KR102322184B1 - Indium zinc oxide (izo) based sputtering target, and method for producing same - Google Patents

Abstract

A sputtering target made of In, Zn, O, wherein the atomic ratio of Zn and In satisfies 0.05 ≤ Zn/(In + Zn) ≤ 0.30, and the standard deviation of the bulk resistivity on the sputtering surface of the target is 1.0 mΩ·cm The following are the sputtering targets characterized by the above-mentioned. Provided is a method of manufacturing an indium oxide-zinc oxide-based oxide (IZO) sintered body target having little warpage of a sintered body and suppressing in-plane variation in bulk resistivity due to grinding for warpage reduction.

Description

Indium oxide-zinc oxide-based (IZO) sputtering target and manufacturing method thereof

The present invention relates to an indium oxide-zinc oxide (IZO) sputtering target and a method for manufacturing the same, and more particularly, to a sputtering target having a small difference in bulk resistivity within the sputtering surface of the target and suitable for forming a film, and a method for manufacturing the same will be.

Since the transparent conductive film made of some metal complex oxide has high conductivity and visible light transmittance, it is used for preventing condensation of liquid crystal display devices, thin film electroluminescence displays, organic EL devices, radiation detection devices, transparent tablets of terminal devices, and window glass. It is used for a wide range of applications, such as a heating film, an antistatic film, or a selective transmission film for a solar collector, and an electrode of a touch panel. Among the transparent conductive films made of such a metal complex oxide, the most prevalent is a transparent conductive film made of indium oxide-tin oxide called ITO.

On the other hand, the demand for the transparent conductive film which has as a main component the complex oxide of indium and zinc (referred to as "IZO") which has a larger etching rate than an ITO film|membrane is increasing. When manufacturing an IZO film, although a sintered compact sputtering target was used, this IZO sintered compact had the problem that curvature generate|occur|produced in a sintering process. In order to align the product shape, it is necessary to grind both surfaces of the warped target so that it becomes flat. There was a problem.

Next, the prior art related to sputtering of the IZO sintered body will be described. In patent document 1, after mixing indium oxide and zinc oxide, and shape|molding this by cold press and hydrostatic cold compression, heating and sintering in oxygen atmosphere or air|atmosphere at 1300-1500 degreeC is indicated. Further, Patent Document 2 discloses the only plasticizer (假燒) ZnO powder prior to mixing the powders of In ₂ O ₃ and ZnO.

Patent Document 3 describes that the indium oxide powder and the zinc oxide powder have specific properties. Moreover, in patent document 4, when sintering IZO, until it reaches 1200 degreeC, it shall be 21% capacity or more in oxygen concentration, and at 1200-1450 degreeC, it is described that sintering in the atmosphere of oxygen concentration less than 21% capacity|capacitance, have. Patent Document 5 describes controlling the crystal grain size of the target by finely pulverizing the raw material powder.

However, under these conventional manufacturing processes, curvature had generate|occur|produced in the produced sintered compact with thermal expansion and thermal contraction by the heating at the time of sintering. When processing a sintered compact with large curvature into a target shape, the difference in resistivity in the sputtering surface of a target may become large. Such variation in resistivity within the target plane causes arcing (abnormal discharge) or the like at the time of sputtering, resulting in a problem of lowering the production yield of the product. In particular, with the recent increase in the area of sputtering targets, the above problems became remarkable.

Japanese Patent Laid-Open No. 2001-131736 Japanese Patent Application Laid-Open No. 9-111444 Japanese Patent Laid-Open No. 2007-8780 Japanese Laid-Open Patent Publication No. 2007-8772 International Publication No. 2001/038599

The present invention has been made in order to solve the above problems, and it is an object to provide a sputtering target with a small difference in bulk resistivity within the sputtering surface, which can suppress the occurrence of arcing (abnormal discharge) during sputtering, and a method for manufacturing the same. . It makes it a subject to provide the sputtering target with a small in-plane difference of bulk resistivity especially even if it is a large area.

As a result of earnest research conducted to solve the above problems, the present inventors start or maintain the temperature in a state where the shrinkage of IZO is started, thereby reducing the temperature distribution in the sintered body, thereby significantly reducing the amount of warpage of the sintered body found out that there is As a result, the knowledge that a sputtering target with a small difference in in-plane bulk resistivity can be obtained was acquired even if it grinded so that the both surfaces might become flat in order to align to a target shape.

