Semiconductor device and a method of manufacturing the same

• US 6,380,011 B1
• Filed: 07/29/1999
• Issued: 04/30/2002
• Est. Priority Date: 08/07/1998
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Nakajima, Setsuo, Yamazaki, Shunpei, Kawasaki, Ritsuko
• Primary Examiner(s): Fahmy, Wael
• Assistant Examiner(s): TOLEDO, FERNANDO L
• Application Number:
  US09/363,954
• Time in Patent Office: 1,006 Days
• Field of Search: 438/149, 438/160, 438/164, 438/166, 438/158, 438/161, 438/163, 257/59, 257/69, 257/72, 349/138
• US Class Current: 438/163
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• CPC Class Codes: H01L 29/66765 Lateral single gate single channel transistors with inverted structure, i.e. the channel layer is formed after the gate

Abstract

To provide a technique required for purifying the interface between an active layer and an insulating film. On a substrate (101), a gate wiring (103) is formed and the surface thereof is covered with a gate oxide film (104). Then, a first insulating film (105a), a second insulating film (105b), a semiconductor film (106) and a protective film (107) are sequentially formed and layered without exposing them to the air. Further, the semiconductor film (106) is irradiated with laser light through the protective film (107). In this way, a TFT may be given good characteristics by completely purifying the interface of the semiconductor film.

Claims

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

forming a gate wiring over a substrate having an insulating surface;

sequentially forming a gate insulating film, a semiconductor film and a first protective film without exposing them to the air;

irradiating said semiconductor film with a laser light through said first protective film to form a crystalline semiconductor film;

forming a second protective film by patterning said first protective film;

introducing an impurity element to said crystalline semiconductor film while using as a mask said second protective film; and

patterning said crystalline semiconductor film into a semiconductor island to form an active layer.

2. A method of claim 1 wherein said gate wiring comprises a tantalum film or a laminated film in which a tantalum film and a tantalum nitride film are layered.

3. A method of claim 1 wherein said gate insulating film is a laminated film containing one layer of silicon nitride film.

4. A method of claim 1 wherein said gate insulating film is a laminated film containing one layer of BCB film.

35. A method of claim 1 wherein said semiconductor device is incorporated into an electronic equipment selected from the group consisting of a video camera, a digital camera, a projector, a head mount display, a navigation system, a personal computer, and a portable information terminal.

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

forming a gate wiring over a substrate having an insulating surface;

sequentially forming a gate insulating film, a semiconductor film and a first protective film without exposing them to the air;

irradiating said semiconductor film with ultraviolet light or infrared light through said first protective film to form a crystalline semiconductor film;

forming a second protective film by patterning said first protective film;

introducing an impurity element to said crystalline semiconductor film while using as a mask said second protective film;

patterning said semiconductor film containing crystals into a semiconductor island to form an active layer; and

etching said gate insulating film while using as a mask said active layer.

6. A method of claim 5 wherein said gate wiring comprises a tantalum film or a laminated film in which a tantalum film and a tantalum nitride film are layered.

7. A method of claim 5 wherein said gate insulating film is a laminated film containing one layer of silicon nitride film.

8. A method of claim 5 wherein said gate insulating film is a laminated film containing one layer of BCB film.

36. A method of claim 5 wherein said semiconductor device is incorporated into an electronic equipment selected from the group consisting of a video camera, a digital camera, a projector, a head mount display, a navigation system, a personal computer, and a portable information terminal.

9. A method of manufacturing a thin film transistor comprising the steps of:

forming a gate wiring over a substrate having an insulating surface;

oxidizing said gate wiring to form a gate oxide film on a surface of said gate wiring;

sequentially forming a gate insulating film, a semiconductor film and a first protective film without exposing them to the air;

irradiating said semiconductor film with ultraviolet light or infrared light through said first protective film to form a crystalline semiconductor film;

forming a second protective film by patterning said first protective film;

introducing an impurity element to said crystalline semiconductor film while using as a mask said second protective film; and

patterning said crystalline semiconductor film a semiconductor island to form an active layer.

10. A method of claim 9 wherein said gate wiring comprises a tantalum film or a laminated film in which a tantalum film and a tantalum nitride film are layered.

11. A method of claim 9 wherein said gate insulating film is a laminated film containing one layer of silicon nitride film.

12. A method of claim 9 wherein said gate insulating film is a laminated film containing one layer of BCB film.

13. A method of claim 9 wherein said gate oxide film is formed by a plasma oxidation method.

37. A method of claim 9 wherein said thin film transistor is incorporated into an electronic equipment selected from the group consisting of a video camera, a digital camera, a projector, a head mount display, a navigation system, a personal computer, and a portable information terminal.

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

forming a gate wiring over a substrate having an insulating surface;

oxidizing said gate wiring to form a gate oxide film on a surface of said gate wiring film;

sequentially forming a gate insulating film, a semiconductor film and a first protective film without exposing them to the air;

irradiating said semiconductor film with ultraviolet light or infrared light through said first protective film to form a crystalline semiconductor film;

forming a second protective film by patterning said first protective film;

introducing an impurity element to said crystalline semiconductor film while using as a mask said second protective film;

patterning said crystalline semiconductor film into a semiconductor island to form an active layer; and

sequentially etching said gate insulating film and said gate oxide film while using as a mask said active layer.

