Method of fabricating a semiconductor device

• US 6,479,331 B1
• Filed: 07/29/1996
• Issued: 11/12/2002
• Est. Priority Date: 06/30/1993
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Takemura, Yasuhiko
• Primary Examiner(s): Nguyen, Tuan H.
• Application Number:
  US08/688,229
• Time in Patent Office: 2,297 Days
• Field of Search: 438/153, 438/154, 438/162, 438/166, 438/232, 438/515, 438/528, 438/532
• US Class Current: 438/153
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02488 Insulating materials
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02667 Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth
• CPC Class Codes: H01L 21/02686 Pulsed laser beam
• 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 29/66757 Lateral single gate single channel transistors with non-inverted structure, i.e. the channel layer is formed before the gate
• CPC Class Codes: Y10S 148/091 Laser beam processing of fets

Abstract

Two kinds of TFTs are fabricated by the same process with a high production yield to manufacture an active-matrix circuit and a peripheral driver circuit on the same substrate. The active-matrix circuit is required to have a high mobility and a high ON/OFF current ratio. The peripheral driver circuit needs a complex interconnection structure. The active-matrix circuit and the peripheral driver circuit comprising the TFTs are fabricated monolithically. In this step, the gate electrodes of the TFTs of the active-matrix circuit is coated with an anodic oxide on their top and side surfaces. The gate electrodes of the TFTs of the peripheral driver circuit is coated with the anodic oxide on only their top surfaces; substantially no anodic oxide is present on the side surfaces.

Claims

1. A method for manufacturing a semiconductor device comprising a plurality of n-channel and p-channel type thin film transistors, said method comprising:

forming a semiconductor film comprising silicon over a substrate comprising a glass;

crystallizing said semiconductor film by a heat treatment;

patterning said semiconductor film to form semiconductor regions;

doping first impurities into said semiconductor regions, wherein said first impurities comprise an n-type impurity and are doped by an ion doping process;

forming a mask over a portion of said semiconductor regions;

doping second impurities into at least one of said semiconductor regions over which said mask is not formed, wherein said second impurities comprise a p-type impurity and are doped by an ion doping process; and

performing a rapid thermal annealing to said semiconductor regions by irradiating a light comprising an infrared light after said doping process.

2. The method of claim 1 wherein said mask comprises photoresist.

3. The method of claim 1 wherein said p-type impurity is boron and a dose of said boron is 4 to 10×

10¹⁵/cm².

4. The method of claim 1 wherein said semiconductor device is at least one selected from a group consisting of a liquid crystal display, an image sensor and a semiconductor integrated circuit comprising at least one of a DRAM and a SRAM circuits.

5. The method of claim 1 wherein a thickness of said semiconductor film is 30 nm or more.

6. A method for manufacturing a semiconductor device comprising a plurality of n-channel and p-channel type thin film transistors, said method comprising:

forming a semiconductor film comprising silicon over a substrate comprising a glass;

crystallizing said semiconductor film by a heat treatment;

patterning said semiconductor film to form semiconductor regions;

doping an n-type impurity by an ion doping process into said semiconductor regions;

forming a mask over a portion of said semiconductor islands;

doping a p-type impurity by an ion doping process into at least one of said semiconductor regions over which said mask is not formed; and

performing a rapid thermal annealing to said semiconductor regions by irradiating a light comprising an infrared light after said doping process,

wherein a mask is provided over channel regions of said semiconductor regions so as not to dope said n-type impurity and said p-type impurity into said channel regions.

7. The method of claim 6 wherein said p-type impurity is introduced more than said n-type impurity.

8. The method of claim 6 wherein sheet resistance is 200 to 800 Ω

/square in said at least one of said semiconductor regions into which said n-type and p-type impurities are doped.

9. The method of claim 6 wherein said mask provided over said channel regions is gate electrodes of said plurality of thin film transistors.

10. The method of claim 6 wherein said mask comprises a photoresist.

11. The method of claim 6 wherein said p-type impurity is boron and a dose of said boron is 4 to 10×

10¹⁵/cm².

12. The method of claim 6 wherein said semiconductor device is at least one selected from a group consisting of a liquid crystal display, an image sensor and a semiconductor integrated circuit comprising at least one of a DRAM and a SRAM circuits.

