Thin film transistor, thin film transistor substrate, processes for producing the same, liquid crystal display using the same, and related devices and processes; and sputtering target, transparent electroconductive film formed by use of this,transparent electrode, and related devices and processes

• US 20070170434A1
• Filed: 03/02/2005
• Published: 07/26/2007
• Est. Priority Date: 03/09/2004
• Status: Active Grant

• Current Assignee: Idemitsu Kosan Company Limited
• Original Assignee: Idemitsu Kosan Company Limited
• Inventors: Inoue, Kazuyoshi, Tomai, Shigekazu, Matsubara, Masato
• Granted Patent: US 8,038,857 B2
• Time in Patent Office: Days
• US Class Current: 257/72
• CPC Class Codes: C04B 2235/3224 Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
• CPC Class Codes: C04B 2235/3227 Lanthanum oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3229 Cerium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3251 Niobium oxides, niobates, tantalum oxides, tantalates, or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3256 Molybdenum oxides, molybdates or oxide forming salts thereof, e.g. cadmium molybdate
• CPC Class Codes: C04B 2235/3258 Tungsten oxides, tungstates, or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3279 Nickel oxides, nickalates, 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 2235/3289 Noble metal oxides
• 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 2235/77 Density
• CPC Class Codes: C04B 35/01 based on oxide ceramics
• CPC Class Codes: C23C 14/08 Oxides C23C14/10 takes precedence
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: H01L 23/53219 : Aluminium alloys
• CPC Class Codes: H01L 23/53247 : Noble-metal alloys
• CPC Class Codes: H01L 27/12 : the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 27/124 : with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 29/458 : for thin film silicon, e.g. source or drain electrode
• CPC Class Codes: H01L 29/4908 : for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/66765 : Lateral single gate single channel transistors with inverted structure, i.e. the channel layer is formed after the gate
• CPC Class Codes: H01L 29/78696 : characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

Provided are a thin film transistor substrate having a transparent electroconductive film in which residues and so on resulting etching are hardly generated; a process for producing the same; and a liquid crystal display using this thin film transistor substrate. A thin film transistor substrate, comprising a transparent substrate, a source electrode formed over the transparent substrate, a drain electrode formed over the transparent substrate, and a transparent pixel electrode formed over the transparent substrate, wherein the transparent pixel electrode is a transparent electroconductive film which is made mainly of indium oxide, and further comprises one or two or more oxides selected from tungsten oxide, molybdenum oxide, nickel oxide and niobium oxide, and the transparent pixel electrode is electrically connected to the source electrode or the drain electrode; a process for producing the same; and a liquid crystal display using this thin film transistor substrate.

Claims

1. A thin film transistor substrate, comprising:

a transparent substrate,

a source electrode formed over the transparent substrate,

a drain electrode formed over the transparent substrate, and

a transparent pixel electrode formed over the transparent substrate, wherein the transparent pixel electrode is a transparent electroconductive film which is made mainly of indium oxide, and further comprises one or two or more oxides selected from tungsten oxide, molybdenum oxide, nickel oxide and niobium oxide, and the transparent pixel electrode is electrically connected to the source electrode or the drain electrode.

3. A process for producing the thin film transistor substrate according to claim 1, comprising:

the step of depositing the transparent electroconductive film over the transparent substrate, and

the step of using an acidic etchant to etch the deposited transparent electroconductive film, thereby forming the transparent pixel electrode.

4. The thin film transistor substrate producing process according to claim 3, wherein the acidic etchant comprises any one or any two or more of oxalic acid, a mixed acid comprising phosphoric acid, acetic acid and nitric acid, or cerium (IV) ammonium nitrate.

