Capping free metal silicide integrated process

摘要

A method is described for fabricating a lightly doped drain MOS FET integrated circuit device with a peeling-free metal silicide gate electrode continues by annealing the gate oxide, the polysilicon layer and the metal silicide layer using a furnace process at a temperature more than about 920 DEG C. and for a time of less than about 40 minutes. A pattern of lightly doped regions is formed in the substrate by ion implantation using the structures as the mask. A low temperature silicon dioxide layer is blanket deposited over the surfaces of the structure. The pattern of lightly doped regions is driven in while maintaining the low temperature silicon oxide over the metal silicide layer by annealing at a temperature of more than about 920 DEG C. The blanket layer is etched to form a dielectric spacer structure upon the sidewalls of each of the gate electrode structures and over the adjacent portions of the substrate, and to remove the silicon oxide layer from the top surfaces of metal silicide layer. Heavily doped regions are formed. A passivation layer which includes a silicon oxide layer and a thicker dielectric layer is formed over the structures. The heavily doped regions are annealed to drivein the impurities at a temperature of more than about 920 DEG C. while maintaining said passivation layer over said metal silicide layer.