Tft Substrate, Reflective Tft Substrate and Method for Manufacturing These Substrates

• US 20090001374A1
• Filed: 01/16/2007
• Published: 01/01/2009
• Est. Priority Date: 01/31/2006
• Status: Abandoned Application

• Current Assignee: Idemitsu Kosan Company Limited
• Original Assignee: Idemitsu Kosan Company Limited
• Inventors: Tanaka, Nobuo, Inoue, Kazuyoshi, Yano, Koki, Tanaka, Tokie
• Application Number:
  US12/162,545
• Publication Number:
  US 20090001374A1
• Time in Patent Office: Days
• US Class Current: 257/59
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1218 with a particular composition or structure of the substrate
• CPC Class Codes: H01L 29/78603 characterised by the insulating substrate or support H01L29/78657 takes precedence
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

An object of the invention is to propose a TFT substrate and a reflective TFT substrate which can be operated stably for a prolonged period of time, can be prevented from being suffering from crosstalk, and is capable of significantly reducing manufacturing cost by decreasing the number of production steps, as well as to propose the method for producing these substrates.

A TFT substrate 1001 comprises: a glass substrate 1010; a gate electrode 1023 and a gate wire 1024 insulated by having their top surfaces covered with a gate insulating film 1030 and by having their side surfaces covered with an interlayer insulating film 1050; an n-type oxide semiconductor layer 1040 formed on the gate insulating film 1030 above the gate electrode 1023; an oxide transparent conductor layer 1060 formed on the n-type oxide semiconductor layer 1040 with a channel part 1044 interposed therebetween; and a channel guard 1500 for protecting the channel part 1044.

Claims

1. A TFT substrate comprising:

a substrate;

a gate electrode and a gate wire formed above the substrate and insulated by having their top surfaces covered with a gate insulating film and by having their side surfaces covered with an interlayer insulating film;

an oxide layer formed above the gate electrode and above the gate insulating film;

a conductor layer formed above the oxide layer with a channel part interposed therebetween; and

a channel guard formed above the channel part for protecting the channel part.

2. The TFT substrate according to claim 1, wherein the oxide layer is an n-type oxide semiconductor layer.

3. The TFT substrate according to claim 1, wherein the channel guard is composed of the interlayer insulating film and a drain electrode and a source electrode composed of the conductor layer are respectively formed in a pair of openings of the interlayer insulating film.

4. The TFT substrate according to claim 1, wherein the conductor layer is an oxide conductor layer and/or a metal layer.

5. The TFT substrate according to claim 1, wherein the conductor layer functions at least as a pixel electrode.

6. The TFT substrate according to claim 1, wherein the oxide layer is formed at predetermined positions corresponding to the channel part, a source electrode and a drain electrode.

7. The TFT substrate according to claim 1, wherein the upper part of the substrate is covered with a protective insulating film and the protective insulating film has openings at positions corresponding to a pixel electrode, a source/drain wire pad and a gate wire pad.

8. The TFT substrate according to claim 1, wherein the TFT substrate comprises at least one of the gate electrode, the gate wire, a source wire, a drain wire, a source electrode, a drain electrode and a pixel electrode, and an auxiliary conductive layer is formed above at least one of the gate electrode, the gate wire, the source wire, the source electrode, the drain electrode and the pixel electrode.

9. The TFT substrate according to claim 1, wherein the TFT substrate comprises a metal layer and comprises a metal layer-protecting oxide conductor layer for protecting the metal layer.

10. The TFT substrate according to claim 1, wherein the TFT substrate comprises at least one of the gate electrode, the gate wire, a source wire, a drain wire, a source electrode, a drain electrode and a pixel electrode, and at least one of the gate electrode, the gate wire, the source wire, the drain wire, the source electrode, the drain electrode and the pixel electrode is formed of an oxide transparent conductor layer.

11. The TFT substrate according to claim 1, wherein the energy gap of the oxide layer and/or the conductor layer is 3.0 eV or more.

12. The TFT substrate according to claim 1, wherein the TFT substrate comprises a pixel electrode and part of the pixel electrode is covered with a reflective metal layer.

13. The TFT substrate according to claim 12, wherein the reflective metal layer functions as at least one of a source wire, a drain wire, a source electrode and a drain electrode.

14. The TFT substrate according to claim 12, wherein the reflective metal layer is formed of a thin film of aluminum, silver or gold or an alloy layer containing aluminum, silver or gold.

