Manufacturing method of semiconductor device

A method of manufacturing a semiconductor device, comprising:

• forming a gate insulation film on a substrate comprising a silicon layer grown on an insulator;
• forming a gate electrode on the gate insulation film, the gate electrode comprising a polysilicon film;
• forming a low impurity concentration region of a first conductivity type in the silicon layer adjacent the gate electrode;
• forming a silicon oxide film to cover the gate insulation film and the gate electrode;
• dry-etching the silicon oxide film so that a thickness of the silicon oxide film becomes 5 to 35% of a thickness of the silicon oxide film at the time of the forming thereof;
• removing by a wet etching using hydrofluoric acid a portion of the silicon oxide film that is on the gate electrode and another portion of the silicon oxide film that is on a portion of the gate insulation film that is not covered by the gate electrode so as to form a spacer that is disposed on a side wall of the gate electrode;
• forming a silicon nitride film over an entire surface of the substrate having the gate electrode and the spacer thereon;
• forming a high impurity concentration region of the first conductivity type in the silicon layer adjacent the spacer so that the high impurity concentration region is deeper than the low impurity concentration region;
• removing by a wet etching using phosphoric acid the silicon nitride film from the substrate in which the high and low concentration regions are formed;
• forming a transition metal film over the substrate from which the silicon nitride film is removed, the transition metal film comprising titanium, cobalt or nickel;
• and
• inducing a chemical reaction between the transition metal layer and silicon so that a silicide layer is formed in the silicon layer of the substrate and another silicide layer is formed in a surface of the gate electrode.