Based on such knowledge, this application provides the following invention.

1) A sputtering target made of In, Zn, O, the atomic ratio of Zn to In satisfies 0.05 ≤ Zn/(In + Zn) ≤ 0.30, and the standard deviation of the bulk resistivity on the sputtering surface of the target is 1.0 mΩ · A sputtering target characterized in that it is cm or less.

2) The sputtering target according to 1) above, wherein the bulk resistivity is 1.0 to 10 mΩ·cm.

3) Relative density is 98% or more, The sputtering target as described in said 1) or 2) characterized by the above-mentioned.

4) The sputtering surface area is 60000 mm2 - 400000 mm2, The sputtering target in any one of said 1) - 3) characterized by the above-mentioned.

5) A sintered body made of In, Zn, O, wherein the atomic ratio of Zn and In satisfies 0.05 ≤ Zn/(In + Zn) ≤ 0.30, and an IZO sintered body, characterized in that the warpage is within 2.0 mm.

6) A method for producing a sputtering target consisting of an IZO sintered body produced by sintering a molded body press-molded with a raw material powder. What consists of a step of holding for 10 hours, a step of raising the temperature from the holding temperature to the sintering temperature in the middle at a rate of 0.2 to 2.0 °C/min, a step of setting the sintering temperature to 1350 to 1500 °C, and a step of sintering for a sintering holding time of 1 to 100 hours The manufacturing method of the sputtering target characterized by the above-mentioned.

7) Sintering temperature shall be 1380-1420 degreeC, The manufacturing method of said sputtering target as described in 6) characterized by the above-mentioned.

8) The method for producing a sputtering target according to the above 6) or 7), wherein the sintering holding time is 5 to 30 hours.

9) It is made to temperature-fall at 1.0-5.0 degreeC/min, The manufacturing method of the sputtering target in any one of said 6)-8) characterized by the above-mentioned.

10) The manufacturing method of the sputtering target in any one of said 6) - 9) characterized by heating up at 0.5-1.5 degree-C/min from an intermediate holding temperature to a sintering temperature.

In the manufacturing method of an indium oxide-zinc oxide type oxide (IZO) sintered compact, this invention discovers that it is effective for the reduction of curvature to maintain at a specific temperature among manufacturing conditions different from the prior art, that is, sintering conditions, sputtering surface It is possible to produce a target with a small difference in the bulk resistivity in the interior, and as a result, there is little occurrence of arcing and the like, enabling good sputtering, and has an excellent effect that the properties of the formed film can be improved. This invention is effective especially in a large-area IZO sputtering target.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the measurement point of the bulk resistivity of the sputtering target (square shape) of this invention.
It is a figure which shows the measurement point of the bulk resistivity of the sputtering target (disk shape) of this invention.
3 : is a schematic diagram which shows the measurement of the curvature amount of the sputtering target of this invention.

The component composition of the sputtering target of the present invention is composed of indium (In), zinc (Zn) and oxygen (O), and the atomic ratio of Zn to In satisfies the condition of 0.05 ≤ Zn/(In + Zn) ≤ 0.30 will be. Although the target of this invention is mainly comprised from the complex oxide of indium and zinc, it may contain the independent oxide of indium oxide or zinc oxide. Moreover, you may contain other elements in the range which does not impair the characteristic of this invention. The atomic ratio of Zn is determined from the viewpoint of conductivity of a film formed by using a target, and if this range is exceeded, desired properties cannot be obtained.

The present invention is characterized in that the standard deviation of the bulk resistivity on the sputtering surface of the sputtering target is 1.0 mΩ·cm or less. When the curvature of the sintered body was large, the dispersion of the bulk resistivity of the sputtering surface of the target was large, so there was a problem of impairing the uniformity of the formed film properties (especially the film resistance). In the present invention, the warpage of the sintered body is remarkably reduced by adjusting the sintering conditions, thereby making it possible to reduce the standard deviation of the bulk resistivity in the sputtering plane to 1.0 mΩ·cm or less. In addition, as a result of grinding a sintered compact and processing a sputtering target with a sputtering surface, the surface sputtered by a sputtering apparatus is meant.

