Abstract: Using a process in accordance with the teachings of this invention, an integrated circuit may be fabricated providing refractory metal silicide layers, such as TiSi.sub.2, of differing thicknesses to provide optimal reductions in the sheet resistances of the regions in which refractory metal silicide layers are formed. In one embodiment of the present invention a field effect transistor having a polycrystalline silicon gate is fabricated to provide a gate having optimally minimized sheet resistance and source and drain regions having TiSi.sub.2 layers of the appropriate thickness to avoid punch-through leakage problems.

Abstract: A method of forming a metallic silicide on silicon or polysilicon in which a masking layer such as silicon dioxide is formed on a silicon slice and patterned to expose selected areas of the slice surface. The slice is then sputter etched followed by in situ deposition of a metal layer. The slice is heated to convert the portion of the metal layer in contact with the silicon and/or polysilicon to a metal silicide, then the non-converted metal is removed by a selective etchant. According to another embodiment of the invention a titanium layer is deposited and reacted in an ambient including nitrogen to prevent the out-diffusion of silicon through the TiSi.sub.2 and titanium layers.