Semiconductor device forming method

• US 6,413,805 B1
• Filed: 06/25/1996
• Issued: 07/02/2002
• Est. Priority Date: 03/12/1993
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Ohtani, Hisashi, Takayama, Toru, Takemura, Yasuhiko, Zhang, Hongyong, Miyanaga, Akiharu
• Primary Examiner(s): TRINH, MICHAEL MANH
• Application Number:
  US08/670,122
• Time in Patent Office: 2,198 Days
• Field of Search: 437/41.TFT, 437/40.TFT, 437/21, 437/247, 437/913, 437/967, 438/486, 438/487, 438/166, 438/164
• US Class Current: 438/166
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02672 using crystallisation enhancing elements
• CPC Class Codes: H01L 27/1277 using a crystallisation promoting species, e.g. local introduction of Ni catalyst
• CPC Class Codes: H01L 27/1296 adapted to increase the uniformity of device parameters
• CPC Class Codes: H01L 29/045 by their particular orientation of crystalline planes
• 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

Abstract

In thin film transistors (TFTS) having an active layer of crystalline silicon adapted for mass production, a catalytic element is introduced into doped regions of an amorphous silicon film by ion implantation or other means. This film is crystallized at a temperature below the strain point of the glass substrate. Further, a gate insulating film and a gate electrode are formed. Impurities are introduced by a self-aligning process. Then, the laminate is annealed below the strain point of the substrate to activate the dopant impurities. On the other hand, Neckel or other element is also used as a catalytic element for promoting crystallization of an amorphous silicon film. First, this catalytic element is applied in contact with the surface of the amorphous silicon film. The film is heated at 450 to 650° C. to create crystal nuclei. The film is further heated at a higher temperature to grow the crystal grains. In this way, a crystalline silicon film having improved crystallinity is formed.

Claims

1. A method for producing a semiconductor device comprising the steps of:

forming a semiconductor film comprising amorphous silicon over a substrate;

disposing a crystallization promoting material in contact with the semiconductor film, said crystallization promoting material being capable of promoting crystallization of the semiconductor film;

crystallizing the semiconductor film using the crystallization promoting material by heating at a first temperature having a range of 450 to 650°

C.;

patterning the crystallized semiconductor film into at least one semiconductor island;

heating the semiconductor island in an oxidizing atmosphere at 800-1100°

C. by furnace annealing to improve crystallinity whereby a thermal oxide layer is formed on a surface of the semiconductor island;

forming a gate electrode over the semiconductor island;

introducing an impurity into the semiconductor island selectively after the formation of the gate electrode; and

then

activating the impurity in the crystallized semiconductor film.

2. A method according to claim 1 wherein the semiconductor film is formed by plasma chemical vapor deposition or low pressure chemical vapor deposition.

3. A method according to claim 1 wherein the introduction of the impurity is conducted by using said gate electrode as a mask by ion doping.

4. A method according to claim 1 wherein the crystallization promoting material comprises a metal selected from the group consisting of Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As, and Sb.

5. A method according to claim 1 wherein the crystallization promoting material has a concentration of 1×

10¹⁵ to 1'"'"'10¹⁹ atoms/cm³ measure by secondary ion mass spectrometry.

6. A method according to claim 1 further comprising the step of producing a thin film transistor using the semiconductor island.

7. A method according to claim 1 wherein said semiconductor film is 500 to 1500 Å

.

8. A method according to claim 1 wherein said substrate is a quartz substrate.

9. A method according to claim 1 wherein said crystallization promoting material is disposed by applying onto said semiconductor film a liquid in which said crystallization promoting material is contained.

10. A method according to claim 1 wherein said semiconductor device is an active matrix device.

11. A method according to claim 1 wherein said semiconductor device is at least one of an input port, a memory, and a CPU for an active matrix device.

12. A method according to claim 1 wherein said metal comprises an element selected from the group consisting of Groups VIII, IIIb, IVb and Vb elements of the Periodic Table.

