Semiconductor device and method of fabricating same

• US 20030001158A1
• Filed: 08/09/2002
• Published: 01/02/2003
• Est. Priority Date: 01/19/1996
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Hamatani, Toshiji, Ohtani, Hisashi, Osame, Mitsuaki, Ogata, Yasushi, Teramoto, Satoshi, Hayakawa, Masahiko, Koyama, Jun, Yamazaki, Shunpei
• Granted Patent: US 7,679,087 B2
• Time in Patent Office: Days
• US Class Current: 257/64
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02595 polycrystalline
• CPC Class Codes: H01L 21/02672 using crystallisation enhancing elements
• CPC Class Codes: H01L 21/02686 Pulsed laser beam
• CPC Class Codes: H01L 21/28158 Making the insulator
• CPC Class Codes: H01L 21/3221 of silicon bodies, e.g. for gettering
• CPC Class Codes: H01L 21/3226 of silicon on insulator
• CPC Class Codes: H01L 27/1203 the substrate comprising an insulating body on a semiconductor body, e.g. SOI three-dimensional layout H01L27/0688
• CPC Class Codes: H01L 27/1229 with different crystal properties within a device or between different devices
• 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 29/04 characterised by their crystalline structure, e.g. polycrystalline, cubic or particular orientation of crystalline planes characterised by physical imperfections H01L29/30
• CPC Class Codes: H01L 29/4908 for thin film semiconductor, e.g. gate of TFT
• 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: H01L 29/66765 Lateral single gate single channel transistors with inverted structure, i.e. the channel layer is formed after the gate
• CPC Class Codes: H01L 29/78621 with LDD structure or an extension or an offset region or characterised by the doping profile
• CPC Class Codes: H01L 29/78675 with normal-type structure, e.g. with top gate

Abstract

There is disclosed a method of fabricating a thin-film transistor having excellent characteristics. Nickel element is held in contact with selected regions of an amorphous silicon film. Then, thermal processing is performed to crystallize the amorphous film. Subsequently, thermal processing is carried out in an oxidizing ambient containing a halogen element to form a thermal oxide film. At this time, the crystallinity is improved. Also, gettering of the nickel element proceeds. This crystalline silicon film consists of crystals grown radially from a number of points. Consequently, the thin-film transistor having excellent characteristics can be obtained.

Claims

1. An electroluminescence device comprising:

a substrate having an insulating surface;

a plurality of thin film transistors over the substrate, each thin film transistor having an active layer formed by patterning a semiconductor film over the substrate and at least one gate electrode adjacent to the active layer with a gate insulating film with interposed therebetween;

a leveled insulating film provided over the thin film transistors; and

a pixel electrode provided on the leveled insulating film, the pixel electrode electrically connected to the thin film transistors, respectively,

wherein the semiconductor film comprises a plurality of radial crystal grains of silicon through the whole area of the semiconductor film, and

wherein crystal growth directions in the active layers differs from one of the plurality of thin film transistors to another, respectively.

2. A device according to claim 1, wherein said semiconductor film comprises silicon.

3. A device according to claim 1, wherein the semiconductor film has a thickness of 100 to 700 Å

.

4. A device according to claim 1, wherein the substrate is selected from the group consisting of a glass substrate, a quartz substrate, and a semiconductor substrate.

5. A device according to claim 1, further comprising auxiliary capacitors using the pixel electrodes.

6. A device according to claim 1, wherein the semiconductor film includes a material for promoting crystallization of silicon introduced into the whole area of the active layer and the material is selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Cu, and Au.

7. A device according to claim 1, wherein the electroluminescence display device is an active matrix type display device.

8. A device according to claim 1, wherein the electroluminescence display device is included in an electric device selected from the group consisting of a portable intelligent terminal, a car navigational system, and a mobile telephone.

