A semiconductor device including source drain stressors is provided. The semiconductor device includes a gate structure including a gate insulating layer and a gate electrode on a semiconductor substrate. Gate spacers may be disposed on sidewalls of the gate structure and a stressor pattern including an impurity region is disposed on a side of the gate structure. The stressor pattern includes a protruded portion having a top surface higher than a bottom surface of the gate structure and a facet in the protruded portion. The facet is slanted at a predetermined angle with respect to an upper surface of the semiconductor substrate and forms a concave portion with one of the gate spacers. A blocking insulating layer may extend conformally on the stressor pattern and the gate spacers and an insulating wing pattern is disposed in the concave portion on the blocking insulating layer.