13. A method for producing a semiconductor device comprising the steps of:

forming a semiconductor film comprising amorphous silicon over a substrate;

providing said semiconductor film with a metal containing material for accelerating crystallization of said amorphous silicon;

crystallizing the semiconductor film by heating at a first temperature after providing said metal containing material;

patterning the crystallized semiconductor film into at least one semiconductor island;

heating the semiconductor island at a second temperature of 800-1100°

C. which is higher than said first temperature in an oxidizing atmosphere by furnace annealing to improve crystallinity, whereby a thermal oxide layer is formed on a surface of the semiconductor island;

forming a gate electrode over said semiconductor island;

introducing an impurity into the semiconductor island selectively after the formation of the gate electrode; and

then activating the impurity in the semiconductor island.

14. A method according to claim 13 wherein the semiconductor film is formed by plasma chemical vapor deposition or low pressure chemical vapor deposition.

15. A method according to claim 13 further comprising the step of forming a gate insulating film on a surface of said semiconductor island prior to said forming of said gate electrode.

16. A method according to claim 13 wherein said semiconductor film is 500 to 1500 Å

.

17. A method according to claim 13 wherein said substrate is a quartz substrate.

18. A method according to claim 13 wherein said semiconductor device is an active matrix device.

19. A method according to claim 13 wherein said semiconductor device is at least one of an input port, a memory, and a CPU for an active matrix device.

20. A method according to claim 13 wherein said metal is selected from the group consisting of Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As and Sb.

21. A method according to claim 13 wherein said metal comprises an element selected from the group consisting of Groups VIII, IIIb, IVb and Vb elements of the Periodic Table.

22. A method of manufacturing a semiconductor device comprising the steps of:

forming a semiconductor film comprising amorphous silicon over a substrate;

providing said semiconductor film with a crystallization promoting material for promoting crystallization thereof;

heating said semiconductor film with the crystallization promoting material at a first temperature not higher than 650°

C. to crystallize said semiconductor film;

patterning the crystallized semiconductor film into at least one semiconductor island;

heating the semiconductor island at a second temperature of 800 to 1100°

C. to improve crystallinity thereof;

introducing an impurity into the semiconductor island selectively; and

then

activating the impurity in the semiconductor island.

23. A method according to claim 22 wherein said heating at the second temperature is conducted in an oxidizing atmosphere to oxidize a surface of the semiconductor island.

24. A method according to claim 22 wherein the crystallization promoting material comprises a metal selected from the group consisting of Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As, and Sb.

25. A method according to claim 22 wherein the crystallization promoting material has a concentration of 1×

10¹⁵ to 1×

10¹⁹ atoms/cm³ measured by secondary ion mass spectrometry.

26. A method according to claim 22 wherein said semiconductor film is 500 to 1500 Å

.

27. A method according to claim 22 wherein said substrate is a quartz substrate.

28. A method according to claim 22 wherein said crystallization promoting material is disposed by applying onto said semiconductor film a liquid in which said crystallization promoting material is contained.

29. A method according to claim 22 wherein said semiconductor device is an active matrix device.

30. A method according to claim 22 wherein said semiconductor device is at least one of an input port, a memory, and a CPU for an active matrix device.

31. A method according to claim 22 wherein said metal comprises an element selected from the group consisting of Groups VIII, IIIb, IVb and Vb elements of the Periodic Table.

32. A method of manufacturing a semiconductor device comprising the steps of:

forming a semiconductor film comprising amorphous silicon over a substrate;

providing said semiconductor film with a crystallization promoting material for promoting crystallization thereof;

heating said semiconductor film with the crystallization promoting material at a first temperature not higher than 650°

C. to crystallize said semiconductor film;

patterning the crystallized semiconductor film into at least one semiconductor island;

heating the semiconductor island in an oxidizing atmosphere by furnace annealing at a second temperature of 800 to 1100°

C. to improve crystallinity thereof whereby a thermal oxide layer is simultaneously formed on the semiconductor island;

introducing an impurity into the semiconductor island selectively; and

then

activating the impurity in the semiconductor island.

33. A method according to claim 32 wherein the crystallization promoting material comprises a metal selected from the group consisting of Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As, and Sb.

34. A method according to claim 33 wherein the crystallization promoting material has a concentration of 1×

10¹⁵ to 1×

10¹⁹ atoms/cm³ measured by secondary ion mass spectrometry.

35. A method according to claim 33 wherein said semiconductor film is 500 to 1500 Å

.

