Self-aligned cobalt disilicide for gate and interconnection and contacts to shallow junctions

In this paper we present a new gate and interconnection and contact metallization technology that uses cobalt disilicide for both purposes. Cobalt disilicide, with a thin polycrystalline film resistivity of 15-20 µ Ω .cm, offers a 0.5-1-Ω/ sheet resistance at the gate level in the popular silicide/polysilicon gate metal scheme. It also offers an excellent contact metallization scheme to shallow junctions. This paper describes a scheme that utilizes self-aligned patterning features and low-temperature processing and shows stability up to 900°C. Various other features of the processing and characteristics of the silicide are also presented.