A semiconductor device in one embodiment includes a semiconductor substrate, a fin disposed on a surface of the semiconductor substrate, an insulator including a gate insulator disposed on a side surface of the fin, and a gate electrode disposed on the insulator that is disposed on side surfaces of the fin and an upper surface of the fin. The device further includes a plurality of epitaxial stripe shaped layers disposed horizontally on the side surface of the fin at different heights, and an interlayer dielectric disposed on the semiconductor substrate to cover the fin and applying a stress to the fin and the epitaxial layers. Any two adjacent epitaxial layers along the fin height direction determine a gap and the gaps between adjacent layers increase or decrease with increasing distance from the substrate.