TWI608112B - ITO sputtering target and its manufacturing method - Google Patents

Description

ITO sputtering target and manufacturing method thereof

The present invention relates to an ITO sputtering target suitable for forming an ITO film. In particular, it relates to an ITO sputtering target having a small change in film characteristics from the initial stage to the end of sputtering of a target, and a method for producing the same.

An ITO (indium-tin composite oxide) film is now widely used as a transparent electrode (conductive film) in a display element centered on a liquid crystal display. The method of forming the ITO film is carried out by a method generally called a physical vapor deposition method such as a vacuum deposition method or a sputtering method. In particular, from the viewpoint of workability or film stability, it is often formed by magnetron sputtering.

The formation of a film by a sputtering method is performed by causing a cation such as Ar ion to physically impact a target provided on a cathode, and using the impact energy to release a material constituting the target to form a composition with the target material. Almost the same film is laminated on the anode side substrate on the opposite side. The coating method by the sputtering method has a feature that a film of several nm can be formed to a thick film of several tens of μm at a stable deposition rate by adjusting the processing time or supplying electric power.

In recent years, there has been a demand for ITO films used in electrostatic capacitance type, resistive film type touch panels, etc., in addition to the ITO sputtering target containing 3.7 at.% of tin (Sn) which has been widely used. A target in which tin oxide is changed in a wide range of 0.3 or more and 14.5 at.% or less is developed in accordance with the required film resistance. For example, it is known in Patent Document 1 that a mixed powder of indium oxide containing 20 to 50% by weight of tin oxide is subjected to press molding, and then in a pure oxygen atmosphere. The molded body was subjected to pressure sintering at a temperature of 1500 to 1650 ° C and a pressure of 0.15 to 1 MPa to produce an ITO sputtering target.

A patent represented by the ITO sputtering target is disclosed in Patent Document 1 below. This patent is "an ITO sputtering target manufactured by powder metallurgy using a raw material of indium oxide and tin oxide. The surface roughness of the sputtering target is 0.5 μm or less, and the density D (g/cm). ³ ) With the bulk resistance ρ (mΩcm), the following two equations are satisfied, a) 6.20≦D≦7.23; b)-0.0676D+0.887≧ρ≧-0.0761D+0.666”, which is about 20 years The former technology.

This patent has almost no abnormal discharge or nodule during sputtering, and has very little gas adsorption. Therefore, it is possible to stably obtain a high-quality ITO film ITO sintered target under a good film forming operation. It can be described as an epoch-making invention.

Further, as a measure for increasing the density of the ITO target, for example, Patent Document 2 listed below discloses an ITO target which is formed by using the following tin oxide powder: a medium diameter of 0.40 (excluding 0.40) is obtained from the particle size distribution. The range of 1.0 μm and the 90% particle diameter determined from the particle size distribution are in the range of 3.0 μm or less.

However, when such an tin oxide powder is used to produce an ITO target containing more tin oxide than in the prior art, micropores and microcracks are generated inside the sintered body, and during or after the processing of the sintered body. A situation in which a crack or crack occurs in the storage. Moreover, they may affect the shipment of target products.

Further, in Patent Document 3 below, as a technique related to ITO, there is disclosed a technique of providing an ITO sputtering target which is present in an In ₂ O ₃ parent phase as a main crystal grain. An ITO sintered body having fine particles composed of In ₄ Sn ₃ O ₁₂ , wherein the fine particles have a three-dimensional star shape, and the three-dimensional star shape is formed with a needle-like protrusion from a virtual center of the particle. The body resistance of the ITO sputtering target is low.

Further, Patent Document 4 listed below discloses a technique of forming an ITO sintered body composed of In, Sn, and O, a sintered density of 7.08 g/cm ³ or more, and a volume resistivity of 80 μΩcm to 100 μΩcm, O/. (In+Sn+O) is 1.75% or less (weight ratio), and the integrated intensity of the X-ray diffraction peak of the (200) plane of the In ₄ Sn ₃ O ₁₂ phase is 30% or less, and the sintered body is sintered by In In the case of a molded body composed of Sn or O, when the sintering temperature is 1400 ° C or higher, the sintering environment is converted from an oxidizing environment to a non-oxidizing environment.