2. A thin film transistor liquid crystal display, comprising:

a thin film transistor substrate comprising a transparent substrate, a source electrode formed over the transparent substrate, a drain electrode formed over the transparent substrate, and a transparent pixel electrode formed over the transparent substrate,

a color filter substrate wherein a colored pattern in plural colors is formed, and

a liquid crystal layer sandwiched between the thin film transistor substrate and the color filter substrate, wherein the transparent pixel electrode is a transparent electroconductive film which is made mainly of indium oxide, and further comprises one or two or more oxides selected from tungsten oxide, molybdenum oxide, nickel oxide and niobium oxide, and the transparent pixel electrode is electrically connected to the source electrode or the drain electrode.

5. A sputtering target, which is made mainly of indium oxide, and comprises:

one or two or more metal(s) selected from the first metal group M1 consisted of W, Mo, Nb, Ni, Pt and Pd, or an oxide or oxides of the metal(s), and

an oxide or oxides of one or two or more metal(s) selected from the second metal group M2 consisted of lanthanoid-based metals.

6. The sputtering target according to claim 5, wherein the value of [M1]/([M1]+[In]), which is the composition of one or two or more metal(s) selected from the first metal group M1 consisted of W, Mo, Nb, Ni, Pt and Pd, or the metal oxide(s) to indium oxide, is from 0.005 to 0.2, and

the value of [M2]/([M2]+[In]), which is the composition of the oxide(s) of one or two or more metal(s) selected from the second metal group M2 of lanthanoid-based metals to indium oxide, is from 0.005 to 0.2, wherein the [M1] represents the number of the atoms of one or two or more metal(s) selected from the first metal group, the [M2] represents the number of the atoms of one or two or more metal(s) selected from the second metal group, and the [In] represents the number of the atoms of metallic indium.

7. The sputtering target according to claim 5, wherein the oxide(s) of one or more metal(s) selected from the second metal group M2 of lanthanoid-based metals is/are an oxide or oxides of one or more metals selected from La, Ce, Ho, and Er.

8. A sputtering target, which is made of indium oxide, and comprises:

one or two or more metal(s) selected from the first metal group M1 consisted of W, Mo, Nb, Ni, Pt and Pd, or an oxide or oxides of the metal(s),

an oxide or oxides of one or two or more metal(s) selected from the second metal group M2 consisted of lanthanoid-based metals, and

an oxide or oxides of one or two or more metal(s) selected from the third metal group M3 consisted of Zn, Sn, Zr, Ga and Ge.

9. The sputtering target according to claim 8, wherein the value of [M1]/([M1]+[In]), which is the composition of one or two or more metal(s) selected from the first metal group M1 consisted of W, Mo, Nb, Ni, Pt and Pd, or the metal oxide(s) to indium oxide, is from 0.005 to 0.2,

the value of [M2]/([M2]+[In]), which is the composition of the oxide(s) of one or two or more metal(s) selected from the second metal group M2 consisted of lanthanoid-based metals to indium oxide, is from 0.005 to 2, and

the value of [M3]/([M3]+[In]), which is the composition of the oxide(s) of the metal(s) selected from the third metal group M3 consisted of Zn, Sn, Zr, Ga and Ge to indium oxide, is from 0.005 to 2, wherein the [M1] represents the number of the atoms of one or two or more metal(s) selected from the first metal group, the [M2] represents the number of the atoms of one or two or more metal(s) selected from the second metal group, the [M3] represents the number of the atoms of the metal(s) selected from the third metal group, and the [In] represents the number of the atoms of metallic indium.

10. The sputtering target according to claim 8, wherein the oxide(s) of one or more metal(s) selected from the second metal group M2 consisted of lanthanoid-based metals is/are an oxide or oxides of one or more metals of La, Ce, Ho and Er.

11. A transparent electroconductive film, which is made mainly of indium oxide, and comprises:

one or two or more metal(s) selected from the first metal group M1 consisted of W, Mo, Nb, Ni, Pt and Pd, or an oxide or oxides of the metal(s), and

an oxide or oxides of one or two or more metal(s) selected from the second metal group M2 consisted of lanthanoid-based metals.

