Semiconductor devices

A semiconductor device includes a device isolation layer on a substrate; pattern groups including fin patterns extending in a first direction; and gate structures extending in a second direction to intersect the fin patterns. A first pattern group, among the pattern groups, may include first fin patterns. At least a portion of the first fin patterns may be arranged with a first pitch in the second direction. The first pattern group may include a first planar portion extending from a first recess portion. A central axis of the first recess portion may be spaced apart from a central axis of one of the first fin patterns by a first distance in the second direction. The first planar portion may have a first width in the second direction and being greater than the first pitch. The first distance may be about 0.8 times to about 1.2 times the first pitch.