The present invention discloses a semiconductor device, comprising a plurality of fins located on a substrate and extending along a first direction; a plurality of gate stack structures extending along a second direction and across each of the fins; a plurality of stress layers located in the fins on both sides of the gate stack structures and having a plurality of source and drain regions therein; a plurality of channel regions located in the fins below the gate stack structures; characterized in that the stress layers have connected parts in the fins and that the channel regions enclose the connected parts.