An semiconductor device is provided. A fin is disposed on a substrate, extending in a lengthwise direction. A first recess is disposed on a sidewall of the fin so that the fin 7and the first recess is arranged in a straight line along the lengthwise direction. A gate structure crosses the fin in the first direction crossing the lengthwise direction. A spacer is disposed on sidewalk of the gate structure. A source/drain region is disposed in the first recess. The source/drain region is formed under the spacer. A silicide layer is disposed on the source/drain region. The silicide layer and the source/drain region fill the first recess.