15. A reflective TFT substrate comprising:

a substrate;

a gate electrode and a gate wire formed above the substrate and insulated by having their top surfaces covered with a gate insulating film and by having their side surfaces covered with an interlayer insulating film;

an oxide layer formed above the gate electrode and above the gate insulating film;

a reflective metal layer formed above the oxide layer with a channel part interposed therebetween; and

a channel guard formed above the channel part for protecting the channel part.

16. The reflective TFT substrate according to claim 15, wherein the oxide layer is an n-type oxide semiconductor layer.

17. The reflective TFT substrate according to claim 15, wherein the channel guard is composed of the interlayer insulating film and a drain electrode and a source electrode are respectively formed in a pair of openings of the interlayer insulating film.

18. The reflective TFT substrate according to claim 15, wherein the reflective metal layer functions at least as a pixel electrode.

19. The reflective TFT substrate according to claim 15, wherein the oxide layer is formed at predetermined positions corresponding to the channel part, a source electrode and a drain electrode.

20. The reflective TFT substrate according to claim 15, wherein the upper part of the substrate is covered with a protective insulating film and the protective insulating film has openings at positions corresponding to a pixel electrode, a source/drain wire pad and a gate wire pad.

21. The reflective TFT substrate according to claim 15, wherein the reflective TFT substrate comprises a reflective metal layer and/or a metal thin film, and comprises a metal layer-protecting oxide transparent conductor layer for protecting the reflective metal layer and/or the metal thin film.

22. The reflective TFT substrate according to claim 15, wherein the energy gap of the oxide layer is 3.0 eV or more.

23. The reflective TFT substrate according to claim 15, wherein the reflective metal layer is formed from a thin film of aluminum, silver or gold or an alloy layer containing aluminum, silver or gold.

24. A method for producing a TFT substrate comprising the steps of:

stacking a thin film for a gate electrode/gate wire from which a gate electrode and a gate wire are formed, a gate insulating film, a first oxide layer and a first resist above a substrate;

forming the first resist into a predetermined shape by half-tone exposure by using a first half-tone mask;

patterning the thin film for a gate electrode/gate wire, the gate insulating film and the first oxide layer with an etching method to form the gate electrode and the gate wire;

reforming the first resist into a predetermined shape;

patterning the first oxide layer with an etching method to form a channel part;

stacking an interlayer insulating film and a second resist;

forming the second resist into a predetermined shape by using a second mask;

patterning the interlayer insulating film with an etching method to form openings at positions where a source electrode and a drain electrode are formed and patterning the interlayer insulating film and the gate insulting film with an etching method to form an opening for a gate wire pad at a position where a gate wire pad is formed;

stacking a second oxide layer and a third resist;

forming the third resist into a predetermined shape by using a third mask; and

patterning the second oxide layer with an etching method to form the source electrode, the drain electrode, a source wire, a drain wire, a pixel electrode and the gate wire pad.

25. A method for producing a TFT substrate comprising the steps of:

stacking a thin film for a gate electrode/gate wire from which a gate electrode and a gate wire are formed, a gate insulating film, a first oxide layer and a first resist above a substrate;

forming the first resist into a predetermined shape by half-tone exposure by using a first half-tone mask;

patterning the thin film for a gate electrode/gate wire, the gate insulating film and the first oxide layer with an etching method to form the gate electrode and the gate wire;

reforming the first resist into a predetermined shape;

patterning the first oxide layer with an etching method to form a channel part;

stacking an interlayer insulating film and a second resist;

forming the second resist into a predetermined shape by using a second mask;

patterning the interlayer insulating film with an etching method to form openings at positions where a source electrode and a drain electrode are formed and patterning the interlayer insulating film and the gate insulting film with an etching method to form an opening for a gate wire pad at a position where a gate wire pad is formed;

stacking a second oxide layer, a protective insulating film and a third resist;

forming the third resist into a predetermined shape by half-tone exposure by using a third mask;

patterning the second oxide layer and the protective insulating film with an etching method to form the source electrode, the drain electrode, a source wire, a drain wire, a pixel electrode and the gate wire pad;

reforming the third resist into a predetermined shape; and

patterning the protective insulating film with an etching method to expose a source/drain wire pad, the pixel electrode and the gate wire pad.

