Method of forming a tantalum-containing gate electrode structure
View Patent ↗A method for forming a tantalum-containing gate electrode structure by providing a substrate having a high-k dielectric layer thereon in a process chamber and forming a tantalum-containing layer on the high-k dielectric layer in a thermal chemical vapor deposition process by exposing the substrate to a process gas containing TAIMATA (Ta(N(CH 3 ) 2 ) 3 (NC(C 2 H 5 )(CH 3 ) 2 )) precursor gas. In one embodiment of the invention, the tantalum-containing layer can include a TaSiN layer formed from a process gas containing TAIMATA precursor gas, a silicon containing gas, and optionally a nitrogen-containing gas. In another embodiment of the invention, a TaN layer is formed on the TaSiN layer. The TaN layer can be formed from a process gas containing TAIMATA precursor gas and optionally a nitrogen-containing gas. A computer readable medium executable by a processor to cause a processing system to perform the method and a processing system for forming a tantalum-containing gate electrode structure are also provided.
1. A method of forming a tantalum-containing gate electrode structure, the method comprising:
providing a substrate having a high-k dielectric layer thereon in a process chamber; and
forming a tantalum-containing layer on the high-k dielectric layer in a thermal chemical vapor deposition process by exposing the substrate in the process chamber to a first process gas containing TAIMATA precursor gas.
2. The method according to claim 1 , wherein the tantalum-containing layer is a TaSiN layer formed on the high-k dielectric layer, and the first process gas containing TAIMATA precursor gas further contains a silicon-containing gas.
3. The method according to claim 2 , wherein the silicon-containing gas flow rate is less than about 500 sccm.
4. The method according to claim 2 , wherein the silicon-containing gas comprises silane (SiH 4 ), disilane (Si 2 H 6 ), dichlorosilane (SiH 2 Cl 2 ), hexachlorodisilane (Si 2 Cl 6 ), bis (tertbutylamino) silane (SiH 2 (NBu t ) 2 ), or tetrakis (dimethylamino) silane (Si(NMe 2 ) 4 ) or a combination of two or more thereof.
5. The method according to claim 2 , wherein the first process gas further comprises a nitrogen-containing gas.
6. The method according to claim 5 , wherein the nitrogen-containing gas flow rate is less than about 1,000 sccm.
7. The method according to claim 5 , wherein the nitrogen-containing gas comprises NH 3 .
8. The method according to claim 2 , further comprising forming a tungsten (W) layer on the TaSiN layer.
9. The method according to claim 8 , wherein the forming a W layer comprises exposing the substrate to a second process gas containing W(CO) 6 , WF 6 , or WCl 6 or a combination of two or more thereof.
10. The method according to claim 2 , further comprising forming a TaN layer on the TaSiN layer in a thermal chemical vapor deposition process by exposing the substrate in the process chamber to a second process gas containing TAIMATA precursor gas.
11. The method according to claim 10 , wherein the second process gas further comprises a nitrogen-containing gas.
12. The method according to claim 11 , wherein the nitrogen-containing gas flow rate is less than about 1,000 sccm.
13. The method according to claim 11 , wherein the nitrogen-containing gas comprises NH 3 .
14. The method according to claim 1 , wherein the first process gas flow rate into the process chamber is less than about 2,000 sccm.
15. The method according to claim 1 , wherein the first process gas further comprises a carrier gas or a dilution gas or a combination thereof.
16. The method according to claim 15 , wherein one or both of the carrier gas and the dilution gas contain Ar or He.
17. The method according to claim 1 , wherein the first process gas further comprises H 2 .
18. The method according to claim 1 , wherein the forming occurs at a process chamber pressure between about 1 mTorr and about 1,000 mTorr.
19. The method according to claim 1 , wherein the forming occurs at a process chamber pressure between about 10 mTorr and about 200 mTorr.
20. The method according to claim 1 , wherein the forming further comprises heating the substrate to between about 250° C. and about 750° C.
21. The method according to claim 1 , wherein the forming further comprises heating the substrate to between about 400° C. and about 600° C.
22. A method of forming a tantalum-containing gate electrode structure, the method comprising:
providing a substrate having a high-k dielectric layer thereon to a process chamber; and
forming a TaSiN layer on the high-k dielectric layer in a thermal chemical vapor deposition process by heating the substrate to between about 250° C. and about 750° C. and exposing the heated substrate in the process chamber to a first process gas containing TAIMATA precursor gas and a silicon-containing gas.
23. The method according to claim 22 , wherein the silicon-containing gas comprises silane (SiH 4 ), disilane (Si 2 H 6 ), dichlorosilane (SiH 2 Cl 2 ), hexachlorodisilane (Si 2 Cl 6 ), bis (tertbutylamino) silane (SiH 2 (NBu t ) 2 ), or tetrakis (dimethylamino) silane (Si(NMe 2 ) 4 ) or a combination of two or more thereof.
24. The method according to claim 22 , wherein the first process gas further comprises NH 3 .
25. The method according to claim 22 , further comprising forming a tungsten (W) layer on the TaSiN layer.
26. The method according to claim 25 , wherein the forming a W layer comprises exposing the substrate to a second process gas containing W(CO) 6 , WF 6 , or WCl 6 or a combination of two or more thereof.
27. The method according to claim 22 , further comprising forming a TaN layer on the TaSiN layer in a thermal chemical vapor deposition process by exposing the substrate in the process chamber to a second process gas containing TAIMATA precursor gas.
28. The method according to claim 27 , wherein the second process gas further comprises NH 3 .
29. The method according to claim 22 , wherein the first process gas further comprises a carrier gas or a dilution gas or a combination thereof.
30. The method according to claim 29 , wherein one or both of the carrier gas and the dilution gas contain Ar or He.
31. The method according to claim 22 , wherein the forming further comprises heating the substrate to between about 400° C. and about 600° C.