Semiconductor device and method for fabricating the same

• US 20070018255A1
• Filed: 08/29/2006
• Published: 01/25/2007
• Est. Priority Date: 05/17/2004
• Status: Abandoned Application

• Current Assignee: Fujitsu Semiconductor Limited (Fujitsu Limited)
• Original Assignee: Fujitsu Limited
• Inventors: Kawamura, Kazuo
• Application Number:
  US11/511,472
• Publication Number:
  US 20070018255A1
• Time in Patent Office: Days
• US Class Current: 257/382
• CPC Class Codes: H01L 21/28518 the conductive layers comprising silicides H01L21/28537 takes precedence
• CPC Class Codes: H01L 21/76897 Formation of self-aligned vias or contact plugs, i.e. involving a lithographically uncritical step self-aligned silicidation on field effect transistors H01L29/665
• CPC Class Codes: H01L 29/665 using self aligned silicidation, i.e. salicide formation of conductive layers comprising silicides H01L21/28518
• CPC Class Codes: H01L 29/6659 with both lightly doped source and drain extensions and source and drain self-aligned to the sides of the gate, e.g. lightly doped drain [LDD] MOSFET, double diffused drain [DDD] MOSFET

Abstract

The method for fabricating a semiconductor device according to the present invention comprises the step of forming a Ni film 66 on source/drain diffused layers 64, the step of performing a first thermal processing to react a lower part of the Ni film 66 and an upper part of the source/drain diffused layers 64 with each other to form Ni₂Si films 70b on the source/drain diffused layers 64, the step of etching off selectively a part of the Ni film 66, which has not reacted, and the step of performing a second thermal processing to further react the Ni₂Si film 70b and an upper part of the source/drain diffused layers 64 with each other.

Claims

1. A semiconductor device comprising:

a gate electrode formed over a semiconductor substrate;

a source/drain diffused layer formed in the semiconductor substrate on both sides of the gate electrode; and

a silicide film formed on the source/drain diffused layer,

the silicide film being formed of nickel monosilicide, and

a film thickness of the silicide film being below 20 nm including 20 nm.

2. A semiconductor device according to claim 1, further comprising:

another silicide film formed on the gate electrode,

said another silicide film being formed of nickel monosilicide,

a film thickness of said another silicide film being below 20 nm including 20 nm.

3. A semiconductor device comprising:

a gate electrode formed over a semiconductor substrate;

a source/drain diffused layer formed in the semiconductor substrate on both sides of the gate electrode;

an Si_1-xGe_x film which is buried in the source/drain diffused layer and whose composition ratio x is 0<

x<

1; and

a silicide film formed on the Si_1-xGe_x film,

the silicide film being formed of NiSi_1-xGe_x whose composition ratio x is 0<

x<

1, and

a film thickness of the silicide film being below 20 nm including 20 nm.

4. A semiconductor device according to claim 3, further comprising:

another Si_1-xGe_x film which is formed on the gate electrode and whose composition ratio x is 0<

x<

1, and

another silicide film formed on said another Si_1-xGe_x film,

said another silicide film being formed of NiSi_1-xGe_x whose composition ratio x is 0<

x<

1, and

a film thickness of said another silicide film being below 20 nm including 20 nm.

5. A semiconductor device comprising:

a gate electrode formed over a semiconductor substrate;

a source/drain diffused layer formed in the semiconductor substrate on both sides of the gate electrode,

an Si_1-x-yGe_xC_y film which is buried in the source/drain diffused layer and whose composition ratios x, y satisfy 0<

x<

1, 0<

y<

0.01 and 1−

x−

y>

0; and

a silicide film formed on the Si_1-x-yGe_xC_y film,

the silicide film being formed of NiSi_1-x-yGe_xC_y whose composition ratios x, y satisfy 0<

x<

1, 0<

y<

0.01 and 1−

x−

y>

0, and

a film thickness of the silicide film being below 20 nm including 20 nm.

6. A semiconductor device according to claim 5, further comprising:

another Si_1-x-yGe_xC_y film which is formed on the gate electrode and whose composition ratios x, y satisfy 0<

x<

1, 0<

y<

0.01 and 1−

x−

y>

0, and

another silicide film formed on said another Si_1-x-yGe_xC_y film,

said another silicide film being formed of NiSi_1-x-yGe_xC_y whose composition ratios x, y satisfy 0<

x<

1, 0<

y<

0.01 and 1−

x−

y>

0, and

a film thickness of said another silicide film being below 20 nm including 20 nm.

7. A method for fabricating a semiconductor device comprising the steps of:

forming a gate electrode over a semiconductor substrate;

forming a source/drain diffused layer in the semiconductor substrate on both sides of the gate electrode;

forming a nickel film on the source/drain diffused layer;

performing a first thermal processing to react a lower part of the nickel film and an upper part of the source/drain diffused layer with each other to form a nickel silicide film on the source/drain diffused layer;

etching off selectively a part of the nickel film, which has not reacted; and

performing a second thermal processing to further react the nickel silicide film and an upper part of the source/drain diffused layer with each other.

8. A method for fabricating a semiconductor device according to claim 7, wherein

in the step of forming the nickel film, the nickel film is formed further on the gate electrode,

in the step of performing a first thermal processing, a lower part of the nickel film and an upper part of the gate electrode are reacted with each other to form the nickel silicide film further on the gate electrode,

in the step of etching off selectively the part of the nickel film, which has not reacted, the part of the nickel film on the gate electrode, which has not reacted, is selectively etched off, and

in step of performing the second thermal processing, the nickel silicide film on the gate electrode and an upper part of the gate electrode is further reacted with each other.