26. A method for producing a TFT substrate comprising the steps of:

stacking a thin film for a gate electrode/gate wire from which a gate electrode and a gate wire are formed, a gate insulating film, a first oxide layer and a first resist above a substrate;

forming the first resist into a predetermined shape by half-tone exposure by using a first half-tone mask;

patterning the thin film for a gate electrode/gate wire, the gate insulating film and the first oxide layer with an etching method to form the gate electrode and the gate wire;

reforming the first resist into a predetermined shape;

patterning the first oxide layer with an etching method to form a channel part;

stacking an interlayer insulating film and a second resist;

forming the second resist into a predetermined shape by using a second mask;

patterning the interlayer insulating film with an etching method to form openings at positions where a source electrode and a drain electrode are formed and patterning the interlayer insulating film and the gate insulting film with an etching method to form an opening for a gate wire pad at a position where a gate wire pad is formed;

stacking a second oxide layer and a third resist;

forming the third resist into a predetermined shape by using a third mask;

patterning the second oxide layer with an etching method to form the source electrode, the drain electrode, a source wire, a drain wire, a pixel electrode and the gate wire pad;

stacking a protective insulating film and a fourth resist;

forming the fourth resist into a predetermined shape; and

patterning the protective insulating film with an etching method to expose a source/drain wire pad, the pixel electrode and the gate wire pad.

27. A method for producing a TFT substrate comprising the steps of:

stacking a thin film for a gate electrode/gate wire from which a gate electrode and a gate wire are formed, a gate insulating film, a first oxide layer and a first resist above a substrate;

forming the first resist into a predetermined shape by half-tone exposure by using a first half-tone mask;

patterning with an etching method the thin film for a gate electrode/gate wire, the gate insulating film and the first oxide layer to form the gate electrode and the gate wire;

reforming the first resist into a predetermined shape;

patterning the first oxide layer with an etching method to form a channel part;

stacking an interlayer insulating film and a second resist;

forming the second resist into a predetermined shape by using a second mask;

patterning the interlayer insulating film with an etching method to form openings at positions where a source electrode and a drain electrode are formed and patterning the interlayer insulating film and the gate insulting film with an etching method to form an opening for a gate wire pad at a position where a gate wire pad is formed;

stacking a second oxide layer, an auxiliary conductive layer, a protective insulating film and a third resist;

forming the third resist into a predetermined shape by using a third half-tone mask by half-tone exposure;

patterning the second oxide layer, the auxiliary conductive layer and the protective insulating film with an etching method to form the source electrode, the drain electrode, a source wire, a drain wire, a pixel electrode and the gate wire pad;

reforming the third resist into a predetermined shape; and

patterning the auxiliary conductive layer and the protective insulating film with an etching method to expose a source/drain wire pad, the pixel electrode and the gate wire pad.

28. A method for producing a TFT substrate comprising the steps of:

stacking a thin film for a gate electrode/gate wire from which a gate electrode and gate wire are formed, a gate insulating film, a first oxide layer and a first resist above a substrate;

forming the first resist into a predetermined shape by half-tone exposure by using a first half-tone mask;

patterning the thin film for a gate electrode/gate wire, the gate insulating film and the first oxide layer with an etching method to form the gate electrode and the gate wire;

reforming the first resist into a predetermined shape;

patterning the first oxide layer with an etching method to form a channel part;

stacking an interlayer insulating film and a second resist;

forming the second resist into a predetermined shape by using a second mask;

patterning the interlayer insulating film with an etching method to form openings at positions where a source electrode and a drain electrode are formed and patterning the interlayer insulating film and the gate insulting film with an etching method to form an opening for a gate wire pad at a position where a gate wire pad is formed;

stacking a second oxide layer, an auxiliary conductive layer and a third resist;

forming the third resist into a predetermined shape by using a third mask; and

patterning the second oxide layer and the auxiliary conductive layer with an etching method to form a source electrode, a drain electrode, a source wire, a drain wire, a pixel electrode and the gate wire pad;

stacking a protective insulating film and a fourth resist;

forming the fourth resist into a predetermined shape; and

patterning the protective insulating film with an etching method to expose a source/drain wire pad, the pixel electrode and the gate wire pad.