It is preferable that the bulk resistivity of this invention is 1.0 mΩ·cm or more and 10 mΩ·cm or less. When bulk resistivity is high, sputter discharge may be made unstable. For the bulk resistivity of the present invention, 16 points or more (in the case of a rectangular target) or 9 or more points (in the case of a disk-shaped target) are measured at equal intervals on the sputtering surface of the target by a four-probe method, and the average value and standard deviation thereof are measured Calculate. For example, as shown in Figs. 1 and 2, the portion 20 mm or more inside the target end is measured three times at equal intervals of 50 mm to 60 mm, and the average of the portion is measured. Bulk resistivity. However, when the area of the target is small, 9 or more points or 16 or more points are ensured by narrowing a measurement interval. In addition, when measuring the bulk resistivity of a target, you may grind as needed.

In general, the larger the area of the sintered body, the larger the amount of warpage. The present invention is characterized in that the amount of warpage can be suppressed to within 2.0 mm even in a sintered compact with a large area. Especially, this invention is excellent at the point which can make the resistivity difference in a sputter|spatter surface fall within the said range even if the area in the sputtering surface of a target is a large area with 60000 mm<2> - 400000 mm<2>. Here, a laser displacement sensor is used for the measurement of warpage, and the laser is used as a probe to match the size of the sintered body, and as shown in FIG. 2 , the height is measured while scanning one side of the sintered body with a laser. . And let the difference between the maximum height and minimum height in a plane be the maximum deflection amount.

Moreover, the sputtering target of this invention is high density with a relative density of 98 % or more, It is characterized by the above-mentioned. A high-density target can reduce the particle|grains etc. at the time of sputtering, and it becomes possible to form the film|membrane provided with favorable characteristics. The relative density is expressed by (actual density of the sintered body measured by Archimedes method)/(theoretical density calculated from the oxide composition) x 100 = relative density (%). Here, the theoretical density calculated from the composition of the oxide is a theoretical density calculated from the elements constituting the raw material, for example, indium oxide (In ₂ O ₃ ) powder, zinc oxide (ZnO) powder, and oxidation When the weight ratio of indium:zinc oxide is 90 wt%:10 wt%, the theoretical density calculated from the oxide composition = (theoretical density of indium oxide x 90 + theoretical density of zinc oxide x 10)/100 (g/cm 3 ) ) to calculate

The indium oxide-zinc oxide (IZO) sintered compact target of this invention can be produced through each process of mixing of raw materials, grinding|pulverization, shaping|molding, and sintering as follows.

(Conditions of mixing, grinding, granulation, and molding of raw materials)

As the raw material powder, indium oxide (In ₂ O ₃ ) powder and zinc oxide (ZnO) powder are prepared. It is preferable to use the raw material powder having a specific surface area of about 5 m 2 /g.

Specifically, the indium oxide powder has a bulk density: 0.5 to 0.7 g/cm 3 , a median diameter (D ₅₀ ): 1.0 to 2.1 μm, a specific surface area: 4.0 to 5.7 m 2 /g, and a zinc oxide powder: bulk density: 0.2 to 0.6 g/cm 3 , median diameter (D ₅₀ ): 1.0 to 2.5 µm, and specific surface area: 3.0 to 6.0 m 2 /g are used.

Next, after weighing each raw material powder so that it may become a desired composition ratio, mixing and grinding are performed. Although there are various methods depending on the particle size to be calculated|required and the material to be grind|pulverized as a grinding|pulverization method, wet medium stirring mills, such as a bead mill, are suitable. In this case, the powder in which the powder is dispersed in water is forcibly stirred together with a grinding medium such as zirconia or alumina, which is a material having high hardness, to obtain a pulverized powder with high efficiency. However, since the grinding medium is also worn at this time, the grinding medium itself is mixed into the grinding powder as an impurity, so that the treatment for a long time is not preferable.

If the grinding amount is defined as the difference between the specific surface areas before and after grinding, in the wet medium stirring mill, the grinding amount is almost proportional to the energy input to the powder. Therefore, when performing grinding, it is important for the wet medium stirring mill to manage the integrated power. The difference (ΔBET) of the specific surface area before and after grinding is 0.5 to 3.0 m 2 /g, and the median diameter (D ₅₀ ) after grinding is set to 1.0 µm or less.

Next, the finely pulverized slurry is granulated. This is for improving the fluidity of the powder by granulation, thereby uniformly filling the mold with the powder during press molding in the next step to obtain a homogeneous molded body. Although there are various methods for granulation, there is a method of using a spray drying apparatus (spray dryer) as one of the methods of obtaining granulated powder suitable for press molding. This is a method of making a powder into a slurry, dispersing it as droplets in hot air, and drying it instantaneously, whereby a spherical granulated powder having a size of 10 to 500 µm can be continuously obtained.

