Improved thermal stability of Ni-silicides on Si:C epitaxial layers

The thermal stability of Ni-silicides on tensily strained in situ P doped Si:C epitaxial layers was evaluated. The baseline Ni silicidation process was shown to be compatible with Si:C Recessed Source-Drain (RSD) stressors for NMOS strain engineering while the thermal stability of NiSi:C contacts was significantly improved compared to NiSi ones. Dominant degradation mechanism was shown to be the transition to the NiSi2:C phase. It was demonstrated that the Si:C strain level affects the silicide formation but has no significant effect on the NiSi:C thermal stability. A mechanism responsible for the improved thermal stability of NiSi:C silicides is discussed.