Silicide-silicon contacts for reduction of MOSFET source-drain resistances

摘要

Methods for reducing the contact resistance presented by the interface between a silicide and a doped silicon region are presented. In a first method, a silicide layer and a doped silicon region form an interface. Either a damage-only species or a heavy, metal is implanted through the silicide layer into the doped silicon region immediately adjacent the interface. In a second method, a second metal is added to the refractory metal before formation of the silicide. After annealing the refractory metal and the doped silicon region, the second metal diffuses into the doped silicion region immediately adjacent the interface without forming additional phases in the silicide.