Surface CoSi2 layers by moderate dose cobalt implantation for self‐aligned contacts

CoSi2 layers produced by implantation of cobalt into silicon at 20 keV with doses 3–6×1016 cm−2 were investigated. Room temperature and 355 °C implants produced continuous layers of silicides with similar electrical properties. The minimum sheet resistivity of annealed samples was 9.2 Ω/sq. and the films were thermally stable up to about 900 °C. Low leakage currents (estimated <1×10−14 A per μm of a typical side‐wall spacer length) in a SiO2 film which was similarly implanted with Co demonstrate the usefulness of this method for the formation of thin (≂20 nm) cobalt silicides for self‐aligned source‐drain contacts in shallow junction complimentary metal‐oxide‐semiconductor technology.