13. The method of claim 6 wherein a thickness of said semiconductor film is 30 nm or more.

14. A method for manufacturing an active matrix type display device comprising a plurality of n-channel and p-channel type thin film transistors, said method comprising:

forming a semiconductor film comprising silicon over a substrate comprising a glass;

crystallizing said semiconductor film by a heat treatment;

patterning said semiconductor film to form semiconductor regions;

doping an n-type impurity by an ion doping process into said semiconductor regions;

forming a mask over a portion of said semiconductor regions;

doping a p-type impurity by an ion doing process into at least one of said semiconductor regions over which said mask is not formed;

performing a rapid thermal annealing to said semiconductor regions by irradiating a light comprising an infrared light after said doping process; and

annealing said plurality of semiconductor regions in hydrogen gas,

wherein said n-channel type thin film transistors comprising the semiconductor regions containing said n-type impurity and said p-channel type thin film transistors comprising the semiconductor regions containing said n-type and ptype impurities are formed as complementary transistors in a driver circuit portion of said active matrix type display device, and thin film transistors of one of said pchannel type and n-channel type are formed in a pixel portion of said active matrix type display device.

15. The method of claim 14 wherein said p-type impurity is doped more than said n-type impurity.

16. The method of claim 14 wherein sheet resistance is 200 to 800 Ω

/square in said at least one of said semiconductor regions into which said n-type and p-type impurities are doped.

17. The method of claim 14 wherein said mask comprises a photoresist.

18. The method of claim 14 wherein said p-type impurity is boron and a dose of said boron is 4 to 10×

10¹⁵/cm².

19. The method of claim 14 wherein a thickness of said semiconductor film is 30 nm or more.

20. A method for manufacturing an active matrix type display device comprising a plurality of n-channel and p-channel type thin film transistors, said method comprising:

forming a semiconductor film comprising silicon over a substrate comprising a glass;

crystallizing said semiconductor film by a heat treatment;

patterning said semiconductor film to form semiconductor regions;

doping an n-type impurity by an ion doping process into said semiconductor regions;

forming a mask over a portion of said semiconductor regions;

doping a p-type impurity by an ion doping process into at least one of said semiconductor regions over which said mask is not formed; and

performing a rapid thermal annealing to said semiconductor regions by irradiating a light comprising an infrared light after said doping step,

wherein a mask is provided over channel regions of said semiconductor regions so as not to dope said n-type impurity and said p-type impurity into said channel regions, and

wherein said n-channel type thin film transistors comprising the semiconductor regions containing said n-type impurity and said p-channel type thin film transistors comprising the semiconductor regions containing said n-type and p-type impurities are formed as complementary transistors in a driver circuit portion of said active matrix type display device, and thin film transistors of one of said p-channel type and n-channel type are formed in a pixel portion of said active matrix type display device.

21. The method of claim 20 wherein said mask provided over said channel regions is gate electrodes of said plurality of thin film transistors.

22. The method of claim 20 wherein said p-type impurity is doped more than said n-type impurity.

23. The method of claim 20 wherein sheet resistance is 200 to 800 Ω

/square in said at least one of said semiconductor regions into which said n-type and p-type impurities are doped.

24. The method of claim 20 wherein said mask formed over said portion of said semiconductor regions comprises a photoresist.

25. The method of claim 20 wherein said p-type impurity is boron and a dose of said boron is 4 to 10×

10¹⁵/cm².

26. The method of claim 20 wherein said active matrix type display device is a liquid crystal display.

27. The method of claim 20 wherein a thickness of said semiconductor film is 30 nm or more.

28. A method for manufacturing a semiconductor device comprising a plurality of n-channel and p-channel type thin film transistors, said method comprising:

forming a semiconductor film comprising silicon over a substrate comprising a glass;

crystallizing said semiconductor film by a heat treatment;

patterning said semiconductor film to form semiconductor regions;

doping first impurities into said semiconductor regions, wherein said first impurities comprise an n-type impurity and are doped by an ion doping process;

forming a mask over a portion of said semiconductor regions;

doping second impurities into at least one of said semiconductor regions over which said mask isnot formed, wherein said second impurities comprise a p-type impurity and are doped by an ion doping process;

performing a rapid thermal annealing to said semiconductor regions by irradiating a light comprising an infrared light after said doping process; and

annealing said semiconductor regions in hydrogen gas.

29. The method of claim 28 wherein said p-type impurity is introduced more than said n-type impurity.

30. The method of claim 28 wherein sheet resistance is 200 to 800 Ω

/square in said at least one of said semiconductor regions into which said n-type and p-type impurities are doped.

