Method of manufacturing semiconductor device having polycrystalline silicon layer with metal silicide film

Claim 1

A method of manufacturing a semiconductor device comprising steps of forming a first silicon oxide film on the major surface of a single crystal silicon substrate, forming a polycrystalline silicon layer on said first silicon oxide film, forming an oxidation resisting layer on said polycrystalline silicon film, patterning said oxidation resisting film and said polycrystalline silicon layer, depositing a first metal film continuously on an exposed side surface of the patterned polycrystalline silicon layer and on an exposed major surface of said substrate in the vicinity of said patterned polycrystalline silicon layer via said first silicon oxide film, performing a heat treatment to form a first metal silicide film at said exposed side surface of said patterned polycrystalline silicon layer and a second metal silicide film at said exposed major surface of said substrate and to leave a portion of said first metal film on said first silicon oxide film unconverted into metal silicide, removing said portion of said first metal film left unconverted into metal silicide from the surface of said first silicon oxide film between said first and second metal silicide films to separate said first metal silicide film from said second metal silicide film, performing thermal oxidation to convert surface portions of said first and second metal silicide films into second oxide films, and thereafter removing said oxidation resisting film to expose said upper surface of said patterned polycrystalline silicon layer, depositing a second metal film on the whole surface including said upper surface of said polycrystalline silicon layer from which said oxidation resisting film has been removed, applying a heat treatment to form a third metal silicide film on said upper surface of said silicon layer, and removing said second metal film at the regions where said second metal silicide is not formed.

Claim 2

A method of manufacturing a semiconductor device comprising steps of forming a first silicon oxide film on the major surface of a single crystal silicon substrate, forming a polycrystalline silicon layer on said first silicon oxide film, forming an oxidation resisting layer on said polycrystalline silicon film, patterning said oxidation resisting film and said polycrystalline silicon layer, depositing a first metal film continuously on an exposed side surface of the patterned polycrystalline silicon layer and on an exposed major surface of said substrate in the vicinity of said patterned polycrystalline silicon layer via said first silicon oxide film, performing a heat treatment to form a first metal silicide film at said exposed side surface of said patterned polycrystalline silicon layer and a second metal silicide film at said exposed major surface of said substrate and to leave a portion of said first metal film on said first silicon oxide film unconverted into metal silicide, removing said portion of said first metal film left unconverted into metal silicide from the surface of said first silicon oxide film between said first and second metal silicide films to separate said first metal silicide film from said second metal silicide film, performing thermal oxidation to convert surface portions of said first and second metal silicide films into second oxide films, and thereafter removing said oxidation resisting film to expose said upper surface of said patterned polycrystalline silicon layer, depositing a second metal film on the whole surface including said upper surface of said polycrystalline silicon layer from which said oxidation resisting film has been removed, applying a heat treatment to form a third metal silicide film on said upper surface of said silicon layer, and removing said second metal film at the regions where said second metal silicide is not formed.