| 摘要 |
PURPOSE:To suppress diffusion to a polysilicon layer, by imparting damages to an oxide film, making the oxide film to be an electrically conducting state, and thereafter implementing silicide from the polysilicon layer, which is to become a gate electrode. CONSTITUTION:Damages are imparted to a silicon oxide film 8. The oxide film is made to be an electrically conducting state. For this purpose, e.g., silicon ions are implanted, and high-melting-point metal, e.g., tungsten 9 is deposited. Then, in order to form a gate electrode, lithography is performed. With resist as a mask, the tungsten 9, the damaged silicon oxide film 8 and polysilicon 4 are sequentially etched. Thereafter, ions for forming source and drain diffusing layers are implanted, and heat treatment is performed for electrically activating ion spiecies of various implanted ions. Since the silicon oxide film 8 is present between the tungsten 9 and polysilicon 4', the diffusion of the tungsten into the polysilicon 4 is suppressed. As a result, silicide is not formed, and abnormal diffusion of impurities through the silicide layer does not occur. |