29. A method for producing a TFT substrate comprising the steps of:

stacking a thin film for a gate electrode/gate wire from which a gate electrode and a gate wire are formed, a gate insulating film, a first oxide layer and a first resist above a substrate;

forming the first resist into a predetermined shape by half-tone exposure by using a first half-tone mask;

patterning the thin film for a gate electrode/gate wire, the gate insulating film and the first oxide layer with an etching method to form the gate electrode and the gate wire;

reforming the first resist into a predetermined shape;

patterning the first oxide layer with an etching method to form a channel part;

stacking an interlayer insulating film and a second resist;

forming the second resist into a predetermined shape by using a second mask;

patterning the interlayer insulating film with an etching method to form openings at positions where a source electrode and a drain electrode are formed and patterning the interlayer insulating film and the gate insulting film with an etching method to form an opening for a gate wire pad at a position where a gate wire pad is formed;

stacking a second oxide layer, a reflective metal layer and a third resist;

forming the third resist into a predetermined shape by half-tone exposure by using a third half-tone mask;

patterning the second oxide layer and the reflective metal layer with an etching method to form the source electrode, the drain electrode, a source wire, a drain wire, a pixel electrode and the gate wire pad;

reforming the third resist into a predetermined shape; and

patterning the reflective metal layer with an etching method to expose a source/drain wire pad, part of the pixel electrode and the gate wire pad and form a reflective metal part composed of the reflective metal layer.

32. The method for producing a TFT substrate according to claim 29, wherein a metal layer-protecting oxide conductor layer for protecting the reflective metal layer is formed above the reflective metal layer.

33. The method for producing a TFT substrate according to claim 29, wherein a thin film for a gate electrode/gate wire-protecting conductive layer for protecting the thin film for a gate electrode/gate wire is formed above the thin film for a gate electrode/gate wire.

30. A method for producing a TFT substrate comprising the steps of:

stacking a thin film for a gate electrode/gate wire from which a gate electrode and a gate wire are formed, a gate insulating film, a first oxide layer and a first resist above a substrate;

forming the first resist into a predetermined shape by half-tone exposure by using a first half-tone mask;

patterning the thin film for a gate electrode/gate wire, the gate insulating film and the first oxide layer with an etching method to form the gate electrode and the gate wire;

reforming the first resist into a predetermined shape;

patterning the first oxide layer with an etching method to form a channel part;

stacking an interlayer insulating film and a second resist;

forming the second resist into a predetermined shape by using a second mask;

patterning the interlayer insulating film with an etching method to form openings at positions where a source electrode and a drain electrode are formed and patterning the interlayer insulating film and the gate insulting film with an etching method to form an opening for a gate wire pad at a position where a gate wire pad is formed;

stacking a second oxide layer, a reflective metal layer, a protective insulating film and a third resist;

forming the third resist into a predetermined shape by half-tone exposure by using a third half-tone mask;

patterning the second oxide layer, the reflective metal layer and the protective insulating layer with an etching method to form the source electrode, the drain electrode, a source wire, a drain wire, a pixel electrode and the gate wire pad;

reforming the third resist into a predetermined shape; and

patterning the reflective metal layer and the protective insulating film with an etching method to expose a source/drain wire pad, part of the pixel electrode and the gate wire pad and form a reflective metal part composed of the reflective metal layer.

42. The method for producing a TFT substrate according to claim 30, wherein a metal layer-protecting oxide conductor layer for protecting the reflective metal layer is formed above the reflective metal layer.

44. The method for producing a TFT substrate according to claim 30, wherein a thin film for a gate electrode/gate wire-protecting conductive layer for protecting the thin film for a gate electrode/gate wire is formed above the thin film for a gate electrode/gate wire.

31. A method for producing a TFT substrate comprising the steps of:

stacking a thin film for a gate electrode/gate wire from which a gate electrode and a gate wire are formed, a gate insulating film, a first oxide layer and a first resist above a substrate;

forming the first resist into a predetermined shape by half-tone exposure by using a first half-tone mask;

patterning the thin film for a gate electrode/gate wire, the gate insulating film and the first oxide layer with an etching method to form the gate electrode and the gate wire;

reforming the first resist into a predetermined shape;

patterning the first oxide layer with an etching method to form a channel part;

stacking an interlayer insulating film and a second resist;

forming the second resist into a predetermined shape by using a second mask;

patterning the interlayer insulating film with an etching method to form openings at positions where a source electrode and a drain electrode are formed and patterning the interlayer insulating film and the gate insulting film with an etching method to form an opening for a gate wire pad at a position where a gate wire pad is formed;

stacking a second oxide layer, a reflective metal layer and a third resist;

forming the third resist into a predetermined shape by half-tone exposure by using a third half-tone mask;

patterning the second oxide layer and the reflective metal layer with an etching method to form the source electrode, the drain electrode, a source wire, a drain wire, a pixel electrode and the gate wire pad;

reforming the third resist into a predetermined shape;

patterning the reflective metal layer with an etching method to expose a source/drain wire pad, part of the pixel electrode and the gate wire pad and form a reflective metal part composed of the reflective metal layer;

stacking a protective insulating film and a fourth resist;

reforming the fourth resist into a predetermined shape; and

patterning the protective insulating film with an etching method to expose the source/drain wire pad, part of the pixel electrode and the gate wire pad.

