Oxide sintered body and sputtering target, and manufacturing method for transparent conductive oxide film as electrode

1. An oxide sintered body comprising:

indium oxide, titanium, and tin as an impurity,

wherein the titanium is contained such that the atomic ratio of Ti/In is in a range from 0.003 to 0.019,

wherein tin as an impurity in an amount such that the atomic ratio of Sn/In is 0.0025 or less, and

wherein the specific resistance is 1 k Ohm cm or less.

2. The oxide sintered body of claim 1 , wherein the specific resistance is 1−10 2 Ohm cm or less.

3. The oxide sintered body of claim 1 , further comprising a main phase of one of a crystal phase of indium oxide having a bixbyite type structure with titanium contained in solid solution, and of a mixture of a crystal phase of indium oxide having a bixbyite type structure with titanium contained in solid solution and a crystal phase of an indium titanate compound.

4. The oxide sintered body of claim 1 , wherein a crystal phase of titanium oxide is not detected by powder X-ray diffraction measurement.

5. The oxide sintered body of claim 1 , wherein the relative density is 95% or greater.

6. The oxide sintered body of claim 1 , wherein a surface roughness Rmax of the surface on a side where sputtering is performed is 3.0 μm or less.

7. The oxide sintered body of claim 1 , further comprising a main phase of one of a crystal phase of indium oxide having a bixbyite type structure with titanium contained in solid solution, and of a mixture of a crystal phase of indium oxide having a bixbyite type structure with titanium contained in solid solution and a crystal phase of an indium titanate compound.

8. The oxide sintered body of claim 1 , further comprising a main phase of one of a crystal phase of indium oxide having a bixbyite type structure with titanium contained in solid solution, and of a mixture of a crystal phase of indium oxide having a bixbyite type structure with titanium contained in solid solution and a crystal phase of an indium titanate compound.

9. The oxide sintered body of claim 1 , wherein a crystal phase of titanium oxide is not detected by powder X-ray diffraction measurement.

10. The oxide sintered body of claim 1 , wherein a crystal phase of titanium oxide is not detected by powder X-ray diffraction measurement.

11. A method for providing an oxide sintered body, the oxide sintered body comprising indium oxide, tin as an impurity, and titanium, wherein the titanium is contained such that an atomic ratio of Ti/In is in a range of 0.003 to 0.019 and wherein a specific resistance is 1 k Ohm cm or less, tin as an impurity in an amount such that the atomic ratio of Sn/In is 0.0025 or less, the method comprising the steps of:

producing raw materials of indium oxide powder and titanium oxide powder having an average particle size of 1 μm or less;

mixing the raw materials in a wet mill;

forming the mixed raw materials with a cold isostatic press, and

sintering the formed and mixed raw materials under oxygen-control.

12. A sputtering target, comprising:

an oxide sintered body comprising indium oxide, tin as an impurity, and titanium, wherein the titanium is contained such that an atomic ratio of Ti/In is in a range of 0.003 to 0.019;

wherein tin as an impurity in an amount such that the atomic ratio of Sn/In is 0.0025 or less, and

wherein a specific resistance is 1 k Ohm cm or less and is applied to a metal plate for cooling.

13. A sputtering target according to claim 12 for use in manufacturing a transparent conductive film having a specific resistance 1×10 −3 Ohm cm or less.

14. A sputtering target according to claim 13 for use in manufacturing a transparent conductive film having an average transmittance of infrared rays in the wavelength range from 1000 nm to 1400 nm is at least 60% for the film itself.

15. A sputtering target according to claim 12 for use in manufacturing a low resistant, transparent conductive film having a specific resistance 5.5×10 31 4 Ohm cm or less.

16. A sputtering target according to claim 15 for use in manufacturing a transparent conductive film having an average transmittance of infrared rays in the wavelength range from 1000 nm to 1400 nm is at least 60% for the film itself.

17. A sputtering target according to claim 12 for use in manufacturing a transparent conductive film having an average transmittance of infrared rays in the wavelength range from 1000 nm to 1400 nm is at least 60% for the film itself.

18. A method of manufacturing an oxide transparent electrode film, the method comprising the steps of:

using a sputtering target, the sputtering target comprising an oxide sintered body comprising indium oxide, tin as an impurity, and titanium, wherein the titanium is contained such that an atomic ratio of Ti/In is in a range of 0.003 to 0.019;

wherein tin as an impurity in an amount such that the atomic ratio of Sn/In is 0.0025 or less, and

wherein a specific resistance is 1 k Ohm cm or less and using a DC sputtering method for forming the film.