Semiconductor device and a method of manufacturing the same

摘要

A low-concentration impurity region and a high-concentration impurity region are formed respectively near the lower surface and the upper surface of an undoped polysilicon film by a first and second ion-implanations. A refractory metal film of tungsten or the like is formed on the polysilicon film. The impurities are thermally diffused to form shallow-junctions of source/drain having low-concentration impurities. Lead-out electrodes having a high-impurity concentration can be formed without impeding formation of the source and drain. The refractory metal film is converted into a silicide with the resistance at the interface between the polysilicon film and the silicide kept lowered.