Non-stoichiometric oxides such as ITO sputtering targets. Because the thermal equilibrium oxygen concentration at high temperatures is higher than room temperature, oxygen in the environment enters the sintered body during cooling at the time of sintering, and the surface of the sintered body Diffusion into the interior, however, since the diffusion rate rapidly decreases with the temperature, the oxygen deficiency concentration cannot be uniformized in a limited cooling time, and the oxygen deficiency concentration near the surface is low at room temperature, and becomes higher as it goes to the inside.

In general, a plate-like sintered body used as a target has a concentration distribution occurring in the thickness direction of the target. Moreover, this concentration distribution depends on the sintering temperature pattern and the oxygen partial pressure of the environment.

On the other hand, the oxygen deficiency concentration of the oxide target affects characteristics such as conductivity of the film. For example, when a sputtering film is formed using an ITO target, about 1% of oxygen is added to the sputtering gas, but the oxygen partial pressure at which the film resistance is extremely small depends on the oxygen deficiency concentration of the target.

Therefore, the optimum oxygen partial pressure of the sputtering gas gradually changes from the sputtering surface to the inside as the target is sputtered. In other words, when the oxygen partial pressure of the sputtering gas is fixed, the film characteristics change depending on the sputtering time.

In the prior art shown above, although it has been proposed to increase the density of the ITO sputtering target or to achieve low resistivity, the current situation is not aware of the following problems and attempts have not been made to solve the above problems. The concentration of oxygen deficiency near the surface of the target is low and the higher the internal portion is, the higher the concentration is in the plate-like sintered body used as a target, and the concentration distribution is generated in the thickness direction of the target.

[Patent Document 1] Japanese Patent No. 2750483

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2009-29706

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2009-40621

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2000-233969

The present invention relates to an ITO sputtering target suitable for forming an ITO film, and more particularly to an ITO sputtering target having a small change in film characteristics from the initial stage to the end of sputtering of the target. In other words, the problem is that the variation in the oxygen defect in the thickness direction of the ITO sputtering target is reduced, and the film characteristics of the sputtering are less changed to ensure the improvement of the film formation quality and the reliability.

In order to solve the above problems, the present invention provides the following invention.

1) Providing an ITO sputtering target which is a sintered body composed of indium (In), tin (Sn), oxygen (O), and unavoidable impurities, and is a tin (Sn) content (atomic composition ratio: at. %) a sintered body ITO sputtering target of 0.3 or more and 14.5 at. % or less; characterized in that the volume resistivity is 0.1 mΩ. Cm~1.4mΩ. In the case where the target thickness is t, the difference between the volume resistivity of the thickness t and the volume resistivity at any position in the thickness direction is 20% or less.

Although the thickness of the sheet is reduced and the resistivity is gradually changed during sputtering, it is preferable that the change in the volume resistivity is small and the variation in the film characteristics is small throughout the life of the target. An object of the present invention is to obtain good film characteristics by setting the difference between the bulk resistivity of the thickness t and the volume resistivity at an arbitrary position in the thickness direction to 20% or less.

Here, the "arbitrary point in the thickness direction" means a position where the thickness of the target is not t, and the position is not the thickness of t, and is the volume resistivity measured in the thickness of the position. Further, "difference" means that the measured volume resistivity is larger, for example, when the volume resistivity is R1, R2 and R1 > R2, (R1 - R2) / R1 × 100 ( %) Calculated by.

Further, the target obtained has a body resistivity which is the lowest in the center portion of the target thickness, and the body resistivity increases when the target exceeds the center portion, and the back surface and the surface have almost the same volume resistivity. Therefore, even in the case of polishing the surface during the processing of the target, the thickness to the back surface has at least the lowest volume resistivity at the center of the original thickness.

Further, the surface of the sintered body before the processing such as polishing has the highest volume resistivity, and therefore the maximum difference in the volume resistivity is usually the difference between the volume resistivity of the surface of the sintered body before the processing such as polishing and the volume resistivity at the center portion of the thickness. . Therefore, in the case where the surface is polished at the time of processing of the target, the difference in the thickness direction becomes a value smaller than the maximum difference. In this case, there will also be cases where the back side becomes higher than the surface.

2) The present invention provides the ITO sputtering target according to the above 1), wherein when the target thickness is set to t, the difference between the volume resistivity of the thickness t and the volume resistivity at any position in the thickness direction is 15% or less.

