Formation of silicided junctions in deep sub-micron MOSFETs by defect enhanced CoSi2 formation

A method of forming silicided junctions in a deep submicron MOSFET, comprising the steps of:

• precleaning, in an acid dip, a silicon wafer having an oxide layer disposed thereon and diffusion window open in the oxide layer so as to expose bulk silicon;
• after the precleaning, transferring the silicon wafer to a sputtering tool;
• in the sputtering tool, sputter cleaning by bombarding the silicon wafer with low energy Ar+ ions, wherein the bombardment with low energy Ar+ ions occurs at about 1.5 KeV at 1 micro-amp, so as to form a damage region in the bulk silicon exposed by the diffusion window, the damage region being of a depth in the range of three to twenty monolayers of the bulk silicon;
• after the bombarding, without removing the silicon wafer from the sputtering tool, depositing cobalt metal at room temperature on the silicon wafer so as to form a cobalt silicide layer;
• and
• wherein the cobalt silicide layer is formed during deposition of the cobalt metal without any further annealing step.