Ion implantation for preventing polycide void

Abstract

A method for fabricating polycide gate electrodes wherein voids at the silicide/polysilicon interface are eliminated by ion implantation is described. A layer of gate silicon oxide is grown over the surface of a semiconductor substrate. A polysilicon layer is deposited overlying the gate silicon oxide layer. A silicide layer is formed overlying the polysilicon layer. Silicon ions are implanted into the silicide layer. A hard mask layer is deposited over the silicide layer. Because of the presence of the silicon ions in the silicide layer, silicon atoms from the polysilicon layer do not diffuse into the silicide layer causing voids to form in the polysilicon layer. Therefore, the formation of silicon pits in the semiconductor substrate is prevented. The silicide, polysilicon and gate silicon oxide layers are patterned to complete fabrication of a gate electrode in the manufacture of an integrated circuit device.