3) Further, the present invention provides a method for producing a sintered body ITO sputtering target for producing a sintered body ITO sputtering target which is indium (In), tin (Sn), oxygen (O), and inevitable The sintered body composed of impurities has a tin (Sn) content (atomic composition ratio: at.%) of 0.3 or more and 14.5 at.% or less; and is characterized by sintering a raw material powder composed of indium oxide powder and tin oxide powder. The sintering temperature is set to 1300 to 1600 ° C, and the average cooling rate from the highest temperature at the time of sintering to 1000 ° C is set to 0.1 to 3.0 ° C / min, and the environment in the cooling at the time of cooling is set to the atmospheric environment (oxygen partial pressure) Less than 30%).

4) Further, the present invention provides a method for producing a sintered body ITO sputtering target according to the above 3), wherein the volume resistivity is 0.10 to 1.40 mΩ. In the case where the target thickness is t, the difference between the volume resistivity of the thickness t and the volume resistivity at any position in the thickness direction is 20% or less.

Further, the present invention provides the method for producing a sintered body ITO sputtering target according to the above 3) or 4), wherein, in the case where the target thickness is t, the bulk resistivity of the thickness t and the thickness direction are The difference in volume resistivity at any location is below 15%.

6) Further, the present invention provides an ITO sputtering film which is obtained by sputtering using a sintered body ITO sputtering target which is made of indium (In), tin (Sn), oxygen. (O), a sintered body composed of unavoidable impurities, and a tin (Sn) content (atomic composition ratio: at.%) of 0.3 or more and 14.5 at.% or less; characterized by an initial stage of the target life and a late target life The difference in resistivity of the film is 5% or less.

Here, at the initial stage of the target life, it can be said that "the period from the splashing of the target to the most splashed portion is less than 1 mm", and the target life can be said to be "the most splashed part of the target and the target of this part." The residual thickness is between 0.01 mm and 1 mm.

The present invention relates to an ITO sputtering target suitable for forming an ITO film, and particularly has an excellent effect of providing an ITO sputtering target having a small change in film characteristics from the initial stage to the end of sputtering of the target.

In other words, by making the oxygen defect variation in the thickness direction of the ITO sputtering target small, and the difference between the volume resistivity of the thickness t and the volume resistivity at any position in the thickness direction is within 20%, The film characteristics of the sputtering are less changed, and the film formation quality can be improved and reliability can be ensured. As a result, it has an excellent effect of improving the productivity or reliability of the ITO target.

Fig. 1 is a view showing an example in which the maximum difference in volume resistivity between the volume resistivity at the thickness t and the volume resistivity at the time t is 13% when the target thickness is t.

In the present invention, the composition of the ITO sputtering target is a sintered body composed of indium (In), tin (Sn), oxygen (O), and unavoidable impurities, and tin (Sn) content (atomic composition ratio: at.%). ) is 0.3 or more and 14.5 at.% or less.

By using such a target, it is possible to provide a liquid crystal television or a plasma television, which is suitable for both electrostatic capacitance type and resistive film type touch panel, and has little change in film characteristics from the initial stage to the end of sputtering. ITO sputtering target.

When the indium oxide-tin oxide-based oxide (ITO) sintered body target of the present invention is produced, it can be produced by mixing, pulverizing, molding, and sintering processes of the respective raw material powders. The raw material powder is indium oxide powder and tin oxide powder, and a specific surface area of about 5 m ² /g can be used.

Specifically, the indium oxide powder has a bulk density of 0.3 to 0.8 g/cm ³ , a medium diameter (D ₅₀ ): 0.5 to 2.5 μm, a specific surface area of 3.0 to 6.0 m ² /g, and a bulk density of 0.2% of the tin oxide powder. ~0.6 g/cm ³ , medium diameter (D ₅₀ ): 1.0 to 2.5 μm, specific surface area: 3.0 to 6.0 m ² /g.

Each raw material powder is weighed to a desired composition ratio, and then mixed and pulverized. The pulverization method has various methods depending on the desired particle size and the pulverized material, and is preferably a wet medium agitating mill such as a bead mill. The slurry obtained by dispersing the powder in water is forcibly stirred together with a pulverizing medium such as zirconia or alumina which is a high hardness material, and the pulverized powder can be obtained efficiently. However, since the pulverizing medium is also worn at this time, the pulverizing medium itself is formed as an impurity and mixed in the pulverized powder, so that long-term processing is not preferable.

