Semiconductor device using a semiconductor film having substantially no grain boundary

• US 6,610,996 B2
• Filed: 08/27/2001
• Issued: 08/26/2003
• 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:
  US09/940,277
• Publication Number:
  US 20020011598A1
• Time in Patent Office: 729 Days
• Field of Search: 257/64, 257/66, 257/72, 257/350, 257/351, 257/627, 257/628
• US Class Current: 257/64
• 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 a thin film transistor, comprising:

a glass substrate;

a semiconductor film comprising crystalline silicon and hydrogen over the glass substrate; and

a channel region in said semiconductor film wherein said channel region has a (100) plane,

wherein a concentration of carbon in said semiconductor film is not higher than 5×

10¹⁸ atoms/cm³.

2. The semiconductor device according to claim 1 wherein said hydrogen is contained at not higher than 1 atm %.

3. A semiconductor device comprising a thin film transistor, comprising:

a glass substrate;

a semiconductor film comprising crystalline silicon and hydrogen over the glass substrate; and

a channel region in said semiconductor film wherein said channel region has a (100) plane,

wherein a concentration of nitrogen in said semiconductor film is not higher than 5×

10¹⁸ atoms/cm³.

4. The semiconductor device according to claim 3 wherein said hydrogen is contained at not higher than 1 atm %.

5. A semiconductor device comprising a thin film transistor, comprising:

a glass substrate;

a semiconductor film comprising crystalline silicon and hydrogen over the glass substrate; and

a channel region in said semiconductor film wherein said channel region has a (100) plane,

wherein a concentration of oxygen in said semiconductor film is not higher than 5×

10¹⁹ atoms/cm³.

6. The semiconductor device according to claim 5 wherein said hydrogen is contained at not higher than 1 atm %.

7. A semiconductor device comprising a thin film transistor, comprising:

a glass substrate;

a semiconductor film comprising crystalline silicon and hydrogen over the glass substrate; and

a channel region in said semiconductor film wherein said channel region has a (100) plane,

wherein a concentration of carbon in said semiconductor film is not higher than 5×

10¹⁸ atoms/cm³, and

wherein said channel region has no grain boundary.

8. The semiconductor device according to claim 7 wherein said hydrogen is contained at not higher than 1 atm %.

9. A semiconductor device comprising a thin film transistor, comprising:

a glass substrate;

a semiconductor film comprising crystalline silicon and hydrogen over the glass substrate; and

a channel region in said semiconductor film wherein said channel region has a (100) plane,

wherein a concentration of nitrogen in said semiconductor film is not higher than 5×

10¹⁸ atoms/cm³,

wherein said channel region has no grain boundary.

10. The semiconductor device according to claim 9 wherein said hydrogen is contained at not higher than 1 atm %.

11. A semiconductor device comprising a thin film transistor, comprising:

a glass substrate;

a semiconductor film comprising crystalline silicon and hydrogen over the glass substrate; and

a channel region in said semiconductor film wherein said channel region has a (100) plane,

wherein a concentration of oxygen in said semiconductor film is not higher than 5×

10¹⁹ atoms/cm³,

wherein said channel region has no grain boundary.

12. The semiconductor device according to claim 11 wherein said hydrogen is contained at not higher than 1 atm %.

13. A semiconductor device comprising at least two thin film transistors, each comprising:

a glass substrate;

a semiconductor film comprising crystalline silicon and hydrogen over the glass substrate; and

a channel region in said semiconductor film wherein said channel region has a (100) plane,

wherein a concentration of carbon in said semiconductor film is not higher than 5×

10¹⁸ atoms/cm³, and

wherein said channel region has no grain boundary.

14. The semiconductor device according to claim 13 wherein said two thin film transistors constitute an inverter.

15. The semiconductor device according to claim 13 wherein said hydrogen is contained at not higher than 1 atm %.

16. A semiconductor device comprising at least two thin film transistors, each comprising:

a glass substrate;

a semiconductor film comprising crystalline silicon and hydrogen over the glass substrate; and

a channel region in said semiconductor film wherein said channel region has a (100) plane,

wherein a concentration of nitrogen in said semiconductor film is not higher than 5×

10¹⁸ atoms/cm³,

wherein said channel region has no grain boundary.

17. The semiconductor device according to claim 16 wherein said two thin film transistors constitute an inverter.

18. The semiconductor device according to claim 16 wherein said hydrogen is contained at not higher than 1 atm %.

19. A semiconductor device comprising at least two thin film transistors, each comprising:

a glass substrate;

a semiconductor film comprising crystalline silicon and hydrogen over the glass substrate; and

a channel region in said semiconductor film wherein said channel region has a (100) plane,

wherein a concentration of oxygen in said semiconductor film is not higher than 5×

10¹⁹ atoms/cm³,

wherein said channel region has no grain boundry.

20. The semiconductor device according to claim 19 wherein said two thin film transistors constitute an inverter.

21. The semiconductor device according to claim 19 wherein said hydrogen is contained at not higher than 1 atm %.

22. A semiconductor device comprising at least first and second thin film transistors, each comprising:

a glass substrate;

a semiconductor film comprising crystalline silicon and hydrogen over the glass substrate; and

a channel region in said semiconductor film wherein said channel region has a <

100>

axis;

wherein a concentration of carbon in said semiconductor film is not higher than 5×

10¹⁸ atoms/cm³, and

wherein the <

100>

axes of the first and second thin film transistors deviate in a range of ±

10°

.

23. The semiconductor device according to claim 22 wherein said first and second thin film transistors constitute an inverter.

24. A semiconductor device comprising at least first and second thin film transistors, each comprising:

a glass substrate;

a semiconductor film comprising crystalline silicon and hydrogen over the glass substrate; and

a channel region in said semiconductor film wherein said channel region has a <

100>

axis;

wherein a concentration of nitrogen in said semiconductor film is not higher than 5×

10¹⁸ atoms/cm³, and

wherein the <

100>

axes of the first and second thin film transistors deviate in a range of ±

10°

.

25. The semiconductor device according to claim 24 wherein said first and second thin film transistors constitute an inverter.

26. A semiconductor device comprising at least first and second thin film transistors, each comprising:

a glass substrate;

a semiconductor film comprising crystalline silicon and hydrogen over the glass substrate; and

a channel region in said semiconductor film wherein said channel region has a <

100>

axis;

wherein a concentration of oxygen in said semiconductor film is not higher than 5×

10¹⁹ atoms/cm³, and

wherein the <

100>

axes of the first and second thin film transistors deviate in a range of ±

10°

.

27. The semiconductor device according to claim 26 wherein said first and second thin film transistors constitute an inverter.