A semiconductor device includes a gate pattern disposed on a semiconductor substrate, a bulk epitaxial pattern disposed in a recess region formed in the semiconductor substrate at a side of the gate pattern, an insert epitaxial pattern disposed on the bulk epitaxial pattern, and a capping epitaxial pattern disposed on the insert epitaxial pattern. The bulk epitaxial pattern has an upper inclined surface that is a {111} crystal plane, and the insert epitaxial pattern includes a specific element that promotes the growth rate of the insert epitaxial pattern on the upper inclined surface.