Method of fabricating a polycidegate employing nitrogen/oxygen implantation

摘要

Disclosed is a method of fabricating a polycidegate in semiconductor device which has a step of forming a conductor film of polysilicon on a substrate, a step of forming an ion implanted layer by implanting nitrogen ions into the polysilicon conductor film, and a step of forming a low resistance conductor film of titanium on the non-monocyrstalline conductor film. When a field effect transistor is formed by this method, using titanium nitride and/or TiSi2 alloy of the polysilicon conductor and low resistance conductor of titanium by heat treatment as a gate electrode material, the thickness of the alloyed layer is uniform, and breakdown of the gate insulating film due to local diffusion of low resistance conductor is not induced. In other embodiments, oxygen ions and silicon ions are also employed to form thin layers of tunnel oxide and amorphous silicon, respectively.