9. An electroluminescence device comprising:

a substrate having an insulating surface;

a plurality of thin film transistors over the substrate, each thin film transistor having an active layer formed by patterning a semiconductor film over the substrate and at least one gate electrode adjacent to the active layer with a gate insulating film with interposed therebetween;

a leveled insulating film provided over the thin film transistors; and

a pixel electrode provided on the leveled insulating film, the pixel electrode electrically connected to the thin film transistors, respectively,

wherein the semiconductor film comprises a plurality of radial crystal grains of silicon through the whole area of the semiconductor film, and

wherein directions of anisotropy of crystal structures in active layers differs from one of said plurality of thin film transistors to another, respectively.

10. A device according to claim 9, wherein said semiconductor film comprises silicon.

11. A device according to claim 9, wherein the semiconductor film has a thickness of 100 to 700 Å

.

12. A device according to claim 9, wherein the substrate is selected from the group consisting of a glass substrate, a quartz substrate, and a semiconductor substrate.

13. A device according to claim 9, further comprising auxiliary capacitors using the pixel electrodes.

14. A device according to claim 9, wherein the semiconductor film includes a material for promoting crystallization of silicon introduced into the whole area of the active layer and the material is selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Cu, and Au.

15. A device according to claim 9, wherein the electroluminescence display device is an active matrix type display device.

16. A device according to claim 9, wherein the electroluminescence display device is included in an electric device selected from the group consisting of a portable intelligent terminal, a car navigational system, and a mobile telephone.

18. A device according to claim 17, wherein said semiconductor film comprises silicon.

19. A device according to claim 17, wherein the semiconductor film has a thickness of 100 to 700 Å

.

20. A device according to claim 17, wherein the substrate is selected from the group consisting of a glass substrate, a quartz substrate, and a semiconductor substrate.

21. A device according to claim 17, further comprising auxiliary capacitors using the pixel electrodes.

22. A device according to claim 17, wherein the semiconductor film includes a material for promoting crystallization of silicon introduced into the whole area of the active layer and the material is selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Cu, and Au.

23. A device according to claim 17, wherein the electroluminescence display device is an active matrix type display device.

24. A device according to claim 17, wherein the electroluminescence display device is included in an electric device selected from the group consisting of a portable intelligent terminal, a car navigational system, and a mobile telephone.

26. A device according to claim 25, wherein said semiconductor film comprises silicon.

27. A device according to claim 25, wherein the semiconductor film has a thickness of 100 to 700 Å

.

28. A device according to claim 25, wherein the substrate is selected from the group consisting of a glass substrate, a quartz substrate, and a semiconductor substrate.

29. A device according to claim 25, further comprising auxiliary capacitors using the pixel electrodes.

30. A device according to claim 25, wherein the semiconductor film includes a material for promoting crystallization of silicon introduced into the whole area of the active layer and the material is selected from the group consisting of Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt, Cu, and Au.

31. A device according to claim 25, wherein the electroluminescence display device is an active matrix type display device.

32. A device according to claim 25, wherein the electroluminescence display device is included in an electric device selected from the group consisting of a portable intelligent terminal, a car navigational system, and a mobile telephone.

17. An electroluminescence device comprising:

a substrate having an insulating surface;

a plurality of thin film transistors over the substrate, each thin film transistor having an active layer formed by patterning a semiconductor film over the substrate and at least one gate electrode adjacent to the active layer with a gate insulating film with interposed therebetween;

a leveled insulating film provided over the thin film transistors; and

a pixel electrode provided on the leveled insulating film, the pixel electrode electrically connected to the thin film transistors, respectively,

wherein said semiconductor film comprises a plurality of crystal grains of silicon through the whole area of the semiconductor film, each of said crystal grains growing radially from each of a plurality of points distributed through the whole surface of said semiconductor film, and

wherein crystal growth directions in said active layers differs from one of said plurality of thin film transistors to another, respectively.

