Fabrication process for thin film transistors in a display or electronic device

• US 20020192885A1
• Filed: 07/08/2002
• Published: 12/19/2002
• Est. Priority Date: 05/14/1998
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Miyasaka, Mitsutoshi
• Granted Patent: US 6,673,126 B2
• Time in Patent Office: Days
• US Class Current: 438/164
• CPC Class Codes: H01L 21/67155 Apparatus for manufacturing or treating in a plurality of work-stations
• CPC Class Codes: H01L 29/66757 Lateral single gate single channel transistors with non-inverted structure, i.e. the channel layer is formed before the gate
• CPC Class Codes: H01L 29/78681 having a semiconductor body comprising AIIIBV or AIIBVI or AIVBVI semiconductor materials, or Se or Te
• CPC Class Codes: H01L 29/78684 having a semiconductor body comprising semiconductor materials of Group IV not being silicon, or alloys including an element of the group IV, e.g. Ge, SiN alloys, SiC alloys H01L29/7869 takes precedence

Abstract

A fabrication process for a thin film transistor including, in the first process step, performing semiconductor layer formation processing, crystallization processing, and first gate insulator formation processing without exposing the substrate to atmosphere. In the second process step, performing rapid thermal processing of the first gate insulator layer and the semiconductor layer. In the third process step, performing patterning of the first gate insulator layer and the semiconductor layer. In the fourth process step, performing cleaning by etching the surface of the first gate insulator layer which has been contaminated by the resist mask. In the fifth process step, performing hydrogenation processing followed by formation of the second gate insulator layer on the surface of the first gate insulator layer.

Claims

1. A fabrication process for a thin film transistor which includes at least:

a first process step which involves the formation of a semiconductor layer on a substrate which is isolated from atmosphere, followed by crystallization of said semiconductor layer in a non-oxidizing atmosphere without exposing said substrate to atmosphere, followed by formation of a first gate insulator layer on top of said semiconductor layer during which said substrate is not exposed to atmosphere;

a second process step, following completion of the first process step, which involves thermal processing of said first gate insulator layer and said semiconductor layer;

a third process step, following completion of the second process step, which involves patterning of said first gate insulator layer and said semiconductor layer;

and a fourth process step, following completion of the third process step, which involves hydrogenation of said substrate followed by formation of a second gate insulator layer on the surface of said first gate insulator layer.

2. A fabrication process of a thin film transistor as described in claim 1 above characterized by crystallization through laser irradiation in the crystallization step of the aforementioned first process step.

3. A fabrication process of a thin film transistor as described in claim 1 above characterized by melt crystallization in the crystallization step of the aforementioned first process step.

4. A fabrication process of a thin film transistor as described in claim 2 or claim 3 above characterized by crystallization under a hydrogen-containing atmosphere in the aforementioned first process step.

5. A fabrication process of a thin film transistor as described in claim 2 or claim 3 above characterized by crystallization under an argon-containing reducing atmosphere in the aforementioned first process step.

6. A fabrication process of a thin film transistor as described in any of claim 1 to claim 5 above characterized by performing the aforementioned second process step under a hydrogen-containing atmosphere.

7. A fabrication process of a thin film transistor as described in any of claim 1 to claim 5 above characterized by performing the aforementioned second process step under an oxygen-containing atmosphere.

8. A fabrication process of a thin film transistor as described in any of claim 1 to claim 5 above characterized by performing the aforementioned second process step under a water vapor-containing atmosphere.

34. A fabrication process of a thin film transistor as described in any of claim 1 to claim 33 above characterized by performing all process steps following formation of the aforementioned second gate insulator layer under temperature conditions of 350°

C. or less.

59. A display device using a thin film transistor fabricated by the fabrication process described in claim 1 above.

60. An electronic device using a thin film transistor fabricated by the fabrication process described in claim 1 above.

64. A manufacturing method for a display device using the fabrication process in claim 1.

68. A manufacturing method for an electronic apparatus using the fabrication process in claim 1.

9. A fabrication process for a thin film transistor which includes at least a first process step which involves the formation of a semiconductor layer on a substrate which is isolated from atmosphere, followed by crystallization of said semiconductor layer in a non-oxidizing atmosphere without exposing said substrate to atmosphere, followed by hydrogenation of said substrate during which said substrate is not exposed to atmosphere, followed by formation of a first gate insulator layer on top of said semiconductor layer during which said substrate is not exposed to atmosphere;

a second process step, following completion of the first process step, which involves thermal processing of said first gate insulator layer and said semiconductor layer;

a third process step, following completion of the second process step, which involves patterning of said first gate insulator layer and said semiconductor layer;

and a fourth process step, following completion of the third process step, which involves hydrogenation of said substrate followed by formation of a second gate insulator layer on the surface of said first gate insulator layer.