15. A method of claim 14 wherein said gate wiring comprises a tantalum film or a laminated film in which a tantalum film and a tantalum nitride film are layered.

16. A method of claim 14 wherein said gate insulating film is a laminated film containing one layer of silicon nitride film.

17. A method of claim 14 wherein said gate insulating film is a laminated film containing one layer of BCB film.

18. A method of claim 14 wherein said gate oxide film is formed by a plasma oxidation method.

19. A method of manufacturing a thin film transistor comprising the steps of:

forming a gate wiring on an insulating surface;

sequentially forming a gate insulating film, a semiconductor film and a first protective film without exposing them to the air;

irradiating said semiconductor film with a laser light through said first protective film to form a crystalline semiconductor film;

forming a second protective film by patterning said first protective film; and

introducing an impurity element to said crystalline semiconductor film to form impurity regions by using said second protective film as a mask.

20. A method of claim 19 wherein said gate wiring comprises a tantalum film or a laminated film in which a tantalum film and a tantalum nitride film are layered.

21. A method of claim 19 wherein said gate insulating film is a laminated film containing one layer of silicon nitride film.

22. A method of claim 19 wherein said gate insulating film is a laminated film containing one layer of BCB film.

32. A method of claim 21 wherein said gate wiring comprises a tantalum film or a laminated film in which a tantalum film and a tantalum nitride film are layered.

33. A method of claim 21 wherein said gate insulating film is a laminated film containing one layer of silicon nitride film.

34. A method of claim 21 wherein said gate insulating film is a laminated film containing one layer of BCB film.

38. A method of claim 19 wherein said thin film transistor is incorporated into an electronic equipment selected from the group consisting of a video camera, a digital camera, a projector, a head mount display, a navigation system, a personal computer, and a portable information terminal.

23. A method of manufacturing a thin film transistor comprising the steps of:

forming a gate wiring on an insulating surface;

sequentially forming a gate insulating film, a semiconductor film and a first protective film without exposing them to the air;

irradiating said semiconductor film with a laser light through said first protective film to form a crystalline semiconductor film;

forming a second protective film by patterning said first protective film;

introducing a first impurity element to said crystalline semiconductor film to form first impurity regions by using said second protective film as a mask;

forming a third protective film by patterning said second protective film; and

introducing a second impurity element to said crystalline semiconductor film to form second impurity regions by using said third protective film as the mask.

24. A method of claim 23 wherein said gate wiring comprises a tantalum film or a laminated film in which a tantalum film and a tantalum nitride film are layered.

25. A method of claim 23 wherein said gate insulating film is a laminated film containing one layer of silicon nitride film.

26. A method of claim 23 wherein said gate insulating film is a laminated film containing one layer of BCB film.

39. A method of claim 23 wherein said thin film transistor is incorporated into an electronic equipment selected from the group consisting of a video camera, a digital camera, a projector, a head mount display, a navigation system, a personal computer, and a portable information terminal.

27. A method of manufacturing a thin film transistor comprising the steps of:

forming a gate wiring on an insulating surface;

sequentially forming a gate insulating film, a semiconductor film and a first protective film without exposing them to the air;

irradiating said semiconductor film with an infrared light through said first protective film to form a crystalline semiconductor film;

forming a second protective film by patterning said first protective film; and

introducing an impurity element to said crystalline semiconductor film to form impurity regions by using said second protective film as a mask.

28. A method of claim 27 wherein said gate wiring comprises a tantalum film or a laminated film in which a tantalum film and a tantalum nitride film are layered.

29. A method of claim 27 wherein said gate insulating film is a laminated film containing one layer of silicon nitride film.

30. A method of claim 27 wherein said gate insulating film is a laminated film containing one layer of BCB film.

40. A method of claim 27 wherein said thin film transistor is incorporated into an electronic equipment selected from the group consisting of a video camera, a digital camera, a projector, a head mount display, a navigation system, a personal computer, and a portable information terminal.

31. A method of manufacturing a thin film transistor comprising the steps of:

forming a gate wiring on an insulating surface;

sequentially forming a gate insulating film, a semiconductor film and a first protective film without exposing them to the air;

irradiating said semiconductor film with an infrared light through said first protective film to form a crystalline semiconductor film;

forming a second protective film by patterning said first protective film;

introducing a first impurity element to said crystalline semiconductor film to form first impurity regions by using said second protective film as a mask;

forming a third protective film by patterning said second protective film; and

introducing a second impurity element to said crystalline semiconductor film to form second impurity regions by using said third protective film as the mask.

41. A method of claim 31 wherein said thin film transistor is incorporated into an electronic equipment selected from the group consisting of a video camera, a digital camera, a projector, a head mount display, a navigation system, a personal computer, and a portable information terminal.