In the drying furnace with a spray dryer, it is important to control the inlet temperature and outlet temperature of a hot air. When the temperature difference between the inlet and outlet is large, the drying amount per unit time increases and productivity is improved. However, when the inlet temperature is too high, the powder and the added binder are deteriorated by heat, and desired properties may not be obtained. Moreover, when the outlet temperature is too low, the granulated powder may not be sufficiently dried.

In addition, by adding a binder such as polyvinyl alcohol (PVA) to the slurry and containing it in the granulated powder, the strength of the molded body can be improved. As for the addition amount of PVA, 50-250 cc/kg of PVA 6 wt% containing aqueous solution is added with respect to raw material powder. In addition, by adding a plasticizer suitable for the binder, the crush strength of the granulated powder at the time of press molding can be adjusted. Moreover, there is also a method of improving the strength of the compact by adding a small amount of water to the obtained granulated powder to wet it.

Next, press molding is performed. The granulated powder is filled in a mold, and a pressure of 400 to 1000 kgf/cm 2 is maintained for 1 to 3 minutes for molding. If the pressure is less than 400 kgf/cm2, a molded body of sufficient strength and density cannot be obtained, and at a pressure of 1000 kgf/cm2 or more, when the molded body is taken out from the mold, the molded body itself is deformed due to release from the pressure. Therefore, it is not preferable in terms of production.

(sintering process)

Using an electric furnace, a compact is sintered in oxygen atmosphere, and a sintered compact is obtained. It heats up to sintering temperature 1350-1500 degreeC. In the middle of temperature increase, in order to make small the temperature distribution in a sintered compact, a holding process is introduce|transduced. In order to make small the temperature distribution in a sintered compact in the temperature range before reaction begins, what is necessary is just to introduce|transduce holding temperature at the temperature of 600-800 degreeC. When the temperature is lower than 600° C., the effect is not exhibited because the temperature is too low. When the temperature is higher than 800° C., since the reaction has already progressed to some extent, the effect of reducing the warpage is not obtained. The holding time on the way is 1 to 10 hours, preferably 4 to 6 hours. Since advancing of reaction cannot fully be suppressed when holding time is too short, on the other hand, when holding time is too long, productivity will fall, it is unpreferable.

And it is made to heat up at 0.2-2.0 degreeC/min from the holding temperature on the way to the sintering temperature. If the temperature increase rate from the holding temperature to the sintering temperature is less than 0.2 °C/min, it takes time unnecessarily to reach the predetermined temperature, and the density does not increase in some cases, and the temperature increase rate is greater than 2.0 °C/min. , the temperature distribution in the sintered compact does not become small, and non-uniformity occurs or the sintered compact is cracked. Preferably, it is 0.5-1.5 degreeC/min.

Sintering temperature shall be 1350-1500 degreeC, hold|maintain for about 1-100 hours, and is made to temperature-fall at a furnace cooling or temperature-fall rate 1.0-5.0 degree-C/min after that. If the sintering temperature is lower than 1350° C., a high-density sintered body cannot be obtained. In addition, at a sintering temperature of 1500°C or higher, since zinc oxide volatilizes, a decrease in the sintered density or a compositional variation occurs, and there is also a cost problem that the furnace heater life is reduced. Therefore, the upper limit is preferably set to 1500°C. do. Preferably, it is 1380-1420 degreeC. Moreover, when the holding time in sintering temperature is shorter than 1 hour, sintering will not fully advance and the density of a sintered compact will not become high enough, or a sintered compact will warp. Even if the holding time exceeds 100 hours, inefficiency that requires unnecessary energy and time occurs, which is undesirable in terms of production. Preferably it is 5 to 30 hours.

Example

Next, an embodiment of the present invention will be described. In Examples and Comparative Examples, the process of producing a compact obtained by press-molding the raw material powder of an indium oxide-zinc oxide-based oxide (IZO) sintered compact is carried out under the conditions described in the identification number to [0040], Furthermore, the sintering process was carried out by appropriately setting within the range of conditions described in the identification number [0041] to the identification number [0044]. The composition of each sintered body is as shown in Table 1.