10. A fabrication process of a thin film transistor as described in claim 9 above characterized by crystallization through laser irradiation in the crystallization step of the aforementioned first process step.

11. A fabrication process of a thin film transistor as described in claim 9 above characterized by melt crystallization in the crystallization step of the aforementioned first process step.

12. A fabrication process of a thin film transistor as described in claim 10 or claim 11 above characterized by crystallization under a hydrogen-containing atmosphere in the aforementioned first process step.

13. A fabrication process of a thin film transistor as described in claim 10 or claim 11 above characterized by crystallization under an argon-containing reducing atmosphere in the aforementioned first process step.

14. A fabrication process of a thin film transistor as described in any of claim 9 to claim 13 above characterized by performing the aforementioned second process step under a hydrogen-containing atmosphere.

15. A fabrication process of a thin film transistor as described in any of claim 9 to claim 13 above characterized by performing the aforementioned second process step under an oxygen-containing atmosphere.

16. A fabrication process of a thin film transistor as described in any of claim 9 to claim 13 above characterized by performing the aforementioned second process step under a water vapor-containing atmosphere.

18. A fabrication process of a thin film transistor as described in claim 17 above characterized by crystallization through laser irradiation in the crystallization step of the aforementioned first process step.

19. A fabrication process of a thin film transistor as described in claim 17 above characterized by melt crystallization in the crystallization step of the aforementioned first process step.

20. A fabrication process of a thin film transistor as described in claim 18 or claim 19 above characterized by crystallization under a hydrogen-containing atmosphere in the aforementioned first process step.

21. A fabrication process of a thin film transistor as described in claim 18 or claim 19 above characterized by crystallization under an argon-containing reducing atmosphere in the aforementioned first process step.

22. A fabrication process of a thin film transistor as described in any of claim 17 to claim 21 above characterized by performing the aforementioned second process step under a hydrogen-containing atmosphere.

23. A fabrication process of a thin film transistor as described in any of claim 17 to claim 21 above characterized by performing the aforementioned second process step under an oxygen-containing atmosphere.

24. A fabrication process of a thin film transistor as described in any of claim 17 to claim 21 above characterized by performing the aforementioned second process step under a water vapor-containing atmosphere.

26. A fabrication process of a thin film transistor as described in claim 25 above characterized by the inclusion of etching of the surface of the aforementioned first gate insulator layer in the aforementioned fourth process step.

27. A fabrication process of a thin film transistor as described in claim 25 or claim 26 above characterized by crystallization through laser irradiation in the crystallization step of the aforementioned first process step.

28. A fabrication process of a thin film transistor as described in claim 25 or claim 26 above characterized by melt crystallization in the crystallization step of the aforementioned first process step.

29. A fabrication process of a thin film transistor as described in claim 27 or claim 28 above characterized by crystallization under a hydrogen-containing atmosphere in the aforementioned first process step.

30. A fabrication process of a thin film transistor as described in claim 27 or claim 28 above characterized by crystallization under an argon-containing reducing atmosphere in the aforementioned first process step.

31. A fabrication process of a thin film transistor as described in any of claim 25 to claim 30 above characterized by performing the aforementioned second process step under a hydrogen-containing atmosphere.

32. A fabrication process of a thin film transistor as described in any of claim 25 to claim 30 above characterized by performing the aforementioned second process step under an oxygen-containing atmosphere.

33. A fabrication process of a thin film transistor as described in any of claim 25 to claim 30 above characterized by performing the aforementioned second process step under a water vapor-containing atmosphere.

36. A fabrication process of a thin film transistor as described in claim 35 above characterized by crystallization through laser irradiation in the crystallization step of the aforementioned first process step.

37. A fabrication process of a thin film transistor as described in claim 35 above characterized by melt crystallization in the crystallization step of the aforementioned first process step.

38. A fabrication process of a thin film transistor as described in claim 36 or claim 37 above characterized by crystallization under a hydrogen-containing atmosphere in the aforementioned first process step.

39. A fabrication process of a thin film transistor as described in claim 36 or claim 37 above characterized by crystallization under an argon-containing reducing atmosphere in the aforementioned first process step.