36. A method according to claim 33 wherein said substrate is a quartz substrate.

37. A method according to claim 33 wherein said crystallization promoting material is disposed by applying onto said semiconductor film a liquid in which said crystallization promoting material is contained.

38. A method according to claim 33 further comprising a step of forming a gate electrode over said semiconductor island with said thermal oxide layer interposed therebetween.

39. A method according to claim 32 wherein said semiconductor device is an active matrix device.

40. A method according to claim 32 wherein said semiconductor device is at least one of an input port, a memory, and a CPU for an active matrix device.

41. A method according to claim 32 wherein said metal comprises an element selected from the group consisting of Groups VIII, IIIb, IVb and Vb elements of the Periodic Table.

42. A method of manufacturing a semiconductor device comprising the steps of:

forming a semiconductor film comprising amorphous silicon over a substrate;

providing a selected portion of said semiconductor film with a crystallization promoting material for promoting crystallization thereof;

heating said semiconductor film with the crystallization promoting material at a first temperature not higher than 650°

C. whereby said semiconductor film is crystallized from said selected portion in a direction parallel with a surface of said substrate;

patterning the crystallized semiconductor film into at least one semiconductor island wherein said selected portion is excluded from said semiconductor island;

heating the semiconductor island in an oxidizing atmosphere by furnace annealing at a second temperature of 800 to 1100°

C. to improve crystallinity thereof

whereby a thermal oxide layer is simultaneously formed on the semiconductor island;

introducing an impurity into the semiconductor island selectively; and

then activating the impurity in the semiconductor island.

43. A method according to claim 42 wherein the crystallization promoting material comprises a metal selected from the group consisting of Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As, and Sb.

44. A method according to claim 42 wherein the crystallization promoting material has a concentration of 1×

10¹⁵ to 1×

10¹⁹ atoms/cm³ measured by secondary ion mass spectrometry.

45. A method according to claim 42 wherein said semiconductor film is 500 to 1500 Å

.

46. A method according to claim 42 wherein said substrate is a quartz substrate.

47. A method according to claim 42 wherein said crystallization promoting material is disposed by applying onto said semiconductor film a liquid in which said crystallization promoting material is contained.

48. A method according to claim 42 further comprising a step of forming a gate electrode over said semiconductor island with said thermal oxide layer interposed therebetween.

49. A method according to claim 42 wherein said semiconductor device is an active matrix device.

50. A method according to claim 42 wherein said semiconductor device is at least one of an input port, a memory, and a CPU for an active matrix device.

51. A method according to claim 42 wherein said metal comprises an element selected from the group consisting of Groups VIII, IIIb, IVb and Vb elements of the Periodic Table.

52. A method according to claim 43 wherein said semiconductor device is an active matrix device.

53. A method of manufacturing a semiconductor device comprising the steps of:

forming a semiconductor film comprising amorphous silicon over a substrate;

providing said semiconductor film with a metal containing material;

crystallizing said semiconductor film by heating at a first temperature after providing said metal containing material;

patterning the crystallized semiconductor film into at least one semiconductor island;

heating the semiconductor island in an oxidizing atmosphere by furnace annealing at a second temperature of 800 to 1100°

C. to improve crystallinity thereof whereby a thermal oxide layer is simultaneously formed on the semiconductor island;

introducing an impurity into the semiconductor island selectively; and

then

activating the impurity in the semiconductor island.

54. A method according to claim 53 wherein said semiconductor film is 500 to 1500 Å

.

55. A method according to claim 53 wherein said substrate is a quartz substrate.

56. A method according to claim 53 further comprising a step of forming a gate electrode over said semiconductor island with said thermal oxide layer interposed therebetween.

57. A method according to claim 53 wherein said first temperature is not higher than 650°

C.

58. A method according to claim 53 wherein said metal is selected from the group consisting of Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As and Sb.

59. A method according to claim 53 wherein said metal comprises an element selected from the group consisting of Groups VIII, IIIb, IVb and Vb elements of the Periodic Table.

