Method for forming metal silicide layer in active area of semiconductor device

1. A method of forming a semiconductor device having a metal silicide by a low pressure chemical vapor deposition (LPCVD) process using a source gas of TiCl 4 , comprising the steps of:

forming a source/drain junction area on a silicon substrate;

forming an attack protection layer on the source/drain junction area, wherein the attack protection layer is electrically conductive and prevents a silicon substrate attack caused by chlorine (Cl) gases generated from the source gas of TiCl 4 ;

forming a titanium (Ti) layer over the attack protection layer through the LPCVD process;

illuminating an ultra violet light having a higher energy than a binding energy of a SiCl reaction product on the surface of the Ti layer to remove remnant chlorine (Cl) components in the Ti layer; and

diffusing the Ti layer into the attack protection layer to thereby form a metal silicide layer.

2. The method as recited in claim 1 , wherein a poly-silicon layer formed by using a chemical vapor deposition (CVD) process is used for forming the attack protection layer.

3. The method as recited in claim 2 , wherein the attack protection layer is formed by the CVD process using a source gas of Si 2 H 6 /Cl/H 2 .

4. The method as recited in claim 2 , wherein a thickness of the attack protection layer ranges from about 50 Å to about 200 Å.

5. The method as recited in claim 3 , wherein the CVD process for forming the attack protection layer is carried out at a temperature ranging from about 600° C. to about 700° C. and at a pressure ranging from about 0.1 mtorr to about 1.0 mtorr.

6. The method as recited in claim 3 , further comprising the step of deoxidizing the surface of the attack protection layer by using hydrogen (H 2 ) gas to remove remnant chlorine (Cl) components in the attack protection layer after depositing the attack protection layer.

7. The method as recited in claim 3 , further comprising the step of illuminating an ultra violet light having a higher energy than a binding energy of SiCl on the surface of the attack protection layer to remove remnant chlorine (Cl) components in the attack protection layer.

8. The method as recited in claim 1 , wherein a titanium nitride (TiN) layer formed by using a chemical vapor deposition (CVD) process is used for forming the attack protection layer.

9. The method as recited in claim 8 , wherein the TiN layer is deposited by using the TiCl 4 source gas added with ammonia (NH 3 ) gas in an identical chamber where the Ti layer is subsequently deposited.

10. The method as recited in claim 8 , wherein a thickness of the attack protection layer ranges from about 50 Å to about 200 Å.

11. The method as recited in claim 1 , wherein the Ti layer is deposited by using the LPCVD process at a temperature ranging from about 600° C. to about 700° C. and at a pressure ranging from about 1 torr to about 50 torr.

12. The method as recited in claim 11 , wherein the LPCVD process is performed by using the TiCl 4 source gas added with ammonia (NH 3 ) gas and hydrogen (H 2 ) gas including argon (Ar) gas and a flow amount ratio of the NH 3 gas to the Ar gas is about 1 to about 5.

13. A method for forming a barrier metal layer for a semiconductor device fabrication, comprising the steps of:

a) forming a contact hole exposing an active area through a selective etch of an insulation layer formed on a silicon substrate providing the active area;

b) forming an attack protection layer for preventing the silicon substrate attack caused by a succeeding titanium layer deposition process on the active area exposed by the contact hole, wherein the attack protection layer is electrically conductive;

c) forming a titanium (Ti) layer along a profile of the attack protection layer formed on the active area by using a low pressure chemical vapor deposition (LPCVD) process using a source gas of TiCl 4 ;

d) diffusing the Ti layer into the attack protection layer, thereby forming a metal silicide layer;

e) illuminating an ultra violet light having a bigger energy than a binding energy of SiCl on the surface of the Ti layer to remove remnant chlorine (Cl) components in the Ti layer; and

f) forming a titanium nitride (TiN) layer on the Ti layer.

14. The method as recited in claim 13 , wherein a poly-silicon layer formed by a chemical vapor deposition (CVD) process is used as the attack protection layer.

15. The method as recited in claim 14 , wherein the CVD process is carried out by using a source gas of Si 2 H 6 /Cl/H 2 .

16. The method as recited in claim 15 , wherein the CVD process for forming the attack protection layer is performed at a temperature ranging from about 600° C. to about 700° C. and at a pressure ranging from about 0.1 mtorr to about 1 mtorr.

17. The method as recited in claim 13 , wherein a titanium nitride (TiN) layer formed by a chemical vapor deposition (CVD) process is used as the attack protection layer.

18. The method as recited in claim 17 , wherein the attack protection layer is deposited by using the TiCl 4 source gas added with ammonia (NH 3 ) gas in an identical chamber where the Ti layer will be deposited.

19. The method as recited in claim 17 , wherein a thickness of the attack protection layer ranges from about 10 Å to about 100 Å.

20. The method as recited in claim 13 , wherein the Ti layer is deposited by using the LPCVD process at a temperature ranging from about 600° C. to about 700° C. and at a pressure ranging from about 1 torr to about 50 torr.

21. The method as recited in claim 20 , wherein the LPCVD process is performed by using the TiCl 4 source gas added with ammonia (NH 3 ) gas and hydrogen (H 2 ) gas including argon (Ar) gas and a flow amount ratio of the NH 2 gas to the Ar gas is about 1 to about 5.

22. The method as recited in claim 13 , wherein the TiN layer is deposited on the Ti layer by using the LPCVD process at a temperature ranging from about 600° C. to about 700° C. and at a pressure ranging from about 1 torr to about 50 torr.

23. The method as recited in claim 22 , wherein the LPCVD process is performed by using the TiCl 4 source gas added with ammonia (NH 3 ) gas and hydrogen (H 2 ) gas including argon (Ar) gas and a flow amount ratio of the NH 3 gas to the Ar gas is about 8 to about 15.

24. The method as recited in claim 23 , wherein the TiN layer is deposited in an identical chamber where the Ti layer is deposited.

25. The method as recited in claim 13 , wherein the titanium silicide layer is produced by carrying out a heat treatment process at a temperature ranging from about 700° C. to about 900° C.

26. The method as recited in claim 13 , wherein further comprising the step of deoxidizing the surface of the Ti layer using hydrogen (H 2 ) gas to remove remnant chlorine components after depositing the Ti layer and the TiN layer.

27. The method as recited in claim 15 , further comprising the step of deoxidizing the surface of the attack protection layer using a hydrogen (H 2 ) gas to remove remnant chlorine components after depositing the attack protection layer, i.e., the poly-silicon layer.

28. The method as recited in claim 15 , further comprising the step of illuminating an ultra violet light having a bigger energy than a binding energy of SiCl to remove remnant chlorine (Cl) components in the attack protection layer.