Process for fabricating semiconductor device

• US 6,184,068 B1
• Filed: 08/11/1998
• Issued: 02/06/2001
• Est. Priority Date: 06/02/1994
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Fukunaga, Takeshi, Ohtani, Hisashi, Miyanaga, Akiharu
• Primary Examiner(s): Elms, Richard
• Assistant Examiner(s): Lebentritt, Michael
• Application Number:
  US09/138,471
• Time in Patent Office: 910 Days
• Field of Search: 438/166, 438/487, 438/486, 438/402, 438/151, 438/764
• US Class Current: 438/151
• 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 21/02595 polycrystalline
• CPC Class Codes: H01L 21/02609 Crystal orientation
• CPC Class Codes: H01L 21/02672 using crystallisation enhancing elements
• CPC Class Codes: H01L 21/02675 using laser beams
• CPC Class Codes: H01L 21/02686 Pulsed laser beam
• 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

A process for fabricating a semiconductor device comprising the steps of: introducing into an amorphous silicon film, a metallic element which accelerates the crystallization of the amorphous silicon film; applying heat treatment to the amorphous silicon film to obtain a crystalline silicon film; irradiating a laser beam or an intense light to the crystalline silicon film; and heat treating the crystalline silicon film irradiated with a laser beam or an intense light.

Claims

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

forming a semiconductor film comprising amorphous silicon on an insulating surface by CVD;

crystallizing said semiconductor film by heating;

annealing said semiconductor film in an oxidizing gas containing atmosphere;

irradiating the crystallized semiconductor film by an excimer laser beam;

heating the semiconductor film at 400°

C. or higher to reduce a spin density of said semiconductor film.

2. A method according to claim 1, wherein said CVD is selected from PCVD and LPCVD.

3. A method according to claim 1, wherein said CVD is LPCVD.

4. A method according to claim 1, wherein said semiconductor film is at a thickness of from 500 to 1500 Å

.

5. A method according to claim 1, wherein said excimer laser is selected from the groups consisting of KrF excimer laser, XeCl excimer laser, ArF excimer laser and XeF excimer laser.

6. A method according to claim 1, wherein said oxidizing gas is selected from oxygen and ozone.

7. A method according to claim 1, wherein said heating step after said irradiating step is carried out in a nitrogen containing atmosphere.

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

forming a semiconductor film comprising amorphous silicon on an insulating surface by CVD;

crystallizing said semiconductor film by heating;

forming a silicon oxide film on said semiconductor film;

irradiating a laser beam to said semiconductor film through said silicon oxide film; and

then

heating the semiconductor film at 400°

C. or higher to reduce a spin density of said semiconductor film.

9. A method according to claim 8, wherein said CVD is selected from PCVD and LPCVD.

10. A method according to claim 8, wherein said CVD is LPCVD.

11. A method according to claim 8, wherein said semiconductor film is at a thickness of from 500 to 1500 Å

.

12. A method according to claim 8, wherein said excimer laser is selected from the groups consisting of KrF excimer laser, XeCl excimer laser, ArF excimer laser and XeF excimer laser.

13. A method according to claim 8, wherein said irradiating a laser beam is carried out in a nitrogen containing atmosphere.

14. A method according to claim 8, wherein said heating step after said irradiating step is carried out in a nitrogen containing atmosphere.

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

forming a semiconductor film comprising amorphous silicon on an insulating surface by CVD;

crystallizing said semiconductor film by heating;

irradiating the crystallized semiconductor film by an excimer laser beam;

heating the semiconductor film at 400°

C. or higher to reduce a spin density of said semiconductor film; and

then

said method further comprising a step of oxidizing a surface of said semiconductor film after the crystallization thereof.

16. A method according to claim 15, wherein said step of oxidizing is performed after the irradiating of said excimer laser beam.

17. A method according to claim 15, wherein said CVD is selected from PCVD and LPCVD.

18. A method according to claim 15, wherein said CVD is LPCVD.

19. A method according to claim 15, wherein said semiconductor film is at a thickness of from 500 to 1500 Å

.

20. A method according to claim 15, wherein said excimer laser is selected from the groups consisting of KrF excimer laser, XeCl excimer laser, ArF excimer laser and XeF excimer laser.

21. A method according to claim 15, wherein said heating step after said irradiating step is carried out in a nitrogen containing atmosphere.

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

heat treating an amorphous semiconductor film in a nitrogen containing atmosphere to crystallize the amorphous semiconductor film;

irradiating a laser beam or an intense light to crystalline semiconductor film to further improve the crystallinity;

heat treating the irradiated semiconductor film to reduce a number of spin density in the crystallized semiconductor film in a nitrogen containing atmosphere; and

then,

heat treating the semiconductor film in a hydrogen containing atmosphere to effect hydrogenation of the semiconductor film.

23. A method according to claim 22, wherein said amorphous semiconductor film is formed by LPCVD.

24. A method according to claim 22, wherein said laser beam is selected from the groups consisting of KrF excimer laser, XeCl excimer laser, ArF excimer laser and XeF excimer laser.

25. A method for fabricating a semiconductor device comprising the steps of:

thermally crystallizing an amorphous semiconductor film;

irradiating a laser beam to crystalline the semiconductor film after said thermally crystallizing step;

annealing the semiconductor film by thermal treatment after said crystallizing step to reduce the number of spin density in the semiconductor film; and

then,

annealing the semiconductor film in a hydrogen containing atmosphere to effect hydrogenation of the semiconductor film.

26. A method according to claim 25, wherein said amorphous semiconductor film is formed by LPCVD.

27. A method according to claim 25, wherein said laser beam is selected from the groups consisting of KrF excimer laser, XeCl excimer laser, ArF excimer laser and XeF excimer laser.

28. A method for fabricating a semiconductor device comprising the steps of:

heat treating an amorphous semiconductor film to crystallize an amorphous semiconductor film;

irradiating a laser beam or an intense light to the crystalline semiconductor film to further improve the crystallinity;

heat treating the irradiated semiconductor film to reduce the number of dangling bonds in the crystallized semiconductor film; and

then,

heat treating the semiconductor film in a hydrogen containing atmosphere to effect hydrogenation of the semiconductor film.

29. A method according to claim 28, wherein said amorphous semiconductor film is formed by LPCVD.

30. A method according to claim 28, wherein said laser beam is selected from the groups consisting of KrF excimer laser, XeCl excimer laser, ArF excimer laser and XeF excimer laser.

31. A method for fabricating a semiconductor device comprising the steps of:

thermally crystallizing an amorphous semiconductor film;

irradiating a laser beam to crystalline the semiconductor film after said thermally crystallizing step;

annealing the semiconductor film by thermal treatment after said crystallizing step to reduce the number of dangling bonds in the semiconductor film; and

then,

annealing the semiconductor film in a hydrogen containing atmosphere to effect hydrogenation of the semiconductor film.

32. A method according to claim 31, wherein said laser beam is selected from the groups consisting of KrF excimer laser, XeCl excimer laser, ArF excimer laser and XeF excimer laser.

33. A method according to claim 31, wherein said amorphous semiconductor film is formed by LPCVD.