60. A method for producing a semiconductor device having a plurality of switching elements for switching pixel and a CPU over a same substrate, said method comprising steps of:

forming a semiconductor film comprising amorphous silicon over said substrate;

disposing a crystallization promoting material in contact with the semiconductor film, said crystallization promoting material being capable of promoting crystallization of the semiconductor film;

crystallizing the semiconductor film using the crystallization promoting material by heating at a first temperature having a range of 450 to 650°

C.;

patterning the crystallized semiconductor film into at least one semiconductor island;

heating the semiconductor island in an oxidizing atmosphere at 800-1100°

C. by furnace annealing to improve crystallinity whereby a thermal oxide layer is formed on a surface of the semiconductor island;

forming a gate electrode over the semiconductor island;

introducing an impurity into the semiconductor island selectively after the formation of the gate electrode; and

then

activating the impurity in the crystallized semiconductor film.

61. A method according to claim 60 wherein the crystallization promoting material comprises a metal selected from the group consisting of Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As, and Sb.

62. A method according to claim 60 further comprising the step of producing a thin film transistor using the semiconductor island.

63. A method according to claim 60 wherein said substrate is a quartz substrate.

64. A method for producing a semiconductor device having a plurality of switching elements for switching pixels and a CPU over a same substrate, said method comprising the steps of:

forming a semiconductor film comprising amorphous silicon over said substrate;

providing said semiconductor film with a metal containing material for accelerating crystallization of said amorphous silicon;

crystallizing the semiconductor film at a first temperature and patterning the crystallized film into at least one semiconductor island;

heating the semiconductor island at a second temperature of 800-1100°

C. which is higher than said first temperature in an oxidizing atmosphere by furnace annealing to improve crystallinity, whereby a thermal oxide layer is formed on a surface of the semiconductor island;

forming a gate electrode over said semiconductor island;

introducing an impurity into the semiconductor island selectively after the formation of the gate electrode; and

then

activating the impurity in the semiconductor island.

65. A method according to claim 64 further comprising the step of forming a gate insulating film on a surface of said semiconductor island prior to said forming said gate electrode.

66. A method according to claim 65 wherein said substrate is a quartz substrate.

67. A method for producing a semiconductor device having a plurality of switching elements for switching pixels and a correction memory over a same substrate, said method comprising the steps of:

forming a semiconductor film comprising amorphous silicon over said substrate;

disposing a crystallization promoting material in contact with the semiconductor film, said crystallization promoting material being capable of promoting crystallization of the semiconductor film;

crystallizing the semiconductor film using the crystallization promoting material by heating at a first temperature having a range of 450 to 650°

C.;

patterning the crystallized semiconductor film into at least one semiconductor island;

heating the semiconductor island in an oxidizing atmosphere at 800-1100°

C. by furnace annealing to improve crystallinity whereby a thermal oxide layer is formed on a surface of the semiconductor island;

forming a gate electrode over the semiconductor island;

introducing an impurity into the semiconductor island selectively after the formation of the gate electrode; and

then

activating the impurity in the crystallized semiconductor film.

68. A method according to claim 67 wherein the crystallization promoting material comprises a metal selected from the group consisting of Ni, Pd, Pt, Cu, Ag, Au, In, Sn, P, As, and Sb.

69. A method according to claim 67 further comprising the step of producing a thin film transistor using the semiconductor island.

70. A method according to claim 67 wherein said substrate is a quartz substrate.

71. A method for producing a semiconductor device having a plurality of switching elements for switching pixels and a correction memory over a same substrate, said method comprising the step of:

forming a semiconductor film comprising amorphous silicon over said substrate;

providing said semiconductor film with a metal containing material for accelerating crystallization of said amorphous silicon;

crystallizing the semiconductor film by heating at a first temperature after providing said metal containing material;

patterning the crystallized semiconductor film into at least on semiconductor island;

heating the semiconductor island at a second temperature of 800-100°

C. which is higher than said first temperature in an oxidizing atmosphere by furnace annealing to improve crystallinity, whereby a thermal oxide layer is formed on a surface of the semiconductor island;

introducing an impurity into the semiconductor island selectively after the formation of the gate electrode; and

then

activating the impurity in the semiconductor island.

72. A method according to claim 71 further comprising the step of forming a gate insulating film on a surface of said semiconductor island prior to said forming of said gate electrode.

73. A method according to claim 71 wherein the substrate is a quartz substrate.