25. An electroluminescence device comprising:

a substrate having an insulating surface;

a plurality of thin film transistors over the substrate, each thin film transistor having an active layer formed by patterning a semiconductor film over the substrate and at least one gate electrode adjacent to the active layer with a gate insulating film with interposed therebetween;

a leveled insulating film provided over the thin film transistors; and

a pixel electrode provided on the leveled insulating film, the pixel electrode electrically connected to the thin film transistors, respectively,

wherein said semiconductor film comprises a plurality of crystal grains of silicon through the whole area of the semiconductor film, each of said crystal grains growing radially from each of a plurality of points distributed through the whole surface of said semiconductor film, and

wherein directions of anisotropy of crystal structures in active layers differs from one of said plurality of thin film transistors to another, respectively.

33. A portable intelligent terminal having an electroluminescence device, comprising:

a substrate having an insulating surface;

a plurality of thin film transistors over the substrate, each thin film transistor having an active layer formed by patterning a semiconductor film over the substrate and at least one gate electrode adjacent to the active layer with a gate insulating film with interposed therebetween;

a leveled insulating film provided over the thin film transistors; and

a pixel electrode provided on the leveled insulating film, the pixel electrode electrically connected to the thin film transistors, respectively.

34. A portable intelligent terminal according to claim 33, wherein the semiconductor film comprises a plurality of radial crystal grains of silicon through the whole area of the semiconductor film.

35. A portable intelligent terminal according to claim 33, wherein crystal growth directions in the active layers differs from one of the plurality of thin film transistors to another, respectively.

36. A portable intelligent terminal according to claim 33, wherein said semiconductor film comprises a plurality of crystal grains of silicon through the whole area of the semiconductor film, each of said crystal grains growing radially from each of a plurality of points distributed through the whole surface of said semiconductor film.

37. A portable intelligent terminal according to claim 33, wherein directions of anisotropy of crystal structures in active layers differs from one of said plurality of thin film transistors to another, respectively.

39. A system according to claim 38, wherein the semiconductor film comprises a plurality of radial crystal grains of silicon through the whole area of the semiconductor film.

40. A system according to claim 38, wherein crystal growth directions in the active layers differs from one of the plurality of thin film transistors to another, respectively.

41. A system according to claim 38, wherein said semiconductor film comprises a plurality of crystal grains of silicon through the whole area of the semiconductor film, each of said crystal grains growing radially from each of a plurality of points distributed through the whole surface of said semiconductor film.

42. A system according to claim 38, wherein directions of anisotropy of crystal structures in active layers differs from one of said plurality of thin film transistors to another, respectively.

38. A car navigation system having an electroluminescence device, comprising:

a substrate having an insulating surface;

a plurality of thin film transistors over the substrate, each thin film transistor having an active layer formed by patterning a semiconductor film over the substrate and at least one gate electrode adjacent to the active layer with a gate insulating film with interposed therebetween;

a leveled insulating film provided over the thin film transistors; and

a pixel electrode provided on the leveled insulating film, the pixel electrode electrically connected to the thin film transistors, respectively.

43. A mobile telephone having an electroluminescence device, comprising:

a substrate having an insulating surface;

a plurality of thin film transistors over the substrate, each thin film transistor having an active layer formed by patterning a semiconductor film over the substrate and at least one gate electrode adjacent to the active layer with a gate insulating film with interposed therebetween;

a leveled insulating film provided over the thin film transistors; and

a pixel electrode provided on the leveled insulating film, the pixel electrode electrically connected to the thin film transistors, respectively.

44. A mobile telephone according to claim 43, wherein the semiconductor film comprises a plurality of radial crystal grains of silicon through the whole area of the semiconductor film.

45. A mobile telephone according to claim 43, wherein crystal growth directions in the active layers differs from one of the plurality of thin film transistors to another, respectively.

46. A mobile telephone according to claim 43, wherein said semiconductor film comprises a plurality of crystal grains of silicon through the whole area of the semiconductor film, each of said crystal grains growing radially from each of a plurality of points distributed through the whole surface of said semiconductor film.

47. A mobile telephone according to claim 43, wherein directions of anisotropy of crystal structures in active layers differs from one of said plurality of thin film transistors to another, respectively.