SEMICONDUCTOR DEVICE AND METHOD FOR FORMING THE SAME

• US 20100041187A1
• Filed: 10/23/2009
• Published: 02/18/2010
• Est. Priority Date: 10/09/1992
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: TAKEMURA, Yasuhiko, ZHANG, Hongyong, TERAMOTO, Satoshi
• Granted Patent: US 8,017,506 B2
• Time in Patent Office: Days
• US Class Current: 438/164
• 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 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 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.

Claims

1. A method for manufacturing a thin film semiconductor device:

forming an island like semiconductor region on an insulator;

forming a gate electrode on the island like semiconductor region with a gate insulator film interposed therebetween;

forming an oxide layer on side and top surfaces of the gate electrode;

forming an insulator film over the oxide layer;

etching the insulator film to form side walls adjacent to the gate electrode with the oxide layer interposed therebetween;

forming a metal film over the side walls, the island like semiconductor region and the gate electrode;

forming silicide regions on a surface of the island like semiconductor by a heat treatment; and

annealing the silicide regions by irradiating a light after removing unreacted portions of the metal film.

2. The method according to claim 1, wherein the heat treatment is conducted by lamp annealing.

3. The method according to claim 1, wherein the metal is one or a plurality of elements selected from the group consisting of molybdenum, tungsten, platinum, chromium, titanium, and cobalt.

4. The method according to claim 1, wherein the light is a laser beam.

5. The method according to claim 1, wherein the oxide layer is formed by oxidizing the gate electrode.

6. A method for manufacturing a thin film semiconductor device:

forming an island like semiconductor region on an insulator;

forming a gate electrode on the island like semiconductor region with a gate insulator film interposed therebetween;

forming a metal film over the island like semiconductor region and the gate electrode;

forming silicide regions on a surface of the island like semiconductor region by a heat treatment;

annealing the silicide regions by irradiating a light after removing unreacted portions of the metal film; and

forming a conductive film comprising titan over the silicide regions,

wherein the conductive film is in contact with at least one of the silicide regions.

7. The method according to claim 6, wherein the heat treatment is conducted by lamp annealing.

8. The method according to claim 6, wherein the metal is one or a plurality of elements selected from the croup consisting of molybdenum, tungsten, platinum, chromium, titanium, and cobalt.

9. The method according to claim 6, wherein the light is a laser beam.

10. The method according to claim 6, wherein the conductive film comprises titanium nitride.

11. A method for manufacturing a thin film semiconductor device:

forming an island like semiconductor region on an insulator;

forming a gate electrode on the island like semiconductor region with a gate insulator film interposed therebetween;

forming a metal film over the island like semiconductor region and the gate electrode;

forming silicide regions on a surface of the island like semiconductor region by a heat treatment;

removing unreacted portions of the metal film;

annealing the silicide regions by irradiating a light; and

forming contacts comprising titan to silicide regions.

12. The method according to claim 11, wherein the heat treatment is conducted by lamp annealing.

13. The method according to claim 11, wherein the metal is one or a plurality of elements selected from the group consisting of molybdenum, tungsten, platinum, chromium, titanium, and cobalt.

14. The method according to claim 11, wherein the light is a laser beam.

15. The method according to claim 11, wherein a titanium nitride film is in contact with the silicide at one of the contacts.

16. A method for manufacturing a thin film semiconductor device:

forming an island like semiconductor region on an insulator;

forming a gate electrode on the island like semiconductor region with a gate insulator film interposed therebetween;

forming side walls adjacent to the gate electrode, wherein an oxide layer is located between each of the side walls and the gate electrode;

forming a metal film over the island like semiconductor region and the gate electrode;

forming silicide regions on a surface of the island like semiconductor region by a first heat treatment;

removing unreacted portions of the metal film; and

conducting a second heat treatment;

wherein the second heat treatment is conducted at a higher temperature than the first heat treatment.

17. The method according to claim 16, wherein the first heat treatment is conducted by lamp annealing.

18. The method according to claim 16, wherein the second heat treatment is conducted by using a laser beam.

19. The method according to claim 16, wherein the metal is one or a plurality of elements selected from the group consisting of molybdenum, tungsten, platinum, chromium, titanium, and cobalt.

20. The method according to claim 16, wherein the oxide layer is formed by oxidizing the gate electrode.