Semiconductor device comprising a semiconductor film having substantially no grain boundary

• US 6,373,075 B1
• Filed: 10/13/2000
• Issued: 04/16/2002
• Est. Priority Date: 03/17/1995
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Teramoto, Satoshi, Yamazaki, Shunpei, Miyanaga, Akiharu
• Primary Examiner(s): Tran, Minh Loan
• Application Number:
  US09/687,290
• Time in Patent Office: 550 Days
• Field of Search: 257/57, 257/66, 257/72, 257/59, 257/627, 257/628, 257/347, 257/350, 257/351, 349/42, 349/43
• US Class Current: 257/72
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• 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 21/02491 Conductive materials
• CPC Class Codes: H01L 21/02496 Layer structure
• CPC Class Codes: H01L 21/02502 consisting of two layers
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02645 Seed materials
• CPC Class Codes: H01L 21/02667 Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth
• CPC Class Codes: H01L 21/02672 using crystallisation enhancing elements
• CPC Class Codes: H01L 21/02675 using laser beams
• CPC Class Codes: H01L 21/02691 Scanning of a beam
• CPC Class Codes: H01L 21/30608 Anisotropic liquid etching H01L21/3063 takes precedence
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 27/1277 using a crystallisation promoting species, e.g. local introduction of Ni catalyst
• CPC Class Codes: H01L 27/1281 by using structural features to control crystal growth, e.g. placement of grain filters
• 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

Abstract

Semiconductor devices based on thin film transistors formed over substrates. In one embodiment, a semiconductor device comprises at least two thin film transistors formed over a substrate, each of said thin film transistors having a crystalline semiconductor film comprising silicon formed on an insulating surface as an active region thereof, wherein said crystalline semiconductor film of each of said two thin film transistors has substantially no grain boundary therein, and a crystal axis of said crystalline semiconductor film in one of said two thin film transistors deviates from a crystal axis of the crystalline semiconductor film of the other, and the deviation of the crystal axis is within ±10°.

Claims

1. A semiconductor device comprising:

at least two thin film transistors formed over a substrate, each of said two thin film transistors having a crystalline semiconductor film comprising silicon formed on an insulating surface as an active region thereof,

wherein said crystalline semiconductor film of each of said two thin film transistors has substantially no grain boundary therein, and a crystal axis of said crystalline semiconductor film in one of said two thin film transistors deviates from a crystal axis of the crystalline semiconductor film of the other and the deviation of the crystal axis is within ±

10°

.

2. The semiconductor device according to claim 1 wherein said crystalline semiconductor film contains hydrogen at a density of 0.001 to 1 atom %.

3. The semiconductor device according to claim 1 wherein a concentration of carbon and nitrogen present in said crystalline semiconductor film is not higher than 5×

10¹⁸ atoms/cm³ and a concentration of oxygen present in said crystalline semiconductor film is not higher than 5×

10¹⁹ atoms/cm³.

4. A semiconductor device comprising:

at least two thin film transistors formed over a substrate, each of said thin film transistors having a crystalline semiconductor film comprising silicon formed on an insulating surface as an active region thereof,

wherein said crystalline semiconductor film of each of said two thin film transistors has substantially no grain boundary therein, and a rotating angle around a crystal axis of said crystalline semiconductor film in one of said two thin film transistors deviates from a rotating angle of a crystal axis of the crystalline semiconductor film of the other, and the deviation of the rotating angle is within ±

10°

.

5. The semiconductor device according to claim 4 wherein said crystalline semiconductor film contains hydrogen at a density of 0.001 to 1 atom %.

6. The semiconductor device according to claim 4 wherein a concentration of carbon and nitrogen present in said crystalline semiconductor film is not higher than 5×

10¹⁸ atoms/cm³ and a concentration of oxygen present in said crystalline semiconductor film is not higher than 5×

10¹⁹ atoms/cm³.