43. The method for producing a TFT substrate according to claim 31, wherein a metal layer-protecting oxide conductor layer for protecting the reflective metal layer is formed above the reflective metal layer.

45. The method for producing a TFT substrate according to claim 31, wherein a thin film for a gate electrode/gate wire-protecting conductive layer for protecting the thin film for a gate electrode/gate wire is formed above the thin film for a gate electrode/gate wire.

34. A method for producing a TFT substrate comprising the steps of:

stacking a thin film for a gate electrode/gate wire from which a gate electrode and a gate wire are formed, a gate insulating film, an oxide layer and a first resist above a substrate;

forming the first resist into a predetermined shape by half-tone exposure by using a first half-tone mask;

patterning the thin film for a gate electrode/gate wire, the gate insulating film and the oxide layer with an etching method to form the gate electrode and the gate wire;

reforming the first resist into a predetermined shape;

patterning the oxide layer with an etching method to form a channel part;

stacking an interlayer insulating film and a second resist;

forming the second resist into a predetermined shape by using a second mask;

patterning the interlayer insulating film with an etching method to form an opening for a source electrode and an opening for a drain electrode at positions where a source electrode and a drain electrode are formed and patterning the interlayer insulating film and the gate insulting film with an etching method to form an opening for a gate wire pad at a position where a gate wire pad is formed;

stacking a conductor layer and a third resist;

forming the third resist into a predetermined shape by using a third mask; and

patterning the conductor layer with an etching method to form the source electrode, the drain electrode, a source wire, a drain wire, a pixel electrode and the gate wire pad.

35. A method for producing a TFT substrate comprising the steps of:

stacking a thin film for a gate electrode/gate wire from which a gate electrode and a gate wire are formed, a gate insulating film, an oxide layer and a first resist above a substrate;

forming the first resist into a predetermined shape by half-tone exposure by using a first half-tone mask;

patterning the thin film for a gate electrode/gate wire, the gate insulating film and the oxide layer with an etching method to form the gate electrode and the gate wire;

reforming the first resist into a predetermined shape;

patterning the oxide layer with an etching method to form a channel part;

stacking an interlayer insulating film and a second resist;

forming the second resist into a predetermined shape by using a second mask;

patterning the interlayer insulating film with an etching method to form an opening for a source electrode and an opening for a drain electrode at positions where a source electrode and a drain electrode are formed and patterning the interlayer insulating film and the gate insulting film with an etching method to form an opening for a gate wire pad at a position where a gate wire pad is formed;

stacking a conductor layer and a third resist;

forming the third resist into a predetermined shape by using a third mask;

patterning the conductor layer with an etching method to form the source electrode, the drain electrode, a source wire, a drain wire, a pixel electrode and the gate wire pad;

stacking a protective insulating film and a fourth resist;

forming the fourth resist into a predetermined shape; and

patterning the protective insulating film with an etching method to expose a source/drain wire pad, the pixel electrode and the gate wire pad.

36. A method for producing a reflective TFT substrate comprising the steps of:

stacking a thin film for a gate electrode/gate wire from which a gate electrode and a gate wire are formed, a gate insulating film, an oxide layer and a first resist above a substrate;

forming the first resist into a predetermined shape by half-tone exposure by using a first half-tone mask;

patterning the thin film for a gate electrode/gate wire, the gate insulating film and the oxide layer with an etching method to form the gate electrode and the gate wire;

reforming the first resist into a predetermined shape;

patterning the oxide layer with an etching method to form a channel part;

stacking an interlayer insulating film and a second resist;

forming the second resist into a predetermined shape by using a second mask;

patterning the interlayer insulating film with an etching method to form an opening for a source electrode and an opening for a drain electrode at positions where a source electrode and a drain electrode are formed and patterning the interlayer insulating film and the gate insulting film with an etching method to form an opening for a gate wire pad at a position where a gate wire pad is formed;

stacking a reflective metal layer and a third resist;

forming the third resist into a predetermined shape by using a third mask;

patterning the reflective metal layer with an etching method to form the source electrode, the drain electrode, a source wire, a drain wire, a pixel electrode and the gate wire pad.

