at a relatively low temperature.

Here, it is recognized that the tin oxide (SnO ₂ ) phase and gallium oxide (Ga ₂ O ₃ ) phase can reduce specific resistance by lack of oxygen, and the gallium stannate compound (Ga ₄ SnO ₈ ) phase has high specific resistance. . That is, according to the embodiment, the formation of a gallium stannate compound (Ga ₄ SnO ₈ ) phase is suppressed by sintering at a low temperature, and the specific resistance can be reduced to 1 × 10 ³ (Ω · cm) or less.

The embodiments of the present invention have been described above, but the present invention is not limited to the above-mentioned embodiments, and various changes can be made without exceeding the gist thereof. For example, in the embodiment, the method of sintering at a lower temperature of 1200 ° C or lower is an example using the SPS method and the HP method. However, the low-temperature sintering method is not limited to the SPS method and the HP method.

Furthermore, although the embodiment shows an example of forming a sputtering target using the oxide sintered body 1 in a disk shape, the shape of the oxide sintered body 1 is not limited to a disk shape, and may be any shape such as a cylindrical shape. shape.

Further effects and variations can be easily derived by those with ordinary knowledge in the technical field to which the invention belongs. Therefore, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described above. Therefore, the present invention can be variously changed without departing from the spirit or scope of the general inventive concept defined by the scope of the attached patent application and its equivalents.

Claims (10)

An oxide sintered body is an oxide sintered body containing tin oxide and gallium oxide, wherein the content of gallium oxide is 20mol% <Ga ₂ O ₃ ≦ 90mol%, and the specific resistance is 1 × 10 ³ Ω‧cm or less. The oxide sintered body according to item 1 of the scope of patent application, wherein the content of gallium oxide is 20 mol% <Ga ₂ O ₃ ≦ 85 mol%. The oxide sintered body according to item 1 of the patent application scope, wherein the content of gallium oxide is 20 mol% <Ga ₂ O ₃ ≦ 75 mol%. The oxide sintered body according to item 1 of the scope of patent application, wherein the content of gallium oxide is 20 mol% <Ga ₂ O ₃ ≦ 65 mol%. The oxide sintered body according to item 1 of the scope of patent application, wherein the content of gallium oxide is 20 mol% <Ga ₂ O ₃ ≦ 50 mol%. The oxide sintered body according to item 1 or 2 of the scope of the patent application is an oxide sintered body containing a tin oxide (SnO ₂ ) phase and a gallium oxide (Ga ₂ O ₃ ) phase, and is measured by X-ray diffraction The intensity ratio of the spectral peak of the (111) plane of the gallium stannate compound (Ga ₄ SnO ₈ ) phase to the spectral peak of the (110) plane of the tin oxide (SnO ₂ ) phase is 0.15 or less. The oxide sintered body according to item 1 or 2 of the scope of the patent application is an oxide sintered body containing a tin oxide (SnO ₂ ) phase and a gallium oxide (Ga ₂ O ₃ ) phase, and is measured by X-ray diffraction The intensity ratio of the spectral peak of the (111) plane of the gallium stannate compound (Ga ₄ SnO ₈ ) phase to the spectral peak of the (110) plane of the tin oxide (SnO ₂ ) phase is 0.10 or less. The oxide sintered body according to item 1 or 2 of the scope of the patent application is an oxide sintered body containing a tin oxide (SnO ₂ ) phase and a gallium oxide (Ga ₂ O ₃ ) phase, and is measured by X-ray diffraction The intensity ratio of the spectral peak of the (111) plane of the gallium stannate compound (Ga ₄ SnO ₈ ) phase to the spectral peak of the (110) plane of the tin oxide (SnO ₂ ) phase is 0.05 or less.     The oxide sintered body according to item 1 or 2 of the patent application scope, wherein the relative density is 90% or more.         A sputtering target uses an oxide sintered body described in item 1 or 2 of the patent application as a target.