Semiconductor devices including a dummy gate structure on a fin are provided. A semiconductor device includes a fin protruding from a substrate. The semiconductor device includes a source/drain region in the fin, and a recess region of the fin that is between first and second portions of the source/drain region. Moreover, the semiconductor device includes a dummy gate structure overlapping the recess region, and a spacer that is on the fin and adjacent a sidewall of the dummy gate structure.