12. The transparent electroconductive film according to claim 11, wherein the value of [M1]/([M1]+[In]), which is the composition of one or two or more metal(s) selected from the first metal group M1 consisted of W, Mo, Nb, Ni, Pt and Pd, or the metal oxide(s) to indium oxide, is from 0.005 to 0.2, and

the value of [M2]/([M2]+[In]), which is the composition of the oxide(s) of one or two or more metal(s) selected from the second metal group M2 of lanthanoid-based metals to indium oxide, is from 0.005 to 0.2, wherein the [M1] represents the number of the atoms of one or two or more metal(s) selected from the first metal group, the [M2] represents the number of the atoms of one or two or more metal(s) selected from the second metal group, and the [In] represents the number of the atoms of indium.

13. The transparent electroconductive film according to claim 11, wherein the oxide(s) of one or more metal(s) selected from the second metal group M2 consisted of lanthanoid-based metals is/are an oxide or oxides of one or more metals of La, Ce, Ho and Er.

14. A transparent electroconductive film, which is made mainly of indium oxide, and comprises:

one or two or more metal(s) selected from the first metal group M1 consisted of W, Mo, Nb, Ni, Pt and Pd, or an oxide or oxides of the metal(s),

an oxide or oxides of one or two or more metal(s) selected from the second metal group M2 consisted of lanthanoid-based metals, and

an oxide or oxides of one or two or more metal(s) selected from the third metal group M3 consisted of Zn, Sn, Zr, Ga and Ge.

15. The transparent electroconductive film according to claim 14, wherein the value of [M1]/([M1]+[In]), which is the composition of one or two or more metal(s) selected from the first metal group M1 consisted of W, Mo, Nb, Ni, Pt and Pd, or the metal oxide(s) to indium oxide, is from 0.005 to 0.2,

the value of [M2]/([M2]+[In]), which is the composition of the oxide(s) of one or two or more metal(s) selected from the second metal group M2 consisted of lanthanoid-based metals to indium oxide, is from 0.005 to 2, and

the value of [M3]/([M3]+[In]), which is the composition of the oxide(s) of the metal(s) selected from the third metal group M3 consisted of Zn, Sn, Zr, Ga and Ge to indium oxide, is from 0.005 to 2, wherein the [M1] represents the number of the atoms of one or two or more metal(s) selected from the first metal group, the [M2] represents the number of the atoms of one or two or more metal(s) selected from the second metal group, the [M3] represents the number of the atoms of the metal(s) selected from the third metal group, and

the [In] represents the number of the indium atoms.

16. The transparent electroconductive film according to claim 14, wherein the oxide(s) of one or more metal(s) selected from the second metal group M2 consisted of lanthanoid-based metals is/are an oxide or oxides of one or more metals of La, Ce, Ho and Er.

17. A transparent electroconductive glass substrate, comprising:

a glass substrate,

a transparent electroconductive film which is formed over the glass substrate, is made mainly of indium oxide, and comprises one or two or more metal(s) selected from the first metal group M1 consisted of W, Mo, Nb, Ni, Pt and Pd, or an oxide or oxides of the metal(s), and an oxide or oxides of one or two or more metal(s) selected from the second metal group M2 consisted of lanthanoid-based metals, and

a metal thin film which is formed over the glass substrate and is made mainly of Al or Ag.

18. The transparent electroconductive glass substrate according to claim 17, wherein the value of [M1]/([M1]+[In]), which is the composition of one or two or more metal(s) selected from the first metal group M1 consisted of W, Mo, Nb, Ni, Pt and Pd, or the metal oxide(s) to indium oxide, is from 0.005 to 0.2, and

the value of [M2]/([M2]+[In]), which is the composition of the oxide(s) of one or two or more metal(s) selected from the second metal group M2 of lanthanoid-based metals to indium oxide, is from 0.005 to 0.2, wherein the [M1] represents the number of the atoms of one or two or more metal(s) selected from the first metal group, and the [M2] represents the number of the atoms of one or two or more metal(s) selected from the second metal group.

