According to example embodiments, a semiconductor device includes a first fin, a second fin that is separated from the first fin, and a gate on the first fin and the second fin. The gate crosses the first fin and the second fin. The first fin includes a first doped area at both sides of the gate. The first doped area is configured to have a first voltage applied thereto. The second fin includes a second doped area at both sides of the gate. The second doped area is configured to have a second voltage applied thereto. The second voltage is different than the first voltage.