If the amount of pulverization is defined by the difference in specific surface area before and after pulverization, the amount of pulverization by the wet medium agitating mill is almost proportional to the energy applied to the powder. Therefore, it is important to manage the cumulative power of the wet medium agitating mill when pulverizing. The difference (ΔBET) between the specific surface areas before and after the pulverization was set to 0.5 to 5.0 m ² /g, and the diameter (D ₅₀ ) after the pulverization was set to 2.5 μm or less.

Next, granulation of the slurry after the fine pulverization is performed. The reason for this is that the pulverization is used to enhance the fluidity of the powder, and at the time of press molding in the next step, the powder is uniformly filled in the metal mold to obtain a homogeneous molded body. There are various ways of granulating, and one of the methods for obtaining a granulated powder suitable for press molding has a method using a spray dryer. In the method of forming a powder into a slurry and dispersing it in hot air in the form of droplets, and drying it instantaneously, a spherical granulated powder of 10 to 500 μm can be continuously obtained.

Further, the strength of the molded body can be improved by adding a binder such as polyvinyl alcohol (PVA) to the slurry and containing it in the granulated powder. The amount of PVA added is 50 to 250 cc/kg of an aqueous solution containing 4 to 10 wt.% of PVA, based on the raw material powder.

Further, the press molding can be adjusted by adding a plasticizer suitable for the adhesive. The crushing strength of the granulated powder. Further, there is also a method of increasing the strength of the molded body by adding a small amount of water to the obtained granulated powder to wet the granulated powder. In the drying by the spray drying method, the management of the inlet temperature and the outlet temperature of the hot air is important.

If the temperature difference between the inlet and the outlet is large, the amount of drying per unit time increases, and productivity is improved. However, when the inlet temperature is too high, the powder and the added binder may deteriorate due to heat, and it is impossible to Get the ideal characteristics. Further, in the case where the outlet temperature is too low, the granulated powder may not be sufficiently dried.

Next, press molding is performed. The granulated powder is filled in a metal mold, and the pressure is maintained at 400 to 1000 kgf/cm ² for 1 to 3 minutes. When the pressure is less than 400 kgf/cm ² , a molded body having sufficient strength and density cannot be obtained. Further, when the pressure is 1000 kgf/cm ² or more, the molded body itself may be subjected to pressure when the molded body is taken out from the metal mold. Damage caused by the liberation of the liberation is not good in production.

The formed body was sintered in an oxygen atmosphere using an electric furnace to obtain a sintered body. The sintering temperature is set to 1300 to 1600 ° C for sintering. In this case, if the sintering temperature is lower than 1300 ° C, a sintered body having a high density cannot be obtained. Further, when a sintering temperature of more than 1600 ° C is used, there is a problem that the sintering density is lowered or the composition is deviated due to the volatilization of tin oxide, and the cost of the furnace heater life is also reduced. Therefore, it is preferable to set the upper limit to 1600 ° C. In the process of raising the temperature to the sintering temperature, the debonding agent step or the like may be introduced as needed.

If the holding time in the sintering temperature is shorter than 1 hour, sintering may not be sufficiently performed, the sintered body density may not be sufficiently high, or the sintered body may be warped. Even if it is kept for more than 100 hours, it will generate unnecessary energy or waste of time, but it is not good in terms of productivity. It is preferably 5 to 30 hr.

The environment during cooling at the time of cooling is set to an atmospheric environment (oxygen partial pressure ratio is less than 30%), and the average cooling rate from the highest temperature at the time of the above sintering to 1000 ° C is set to 0.1 to 3.0 ° C / min.

For the measurement method of the volume resistivity, for example, NPS Co., Ltd. can be used. Manufacturing type: Σ-5+ for measurement. In the measurement, first, four metal probes were placed on the straight line of the sample surface, and then a fixed current was passed between the two probes on the outer side, and a potential difference generated between the two inner probes was measured to obtain a resistance. The obtained resistivity can be multiplied by the sample thickness and the correction coefficient RCF (Resistivity Correction Factor) to calculate the volume resistivity (volume resistivity).

The sintered body obtained by sintering under such conditions has a relative density of 90% or more and a volume resistivity of 0.10 to 1.40 mΩ. In the case where the target thickness is set to t, the difference between the volume resistivity of the thickness t and the volume resistivity at any position in the thickness direction may be within 20%. This is a major feature of the invention of this case.