19. The transparent electroconductive glass substrate according to claim 17, wherein the oxide(s) of one or two or more metal(s) selected from the second metal group M2 consisted of lanthanoid-based metals is/are an oxide or oxides of one or more metals of La, Ce, Ho and Er.

20. A transparent electroconductive glass substrate, comprising:

a glass substrate,

a transparent electroconductive film which is formed over the glass substrate, is made mainly of indium oxide, and comprises one or two or more metal(s) selected from the first metal group M1 consisted of W, Mo, Nb, Ni, Pt and Pd, or an oxide or oxides of the metal(s), an oxide or oxides of one or two or more metal(s) selected from the second metal group M2 consisted of lanthanoid-based metals, and an oxide or oxides of one or two or more metal(s) selected from the third metal group M3 consisted of Zn, Sn, Zr, Ga and Ge, and

a metal thin film which is formed over the glass substrate and is made mainly of Al or Ag.

21. The transparent electroconductive glass substrate according to claim 20, wherein the value of [M1]/([M1]+[In]), which is the composition of one or two or more metal(s) selected from the first metal group M1 consisted of W, Mo, Nb, Ni, Pt and Pd, or the metal oxide(s) to indium oxide, is from 0.005 to 0.2,

the value of [M2]/([M2]+[In]), which is the composition of the oxide(s) of one or two or more metal(s) selected from the second metal group M2 consisted of lanthanoid-based metals to indium oxide, is from 0.005 to 2, and

the value of [M3]/([M3]+[In]), which is the composition of the oxide(s) of the metal(s) selected from the third metal group M3 consisted of Zn, Sn, Zr, Ga and Ge to indium oxide, is from 0.005 to 2, wherein the [M1] represents the number of the atoms of one or two or more metal(s) selected from the first metal group, the [M2] represents the number of the atoms of one or two or more metal(s) selected from the second metal group, the [M3] represents the number of the atoms of the metal(s) selected from the third metal group, and the [In] represents the number of the indium atoms.

22. The transparent electroconductive glass substrate according to claim 20, wherein the oxide(s) of one or more metal(s) selected from the second metal group M2 consisted of lanthanoid-based metals is/are an oxide or oxides of one or more metals of La, Ce, Ho and Er.

23. A process for producing a thin film transistor substrate, comprising:

a first conductor forming step of using an Al alloy comprising one or more metals selected from a metal group M1 consisted of W, Mo, La, Nb, Fe, Pd, Pt, Ce, Ho and Er to form, over a transparent insulating substrate, a first conductor which is any conductor contained in a conductor group E1 consisted of a gate, a source and a drain,

an insulation film forming step of forming an insulation film to cover the formed first conductor and the transparent insulating substrate,

a contact hole making step of making a contact hole in the formed insulation film, and

an electrically connecting step which is a step of forming a second conductor comprising a transparent film electrode onto the insulation film, and which is a step of connecting the second conductor and the first conductor electrically to each other through the contact hole.

24. A thin film transistor, comprising a transparent insulating substrate, and a first conductor which is formed over the transparent insulating substrate and is any conductor contained in a conductor group E1 consisted of a gate, a source and a drain,

wherein the first conductor comprises an Al layer made of an Al alloy comprising one or more metals selected from a metal group M1 consisted of W, Mo, La, Nb, Fe, Pd, Pt, Ce, Ho and Er, and is connected to a second conductor made of a transparent film electrode through a contact hole made in the insulation film over the first conductor.

25. The thin film transistor according to claim 24, wherein the first conductor comprises the Al layer comprising 0.5 to 5% by weight of the one or two or more metal(s) selected from the metal group M1.

