Thin film transistor having enhanced field mobility

• US 6,455,875 B2
• Filed: 08/31/1999
• Issued: 09/24/2002
• Est. Priority Date: 10/09/1992
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Teramoto, Satoshi, Takemura, Yasuhiko, Zhang, Hongyong
• Primary Examiner(s): Tran, Minh Loan
• Application Number:
  US09/387,054
• Publication Number:
  US 20020011627A1
• Time in Patent Office: 1,120 Days
• Field of Search: 257/288, 257/368, 257/388, 257/412, 257/751, 257/72, 257/66, 257/347, 257/352, 257/384, 438/149, 438/151, 438/157, 438/166, 438/165, 438/216, 438/261
• US Class Current: 257/72
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 29/458 for thin film silicon, e.g. source or drain electrode
• 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 29/78621 with LDD structure or an extension or an offset region or characterised by the doping profile
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621
• CPC Class Codes: Y10S 257/90 MOSFET type gate sidewall insulating spacer

Abstract

A thin film transistor device reduced substantially in resistance between the source and the drain regions by incorporating a silicide film, which is fabricated by a process comprising forming a gate insulator film and a gate contact on a silicon substrate, anodically oxidizing the gate contact, covering an exposed surface of the silicon semiconductor with a metal, and irradiating an intense light such as a laser beam to the metal film either from the upper side or from an insulator substrate side to allow the metal coating to react with silicon to obtain a silicide film. The metal silicide layer may be obtained otherwise by tightly adhering a metal coating to the exposed surface of the source and drain regions using an insulator formed into an approximately triangular shape, preferably 1 μm or less in width, and allowing the metal to react with silicon. Accordingly, a high performance TFT is realized since the metal silicide layer achieves favorable contact with the source and drain regions, and, since it has lower resistivity than silicon, the parasitic resistance between the source and drain regions can be considerably lowered.

Claims

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

forming a semiconductor film over a substrate;

forming a gate insulating film by using organic silane over said semiconductor film, said gate insulating film comprising silicon oxide;

forming a gate electrode over said gate insulating film, said gate electrode comprising aluminum;

introducing an impurity element into said semiconductor film; and

activating said impurity element in said semiconductor film by irradiating an infrared light.

2. A method according to claim 1, wherein said impurity element is phosphorus.

3. A method according to claim 1, wherein said organic silane is TEOS.

4. A method according to claim 1, wherein said semiconductor device is incorporated into a device selected from the group consisting of a liquid crystal display device, a SOI integrated circuit, a microprocessors, a microcomputer and a semiconductor memory.

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

forming a semiconductor film over a substrate;

crystallizing said semiconductor film by heating

forming a gate insulating film by using organic silane over said crystalline semiconductor film, said gate insulating film comprising silicon oxide;

forming a gate electrode over said gate insulating film, said gate electrode comprising aluminum;

introducing an impurity element into said crystalline semiconductor film; and

activating said impurity element in said crystalline semiconductor film by irradiating an infrared light.

6. A method according to claim 5, wherein said impurity element is phosphorus.

7. A method according to claim 5, wherein said organic silane is TEOS.

8. A method according to claim 5, wherein said semiconductor device is incorporated into a device selected from the group consisting of a liquid crystal display device, a SOI integrated circuit, a microprocessors, a microcomputer and a semiconductor memory.

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

forming a semiconductor film over a substrate;

crystallizing said semiconductor film by irradiating a light;

forming a gate insulating film by using organic silane over said crystalline semiconductor film, said gate insulating film comprising silicon oxide;

forming a gate electrode over said gate insulating film, said gate electrode comprising aluminum;

introducing an impurity element into said crystalline semiconductor film; and

activating said impurity element in said crystalline semiconductor film by irradiating an infrared light.

10. A method according to claim 9, wherein said impurity element is phosphorus.

11. A method according to claim 9, wherein said organic silane is TEOS.

12. A method according to claim 9, wherein said semiconductor device is incorporated into a device selected from the group consisting of a liquid crystal display device, a SOI integrated circuit, a microprocessors, a microcomputer and a semiconductor memory.

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

forming a semiconductor film over a substrate;

forming a gate insulating film by using organic silane over said semiconductor film, said gate insulating film comprising silicon oxide;

forming a gate electrode over said gate insulating film, said gate electrode comprising aluminum;

introducing an impurity element into said semiconductor film; and

activating said impurity element in said semiconductor film by irradiating a laser light.

14. A method according to claim 13, wherein said impurity element is phosphorus.

15. A method according to claim 13, wherein said organic silane is TEOS.

16. A method according to claim 13, wherein said semiconductor device is incorporated into a device selected from the group consisting of a liquid crystal display device, a SOI integrated circuit, a microprocessors, a microcomputer and a semiconductor memory.

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

forming a semiconductor film over a substrate;

crystallizing said semiconductor film by heating

forming a gate insulating film by using organic silane over said crystalline semiconductor film, said gate insulating film comprising silicon oxide;

forming a gate electrode over said gate insulating film, said gate electrode comprising aluminum;

introducing an impurity element into said crystalline semiconductor film; and

activating said impurity element in said crystalline semiconductor film by irradiating a laser light.

18. A method according to claim 17, wherein said impurity element is phosphorus.

19. A method according to claim 17, wherein said organic silane is TEOS.

20. A method according to claim 17, wherein said semiconductor device is incorporated into a device selected from the group consisting of a liquid crystal display device, a SOI integrated circuit, a microprocessors, a microcomputer and a semiconductor memory.

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

forming a semiconductor film over a substrate;

crystallizing said semiconductor film by irradiating a light;

forming a gate insulating film by using organic silane over said crystalline semiconductor film, said gate insulating film comprising silicon oxide;

forming a gate electrode over said gate insulating film, said gate electrode comprising aluminum;

introducing an impurity element into said crystalline semiconductor film; and

activating said impurity element in said crystalline semiconductor film by irradiating a laser light.

22. A method according to claim 21, wherein said impurity element is phosphorus.

23. A method according to claim 21, wherein said organic silane is TEOS.

24. A method according to claim 21, wherein said semiconductor device is incorporated into a device selected from the group consisting of a liquid crystal display device, a SOI integrated circuit, a microprocessors, a microcomputer and a semiconductor memory.