Disclosed is a semiconductor device, comprising a substrate, a channel region in the substrate, source/drain regions on both sides of the channel region, a gate structure on the channel region, and gate sidewall spacers formed on the sidewalls of the gate structure, characterized in that each of the source/drain regions comprises an epitaxially grown metal silicide region, and dopant segregation regions are formed at the interfaces between the epitaxially grown metal silicide source/drain regions and the channel region. By employing the semiconductor device and the method for manufacturing the same according to embodiments of the present invention, the Schottkey Barrier Height of the MOSFETs with epitaxially grown ultrathin metal silicide source/drain may be lowered, thereby improving the driving capability.