A semiconductor device includes a substrate including an active pattern, a first interlayer dielectric layer on the substrate, the first interlayer dielectric layer including a recess on an upper portion thereof, and a lower connection line in the first interlayer dielectric layer, the lower connection line being electrically connected to the active pattern, and the lower connection line including a conductive pattern, the recess of the first interlayer dielectric layer selectively exposing a top surface of the conductive pattern, and a barrier pattern between the conductive pattern and the first interlayer dielectric layer, the first interlayer dielectric layer covering a top surface of the barrier pattern.