26. A thin film transistor substrate, comprising a transparent insulating substrate, an insulation film which is formed over the transparent insulating substrate, comprises a first conductor which is any conductor contained in a conductor group E1 consisted of a gate, a source and a drain, and is further formed to cover at least the transparent insulating substrate, and a second conductor formed over the insulation film,

wherein the first conductor comprises an Al layer made of an Al alloy comprising one or more metals selected from a metal group M1 consisted of W, Mo, La, Nb, Fe, Pd, Pt, Ce, Ho and Er,

the insulation film has a given contact hole which penetrates through this film in the direction of the first conductor and second conductor,

the second conductor is made of a transparent film electrode, and

the second conductor is electrically connected to the Al layer of the first conductor through the contact hole.

27. The thin film transistor substrate according to claim 26, wherein the transparent film electrode comprises any one of indium oxide, tin oxide, indium tin oxide, and indium zinc oxide, and zinc oxide.

28. The thin film transistor substrate according to claim 26, wherein the first conductor comprises the Al layer comprising 0.5 to 5% by weight of the one or two or more metal(s) selected from the metal group M1.

29. A liquid crystal display, comprising the thin film transistor substrate according to claim 26, and

a liquid crystal layer which is driven by the thin film transistor substrate.

30. A TFT substrate for a liquid crystal display, comprising:

a transparent substrate,

a gate electrode which is formed over the transparent substrate, and is made mainly of Al,

a source electrode formed over the transparent substrate,

a drain electrode formed over the transparent substrate,

a silicon layer formed over the transparent substrate, and

a transparent electrode formed over the transparent substrate,

wherein the transparent electrode is an electroconductive oxide containing;

indium oxide, and

an oxide or oxides of one or two or more metal(s) selected from the first group M1 consisted of W, Mo, Ni, Nb, Fe, Pt, Pd, and lanthanoids, and

this transparent electrode is jointed directly to at least one electrode selected from the group consisted of the gate electrode made mainly of Al, the source electrode and the drain electrode.

31. The TFT substrate according to claim 30, wherein [M1]/([In]+[M1]), which is the atomic composition ratio of the oxide(s) of the metal(s) selected from the first group M1 to indium in the electroconductive oxide, is from 0.005 to 0.2 wherein the [M1] represents the number of the atoms of one or two or more metal(s) selected from the first group M1 and the [In] represents the number of the atoms of indium.

32. The TFT substrate according to claim 30, wherein the electroconductive oxide comprises an oxide or oxides of one or two or more metal(s) selected from the second group M2 consisted of tin, zinc, germanium, and gallium beside indium oxide.

33. The TFT substrate according to claim 32, wherein [M2]/([In]+[M2]), which is the atomic composition ratio of the oxide(s) of one or two or more metal(s) selected from the second group M2 to indium in the electroconductive oxide, is from 0.01 to 0.3 wherein the [M2] represents the number of the atoms of one or two or more metal(s) selected from the second group M2, that is, the number of the atoms of any one or any two or more of tin, zinc, germanium, and gallium, and the [In] represents the number of the atoms of indium.

50. A process for producing the TFT substrate according to claim 30, comprising:

the step of depositing the electroconductive oxide onto the transparent substrate, thereby forming a thin film of the electroconductive oxide, and

the step of etching the formed thin film of the electroconductive oxide with an aqueous solution containing oxalic acid, thereby forming the transparent electrode.

51. A process for producing the TFT substrate according to claim 30, comprising:

the step of depositing the electroconductive oxide onto the transparent substrate, thereby forming a thin film of the electroconductive oxide, and

the step of etching the formed thin film of the electroconductive oxide with an aqueous solution containing phosphoric acid, acetic acid and nitric acid, thereby forming the transparent electrode.

52. A process for producing the TFT substrate according to claim 30, comprising:

the step of depositing the electroconductive oxide onto the transparent substrate, thereby forming a thin film of the electroconductive oxide, and

the step of etching the formed thin film of the electroconductive oxide with an aqueous solution containing a cerium aluminum salt of nitric acid, thereby forming the transparent electrode.