17. A fabrication process for a thin film transistor which includes at least a first process step which involves the formation of a semiconductor layer on a substrate which is isolated from atmosphere, followed by crystallization of said semiconductor layer in a non-oxidizing atmosphere without exposing said substrate to atmosphere, followed by hydrogenation and oxidation of said substrate during which said substrate is not exposed to atmosphere, followed by formation of a first gate insulator layer on top of said semiconductor layer during which said substrate is not exposed to atmosphere;

a second process step, following completion of the first process step, which involves thermal processing of said first gate insulator layer and said semiconductor layer;

a third process step, following completion of the second process step, which involves patterning of said first gate insulator layer and said semiconductor layer;

and a fourth process step, following completion of the third process step, which involves hydrogenation of said substrate followed by formation of a second gate insulator layer on the surface of said first gate insulator layer.

25. A fabrication process for a thin film transistor which includes at least a first process step which involves the formation of a semiconductor layer on a substrate which is isolated from atmosphere, followed by crystallization of said semiconductor layer in a non-oxidizing atmosphere without exposing said substrate to atmosphere, followed by formation of a first gate insulator layer on top of said semiconductor layer during which said substrate is not exposed to atmosphere;

a second process step, following completion of the first process step, which involves thermal processing of said first gate insulator layer and said semiconductor layer;

a third process step, following completion of the second process step, which involves patterning of said first gate insulator layer and said semiconductor layer;

a fourth process step, following completion of the third process step, which involves cleaning of the surface of said first gate insulator layer;

and a fifth process step, immediately following completion of the fourth process step, which involves hydrogenation of said substrate followed by formation of a second gate insulator layer on the surface of said first gate insulator layer.

35. A fabrication process for a thin film transistor which includes at least a first process step which involves the formation of a semiconductor layer on a substrate which is isolated from atmosphere, followed by crystallization of said semiconductor layer in a non-oxidizing atmosphere without exposing said substrate to atmosphere, followed by formation of a first gate insulator layer on top of said semiconductor layer during which said substrate is not exposed to atmosphere;

a second process step, following completion of the first process step, which involves patterning of said first gate insulator layer and said semiconductor layer;

and a third process step, following completion of the second process step, which involves thermal treatment of said substrate in an oxidizing environment and the formation on the surface of said semiconductor layer of an oxide layer as a second gate insulator layer.

40. A fabrication process for a thin film transistor which includes at least a first process step which involves the formation of a semiconductor layer on a substrate which is isolated from atmosphere, followed by crystallization of said semiconductor layer in a non-oxidizing atmosphere without exposing said substrate to atmosphere, followed by formation of a first gate insulator layer on top of said semiconductor layer during which said substrate is not exposed to atmosphere;

a second process step, following completion of the first process step, which involves thermal processing of said first gate insulator layer and said semiconductor layer;

a third process step, following completion of the second process step, which involves patterning of said first gate insulator layer and said semiconductor layer;

and a fourth process step, following completion of the third process step, which involves thermal treatment of said substrate in an oxidizing environment and the formation on the surface of said semiconductor layer of an oxide layer as a second gate insulator layer.

41. A fabrication process of a thin film transistor as described in claim 40 above characterized by crystallization through laser irradiation in the crystallization step of the aforementioned first process step.

42. A fabrication process of a thin film transistor as described in claim 40 above characterized by melt crystallization in the crystallization step of the aforementioned first process step.

43. A fabrication process of a thin film transistor as described in claim 41 or claim 42 above characterized by crystallization under a hydrogen-containing atmosphere in the aforementioned first process step.

44. A fabrication process of a thin film transistor as described in claim 41 or claim 42 above characterized by crystallization under an argon-containing reducing atmosphere in the aforementioned first process step.

45. A fabrication process of a thin film transistor as described in any of claim 40 to claim 44 above characterized by performing the aforementioned second process step under a hydrogen-containing atmosphere.

46. A fabrication process of a thin film transistor as described in any of claim 40 to claim 44 above characterized by performing the aforementioned second process step under an oxygen-containing atmosphere.

47. A fabrication process of a thin film transistor as described in any of claim 40 to claim 44 above characterized by performing the aforementioned second process step under a water vapor-containing atmosphere.

49. A fabrication process of a thin film transistor as described in claim 48 above characterized by crystallization through laser irradiation in the crystallization step of the aforementioned first process step.

50. A fabrication process of a thin film transistor as described in claim 48 above characterized by melt crystallization in the crystallization step of the aforementioned first process step.

51. A fabrication process of a thin film transistor as described in claim 49 or claim 50 above characterized by crystallization under a hydrogen-containing atmosphere in the aforementioned first process step.

52. A fabrication process of a thin film transistor as described in claim 49 or claim 50 above characterized by crystallization under an argon-containing reducing atmosphere in the aforementioned first process step.

