Metal-gettering method used in the manufacture of crystalline-Si TFT

• US 6,551,907 B2
• Filed: 04/04/2001
• Issued: 04/22/2003
• Est. Priority Date: 07/22/1997
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Ohtani, Hisashi
• Primary Examiner(s): Fahmy, Wael
• Assistant Examiner(s): PIZARRO CRESPO, MARCOS D
• Application Number:
  US09/824,688
• Publication Number:
  US 20010019878A1
• Time in Patent Office: 748 Days
• Field of Search: 257/913, 438/143, 438/166, 438/471, 438/476, 438/486, 438/FOR.144, 438/FOR.146
• US Class Current: 438/476
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• CPC Class Codes: H01L 21/02488 Insulating materials
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02672 using crystallisation enhancing elements
• CPC Class Codes: H01L 21/3226 of silicon on insulator
• CPC Class Codes: Y10S 257/913 with means to absorb or localize unwanted impurities or defects from semiconductors, e.g. heavy metal gettering

Abstract

Disclosed is a simplified technique of introducing a metal element capable of promoting the crystallization of silicon into an amorphous silicon film to be crystallized, and of removing the metal element from the film. An amorphous silicon film 102 is formed on a substrate, a mask 103 is formed thereon, and a nickel-containing PSG film is further formed thereover. This is heated at 560° C. to thereby make nickel diffused in the direction 106, and the film is crystallized. Next, this is further heated at 850° C. to thereby make phosphorus diffused into the region 107, in which nickel is gettered by the thus-diffused phosphorus. Thus, the crystallization of silicon is promoted by the metal element nickel, and the nickel is then removed from the crystallized silicon film.

Claims

1. A method of manufacturing a semiconductor device comprising:

forming an amorphous semiconductor film over a substrate;

providing a material in contact with said amorphous semiconductor film, said material containing a crystallization promoting material and a gettering material;

first heating said amorphous semiconductor film and said material to crystallize said semiconductor film; and

second heating said semiconductor film and said material thereby gettering said crystallization promoting material in a crystallized semiconductor film.

2. The method according to claim 1 wherein said first heating is performed between 500 and 750°

C., and said second heating is performed between 800 and 1100°

C.

3. The method according to claim 1 wherein said crystallization promoting material is one selected from the group consisting of Ni, Fe, Co, Ru, Rh, Pd, Os, Ir, Pt, Cu, Au, Ge, and In.

4. The method according to claim 1 wherein said gettering material is one selected from the group consisting of phosphorus, arsenic, and antimony.

5. The method according to claim 1 wherein said amorphous semiconductor film comprises Si_xGe₍₁₋

X) (0.5<

×

<

1).

6. The method according to claim 1 wherein said semiconductor device is an EL display device.

7. The method according to claim 1 wherein said semiconductor device is one selected from the group consisting of a portable information-processing terminal, a head-mount display, a car navigation system, a portable telephone, a video camera, and a projector.

8. The method according to claim 1 wherein said semiconductor device is an integrated circuit including at least one selected from the group consisting of a CPU, a memory, an arithmetic circuit, an amplifier circuit, and a switching circuit.

9. A method of manufacturing a semiconductor device comprising:

forming an amorphous semiconductor film over a substrate;

crystallizing said amorphous semiconductor film by diffusing a crystallization promoting material selectively provided on said amorphous semiconductor film; and

reducing a concentration of said crystallization promoting material by a gettering material selectively diffused into a crystallized semiconductor film,

wherein said crystallization promoting material and said gettering material are diffused from a same portion of said semiconductor film.

10. The method according to claim 9 wherein said crystallizing step is performed between 500 and 750°

C., and said reducing step is performed between 800 and 1100°

C.

11. The method according to claim 9 wherein said crystallization promoting material is one selected from the group consisting of Ni, Fe, Co, Ru, Rh, Pd, Os, fr, Pt, Cu, Au, Ge, and In.

12. The method according to claim 9 wherein said gettering material is one selected from the group consisting of phosphorus, arsenic, and antimony.

13. The method according to claim 9 wherein said amorphous semiconductor film comprises Si_xGe₍₁₋

x) (0.5<

×

<

1).

14. The method according to claim 9 wherein said semiconductor device is an EL display device.

15. The method according to claim 9 wherein said semiconductor device is one selected from the group consisting of a portable information-processing terminal, a head-mount display, a car navigation system, a portable telephone, a video camera, and a projector.

16. The method according to claim 9 wherein said semiconductor device is an integrated circuit including at least one selected from the group consisting of a CPU, a memory, an arithmetic circuit, an amplifier circuit, and a switching circuit.