53. A process for producing the TFT substrate, the sputtering target for producing a transparent electrode, the liquid crystal display, the pixel electrode, the transparent electrode, or the TFT substrate according to claim 30, wherein the lanthanoid(s) are one or more lanthanoids selected from Ce, Nd, Er and Ho.

34. A sputtering target used at the time of producing a transparent electrode which is used in a TFT substrate for a liquid crystal display and is for driving the liquid crystal by sputtering, the transparent electrode being capable of being jointed electrically to an electrode or wiring made mainly of Al, and the sputtering target being made of an electroconductive oxide comprising:

indium oxide, and

an oxide or oxides of one or two or more metal(s) selected from the first group M1 consisted of W, Mo, Ni, Nb, Fe, Pt, Pd, and lanthanoids.

35. The sputtering target according to claim 34, wherein [M1]/([In]+[M1]), which is the atomic composition ratio of the oxide(s) of one or two or more metal(s) selected from the first group M1 to indium in the electroconductive oxide, is from 0.005 to 0.2 wherein the [M1] represents the number of the atoms of one or two or more metal(s) selected from the first group M1 and the [In] represents the number of the atoms of indium.

36. The sputtering target according to claim 34, wherein the electroconductive oxide comprises an oxide or oxides of one or two or more metal(s) selected from the second group M2 consisted of tin, zinc, germanium, and gallium beside indium oxide.

37. The sputtering target according to claim 36, wherein [M2]/([In]+[M2]), which is the atomic composition ratio of the oxide(s) of the metal(s) selected from the second group M2 to indium in the electroconductive oxide, is from 0.01 to 0.3 wherein the [M2] represents the number of the atoms of one or two or more metal(s) selected from the second group M2, that is, the number of the atoms of any one or any two or more of tin, zinc, germanium, and gallium, and the [In] represents the number of the atoms of indium.

38. A liquid crystal display provided with a TFT substrate and a liquid crystal,

wherein the TFT substrate comprises:

a transparent substrate,

a gate electrode which is formed over the transparent substrate, and is made mainly of Al,

a source electrode formed over the transparent substrate,

a drain electrode formed over the transparent substrate,

a silicon layer formed over the transparent substrate, and

a pixel electrode, for driving the liquid crystal, which is formed over the transparent substrate, and

a transparent electrode for protecting the gate electrode and the source/drain electrodes,

wherein the pixel electrode or transparent electrode is an electroconductive oxide containing;

indium oxide, and

an oxide or oxides of one or two or more metal(s) selected from the first group M1 consisted of W, Mo, Ni, Nb, Fe, Pt, Pd, and lanthanoids, and

this pixel electrode or transparent electrode is jointed directly to at least one electrode selected from the group consisted of the gate electrode made mainly of Al, the source electrode and the drain electrode.

39. The liquid crystal display according to claim 38, wherein [M1]/([In]+[M1]), which is the atomic composition ratio of the oxide(s) of one or two or more metal(s) selected from the first group M1 to indium in the electroconductive oxide, is from 0.005 to 0.2 wherein the [M1] represents the number of the atoms of one or two or more metal(s) selected from the first group M1 and the [In] represents the number of the atoms of indium.

40. The liquid crystal display according to claim 38, wherein the electroconductive oxide comprises an oxide or oxides of one or two or more metal(s) selected from the second group M2 consisted of tin, zinc, germanium, and gallium beside indium oxide.

41. The liquid crystal display according to claim 40, wherein [M2]/([In]+[M2]), which is the atomic composition ratio of the oxide(s) of the more metal(s) selected from the second group M2 to indium in the electroconductive oxide, is from 0.01 to 0.3 wherein the [M2] represents the number of the atoms of one or two or more metal(s) selected from the second group M2, that is, the number of the atoms of any one or any two or more of tin, zinc, germanium, and gallium, and the [In] represents the number of the atoms of indium.