31. The method of claim 28 wherein hydrogen is contained in at least source and drain regions of said plurality of thin film transistors.

32. The method of claim 28 wherein said mask comprises a photoresist.

33. The method of claim 28 wherein said p-type impurity is boron and a dose of said boron is 4 to 10×

10¹⁵/cm².

34. The method of claim 28 wherein said semiconductor device is at least one selected from a group consisting of a liquid crystal display, an image sensor and a semiconductor integrated circuit comprising at least one of a DRAM and a SRAM circuits.

35. The method of claim 28 wherein a thickness of said semiconductor film is 30 nm or more.

36. A method for manufacturing a semiconductor device comprising a plurality of n-channel and p-channel type thin film transistors, said method comprising:

forming a semiconductor film comprising silicon over a substrate comprising a glass;

crystallizing said semiconductor film by a heat treatment;

patterning said semiconductor film to form semiconductor regions;

doping first impurities into said semiconductor regions, wherein said first impurities comprise an n-type impurity and are doped by an ion doping process;

forming a mask over a portion of said semiconductor regions;

doping second impurities into at least one of said semiconductor regions over which said mask is not formed, wherein said second impurities comprise a p-type impurity and are doped by an ion doping process; and

performing a rapid thermal annealing to said semiconductor regions by irradiating a light comprising an infrared light after said doping process,

wherein a mask is provided over channel regions of said semiconductor regions so as not to dope said n-type impurity and said p-type impurity into said channel regions.

37. The method of claim 36 wherein said mask provided over said channel regions is gate electrodes of a plurality of thin film transistors.

38. The method of claim 36 wherein said p-type impurity is doped more than said n-type impurity.

39. The method of claim 36 wherein sheet resistance is 200 to 800 Ω

/square in said at least one of said semiconductor regions into which said n-type and p-type impurities are introduced.

40. The method of claim 36 wherein hydrogen is contained in at least source and drain regions of said plurality of thin film transistors.

41. The method of claim 36 wherein said mask formed over said portion of said semiconductor regions comprises a photoresist.

42. The method of claim 36 wherein said p-type impurity is boron and a dose of said boron is 4 to 10×

10¹⁵/cm².

43. The method of claim 36 wherein said semiconductor device is at least one selected from a group consisting of a liquid crystal display, an image sensor and a semiconductor integrated circuit comprising at least one of a DRAM and a SRAM circuits.

44. The method of claim 36 wherein a thickness of said semiconductor film is 30 nm or more.

45. A method for manufacturing an active matrix type display device comprising a plurality of n-channel and p-channel type thin film transistors, said method comprising:

forming a semiconductor film comprising silicon over a substrate comprising a glass;

crystallizing said semiconductor film by a heat treatment;

patterning said semiconductor film to form semiconductor regions;

doping an n-type impurity by an ion doping process into said semiconductor regions;

forming a mask over a portion of said semiconductor regions;

doping a p-type impurity by an ion doping process into at least one of said semiconductor regions over which said mask is not formed;

performing a rapid thermal annealing to said n-type impurity and said p-type impurity by irradiating a light comprising an infrared light to said semiconductor regions; and

annealing said semiconductor regions in hydrogen gas,

wherein the n-channel thin film transistors comprising the semiconductor regions containing said n-type impurity and the p-channel thin film transistors comprising the semiconductor regions containing said n-type and p-type impurities are formed as complementary transistors in a driver circuit portion of said active matrix type display device, and thin film transistors of one of said p-channel type and n-channel type are formed in a pixel portion of said active matrix type display device.

46. The method of claim 45 wherein said mask comprises a photoresist.

47. The method of claim 45 wherein said ion doping process for doping said impurities uses of borane as a doping gas.

48. The method of claim 45 wherein said p-type impurity is boron and a dose of said boron is 4 to 10×

10¹⁵/cm².

49. The method of claim 45 wherein said active matrix type display device is a liquid crystal display.

50. The method of claim 45 wherein said rapid thermal annealing step is performed for several seconds to several minutes.

