ZINC OXIDE CERAMICS AND A MANUFACTURING METHOD FOR THE SAME, A SPUTTERING TARGET

• US 20090197757A1
• Filed: 08/06/2007
• Published: 08/06/2009
• Est. Priority Date: 08/11/2006
• Status: Abandoned Application

• Current Assignee: Hitachi Metals (Thailand) Ltd.
• Original Assignee: Hitachi Metals (Thailand) Ltd.
• Inventors: Fukushima, Hideko
• Application Number:
  US12/310,080
• Publication Number:
  US 20090197757A1
• Time in Patent Office: Days
• US Class Current: 501/127
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3222 Aluminates other than alumino-silicates, e.g. spinel (MgAl2O4)
• CPC Class Codes: C04B 2235/3232 Titanium oxides or titanates, e.g. rutile or anatase
• CPC Class Codes: C04B 2235/3234 Titanates, not containing zirconia
• CPC Class Codes: C04B 2235/3284 Zinc oxides, zincates, cadmium oxides, cadmiates, mercury oxides, mercurates or oxide forming salts thereof
• CPC Class Codes: C04B 2235/3286 Gallium oxides, gallates, indium oxides, indates, thallium oxides, thallates or oxide forming salts thereof, e.g. zinc gallate
• CPC Class Codes: C04B 2235/3287 Germanium oxides, germanates or oxide forming salts thereof, e.g. copper germanate
• CPC Class Codes: C04B 2235/3293 Tin oxides, stannates or oxide forming salts thereof, e.g. indium tin oxide [ITO]
• CPC Class Codes: C04B 2235/3418 Silicon oxide, silicic acids, or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint glass constituents C04B2235/36
• CPC Class Codes: C04B 2235/3427 Silicates other than clay, e.g. water glass
• CPC Class Codes: C04B 2235/5409 expressed by specific surface values
• CPC Class Codes: C04B 2235/656 characterised by specific heating conditions during heat treatment
• CPC Class Codes: C04B 2235/77 Density
• CPC Class Codes: C04B 2235/80 Phases present in the sintered or melt-cast ceramic products other than the main phase
• CPC Class Codes: C04B 35/453 based on zinc, tin, or bismuth oxides or solid solutions thereof with other oxides, e.g. zincates, stannates or bismuthates
• CPC Class Codes: C04B 35/62675 characterised by the treatment temperature
• CPC Class Codes: C04B 35/62685 characterised by the order of addition of constituents or additives
• CPC Class Codes: C23C 14/086 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• CPC Class Codes: H01L 31/022483 composed of zinc oxide [ZnO]

Abstract

Densified zinc oxide ceramics can be obtained so that transparent electrodes with good characteristics can be obtained using the ceramics as a sputtering target. This manufacturing method is used to manufacture the zinc oxide ceramics doped with Al in ZnO. This method comprises, calcination powder production process by which calcination powder is produced after blending Al2O3 powder and a 1st ZnO powder and by calcinating them, and sintering process by which said zinc oxide ceramics are manufactured after sintering formed body composed of powder before the sintering which is made by blending said calcination powder and a 2nd ZnO powder. Here, the ceramics are manufactured not by sintering a formed body composed of Al2O3 powder and ZnO powder, but by sintering the formed body composed of the calcination powder containing ZnAl2O4 phase and ZnO powder.

Claims

1. A manufacturing method for zinc oxide ceramics, in which said ceramics contain more than one of Al, Ga, In, Ti, Si, Ge and Sn as dopants in ZnO, comprising;

calcination powder production process by which calcination powder is produced after blending oxide powder made of oxide of said dopant and a 1st ZnO powder, and

calcinating them at temperature of 900˜

1300°

C.,

sintering process by which said zinc oxide ceramics are manufactured after sintering at temperature of 1100˜

1600°

C. formed body composed of powder before the sintering which is made by blending said calcination powder and a 2nd ZnO powder.

2. The manufacturing method for zinc oxide ceramics according to claim 1,

wherein, mixing molar ratio of said 1st ZnO powder to said oxide powder is 1 or more, and is 200 or less in said calcination powder production process.

3. The manufacturing method for zinc oxide ceramics according to claim 1,

wherein, BET specific surface area of said 1st ZnO powder is in a range of 2˜

30 m²/g.

4. The manufacturing method for zinc oxide ceramics according to claim 1,

wherein, BET specific surface area of said oxide powder is in a range of 2˜

100 m²/g.

5. The manufacturing method for zinc oxide ceramics according to claim 1,

wherein, said oxide powder is made of at least one selected among Al₂O₃, Ga₂O₃, In₂O₃, TiO₂, SiO₂, GeO₂, and SnO₂.

6. The manufacturing method for zinc oxide ceramics according to claim 1,

wherein, calcination in said calcination powder production process is carried in non-reducing atmosphere.

7. The manufacturing method for zinc oxide ceramics according to claim 1,

wherein, BET specific surface area of said powder before the sintering is in a range of 1˜

20 m²/g.

8. The manufacturing method for zinc oxide ceramics according to claim 1,

wherein, sintering in said sintering process is carried in non-reducing atmosphere.

