Method or manufacturing a semiconductor device and semiconductor device obtained by using such a method

A method of manufacturing a semiconductor device consisting of a substrate and a semiconductor body comprising a field effect transistor having a source and drain region and a channel region of a first conductivity type located therebetween and a gate electrode separated from the channel region by a dielectric layer, which gate electrode comprises a conductor, wherein a polycrystalline silicon layer is deposited on the semiconductor body provided with said dielectric layer so as to form the gate electrode, which polycrystalline silicon layer is subsequently removed again outside the channel region, and wherein a metal layer is deposited on the semiconductor body on top of the remaining portion of the polycrystalline silicon layer above the channel region, after which the remaining portion of the polycrystalline silicon layer is reacted with the metal layer by means of a thermal treatment, forming a metal suicide that forms the conductor for the gate electrode, after which the portion of the metal layer that remains after the reaction is removed by etching, characterized in that the semiconductor bodying is exposed in a thermal treatment to an atmosphere that comprises an oxygen-containing compound during or after the formation of the metal suicide.