Method of manufacturing semiconductor device

Abstract

After a silicon oxide film is formed on a main surface of a semiconductor substrate so as to cover a floating gate electrode and a gate electrode, an isotropic etching is performed on the silicon oxide film with a photoresist pattern formed thereon used as an etching mask, and an anisotropic etching is further performed on the silicon oxide film. Accordingly, the silicon oxide film exposed from the photoresist pattern is removed, and a first insulating film made of the silicon oxide film remaining below the photoresist pattern is formed. The first insulating film covers the floating gate electrode. After a metal silicide layer is formed on the gate electrode, a second insulating film made of silicon nitride is formed on the main surface of the semiconductor substrate so as to cover the floating gate electrode, the gate electrode, the metal silicide layer, and the first insulating film.

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