Semiconductor device and display device

• US 10,396,236 B2
• Filed: 08/24/2017
• Issued: 08/27/2019
• Est. Priority Date: 11/27/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Hosoba, Miyuki, Hiraishi, Suzunosuke
• Primary Examiner(s): Hoang, Quoc D
• Application Number:
  US15/685,005
• Publication Number:
  US 20170352777A1
• Time in Patent Office: 733 Days
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• 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 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• 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
• CPC Class Codes: H01L 33/0041 characterised by field-effect operation
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs

Abstract

Disclosed is a semiconductor device comprising a thin film transistor and wirings connected to the thin film transistor, in which the thin film transistor has a channel formation region in an oxide semiconductor layer, and a copper metal is used for at least one of a gate electrode, a source electrode, a drain electrode, a gate wiring, a source wiring, and a drain wiring. The extremely low off current of the transistor with the oxide semiconductor layer contributes to reduction in power consumption of the semiconductor device. Additionally, the use of the copper metal allows the combination of the semiconductor device with a display element to provide a display device with high display quality and negligible defects, which results from the low electrical resistance of the wirings and electrodes formed with the copper metal.

Claims

1. A semiconductor device comprising:

a first electrode;

a first insulating layer over the first electrode, wherein the first insulating layer comprises nitrogen;

a second insulating layer over the first insulating layer, wherein the second insulating layer comprises oxygen;

a first oxide semiconductor layer over the second insulating layer and overlapping with the first electrode, wherein the first oxide semiconductor layer comprises indium, gallium, and zinc;

a second electrode and a third electrode each over the first oxide semiconductor layer, wherein the second electrode and the third electrode each comprise copper;

a third insulating layer over the first oxide semiconductor layer, the second electrode, and the third electrode, wherein the third insulating layer comprises oxygen and is in contact with the first oxide semiconductor layer; and

a fourth insulating layer over the third insulating layer, wherein the fourth insulating layer comprises nitrogen.

2. The semiconductor device according to claim 1, wherein the first electrode comprises copper.

3. The semiconductor device according to claim 1, further comprising a second oxide semiconductor layer between the first electrode and the second electrode.

4. The semiconductor device according to claim 1, wherein an entirety of the first oxide semiconductor layer overlaps with the first electrode.

5. The semiconductor device according to claim 1, wherein a side surface of the first oxide semiconductor layer is in contact with the second electrode and the third electrode.

6. The semiconductor device according to claim 1, wherein the first oxide semiconductor layer comprises a crystal region.

7. The semiconductor device according to claim 6, wherein the crystal region exists in a superficial portion of the first oxide semiconductor layer.

8. The semiconductor device according to claim 1, further comprising:

a first conductive layer between the second electrode and the first oxide semiconductor layer; and

a second conductive layer between the third electrode and the first oxide semiconductor layer.

9. The semiconductor device according to claim 8, wherein the first conductive layer and the second conductive layer each comprises titanium.

10. The semiconductor device according to claim 8, wherein the first conductive layer and the second conductive layer each comprises a conductive metal oxide.

11. The semiconductor device according to claim 1, wherein the first electrode comprises copper.

12. The semiconductor device according to claim 1, further comprising a second oxide semiconductor layer between the first electrode and the second electrode.

13. The semiconductor device according to claim 1, wherein an entirety of the first oxide semiconductor layer overlaps with the first electrode.

14. The semiconductor device according to claim 1, wherein a side surface of the first oxide semiconductor layer is in contact with the second electrode and the third electrode.

15. The semiconductor device according to claim 1, wherein the first oxide semiconductor layer comprises a crystal region.

16. The semiconductor device according to claim 15, wherein the crystal region exists in a superficial portion of the first oxide semiconductor layer.

17. The semiconductor device according to claim 1, further comprising:

a first conductive layer between the second electrode and the first oxide semiconductor layer; and

a second conductive layer between the third electrode and the first oxide semiconductor layer.