9. The manufacturing method for zinc oxide ceramics according to claim 1,

wherein, said dopants comprise a 1st dopant which is one selected among Al, Ga, In, Ti, Si, Ge, and Sn, and a 2nd dopant which is one selected among Al, Ga, In, Ti, Si, Ge, and Sn except for said 1st dopant,

wherein, said oxide powder in said calcination powder production process comprises a 1st oxide powder made of oxide of said 1st dopant and a 2nd oxide powder made of oxide of said 2nd dopant.

10. The manufacturing method for zinc oxide ceramics according to claim 9,

wherein, a 1st calcinated body is produced after blending said 1st oxide powder and said 1st ZnO powder and calcinating them at temperature of 900˜

1300°

C., and a 2nd calcinated body is produced after blending said 2nd oxide powder and 3rd ZnO powder and calcinating them at temperature of 900˜

1300°

C., and said calcination powder is produced by mixing said 1st calcinated body and said 2nd calcinated body in said calcination powder production process.

11. The manufacturing method for zinc oxide ceramics according to claim 10,

wherein, mixing molar ratio of sum of said 1st ZnO powder and said 3rd ZnO powder to sum of said 1st oxide powder and said 2nd oxide powder is 1 or more, and 200 or less, in said calcination powder production process.

12. The manufacturing method for zinc oxide ceramics according to claim 10,

wherein, both mixing molar ratio of said 1st ZnO powder to said 1st oxide powder, and mixing molar ratio of said 3rd ZnO powder to said 2nd oxide powder, are 1 or more, and 200 or less, in said calcination powder production process.

13. The manufacturing method for zinc oxide ceramics according to claim 10,

wherein, BET specific surface area of said 3rd ZnO powder is in a range of 2˜

30 m²/g.

14. The manufacturing method for zinc oxide ceramics according to claim 10, further comprising;

a 1st mixing process, in which a 1st mixture solution is produced by mixing said calcination powder produced by said calcination powder production process with a solvent, a 2nd mixing process, in which a 2nd mixture solution is produced by mixing a 2nd ZnO powder with said 1st mixture solution,

wherein, a powder produced from said 2nd mixture solution is formed into a formed body, and said ceramics are manufactured by sintering said formed body.

15. The manufacturing method for zinc oxide ceramics according to claim 14,

wherein, said 2nd mixture solution is produced by mixing said 1st mixture solution with another solution in which said 2nd ZnO powder is mixed with a solvent.

18. A zinc oxide ceramics manufactured by the manufacturing method for zinc oxide ceramics according to claim 1.

25. The zinc oxide ceramics according to one of claims 18, 91, 21,

wherein, density of said ceramics is 5.5 g/cm³ or higher.

26. A sputtering target made of the zinc oxide ceramics according to one of claims 18, 19 or 21.

16. A manufacturing method for zinc oxide ceramics, in which said ceramics contain more than one of Al, Ga, In, Ti, Si, Ge and Sn as dopants in ZnO, comprising;

mixing a powder made of complex oxide composed mainly of both said dopant and Zn, with ZnO powder,

forming said mixed powder into a formed body,

manufacturing said ceramics by sintering said formed body at a temperature of 1100˜

1600°

C.

17. The manufacturing method for zinc oxide ceramics according to claim 16,

wherein, said complex oxide is made of at least one among ZnAl₂O₄, ZnGa₂O₄, ZnIn₂O₄, Zn₂TiO₄, Zn₂SiO₄, Zn₂GeO₄, and Zn₂SnO₄.

19. A zinc oxide ceramics containing more than one of Al, Ga, In, Ti, Si, Ge and Sn as dopants in ZnO,

wherein, both precipitates containing complex oxide of said dopant and Zn and voids around said precipitates, are formed inside,

wherein, ratio of said precipitates in which diameter of equivalent circle is 3 μ

m or larger to all of said precipitates is 20% or less, and ratio of said voids in which diameter of equivalent circle is 3 μ

m or larger to all of said voids, is 50% or less.

20. The zinc oxide ceramics according to claim 19,

wherein, composition ratio of said dopant in said ceramics is 0.5˜

10 wt %, expressed as oxides.

21. A zinc oxide ceramics containing one among Al, Ga, In, Ti, Si, Ge and Sn as a 1st dopant, and also containing one among Al, Ga, In, Ti, Si, Ge and Sn except for said 1st dopant as a 2nd dopant in ZnO,

wherein, a co-precipitation part in which a 1st precipitate containing complex oxide of said 1st dopant and Zn, and a 2nd precipitate containing complex oxide of said 2nd dopant and Zn, are co-existing, is formed in zinc oxide phase which is a main phase.

22. The zinc oxide ceramics according to claim 21,

wherein volume ratio of said co-precipitation parts whose diameter of equivalent circle is 10 μ

m or smaller is 90% or more.

23. The zinc oxide ceramics according to claim 21 or 22,

wherein, composition ratio of said 2nd dopant in said ceramics is 0.05˜

5 wt %, expressed as oxides.

24. The zinc oxide ceramics according to claim 21,

wherein, composition ratio of sum of said 1st dopant and said 2nd dopant in said ceramics is 0.5˜

10 wt %, expressed as oxides.