A single-step, low temperature self-aligned CoSi2 process using Ti/Co source material has been developed for use in extreme submicrometer MOSFET applications. Ultra-thin CoSi2 films (∼ 20 nm) were obtained from a single-step RTA anneal at 550°C for 30 sec using Ti/Co source material on patterned n+ implanted (100) Si. X-ray diffraction was used to verify CoSi2 formation. Highresolution SEM and TEM examination showed the silicide to be microstructurally smooth and the devices showed no lateral growth of the silicide at the polysilicon spacer edge. Some voiding and lateral overgrowth was observed at the LOCOS isolation edge and this effect was exacerbated at higher anneal temperatures. This single-step low temperature CoSi2 process is a promising technology for deep-submicron MOSFET applications.