18. The semiconductor device according to claim 17, wherein the first conductive layer and the second conductive layer each comprises titanium.

19. The semiconductor device according to claim 17, wherein the first conductive layer and the second conductive layer each comprises a conductive metal oxide.

20. A semiconductor device comprising:

a first electrode;

a first insulating layer over the first electrode, wherein the first insulating layer comprises nitrogen;

a second insulating layer over the first insulating layer, wherein the second insulating layer comprises oxygen;

a first oxide semiconductor layer over the second insulating layer and overlapping with the first electrode, wherein the first oxide semiconductor layer comprises indium, gallium, and zinc;

a second electrode and a third electrode each over the first oxide semiconductor layer, wherein the second electrode and the third electrode each comprise copper;

a third insulating layer over the first oxide semiconductor layer, the second electrode, and the third electrode, wherein the third insulating layer comprises oxygen and is in contact with the first oxide semiconductor layer;

a fourth insulating layer over the third insulating layer, wherein the fourth insulating layer comprises nitrogen; and

a fourth electrode over the fourth insulating layer,

wherein the first electrode and the fourth electrode overlap with each other with the first oxide semiconductor layer interposed therebetween.

21. A semiconductor device comprising:

a first electrode;

a first insulating layer over the first electrode, wherein the first insulating layer comprises nitrogen;

a second insulating layer over the first insulating layer, wherein the second insulating layer comprises oxygen;

a first oxide semiconductor layer over the second insulating layer and overlapping with the first electrode, wherein the first oxide semiconductor layer comprises indium, gallium, and zinc;

a third insulating layer over the first oxide semiconductor layer, wherein the third insulating layer comprises oxygen;

a second electrode and a third electrode each over the first oxide semiconductor layer and the third insulating layer, wherein the second electrode and the third electrode each comprise copper; and

a fourth insulating layer over the second electrode and the third electrode.

22. The semiconductor device according to claim 21, wherein the first electrode comprises copper.

23. The semiconductor device according to claim 21, further comprising a second oxide semiconductor layer between the first electrode and the second electrode.

24. The semiconductor device according to claim 21, wherein an entirety of the first oxide semiconductor layer overlaps with the first electrode.

25. The semiconductor device according to claim 21, wherein a side surface of the first oxide semiconductor layer is in contact with the second electrode and the third electrode.

26. The semiconductor device according to claim 21, wherein the first oxide semiconductor layer comprises a crystal region.

27. The semiconductor device according to claim 26, wherein the crystal region exists in a superficial portion of the first oxide semiconductor layer.

28. The semiconductor device according to claim 21, further comprising:

a first conductive layer between the second electrode and the first oxide semiconductor layer; and

a second conductive layer between the third electrode and the first oxide semiconductor layer.

29. The semiconductor device according to claim 28, wherein the first conductive layer and the second conductive layer each comprises titanium.

30. The semiconductor device according to claim 28, wherein the first conductive layer and the second conductive layer each comprises a conductive metal oxide.

31. The semiconductor device according to claim 21, wherein the fourth insulating layer comprises nitrogen.

32. A display device comprising:

a first electrode;

a first insulating layer over the first electrode, wherein the first insulating layer comprises nitrogen;

a second insulating layer over the first insulating layer, wherein the second insulating layer comprises oxygen;

a first oxide semiconductor layer over the second insulating layer and overlapping with the first electrode, wherein the first oxide semiconductor layer comprises indium, gallium, and zinc;

a second electrode and a third electrode each over the first oxide semiconductor layer, wherein the second electrode and the third electrode each comprise copper;

a third insulating layer over the first oxide semiconductor layer, the second electrode, and the third electrode, wherein the third insulating layer comprises oxygen and is in contact with the first oxide semiconductor layer;

a fourth insulating layer over the third insulating layer, wherein the fourth insulating layer comprises nitrogen;

a fifth insulating layer over the fourth insulating layer; and

a pixel electrode over the fifth insulating layer and electrically connected to the third electrode.