That is, a sintered body composed of indium (In), tin (Sn), oxygen (O), and unavoidable impurities, and has a tin (Sn) content (atomic composition ratio: at.%) of 0.3 or more. 14.5at.% or less of the sintered body ITO sputtering target, the volume resistivity is 0.1mΩ. Cm~1.4mΩ. In the case of cm, when the target thickness is set to t, the difference between the volume resistivity of the thickness t and the volume resistivity at any position in the thickness direction may be within 20% or even within 15%.

This representative example is shown in Fig. 1. In FIG. 1, when the thickness of the target is t, the maximum difference in volume resistivity between the volume resistivity at a thickness t and the volume resistivity at a time t is 13%. Generally, in the case where the thickness of the sintered body before the target is polished is T, the difference between the bulk resistivity of T and the volume resistivity of T/2 is maximized, and thus the volume resistivity of the target T/2 is measured. The approximate characteristics of the bulk resistance inside the target (thickness direction) are known.

In the production of the sintered body ITO sputtering target of the present invention, the indium oxide powder and the tin oxide powder are adjusted so that the tin (Sn) content (atomic composition ratio: at.%) is 0.3 or more and 14.5 at.% or less, and the remainder is Indium oxide, the raw material powder is sintered at a sintering temperature of 1300 to 1600 ° C and a predetermined pressure. Then, the average cooling rate from the highest temperature at the time of sintering to 1000 ° C is set to 0.1 to 3.0 ° C / min, and the environment in the cooling at the time of cooling is set to the atmospheric environment (the oxygen partial pressure ratio is less than 30%).

Thereby, it can be achieved that the volume resistivity is 0.10~1.40mΩ. Cm, the target thickness When it is set to t, the difference between the bulk resistivity of the thickness t and the volume resistivity at any position in the thickness direction (the difference in the volume resistivity between the two sides) can be made within 20%, or even the target thickness is set to In the case of t, the difference between the bulk resistivity of the thickness t and the volume resistivity at any position in the thickness direction (the difference in bulk resistivity between the two sides) can be made within 15%.

The surface of the sintered body obtained in this manner was ground, and the side was cut into a size of 127 mm × 508 mm using a diamond cutter.

Next, the bottom plate made of oxygen-free copper was placed on a hot plate set at 200 ° C, and indium was used as a solder material to be applied so as to have a thickness of about 0.2 mm. The ITO sintered body was bonded to this substrate and left to cool to room temperature.

The target was mounted on a magnetron sputtering device (BSC-7011) manufactured by Synchron, and the input power was set to 2.3 W/cm ² in terms of DC power supply, the gas pressure was set to 0.6 Pa, and the sputtering gas was argon (Ar). Oxygen (O ₂ ), and the total gas flow rate was 300 sccm, and the oxygen concentration was 1%. In order to compare the film resistivity at the initial stage of life and the late life, film formation was carried out at a film formation temperature of 200 ° C and a film thickness of 150 nm.

By performing sputtering using the sintered body ITO target, an ITO sputtering film having a difference in film resistivity of 5% or less between the initial stage of the target life and the target lifetime can be obtained.

Hereinafter, the present invention will be described based on examples and comparative examples.

[Examples]

The embodiments shown below are for the purpose of making the understanding easier, and the present invention is not limited by the embodiments. That is, the present invention naturally includes modifications and other embodiments based on the technical idea of the present invention.

(Example 1)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at.%) of 3.7 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C is set to 0.5 ° C / min, the environment when cooling is set to oxygen The partial pressure ratio is less than 30%. As a result, the volume resistivity at the initial stage of the target life was 0.142 mΩ. Cm, the body resistivity at the end of the target life is 0.130mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 8%.

Again, as shown in Figure 1, the difference is as much as 12%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 1.3%, and the variation was small. The results are shown in Table 1.

(Example 2)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at.%) of 3.7 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 1.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life was 0.138 mΩ. Cm, the body resistivity at the end of the target life is 0.125mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 9%.

Also, as shown in Figure 1, the difference in the survey is a maximum of 13%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 0.6%, and the variation was small. The results are shown in Table 1 in the same manner.

(Example 3)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at.%) of 3.7 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 1.5 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life was 0.135 mΩ. Cm, the body resistivity at the end of the target life is 0.121mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 10%.