48. A fabrication process for a thin film transistor which includes at least a first process step which involves the formation of a semiconductor layer on a substrate which is isolated from atmosphere, followed by crystallization of said semiconductor layer in a non-oxidizing atmosphere without exposing said substrate to atmosphere, followed by at least either hydrogenation or oxidation treatment of said substrate without exposing said substrate to atmosphere, followed by formation of a first gate insulator layer on top of said semiconductor layer during which said substrate is not exposed to atmosphere;

a second process step, following completion of the first process step, which involves patterning of said first gate insulator layer and said semiconductor layer;

and a third process step, following completion of the second process step, which involves the formation of a second gate insulator layer on the surface of said first gate insulator layer.

53. A fabrication process for a thin film transistor which includes at least a first process step which involves the formation of a semiconductor layer on a substrate which is isolated from atmosphere, followed by crystallization of said semiconductor layer in a non-oxidizing atmosphere without exposing said substrate to atmosphere, followed by at least either hydrogenation or oxidation treatment of said substrate without exposing said substrate to atmosphere, followed by formation of a first gate insulator layer on top of said semiconductor layer during which said substrate is not exposed to atmosphere;

a second process step, following completion of the first process step, which involves patterning of said first gate insulator layer and said semiconductor layer;

a third process step, following completion of the second process step, which involves cleaning the surface of the first gate insulator layer;

and a fourth process step, following completion of the third process step, which involves the formation of a second gate insulator layer on the surface of said first gate insulator layer.

54. A fabrication process of a thin film transistor as described in claim 53 above characterized by the inclusion of etching of the surface of the aforementioned first gate insulator layer in the aforementioned second process step.

55. A fabrication process of a thin film transistor as described in claim 53 or claim 54 above characterized by crystallization through laser irradiation in the crystallization step of the aforementioned first process step.

56. A fabrication process of a thin film transistor as described in claim 53 or claim 54 above characterized by melt crystallization in the crystallization step of the aforementioned first process step.

57. A fabrication process of a thin film transistor as described in claim 55 or claim 56 above characterized by crystallization under a hydrogen-containing atmosphere in the aforementioned first process step.

58. A fabrication process of a thin film transistor as described in claim 55 or claim 56 above characterized by crystallization under an argon-containing reducing atmosphere in the aforementioned first process step.

61. A fabrication process for a thin film transistor that includes at least:

a first process step comprising;

formation of an underlevel protection layer on a substrate without exposing the substrate to atmosphere;

formation of a semiconductor layer on the underlevel protection layer without exposing the substrate to atmosphere;

crystallization of the semiconductor layer without exposing the substrate to atmosphere, followed by formation of a first gate insulator layer on the semiconductor layer during which the substrate is not exposed to atmosphere,

a second process step, following completion of the first step, which involves a patterning of the semiconductor layer and the first gate insulator layer by using a single mask;

a third process step, following completion of the second step, which involves formation of a second gate insulator layer at least on the first gate insulator layer.

65. A manufacturing method for a display device using the fabrication process in claim 61.

69. A manufacturing method for an electronic apparatus using the fabrication process in claim 61.

62. A fabrication process for a thin film transistor that includes at least:

a first process step comprising;

formation of a semiconductor layer on a substrate without exposing the substrate to atmosphere;

crystallization of the semiconductor layer without exposing to the substrate, followed by oxidation of the substrate without exposing the substrate to atmosphere, followed by formation of a first gate insulator layer on the semiconductor layer during which the substrate is not exposed to atmosphere;

a second process step, following completion of the first step, which involves a patterning of the semiconductor layer and the first gate insulator layer by using a single mask;

a third process step, following completion of the second step, which involves formation of a second gate insulator layer at least on the first gate insulator layer.

66. A manufacturing method for a display device using the fabrication process in claim 62.

70. A manufacturing method for an electronic apparatus using the fabrication process in claim 62.

63. A fabrication process for a thin film transistor, which includes at least:

a first process step comprising;

formation of a semiconductor layer on a substrate, followed by crystallization of the semiconductor layer during which the substrate is isolated from atmosphere;

formation of a first gate insulator layer on the semiconductor layer without exposing the substrate to atmosphere,

a second process step, following completion of the first step, which involves a patterning of the semiconductor layer and the first gate insulator layer by using a single mask;

a third process step, following completion of the second step, which involves formation of a second gate insulator layer at least on the first gate insulator layer;

a fourth process step, following completion of the third process step, which involves thermal processing of the first gate insulator layer, the second gate insulator layer, and the semiconductor layer.

67. A manufacturing method for a display device using the fabrication process in claim 63.

71. A manufacturing method for an electronic apparatus using the fabrication process in claim 63.