Sputtering target, transparent conductive film, and their manufacturing method

• US 20040180217A1
• Filed: 01/30/2004
• Published: 09/16/2004
• Est. Priority Date: 08/02/2001
• Status: Abandoned Application

• Current Assignee: Idemitsu Kosan Company Limited
• Original Assignee: Idemitsu Kosan Company Limited
• Inventors: Inoue, Kazuyoshi, Matsuzaki, Shigeo
• Application Number:
  US10/485,343
• Publication Number:
  US 20040180217A1
• Time in Patent Office: Days
• US Class Current: 428/432
• CPC Class Codes: C04B 2235/3229 Cerium oxides or oxide-forming salts thereof
• 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 2235/5436 micrometer sized, i.e. from 1 to 100 micron
• CPC Class Codes: C04B 2235/5445 submicron sized, i.e. from 0,1 to 1 micron
• CPC Class Codes: C04B 2235/6562 Heating rate
• CPC Class Codes: C04B 2235/6567 Treatment time
• CPC Class Codes: C04B 2235/6585 at an oxygen percentage above that of air
• CPC Class Codes: C04B 2235/767 Hexagonal symmetry, e.g. beta-Si3N4, beta-Sialon, alpha-SiC or hexa-ferrites
• CPC Class Codes: C04B 2235/77 Density
• CPC Class Codes: C04B 2235/786 Micrometer sized grains, i.e. from 1 to 100 micron
• CPC Class Codes: C04B 35/01 based on oxide ceramics
• 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 35/457 based on tin oxides or stannates
• CPC Class Codes: C04B 35/6262 of calcined, sintered clinker or ceramics
• CPC Class Codes: C04B 35/62685 characterised by the order of addition of constituents or additives
• CPC Class Codes: C04B 35/62695 Granulation or pelletising devices for shaping artificial aggregates from ceramic mixtures B28B1/004
• 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 31/1884 : Manufacture of transparent electrodes, e.g. TCO, ITO
• CPC Class Codes: Y02E 10/50 : Photovoltaic [PV] energy

Abstract

A sputtering target including indium oxide and tin oxide, the content by percentage of the tin atoms therein being from 3 to 20 atomic % of the total of the indium atoms and the tin atoms, and the maximum grain size of indium oxide crystal in the sputtering target being 5 μm or less. When a transparent conductive film is formed by sputtering, this sputtering target makes it possible to suppress the generation of nodules on the surface of the target and to conduct the sputtering stably.

Claims

1. A sputtering target, comprising indium oxide and tin oxide, the content by percentage of the tin atoms therein being from 3 to 20 atomic % of the total of the indium atoms and the tin atoms, and the maximum grain size of indium oxide crystal in the sputtering target being 5 μ

m or less.

2. The sputtering target according to claim 1, which further comprises an oxide of a metal the valence of which is trivalent or more as a third element, the content by percentage of the third element being from 0.1 to 10 atomic % of all metal atoms.

3. The sputtering target according to claim 2, wherein the oxide of the third element is one or more metal oxides selected from the group consisting of gallium oxide, germanium oxide, yttrium oxide, scandium oxide, lanthanum oxide, niobium oxide, cerium oxide, zirconium oxide, hafnium oxide and tantalum oxide.

4. A process for producing the sputtering target according to claim 1, comprising the steps of:

granulating, by casting or by means of a spray drier, fine particles obtained by drying fine particles yielded by wet-pulverizing a mixture of indium oxide and tin oxide, sintering the dried fine particles, adding indium oxide and tin oxide to the sintered pulverized product and wet-pulverizing the resultant;

press-molding the granulated particles;

sintering the molded particles; and

then

cutting the sintered molded product.

5. A process for producing the sputtering target according to claim 2, comprising the steps of:

granulating, by casting or by means of a spray drier, fine particles obtained by drying fine particles yielded by wet-pulverizing a mixture of indium oxide, tin oxide and an oxide of a metal the valence of which is trivalent or more, sintering the dried fine particles, adding indium oxide, tin oxide and an oxide of a metal the valence of which is trivalent or more to the sintered pulverized product, and then wet-pulverizing the resultant;

press-molding the granulated particles;

sintering the molded particles; and

then

cutting the sintered molded product.

6. A process for producing a transparent conductive film, wherein the sputtering target according to claim 1 is used to form the film by sputtering.

7. A sputtering target, comprising a sintered product of a metal oxide comprising 85 to 99% by mass of [A1] (a1) indium oxide, and 1 to 15% by mass of the total of [B] gallium oxide and [C] germanium oxide, wherein the sintered product comprises, as components of the indium oxide, indium oxide wherein gallium atoms are solid-dissolved by substitution and indium oxide wherein germanium atoms are solid-dissolved by substitution.

8. The sputtering target according to claim 7, wherein the maximum grain size of each of crystal of the indium oxide wherein the gallium atoms are solid-dissolved by substitution and crystal of the indium oxide wherein the germanium atoms are solid-dissolved by substitution is 5 μ

m or less.