Again, as shown in Figure 1, the difference in the survey is a maximum of 15%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 2.5%, and the variation was small.

(Example 4)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at.%) of 3.7 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 2.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life was 0.134 mΩ. Cm, the body resistivity at the end of the target life is 0.119mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 11%.

Also, as shown in Figure 1, the difference in the survey is a maximum of 17%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 1.2%, and the variation was small. The results are shown in Table 1 in the same manner.

(Example 5)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at.%) of 3.7 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 2.5 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the volume resistivity at the initial stage of the target life was 0.132 mΩ. Cm, the body resistivity at the end of the target life is 0.118mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 11%.

Also, as shown in Figure 1, the difference in the survey is up to 14%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 2.4%, and the variation was small. The results are shown in Table 1 in the same manner.

(Example 6)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at.%) of 3.7 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 3.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the volume resistivity at the initial stage of the target life is 0.130 mΩ. Cm, the body resistivity at the end of the target life is 0.116mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 11%.

Also, as shown in Figure 1, the difference in the survey is a maximum of 13%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 3.5%, and the variation was small. The results are shown in Table 1 in the same manner.

(Comparative Example 1)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at.%) of 3.7 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 0.05 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the volume resistivity at the initial stage of the target life was 0.163 mΩ. Cm, the body resistivity at the end of the target life is 0.130mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 20%.

Also, as shown in Figure 1, the difference in the survey is at most 25%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 10.4%, which was large. The results are shown in Table 1 in the same manner.

(Comparative Example 2)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at.%) of 3.7 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 5.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life was 0.131 mΩ. Cm, the body resistivity at the end of the target life is 0.106 Ω. Cm, the difference between the body resistivity at the beginning and the end of the target life is 19%.

Also, as shown in Figure 1, the difference in the survey is up to 24%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 9.4%, and the variation was large. The results are shown in Table 1 in the same manner.

(Comparative Example 3)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at.%) of 3.7 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 1.0 ° C / min, and the environment at the time of cooling was set to have an oxygen partial pressure ratio of 30% or more. As a result, the volume resistivity at the initial stage of the target life is 0.160 mΩ. Cm, the body resistivity at the end of the target life is 0.130mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life It is 19%.

Also, as shown in Figure 1, the difference in the survey is at most 23%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 10.0%, and the variation was large. The results are shown in Table 1 in the same manner.

(Comparative Example 4)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at.%) of 3.7 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 3.0 ° C / min, and the environment at the time of cooling was set to have an oxygen partial pressure ratio of 30% or more. As a result, the bulk resistivity at the initial stage of the target life was 0.152 mΩ. Cm, the body resistivity at the end of the target life is 0.123mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 19%.

Also, as shown in Figure 1, the difference in the survey is up to 24%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 11.7%, and the variation was large. The results are shown in Table 1 in the same manner.

(Example 7)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 0.4 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 1.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life is 0.250 mΩ. Cm, the body resistivity at the end of the target life is 0.230mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 8%.

Also, as shown in Figure 1, the difference in the survey is 10%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 4.4%, and the variation was small. The results are shown in Table 1.

(Example 8)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 0.4 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 3.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life was 0.231 mΩ. Cm, the body resistivity at the end of the target life is 0.209mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 10%.

Again, as shown in Figure 1, the difference is as much as 12%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 1.6%, and the variation was small. The results are shown in Table 1.

(Example 9)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 1.1 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 1.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the volume resistivity at the initial stage of the target life was 0.121 mΩ. Cm, the body resistivity at the end of the target life is 0.109mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 10%.

Also, as shown in Figure 1, the difference between the surveys was 11%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 4.5%, and the variation was small. The results are shown in Table 1.

(Embodiment 10)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 1.1 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 3.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life was 0.113 mΩ. Cm, the body resistivity at the end of the target life is 0.101mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 11%.

Also, as shown in Figure 1, the difference in the survey is up to 14%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 2.2%, and the variation was small. The results are shown in Table 1 in the same manner.

(Example 11)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 1.8 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 1.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life is 0.119 mΩ. Cm, the body resistivity at the end of the target life is 0.109mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 8%.

Also, as shown in Figure 1, the difference in the survey is a maximum of 9%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 3.2%, and the variation was small. The results are shown in Table 1.

(Embodiment 12)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 1.8 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 3.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the volume resistivity at the initial stage of the target life was 0.110 mΩ. Cm, the body resistivity at the end of the target life is 0.100mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 9%.