13. A method for fabricating a semiconductor device according to claim 7, wherein

in the step of forming the nickel film, the nickel film is formed in a thickness of above 17 nm including 17 nm.

14. A method for fabricating a semiconductor device according to claim 7, wherein

a temperature of the second thermal processing is higher than a temperature of the first thermal processing.

15. A method for fabricating a semiconductor device according to claim 7, wherein

a temperature of the first thermal processing is 200-400°

C., and

a temperature of the second thermal processing is 350-650°

C.

16. A method for fabricating a semiconductor device according to claim 7, wherein

in the step of performing the second thermal processing, a thermal processing is performed by spike annealing of 450-650°

C.

17. A method for fabricating a semiconductor device according to claim 7, wherein

in the step of forming the nickel film, the nickel film is formed by sputtering.

18. A method for fabricating a semiconductor device according to claim 7, further comprising, after the step of forming the nickel film and before the step of performing the first thermal processing, the step of:

amorphizing the nickel film.

19. A method for fabricating a semiconductor device according to claim 18, wherein

in the step of amorphizing the nickel film, nickel ions are implanted into the nickel film to amorphize the nickel film.

20. A method for fabricating a semiconductor device according to claim 19, wherein

in the step of amorphizing the nickel film, the nickel ions are implanted into the nickel film under conditions of a 5-500 keV acceleration voltage and a 1×

10¹⁴-1×

10¹⁵ cm<sup>−

2</sup> dose.

21. A method for fabricating a semiconductor device according to claim 7, further comprising, after the step of forming the nickel film and before the step of performing the first thermal processing, the step of:

forming a protection film for preventing oxidation of the nickel film on the nickel film.

22. A method for fabricating a semiconductor device according to claim 7, wherein

the steps from the step of forming the nickel film to the step of performing the first thermal processing are performed continuously without an exposure to the atmospheric air.

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

forming a gate electrode over a semiconductor substrate;

forming a source/drain diffused layer in the semiconductor substrate on both sides of the gate electrode;

burying Si_1-xGe_x film whose composition ratio x is 0<

x<

1 in the source/drain diffused layer;

forming a nickel film on the Si_1-xGe_x film;

performing a first thermal processing to react a lower part of the nickel film and an upper part of the Si_1-xGe_x film to form a nickel silicide film on the Si_1-xGe_x film;

etching off selectively a part of the nickel film, which has not reacted; and

performing a second thermal processing to further react the nickel silicide film and an upper part of the Si_1-xGe_x film with each other.

10. A method for fabricating a semiconductor device according to claim 9, further comprising before the step of forming the nickel film, the step of:

forming another Si_1-xGe_x film whose composition ratio x is 0<

x<

1 on the gate electrode,

in the step of forming the nickel film, the nickel film being formed further on said another Si_1-xGe_x film,

in the step of performing the first thermal processing, a lower part of the nickel film and an upper part of said another Si_1-xGe_x film being reacted with each other to further form the nickel silicide film on said another Si_1-xGe_x film,

in the step of etching off selectively the part of the nickel film, which has not reacted, a part of the nickel film on said another Si_1-xGe_x film, which has not reacted, being selectively etched off, and

in the step of performing the second thermal processing, the nickel silicide film on said another Si_1-xGe_x film and an upper part of the said another Si_1-xGe_x film being further reacted with each other.

11. A method for fabricating a semiconductor device comprising the steps of:

forming a gate electrode over a semiconductor substrate;

forming a source/drain diffused layer in the semiconductor substrate on both sides of the gate electrode;

burying an Si_1-x-yGe_xC_y film whose composition ratios x, y satisfy 0<

x<

1, 0<

y<

0.01 and 1−

x−

y>

0 in the source/drain diffused layer;

forming a nickel film on the Si_1-x-yGe_xC_y film;

performing a first thermal processing to react a lower part of the nickel film and an upper part of the Si_1-x-yGe_xC_y film with each other to form a nickel silicide film on the Si_1-x-yGe_xC_y film;

etching off selectively a part of the nickel film, which has not reacted; and

performing a second thermal processing to further react the nickel silicide film and an upper part of the Si_1-x-yGe_xC_y film with each other.

12. A method for fabricating a semiconductor device according to claim 11, further comprising before the step of forming the nickel silicide film, the step of:

forming another Si_1-x-yGe_xC_y film whose composition ratios x, y satisfy 0<

x<

1.0, 0<

y<

0.01 and 1−

x−

y>

0 on the gate electrode,

in the step of forming the nickel film, the nickel film being formed further on said another Si_1-x-yGe_xC_y film,

in the step of performing the first thermal processing, a lower part of the nickel film and an upper part of said another Si_1-x-yGe_xC_y film being reacted with each other to further form the nickel silicide film on said another Si_1-x-yGe_xC_y film,

in the step of etching off selectively the part of the nickel film, which has not reacted, a part of the nickel film on said another Si_1-x-yGe_xC_y film, which has not reacted, being selectively etched off, and

in the step of performing the second thermal processing, the nickel silicide film on said another Si_1-x-yGe_xC_y film and an upper part of said another Si_1-x-yGe_xC_yfilm being further reacted with each other.