51. The method of claim 45 wherein a thickness of said semiconductor film is 30 nm or more.

52. A method for manufacturing an active matrix type display device comprising a plurality of n-channel and p-channel type thin film transistors, said method comprising:

forming a semiconductor film comprising silicon over a substrate comprising a glass;

crystallizing said semiconductor film by a heat treatment;

patterning said semiconductor film to form semiconductor regions;

doping an n-type impurity by an ion doping process into said semiconductor regions;

forming a mask over a portion of said semiconductor regions;

doping a p-type impurity by an ion doping process into at least one of said semiconductor regions over which said mask is not formed; and

performing a rapid thermal annealing to said n-type impurity and said p-type impurity by irradiating a light comprising an infrared light to said semiconductor regions,

wherein the n-channel thin film transistors comprising the semiconductor regions containing said n-type impurity and the p-channel thin film transistors comprising the semiconductor regions containing said n-type and p-type impurities are formed as complementary transistors in a driver circuit portion of said active matrix type display device, and thin film transistors of one of said p-channel type and n-channel type are formed in a pixel portion of said active matrix type display device, and

wherein said p-type impurity is doped more than said n-type impurity.

53. The method of claim 52 wherein sheet resistance is 200 to 800 Ω

/square in said at least one of said semiconductor regions into which said n-type and p-type impurities are doped.

54. The method of claim 52 wherein said mask comprises a photoresist.

55. The method of claim 52 wherein said p-type impurity is boron and a dose of said boron is 4 to 10×

10¹⁵/cm².

56. The method of claim 52 wherein said active matrix type display device is a liquid crystal display.

57. The method of claim 52 wherein said rapid thermal annealing step is performed for several seconds to several minutes.

58. The method of claim 52 wherein a thickness of said semiconductor film is 30 nm or more.

59. A method for manufacturing a semiconductor device comprising a plurality of n-channel and p-channel type thin film transistors, said method comprising:

forming a semiconductor film comprising silicon on an insulating surface comprising a glass;

irradiating a laser light to crystallize said semiconductor film;

patterning said semiconductor film to form semiconductor regions;

forming at least one film over each of said semiconductor regions;

doping first impurities into said semiconductor regions, wherein said first impurities comprise an n-type impurity and are doped by an ion doping process;

forming a mask over a portion of said semiconductor islands; and

doping second impurities into said semiconductor regions over which said mask is not formed, wherein said second impurities comprise p-type impurity and are doped by an ion doping process; and

performing a rapid thermal annealing to said semiconductor regions by irradiating a light comprising an infrared light after said doping process,

wherein said p-type impurity is doped more than said n-type impurity.

60. The method of claim 59 wherein said laser light is KrF excimer laser.

61. The method of claim 59 wherein said at least one film is used as a gate electrode.

62. The method of claim 59 wherein said p-type impurity is boron and a dose of said boron is 4 to 10×

10¹⁵/cm².

63. The method of claim 59 wherein said semiconductor device is at least one selected from a group consisting of a liquid crystal display, an image sensor and a semiconductor integrated circuit comprising at least one of a DRAM and a SRAM circuits.

64. The method of claim 59 wherein an energy density of said laser light is 200 to 400 mJ/cm².

65. The method of claim 59 wherein a thickness of said semiconductor film is 30 nm or more.

66. A method for manufacturing a semiconductor device comprising a plurality of n-channel and p-channel type thin film transistors, said method comprising:

forming a semiconductor film comprising silicon on an insulating surface comprising a glass;

irradiating a laser light to crystallize said semiconductor film;

patterning said semiconductor film to form semiconductor regions;

forming at least one film over each of said semiconductor regions;

doping first impurities comprising phosphorus into said semiconductor regions by an ion doping process;

forming a mask over a portion of said semiconductor regions;

doping second impurities comprising boron into said semiconductor regions over which said mask is not formed by an ion doping process; and

performing a rapid thermal annealing to said semiconductor regions by irradiating a light comprising an infrared light after said doping process.

67. The method of claim 66 wherein said laser light is KrF excimer laser.

68. The method of claim 66 wherein said at least one film is used as a gate electrode.

69. The method of claim 66 wherein a dose of said boron is 4 to 10×

10¹⁵/cm².

70. The method of claim 66 wherein said semiconductor device is at least one selected from a group consisting of a liquid crystal display, an image sensor and a semiconductor integrated circuit comprising at least one of a DRAM and a SRAM circuits.

71. The method of claim 66 wherein an energy density of said laser light is 200 to 400 mJ/cm².

72. The method of claim 66 wherein a thickness of said semiconductor film is 30 nm or more.