New carbon-based thermal stability improvement technique for NiPtSi used in CMOS technology

A new carbon-based thermal stability improvement technique is proposed for nickel silicide. Carbon implantation is well known to improve the thermal stability of Ni-based silicides, but its process window is small. An experiment has been performed to identify and introduce new process steps which improve the thermal stability and which can be integrated into a CMOS technology platform without a significant cost increase. No yield issues have been observed up to 700 °C 30 min post-silicidation thermal budget even for the narrowest silicided silicon lines. NiPtSi encroachment, which is one of the main yield killers for Sub-65 nm technologies, has not been seen. The device scalability is not affected and a similar performance has been achieved with an additional post-silicidation thermal budget. Through in-depth understanding of this approach, new integration schemes like for instance a gate-last process flow can be envisioned.