14. A process for producing a transparent conductive film, wherein the sputtering target according to claim 7 is used to form the film by sputtering.

9. A sputtering target, comprising a sintered product of a metal oxide comprising 90 to 99% by mass of the total of [A2] (a2) indium oxide and (a3) tin oxide, and 1 to 10% by mass of the total of [B] gallium oxide and [C] germanium oxide, wherein the sintered product comprises, as components of the indium oxide, indium oxide wherein tin atoms are solid-dissolved by substitution, indium oxide wherein gallium atoms are solid-dissolved by substitution, and indium oxide wherein germanium atoms are solid-dissolved by substitution.

10. The sputtering target according to claim 9, wherein the maximum grain size of each of crystal of the indium oxide wherein the tin atoms are solid-dissolved by substitution, crystal of the indium oxide wherein the gallium atoms are solid-dissolved by substitution, and crystal of the indium oxide wherein the germanium atoms are solid-dissolved by substitution is 5 μ

m or less.

15. A process for producing a transparent conductive film, wherein the sputtering target according to claim 9 is used to form the film by sputtering.

11. A transparent conductive film, comprising a sintered product of a metal oxide comprising 85 to 99% by mass of [A1] (a1) indium oxide, and 1 to 15% by mass of the total of [B] gallium oxide and [C] germanium oxide, wherein the sintered product comprises, as components of the indium oxide, indium oxide wherein gallium atoms are solid-dissolved by substitution and indium oxide wherein germanium atoms are solid-dissolved by substitution.

12. A transparent conductive film, comprising a sintered product of a metal oxide comprising 90 to 99% by mass of the total of [A2] (a2) indium oxide and (a3) tin oxide, and 1 to 10% by mass of the total of [B] gallium oxide and [C] germanium oxide, wherein the sintered product comprises, as components of the indium oxide, indium oxide wherein tin atoms are solid-dissolved by substitution, indium oxide wherein gallium atoms are solid-dissolved by substitution, and indium oxide wherein germanium atoms are solid-dissolved by substitution.

13. The transparent conductive film according to claim 12, which is subjected to heat treatment at a temperature of 230°

C. or higher.

16. A sputtering target, comprising a sintered product of a metal oxide comprising indium oxide, gallium oxide and zinc oxide, the metal oxide comprising one or more hexagonal crystal lamellar compounds selected from In₂O₃(ZnO)_m [wherein m is an integer of 2 to 10], In₂Ga₂ZnO₇, InGaZnO₄, InGaZn₂O₅, InGaZn₃O₆, InGaZn₄O₇, InGaZn₅O₈, InGaZn₆O₉, and InGaZn₇O₁₀, and the sintered product having a composition of 90 to 99% by mass of the indium oxide and 1 to 10% by mass of the total of the gallium oxide and the zinc oxide.

17. The sputtering target according to claim 16, wherein the maximum grain size of crystal of the hexagonal crystal lamellar compound is 5 μ

m or less.

24. A process for producing a transparent conductive film, wherein the sputtering target according to claim 16 is used to form the film by sputtering.

18. A sputtering target, comprising a sintered product of a metal oxide comprising indium oxide, tin oxide, gallium oxide and zinc oxide, the metal oxide comprising one or more hexagonal crystal lamellar compounds selected from In₂O₃(ZnO)_m [wherein m is an integer of 2 to 10], In₂Ga₂ZnO₇, InGaZnO₄, InGaZn₂O₅, InGaZn₃O₆, InGaZn₄O₇, InGaZn₅O₈, InGaZn₆O₉, and InGaZn₇O₁₀, and the sintered product having a composition of 70 to 94% by mass of the indium oxide, 5 to 20% by mass of the tin oxide, and 1 to 10% by mass of the total of the gallium oxide and the zinc oxide.

19. The sputtering target according to claim 18, wherein the maximum grain size of crystal of the hexagonal crystal lamellar compound is 5 μ

m or less.

25. A process for producing a transparent conductive film, wherein the sputtering target according to claim 18 is used to form the film by sputtering.

20. A transparent conductive film, comprising a metal oxide comprising indium oxide, gallium oxide, and zinc oxide, the metal oxide having a composition of 90 to 99% by mass of the indium oxide, and 1 to 10% by mass of the total of the gallium oxide and the zinc oxide.

21. A transparent conductive film, comprising a metal oxide comprising indium oxide, tin oxide, gallium oxide, and zinc oxide, the metal oxide having a composition of 70 to 94% by mass of the indium oxide, 5 to 20% by mass of the tin oxide, and 1 to 10% by mass of the total of the gallium oxide and the zinc oxide.

22. The transparent conductive film according to claim 21, which is subjected to heat treatment at a temperature of 230°

C. or higher.

23. The transparent conductive film according to claim 21, which is patterned and subsequently subjected to heat temperature at a temperature of 230°

C. or higher.