17. A method of manufacturing a semiconductor device comprising:

forming an amorphous semiconductor film over a substrate;

providing a material in contact with a selected portion of said amorphous semiconductor film, said material containing a crystallization promoting material and a gettering material;

first heating said amorphous semiconductor film and said material to crystallize said semiconductor film; and

second heating said semiconductor film and said material thereby gettering said crystallization promoting material in a crystallized semiconductor film.

18. The method according to claim 17 wherein said first heating is performed between 500 and 750°

C., and said second heating is performed between 800 and 1100°

C.

19. The method according to claim 17 wherein said crystallization promoting material is one selected from the group consisting of Ni, Fe, Co, Ru, Rh, Pd, Os, Ir, Pt, Cu, Au, Ge, and In.

20. The method according to claim 17 wherein said gettering material is one selected from the group consisting of phosphorus, arsenic, and antimony.

21. The method according to claim 17 wherein said amorphous semiconductor film comprises Si_xGe₍₁₋

x) (0.5<

×

<

1).

22. The method according to claim 17 wherein said semiconductor device is an EL display device.

23. The method according to claim 17 wherein said semiconductor device is one selected from the group consisting of a portable information-processing terminal, a head-mount display, a car navigation system, a portable telephone, a video camera, and a projector.

24. The method according to claim 17 wherein said semiconductor device is an integrated circuit including at least one selected from the group consisting of a CPU, a memory, an arithmetic circuit, an amplifier circuit, and a switching circuit.

25. A method of manufacturing a semiconductor device comprising:

forming an amorphous semiconductor film over a substrate;

crystallizing said amorphous semiconductor film by diffusing a crystallization promoting material selectively provided on said amorphous semiconductor film;

reducing a concentration of said crystallization promoting material by a gettering material selectively diffused into a crystallized semiconductor film; and

patterning said crystallized semiconductor film into a plurality of active layers,

wherein said crystallization promoting material and said gettering material are diffused from a same portion of said semiconductor film.

26. The method according to claim 25 wherein said crystallizing step is performed between 500 and 750°

C., and said reducing step is performed between 800 and 1100°

C.

27. The method according to claim 25 wherein said crystallization promoting material is one selected from the group consisting of Ni, Fe, Co, Ru, Rh, Pd, Os, Ir, Pt, Cu, Au, Ge, and In.

28. The method according to claim 25 wherein said gettering material is one selected from the group consisting of phosphorus, arsenic, and antimony.

29. The method according to claim 25 wherein said amorphous semiconductor film comprises Si_xGe_(1-x) (0.5<

×

<

1).

30. The method according to claim 25 wherein said semiconductor device is an EL display device.

31. The method according to claim 25 wherein said semiconductor device is one selected from the group consisting of a portable information-processing terminal, a head-mount display, a car navigation system, a portable telephone, a video camera, and a projector.

32. The method according to claim 25 wherein said semiconductor device is an integrated circuit including at least one selected from the group consisting of a CPU, a memory, an arithmetic circuit, an amplifier circuit, and a switching circuit.

33. A method of manufacturing a semiconductor device comprising:

forming an amorphous semiconductor film over a substrate;

providing a material in contact with said amorphous semiconductor film, said material containing a crystallization promoting material and a gettering material;

first heating said amorphous semiconductor film and said material to crystallize said semiconductor film;

second heating said semiconductor film and said material thereby gettering said crystallization promoting material in a crystallized semiconductor film; and

patterning said crystallized semiconductor film into a plurality of active layers.

34. The method according to claim 33 wherein said first heating is performed between 500 and 750°

C., and said second heating is performed between 800 and 1100°

C.

35. The method according to claim 33 wherein said crystallization promoting material is one selected from the group consisting of Ni, Fe, Co, Ru, Rh, Pd, Os, Ir, Pt, Cu, Au, Ge, and In.

36. The method according to claim 33 wherein said gettering material is one selected from the group consisting of phosphorus, arsenic, and antimony.

37. The method according to claim 33 wherein said amorphous semiconductor film comprises Si_xGe₍₁₋

x) (0.5<

×

<

1).

38. The method according to claim 33 wherein said semiconductor device is an EL display device.

39. The method according to claim 33 wherein said semiconductor device is one selected from the group consisting of a portable information-processing terminal, a head-mount display, a car navigation system, a portable telephone, a video camera, and a projector.

40. The method according to claim 33 wherein said semiconductor device is an integrated circuit including at least one selected from the group consisting of a CPU, a memory, an arithmetic circuit, an amplifier circuit, and a switching circuit.