Method for manufacturing semiconductor device

Abstract

A semiconductor device manufacturing method includes: forming a sidewall spacer on a sidewall surface of a gate electrode; forming a pair of second conductive type source and drain regions in an active region; covering top surfaces of a semiconductor layer, a device isolation region, the sidewall spacer and the gate electrode with a metal film; reducing resistance of the source and drain regions and the gate electrode partially by making the metal film react with the semiconductor layer and the gate electrode; and removing an unreacted portion of the metal film and the sidewall spacer simultaneously by using an etchant which readily etches the unreacted portion of the metal film and the sidewall spacer while hardly etching the device isolation region, resistance-reduced portions of the gate electrode and resistance-reduced portions of the source and drain regions.