Also, as shown in Figure 1, the difference between the surveys was 11%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 1.6%, and the variation was small. The results are shown in Table 1.

(Example 13)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 5.4 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 1.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life was 0.176 mΩ. Cm, the body resistivity at the end of the target life is 0.161mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 9%.

Also, as shown in Figure 1, the difference between the surveys was 11%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 2.4%, and the variation was small. The results are shown in Table 1.

(Example 14)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 5.4 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 3.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the volume resistivity at the initial stage of the target life was 0.167 mΩ. Cm, the body resistivity at the end of the target life is 0.155mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 7%.

Also, as shown in Figure 1, the difference in the survey is a maximum of 9%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 4.2%, and the variation was small. The results are shown in Table 1.

(Example 15)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 7.2 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 1.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life was 0.220 mΩ. Cm, the body resistivity at the end of the target life is 0.200mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 9%.

Again, as shown in Figure 1, the difference is as much as 12%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 3.5%, and the variation was small. The results are shown in Table 1 in the same manner.

(Embodiment 16)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 7.2 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 3.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life is 0.200 mΩ. Cm, the body resistivity at the end of the target life is 0.180mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 10%.

Also, as shown in Figure 1, the difference between the surveys was 11%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 2.1%, and the variation was small. The results are shown in Table 1.

(Example 17)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 12.8 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 1.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life is 1.302 mΩ. Cm, the body resistivity at the end of the target life is 1.172mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 10%.

Again, as shown in Figure 1, the difference is as much as 12%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 3.3%, and the variation was small. The results are shown in Table 1.

(Embodiment 18)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 12.8 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 3.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life was 1.251 mΩ. Cm, the body resistivity at the end of the target life is 1.151mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 8%.

Also, as shown in Figure 1, the difference in the survey is 10%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 2.1%, and the variation was small. The results are shown in Table 1 in the same manner.

(Comparative Example 5)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 0.4 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 0.05 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life was 0.277 mΩ. Cm, the body resistivity at the end of the target life is 0.228mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 18%.

Also, as shown in Figure 1, the results of the survey were as large as 22%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 9.9%, and the variation was large. The results are shown in Table 1.

(Comparative Example 6)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 0.4 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 5.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life is 0.228 mΩ. Cm, the body resistivity at the end of the target life is 0.187mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 18%.

Also, as shown in Figure 1, the difference in the survey is at most 23%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 10.3%, and the variation was large. The results are shown in Table 1.

(Comparative Example 7)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 1.1 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 0.05 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life was 0.131 mΩ. Cm, the body resistivity at the end of the target life is 0.105mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 20%.

Also, as shown in Figure 1, the difference in the survey is at most 25%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 10.8%, and the variation was large. The results are shown in Table 1.

(Comparative Example 8)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 1.1 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 5.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life was 0.105 mΩ. Cm, the body resistivity at the end of the target life is 0.085mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 19%.

Also, as shown in Figure 1, the difference in the survey was 21%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 11.1%, and the variation was also large. The results are shown in Table 1.

(Comparative Example 9)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 1.8 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 0.05 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life was 0.129 mΩ. Cm, the body resistivity at the end of the target life is 0.104mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 19%.

Also, as shown in Figure 1, the results of the survey were as large as 22%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 7.4%, and the variation was large. The results are shown in Table 1.

(Comparative Example 10)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 1.8 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 5.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the volume resistivity at the initial stage of the target life was 0.101 mΩ. Cm, the body resistivity at the end of the target life is 0.083mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 18%.

Also, as shown in Figure 1, the results of the survey were as large as 22%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 10.7%, and the variation was large. The results are shown in Table 1.

(Comparative Example 11)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 5.4 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 0.05 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life was 0.191 mΩ. Cm, the body resistivity at the end of the target life is 0.155mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 19%.

Also, as shown in Figure 1, the difference in the survey is up to 24%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 9.0%, and the variation was large. The results are shown in Table 1.

(Comparative Example 12)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 5.4 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 5.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the volume resistivity at the initial stage of the target life is 0.160 mΩ. Cm, the body resistivity at the end of the target life is 0.128mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 20%.

Also, as shown in Figure 1, the results of the survey were as large as 22%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 12.3%, and the variation was large. The results are shown in Table 1.

