JPS6447050A - Manufacture of mos-type semiconductor device - Google Patents

Abstract

PURPOSE:To obtain a MOS-type semiconductor device with its sheet resistance low enough by a method wherein a metal-rich high-melting metal silicide layer is formed on a gate electrode and a high-concentration second conductivity type impurity diffusion layer, polycrystalline Si is deposited on the entire surface, and then metal-rich high-melting metal silicide is formed. CONSTITUTION:On a P-type Si substrate 101, an element isolating oxide film 102, a gate oxide film 103, a polycrystalline silicon gate electrode 104, a low- concentration N-type impurity diffusion layer 105, an insulating film side wall 106, and a high-concentration N-type impurity diffusion layer 107 are formed, in that order. Ti 108 is deposited on the entire surface by spattering and, after a short-period heat treatment, a Ti-rich silicide layer 109 is formed only on the polycrystalline silicon gate electrode 104 and source.drain 107. In a short- period heat treatment, the Ti-rich silicide layer 109 reacts with polycrystalline Si 110 for the formation of TiSi2 111. In this process, Si on the substrate side is slower than polycrystalline Si in reacting for the formation of TiSi2. Consumption is kept at the minimum of the substrate-side Si, which keeps high the impurity concentration along the TiSi2-Si interface.