39. The method for producing a reflective TFT substrate according to claim 36, wherein an oxide conductor layer is stacked between the oxide layer and the reflective metal layer.

40. The method for producing a reflective TFT substrate according to claim 36, wherein a metal layer-protecting oxide transparent conductor layer is stacked above the reflective metal layer.

41. The method for producing a reflective TFT substrate according to claim 36, wherein the thin film for a gate electrode/gate wire comprises a metal layer and a metal layer-protecting oxide transparent conductor layer is stacked above the metal layer.

37. A method for producing a reflective TFT substrate comprising the steps of:

stacking a thin film for a gate electrode/gate wire from which a gate electrode and a gate wire are formed, a gate insulating film, an oxide layer and a first resist above a substrate;

forming the first resist into a predetermined shape by half-tone exposure by using a first half-tone mask;

patterning the thin film for a gate electrode/gate wire, the gate insulating film and the oxide layer with an etching method to form the gate electrode and the gate wire;

reforming the first resist into a predetermined shape;

patterning the oxide layer with an etching method to form a channel part;

stacking an interlayer insulating film and a second resist;

forming the second resist into a predetermined shape by using a second mask;

patterning the interlayer insulating film with an etching method to form an opening for a source electrode and an opening for a drain electrode at positions where a source electrode and a drain electrode are formed and patterning the interlayer insulating film and the gate insulting film with an etching method to form an opening for a gate wire pad at a position where a gate wire pad is formed;

stacking a reflective metal layer, a protective insulating layer and a third resist;

forming the third resist into a predetermined shape by half-tone exposure by using a third half-tone mask;

patterning the reflective metal layer and the protective insulating film with an etching method to form the source electrode, the drain electrode, a source wire, a drain wire, a pixel electrode and the gate wire pad;

reforming the third resist into a predetermined shape; and

patterning the protective insulating film with an etching method to expose a source/drain wire pad, the pixel electrode and the gate wire pad.

46. The method for producing a reflective TFT substrate according to claim 37, wherein an oxide conductor layer is stacked between the oxide layer and the reflective metal layer.

48. The method for producing a reflective TFT substrate according to claim 37, wherein a metal layer-protecting oxide transparent conductor layer is stacked above the reflective metal layer.

50. The method for producing a reflective TFT substrate according to claim 37, wherein the thin film for a gate electrode/gate wire comprises a metal layer and a metal layer-protecting oxide transparent conductor layer is stacked above the metal layer.

38. A method for producing a reflective TFT substrate comprising the steps of:

stacking a thin film for a gate electrode/gate wire from which a gate electrode and a gate wire are formed, a gate insulating film, an oxide layer and a first resist above a substrate;

forming the first resist into a predetermined shape by half-tone exposure by using a first half-tone mask;

patterning the thin film for a gate electrode/gate wire, the gate insulating film and the oxide layer with an etching method to form the gate electrode and the gate wire;

reforming the first resist into a predetermined shape;

patterning the oxide layer with an etching method to form a channel part;

stacking an interlayer insulating film and a second resist;

forming the second resist into a predetermined shape by using a second mask;

patterning the interlayer insulating film with an etching method to form an opening for a source electrode and an opening for a drain electrode at positions where a source electrode and a drain electrode are formed and patterning the interlayer insulating film and the gate insulting film with an etching method to form an opening for a gate wire pad at a position where a gate wire pad is formed;

stacking a reflective metal layer and a third resist;

forming the third resist into a predetermined shape by using a third mask;

patterning the reflective metal layer with an etching method to form the source electrode, the drain electrode, a source wire, a drain wire, a pixel electrode and the gate wire pad;

stacking the protective insulting film and a fourth resist;

forming the fourth resist into a predetermined shape; and

patterning the protective insulating film with an etching method to expose a source/drain wire pad, the pixel electrode and the gate wire pad.

47. The method for producing a reflective TFT substrate according to claim 38, wherein an oxide conductor layer is stacked between the oxide layer and the reflective metal layer.

49. The method for producing a reflective TFT substrate according to claim 38, wherein a metal layer-protecting oxide transparent conductor layer is stacked above the reflective metal layer.

51. The method for producing a reflective TFT substrate according to claim 38, wherein the thin film for a gate electrode/gate wire comprises a metal layer and a metal layer-protecting oxide transparent conductor layer is stacked above the metal layer.