In the arcing test in Examples, etc., using a magnetron sputtering device manufactured by Syncron (model number: BSC7011), DC power density: 2.3 W/cm 2 , gas pressure: 0.6 Pa, and gas flow rate 300 sccm in an argon atmosphere, Sputtering was performed continuously for 35 hours, and the generation|occurrence|production state of arcing was investigated. Arcing was detected using a micro arc monitor (MAM genesis) manufactured by Landmark Technology, and the number of arcing (micro arc) occurrences (times) was measured. Arcing judgment criterion is to count arcs with a detection voltage of 100 V or more and a discharge energy (sputter voltage when arc discharge is occurring × sputter current × generation time) of 20 mJ or less, and if it is 10 times or less, ○, if it exceeds it was denoted by ×.

(Example 1)

In Example 1, the maximum sintering temperature was 1400°C, the sintering holding time was 10 hours, and the intermediate holding temperature was 800°C. As a result, the density of the sintered compact was 98.41 %, and the maximum warpage value was 1.39 mm. Moreover, in order to align the sintered compact with a target shape, as a result of grinding the both surfaces so that it might become flat, the bulk resistivity of the target was 2.43 mΩ·cm, and its standard deviation was 0.78 mΩ·cm. In Example 1, there was little warpage of a sintered compact in this way, and the favorable result that the dispersion|variation in the bulk resistivity of a target was small was obtained. Moreover, as a result of sputtering the target produced in this way, generation|occurrence|production of arcing was hardly seen. The above results are shown in Table 1.

(Examples 2 to 15)

In Examples 2 to 15, each condition of the composition of the sintered compact, the maximum sintering temperature, the sintering holding time, the intermediate holding temperature, the intermediate holding time, the temperature increase rate from the intermediate holding temperature to the sintering holding temperature, and the area of the sintered body was changed. As a result, as shown in Table 1, the density of any sintered compact was 98 % or more, and the maximum deflection value was less than 2.0 mm. Moreover, in order to align the sintered compact with a target shape, as a result of grinding the both surfaces so that it might become flat, the bulk resistivity of a certain target was 1.0-10.0 mΩ·cm, and the standard deviation was within 1.0 mΩ·cm. In Examples 2-15, there was little curvature of a sintered compact in this way, and the favorable result that the dispersion|variation in the bulk resistivity of a target was small was acquired. Moreover, as a result of sputtering these targets, generation|occurrence|production of arcing was hardly seen.

(Comparative Example 1)

In Comparative Example 1, the maximum sintering temperature was 1400°C, and the sintering holding time was 10 hours, and holding in the middle was not performed. As a result, the maximum warpage value of the sintered compact was 2.30 mm. Moreover, in order to align the sintered compact with a target shape, as a result of grinding the both surfaces so that it might become flat, the standard deviation of the bulk resistivity of a target was 1.40 mΩ·cm. In Comparative Example 1, the result that the amount of curvature of the sintered compact was large and the dispersion|variation in the bulk resistivity of a target was large in this way was obtained. Moreover, as a result of sputtering the target produced in this way, there were many generation|occurrence|production of arcing.

(Comparative Example 2)

In Comparative Example 2, the maximum sintering temperature was 1400°C and the sintering holding time was 10 hours, and the intermediate holding temperature was made as low as 500°C. As a result, the maximum warpage value of the sintered compact was 2.06 mm. Moreover, in order to align the sintered compact with a target shape, as a result of grinding the both surfaces so that it might become flat, the standard deviation of the bulk resistivity of a target was 1.18 mΩ·cm. In the comparative example 2, the amount of curvature of a sintered compact was large in this way, and the result that the dispersion|variation in the bulk resistivity of a target was large was obtained. Moreover, as a result of sputtering the target produced in this way, there were many generation|occurrence|production of arcing.

(Comparative Example 3)

In Comparative Example 3, the maximum sintering temperature was 1400°C, the sintering holding time was 10 hours, and the intermediate holding temperature was made high at 900°C. As a result, the maximum warpage value of the sintered compact was 2.14 mm. Moreover, in order to align the sintered compact with a target shape, as a result of grinding the both surfaces so that it might become flat, the standard deviation of the bulk resistivity of a target was 1.24 mΩ·cm. In the comparative example 3, the amount of curvature of a sintered compact was large in this way, and the result that the dispersion|variation in the bulk resistivity of a target was large was obtained. Moreover, as a result of sputtering the target produced in this way, there were many generation|occurrence|production of arcing.