33. The display device according to claim 32, wherein the first electrode comprises copper.

34. The display device according to claim 32, further comprising a second oxide semiconductor layer between the first electrode and the second electrode.

35. The display device according to claim 32, wherein an entirety of the first oxide semiconductor layer overlaps with the first electrode.

36. The display device according to claim 32, wherein a side surface of the first oxide semiconductor layer is in contact with the second electrode and the third electrode.

37. The display device according to claim 32, wherein the first oxide semiconductor layer comprises a crystal region.

38. The display device according to claim 37, wherein the crystal region exists in a superficial portion of the first oxide semiconductor layer.

39. The display device according to claim 32, further comprising:

a first conductive layer between the second electrode and the first oxide semiconductor layer; and

a second conductive layer between the third electrode and the first oxide semiconductor layer.

40. The display device according to claim 39, wherein the first conductive layer and the second conductive layer each comprises titanium.

41. The display device according to claim 39, wherein the first conductive layer and the second conductive layer each comprises a conductive metal oxide.

42. The display device according to claim 32, wherein the fifth insulating layer comprises an organic resin.

43. The display device according to claim 32, further comprising a liquid crystal layer over the pixel electrode.

44. The display device according to claim 32, further comprising a light-emitting layer over the pixel electrode, wherein the light-emitting layer comprises an organic compound.

45. The display device according to claim 32, further comprising a spherical particle over the pixel electrode.

46. A display device comprising:

a first electrode;

a first insulating layer over the first electrode, wherein the first insulating layer comprises nitrogen;

a second insulating layer over the first insulating layer, wherein the second insulating layer comprises oxygen;

a first oxide semiconductor layer over the second insulating layer and overlapping with the first electrode, wherein the first oxide semiconductor layer comprises indium, gallium, and zinc;

a third insulating layer over the first oxide semiconductor layer, wherein the third insulating layer comprises oxygen;

a second electrode and a third electrode each over the first oxide semiconductor layer and the third insulating layer, wherein the second electrode and the third electrode each comprise copper;

a fourth insulating layer over the second electrode and the third electrode;

a fifth insulating layer over the fourth insulating layer; and

a pixel electrode over the fifth insulating layer and electrically connected to the third electrode.

47. The display device according to claim 46, wherein the first electrode comprises copper.

48. The display device according to claim 46, further comprising a second oxide semiconductor layer between the first electrode and the second electrode.

49. The display device according to claim 46, wherein an entirety of the first oxide semiconductor layer overlaps with the first electrode.

50. The display device according to claim 46, wherein a side surface of the first oxide semiconductor layer is in contact with the second electrode and the third electrode.

51. The display device according to claim 46, wherein the first oxide semiconductor layer comprises a crystal region.

52. The display device according to claim 51, wherein the crystal region exists in a superficial portion of the first oxide semiconductor layer.

53. The display device according to claim 46, further comprising:

a first conductive layer between the second electrode and the first oxide semiconductor layer; and

a second conductive layer between the third electrode and the first oxide semiconductor layer.

54. The display device according to claim 53, wherein the first conductive layer and the second conductive layer each comprises titanium.

55. The display device according to claim 53, wherein the first conductive layer and the second conductive layer each comprises a conductive metal oxide.

56. The display device according to claim 46, wherein the fourth insulating layer comprises nitrogen.

57. The display device according to claim 46, wherein the fifth insulating layer comprises an organic resin.

58. The display device according to claim 46, further comprising a liquid crystal layer over the pixel electrode.

59. The display device according to claim 46, further comprising a light-emitting layer over the pixel electrode, wherein the light-emitting layer comprises an organic compound.

60. The display device according to claim 46, further comprising a spherical particle over the pixel electrode.