7. A semiconductor device comprising:

at least two thin film transistors formed over a substrate, each of said thin film transistors having a crystalline semiconductor film comprising silicon formed on an insulating surface as an active region thereof,

wherein said crystalline semiconductor film of each of said two thin film transistors has substantially no grain boundary therein, and

wherein a crystal axis of the semiconductor film in one of the two thin film transistors deviate with a crystal axis of the semiconductor film in the other, and the deviation of the crystal axis is within ±

10°

, and

wherein a rotating angle around a crystal axis of said crystalline semiconductor film in one of said two thin film transistors deviates from a rotating angle of a crystal axis of the crystalline semiconductor film of the other, and the deviation of the rotating angle is within ±

10°

.

8. The semiconductor device according to claim 7 wherein said crystalline semiconductor film contains hydrogen at a density of 0.001 to 1 atom %.

9. The semiconductor device according to claim 7 wherein a concentration of carbon and nitrogen present in said crystalline semiconductor film is not higher than 5×

10¹⁸ atoms/cm³ and a concentration of oxygen present in said crystalline semiconductor film is not higher than 5×

10¹⁹ atoms/cm³.

10. A semiconductor device comprising:

at least a pair of complementary n-channel and p-channel thin film transistors formed over a substrate, each of said thin film transistors having a crystalline semiconductor film comprising silicon formed on an insulating surface as an active region thereof,

wherein said crystalline semiconductor film of each of said thin film transistors has substantially no grain boundary therein, and a crystal axis of said crystalline semiconductor film in one of said thin film transistors deviates from a crystal axis of the crystalline semiconductor film of the other, and the deviation of the crystal axis is within ±

10°

.

11. The semiconductor device according to claim 10 wherein said crystalline semiconductor film contains hydrogen at a density of 0.001 to 1 atom %.

12. The semiconductor device according to claim 10 wherein a concentration of carbon and nitrogen present in said crystalline semiconductor film is not higher than 5×

10¹⁸ atoms/cm³ and a concentration of oxygen present in said crystalline semiconductor film is not higher than 5×

10¹⁹ atoms/cm³.

13. A semiconductor device comprising:

at least one pair of n-channel and p-channel thin film transistors formed over a substrate, each of said thin film transistors having a crystalline semiconductor film comprising silicon formed on an insulating surface as an active region thereof,

wherein said crystalline semiconductor film of each of said thin film transistors has substantially no grain boundary therein, and has a rotating angle around a crystal axis of said crystalline semiconductor thin film in one of said thin film transistors deviates from a rotating angle of a crystal axis the crystalline semiconductor film of the other, and the deviation of the rotating angle is within ±

10°

.

14. The semiconductor device according to claim 13 wherein said crystalline semiconductor film contains hydrogen a density of 0.001 to 1 atom %.

15. The semiconductor device according to claim 13 wherein a concentration of carbon and nitrogen present in said crystalline semiconductor film is not higher than 5×

10¹⁸ atoms/cm³ and a concentration of oxygen present in said crystalline semiconductor film is not higher than 5×

10¹⁹ atoms/cm³.

16. A semiconductor device comprising:

at least one pair of n-channel and p-channel thin film transistors formed over a substrate, each of said thin film transistors having a crystalline semiconductor film comprising silicon formed on an insulating surface as an active region thereof,

wherein said crystalline semiconductor film of each of said thin film transistors has substantially no grain boundary therein, and

wherein a crystal axis of the semiconductor film in one of the thin film transistors deviate with a crystal axis of the semiconductor film in the other, and the deviation of the crystal axis is within ±

10°

, and

wherein a rotating angle around a crystal axis of said crystalline semiconductor film in one of said thin film transistors deviates from a rotating angle of a crystal axis of the crystalline semiconductor film of the other, and the deviation of the rotating angle is within ±

10°

.

17. The semiconductor device according to claim 16 wherein said crystalline semiconductor film contains hydrogen at a density of 0.001 to 1 atom %.

18. The semiconductor device according to claim 16 wherein a concentration of carbon and nitrogen present in said crystalline semiconductor film is not higher than 5×

10¹⁸ atoms/cm³ and a concentration of oxygen present in said crystalline semiconductor film is not higher than 5×

10¹⁹ atoms/cm³.