(Comparative Example 4)

In Comparative Example 4, the maximum sintering temperature was 1400°C and the sintering holding time was 10 hours, and the intermediate holding temperature was made high to 1100°C. As a result, the maximum warpage value of the sintered compact was 2.11 mm. Moreover, in order to align a sintered compact with a target shape, as a result of grinding the both surfaces so that it might become flat, the standard deviation of the bulk resistivity of a target was 1.11 mΩ·cm. In the comparative example 4, the amount of curvature of a sintered compact was large in this way, and the result that the dispersion|variation in the bulk resistivity of a target was large was obtained. Moreover, as a result of sputtering the target produced in this way, there were many generation|occurrence|production of arcing.

(Comparative Example 5)

In Comparative Example 5, the maximum sintering temperature was 1400°C, the sintering holding time was 10 hours, the intermediate holding temperature was 800°C, and the temperature increase rate from the intermediate holding temperature to the highest sintering temperature was increased to 5°C/min. As a result, the maximum warpage value of the sintered compact was 2.23 mm. Moreover, in order to align a sintered compact with a target shape, as a result of grinding the both surfaces so that it might become flat, the standard deviation of the bulk resistivity of a target was 1.26 mΩ·cm. In Comparative Example 5, the result that the amount of curvature of the sintered compact was large and the dispersion|variation in the bulk resistivity of a target was large in this way was obtained. Moreover, as a result of sputtering the target produced in this way, there were many generation|occurrence|production of arcing.

(Comparative Example 6)

In Comparative Example 6, the highest sintering temperature was 1400°C, the sintering holding time was 10 hours, the intermediate holding temperature was 800°C, and the intermediate holding time was shortened to 1 hour. As a result, the maximum warpage value of the sintered compact was 2.31 mm. Moreover, in order to align the sintered compact with a target shape, as a result of grinding the both surfaces so that it might become flat, the standard deviation of the bulk resistivity of the target was 1.31 mΩ·cm. In the comparative example 6, the amount of curvature of a sintered compact was large in this way, and the result that the dispersion|variation in the bulk resistivity of a target was large was obtained. Moreover, as a result of sputtering the target produced in this way, there were many generation|occurrence|production of arcing.

(Comparative Example 7)

In Comparative Example 7, the intermediate holding temperature was set to 800°C, and the highest sintering temperature was made high to 1600°C. As a result, the maximum deflection amount of the sintered compact was 2.33 mm, and the relative density was 97.5%. Moreover, in order to align the sintered compact with a target shape, as a result of grinding the both surfaces so that it might become flat, the standard deviation of the bulk resistivity of the target was 1.42 mΩ·cm. In the comparative example 7, the amount of curvature of a sintered compact was large in this way, and the result that the dispersion|variation in the bulk resistivity of a target was large was obtained. Moreover, as a result of sputtering the target produced in this way, there were many generation|occurrence|production of arcing.

(Comparative Example 8)

In Comparative Example 8, the intermediate holding temperature was set to 800°C, and the highest sintering temperature was made high to 1500°C. As a result, the maximum deflection amount of the sintered compact was 2.37 mm. Moreover, in order to align the sintered compact with a target shape, as a result of grinding the both surfaces so that it might become flat, the standard deviation of the bulk resistivity of a target was 1.53 mohm*cm. In Comparative Example 8, the result that the amount of curvature of the sintered compact was large and the dispersion|variation in the bulk resistivity of a target was large in this way was obtained. Moreover, as a result of sputtering the target produced in this way, there were many generation|occurrence|production of arcing.

As described above, the present invention has an excellent effect that a sintered compact having a small warpage can be produced in a good yield according to sintering conditions different from those of the prior art, and thus productivity can be remarkably improved. In addition, the present invention has an excellent effect that, by reducing the curvature of the sintered body, the variation in the bulk resistivity of the sputtered surface of the target after processing the sintered body can be small, and a film with uniform properties can be formed. The sputtering target of this invention is useful for formation of the transparent conductive film used for a liquid crystal display device, a thin film electroluminescence display device, organic electroluminescent etc..

Claims (3)

As a sputtering target for forming a transparent conductive film made of In, Zn, O,
When the atomic ratio Zn/(In + Zn) of Zn and In is more than 0.08 and not more than 0.3, and the area of the sputtering surface of the target is 60000 mm2 or more and 400000 mm2 or less, the bulk resistivity is 1.0 mΩ·cm or more and 10 mΩ·cm or less, , the standard deviation of the bulk resistivity in the sputtering surface is 1.0 mΩ·cm or less, and the relative density is 98% or more. delete delete

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