Methods of forming self-aligned silicide layers using multiple thermal processes
Methods of forming a metal salicide layer can include forming a metal layer on a substrate and forming a metal silicide layer on the metal layer using a first thermal process at a first temperature. Then a second process is performed, in-situ with the first thermal process, on the metal layer at a second temperature that is less than the first temperature.
1. A method of forming a metal salicide layer comprising:
forming a metal layer on a substrate;
forming a metal silicide layer on the metal layer using a first thermal process at a first temperature; and then
performing, in-situ with the first thermal process, a second thermal process on the metal layer at second temperature that is less than the first temperature.
2. A method according to claim 1 wherein the metal layer comprises a nickel layer.
3. A method according to claim 1 wherein the first temperature is about 300 to about 600° C.
4. A method according to claim 1 wherein the second temperature is about 200 to about 300° C.
5. A method according to claim 1 wherein the second thermal process is performed for about 10 minutes or more.
6. A method according to claim 5 wherein the second thermal process is performed for about 30 minutes or less.
7. A method according to claim 1 further comprising:
removing a non-reacted portion of the metal layer remaining after the second thermal process.
8. A method according to claim 7 further comprising;
performing a third thermal process on the metal silicide layer after removing the non-reacted portion of the metal layer.
9. A method according to claim 8 wherein the third thermal process is performed at a temperature of about 300 to about 600° C.
10. A method according to claim 1 further comprising:
forming a capping layer on the metal layer before forming the metal silicide layer, wherein the capping layer is removed together with a non-reacted portion of the metal layer remaining after forming the metal suicide layer.
11. A method according to claim 1 wherein the substrate is doped with n-type impurity ions.
12. A method of fabricating a semiconductor device, the method comprising:
forming a metal oxide semiconductor (MOS) transistor including source/drain regions separated from each other in a substrate, a gate pattern on a channel region in the substrate between the source/drain regions, and a spacer covering the sidewalls of the gate pattern;
forming a metal layer on the entire surface of the MOS transistor;
forming a metal silicide layer on the metal layer using a first thermal process at a first temperature; and then
performing a second thermal process on the metal layer, in-situ with the first thermal process, at a second temperature that is less than the first temperature.
13. A method according to claim 12 further comprising:
forming a suicide blocking pattern that exposes a top surface of the source/drain regions and/or the gate pattern before forming the metal layer.
14. A method according to claim 12 wherein the gate pattern includes a gate electrode and a gate capping layer.
15. A method according to claim 12 wherein the gate pattern is formed by depositing a polysilicon layer and a tungsten suicide layer or a tungsten layer on the polysilicon layer.
16. A method according to claim 12 wherein the metal layer comprises a nickel layer.
17. A method according to claim 12 wherein the first temperature is about 300 to about 600° C.
18. A method according to claim 12 wherein the second temperature is about 200 to about 300° C.
19. A method according to claim 12 wherein the second thermal process is performed for about 10 minutes or more.
20. A method according to claim 19 wherein the second thermal process is performed for about 30 minutes or less.
21. A method of fabricating a semiconductor device, the method comprising:
performing a silicidation anneal process on a nickel layer on a source/drain region at a first temperature of about 300° C. to about 400° C.; and then
forming a Ni 2 Si layer from the nickel layer using a thermal process to react the nickel layer with silicon in the source/drain region, in-situ with the silicidation anneal process, at second temperature of about 200-300° C. for about 10 to about 30 minutes; and
phase-shifting the Ni 2 Si layer using a thermal process at a temperature of about 400° C. to about 500° C. to form a NiSi layer.
22. A method according to claim 21 wherein each of the performing a silicidation anneal process, forming a Ni 2 Si layer, and phase-shifting the Ni 2 Si is ceased before initiating a subsequent process.