A semiconductor device having an impurity region is provided. The semiconductor device includes a fin active region having protruding regions and a recessed region between the protruding regions. Gate structures overlapping the protruding regions are disposed. An epitaxial layer is disposed in the recessed region to have a height greater than a width. An impurity region is disposed in the fin active region, surrounds side walls and a bottom of the recessed region, has the same conductivity type as a conductivity type of the epitaxial layer, and includes a majority impurity that is different from a majority impurity included in at least a portion of the epitaxial layer.