(Comparative Example 13)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 7.2 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 0.05 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life is 0.259 mΩ. Cm, the body resistivity at the end of the target life is 0.213mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 18%.

Also, as shown in Figure 1, the difference in the survey is at most 23%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 13.8%, and the variation was large. The results are shown in Table 1.

(Comparative Example 14)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 7.2 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 5.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life was 0.184 mΩ. Cm, the body resistivity at the end of the target life is 0.142mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 23%.

Also, as shown in Figure 1, the difference in the survey is a maximum of 26%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 7.9%, and the variation was large. The results are shown in Table 1.

(Comparative Example 15)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 12.8 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 0.05 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life was 1.355 mΩ. Cm, the body resistivity at the end of the target life is 1.070mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 21%.

Also, as shown in Figure 1, the difference in the survey is at most 25%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 10.3%, and the variation was large. The results are shown in Table 1.

(Comparative Example 16)

Sintering was carried out using the following sintering raw material: tin oxide powder having a tin (Sn) content (atomic composition ratio: at. %) of 12.8 at.% was used, and the remainder was adjusted to indium oxide. The average cooling rate from the maximum sintering temperature of 1560 ° C to 1000 ° C was set to 5.0 ° C / min, and the environment at the time of cooling was set to an oxygen partial pressure ratio of less than 30%. As a result, the bulk resistivity at the initial stage of the target life was 1.259 mΩ. Cm, the body resistivity at the end of the target life is 0.944mΩ. Cm, the difference between the body resistivity at the beginning and the end of the target life is 25%.

Also, as shown in Figure 1, the difference in the survey is up to 30%. As a result of film formation at the initial stage and the later stage of the target life, the difference in film resistivity was 9.5%, and the variation was large. The results are shown in Table 1.

[Industrial availability]

The present invention relates to an ITO sputtering target suitable for forming an ITO film, and more particularly to an ITO sputtering target having a small change in film characteristics from the initial stage to the end of sputtering of a target, and a method for producing the same. In other words, when the oxygen defect variation in the thickness direction of the ITO sputtering target is small and the thickness of the target is t, the volume resistivity at the thickness t of the target and any position in the thickness direction are made. The difference in volume resistivity is within 20%, and the film characteristics change with sputtering are small, thereby ensuring improvement in film formation quality and reliability. As a result, it has an excellent effect of improving the productivity or reliability of the ITO target. The ITO sputtering target of the present invention is particularly useful for forming an ITO film.

Claims (6)

An ITO sputtering target which is a sintered body composed of indium (In), tin (Sn), oxygen (O), and unavoidable impurities; characterized by: tin (Sn) content (atomic composition ratio: at.%) ) is 0.3 or more and 14.5 at.% or less, and the volume resistivity is 0.1 mΩ ‧ cm to 1.4 mΩ ‧ cm. When the target thickness is t, the bulk resistivity of the thickness t and any position in the thickness direction The difference in volume resistivity is below 20%. The ITO sputtering target according to claim 1, wherein when the target thickness is t, the difference between the volume resistivity of the thickness t and the volume resistivity at any position in the thickness direction is 15% or less. A method for producing a sintered body ITO sputtering target, which is the method for producing an ITO sputtering target according to claim 1 or 2, wherein the method is: sintering a raw material powder composed of indium oxide powder and tin oxide powder The sintering temperature is set to 1300 to 1600 ° C, and the average cooling rate from the highest temperature at the time of sintering to 1000 ° C is set to 0.1 to 3.0 ° C / min, and the environment in the cooling at the time of cooling is set to the atmospheric environment (oxygen partial pressure) Less than 30%). The method for producing a sintered body ITO sputtering target according to claim 3, wherein the volume resistivity is 0.10 to 1.40 mΩ·cm, and when the target thickness is t, the volume resistivity of the thickness t is The difference in volume resistivity at any location in the plate thickness direction is less than 20%. The method for producing a sintered body ITO sputtering target according to claim 3 or 4, wherein when the target thickness is t, the bulk resistivity of the thickness t and the bulk resistance at any position in the thickness direction are obtained. The rate is below 15%. An ITO sputtering film formed by using an ITO sputtering target of claim 1 or 2, and the ITO sputtering film has an initial target life (from the start of sputtering for 10 minutes) and a late target life The difference in resistivity of the film (at the end of sputtering) is 5% or less.