42. A pixel electrode for driving a liquid crystal, which is used in a TFT substrate, for a liquid crystal display, comprising:

a transparent substrate,

a gate electrode which is formed over the transparent substrate, and is made mainly of Al,

a source electrode formed over the transparent substrate,

a drain electrode formed over the transparent substrate,

a silicon layer formed over the transparent substrate,

the pixel electrode formed over the transparent substrate, and

a transparent electrode for protecting the gate electrode, the source electrode and the drain electrode,

the pixel electrode being an electroconductive oxide containing;

indium oxide, and

an oxide or oxides of one or two or more metal(s) selected from the first group M1 consisted of W, Mo, Ni, Nb, Fe, Pt, Pd, and lanthanoids, and

the pixel electrode being jointed directly to at least one electrode selected from the group consisted of the gate electrode made mainly of Al, the source electrode and the drain electrode.

43. The pixel electrode according to claim 42, wherein [M1]/([In]+[M1]), which is the atomic composition ratio of the oxide(s) of one or two or more metal(s) selected from the first group M1 to indium in the electroconductive oxide, is from 0.005 to 0.2 wherein the [M1] represents the number of the atoms of one or two or more metal(s) selected from the first group M1 and the [In] represents the number of the atoms of indium.

44. The pixel electrode according to claim 42, wherein the electroconductive oxide comprises an oxide or oxides of one or two or more metal(s) selected from the second group M2 consisted of tin, zinc, germanium, and gallium beside indium oxide.

45. The pixel electrode according to claim 44, wherein [M2]/([In]+[M2]), which is the atomic composition ratio of the oxide(s) of the metal(s) selected from the second group M2 to indium in the electroconductive oxide, is from 0.01 to 0.3 wherein the [M2] represents the number of the atoms of one or two or more metal(s) selected from the second group M2, that is, the number of the atoms of any one or any two or more of tin, zinc, germanium, and gallium, and the [In] represents the number of the atoms of indium.

46. A transparent electrode, which is used in a TFT substrate, for a liquid crystal display, comprising:

a transparent substrate,

a gate electrode which is formed over the transparent substrate, and is made mainly of Al,

a source electrode formed over the transparent substrate,

a drain electrode formed over the transparent substrate,

a silicon layer formed over the transparent substrate,

a pixel electrode formed over the transparent substrate, and

the transparent electrode for protecting the gate electrode, the source electrode and the drain electrode,

the transparent electrode being an electroconductive oxide containing;

indium oxide, and

an oxide or oxides of one or two or more metal(s) selected from the first group M1 consisted of W, Mo, Ni, Nb, Fe, Pt, Pd, and lanthanoids, and

the transparent electrode being jointed directly to at least one electrode selected from the group consisted of the gate electrode made mainly of Al, the source electrode and the drain electrode.

47. The transparent electrode according to claim 46, wherein [M1]/([In]+[M1]), which is the atomic composition ratio of the oxide(s) of one or two or more metal(s) selected from the first group M1 to indium in the electroconductive oxide, is from 0.005 to 0.2 wherein the [M1] represents the number of the atoms of one or two or more metal(s) selected from the first group M1 and the [In] represents the number of the atoms of indium.

48. The transparent electrode according to claim 46, wherein the electroconductive oxide comprises an oxide or oxides of one or two or more metal(s) selected from the second group M2 consisted of tin, zinc, germanium, and gallium beside indium oxide.

49. The transparent electrode according to claim 48, wherein [M2]/([In]+[M2]), which is the atomic composition ratio of the oxide(s) of one or two or more metal(s) selected from the second group M2 to indium in the electroconductive oxide, is from 0.01 to 0.3 wherein the [M2] represents the number of the atoms of one or two or more metal(s) selected from the second group M2, that is, the number of the atoms of any one or any two or more of tin, zinc, germanium, and gallium, and the [In] represents the number of the atoms of indium.