A semiconductor device includes a first lower insulating interlayer, a protection insulating layer, and a first upper insulating interlayer that are sequentially stacked on a substrate, and a conductive pattern penetrating the first upper insulating interlayer, the protection insulating layer; and the first lower insulating interlayer. The conductive pattern includes a line part extending in a direction parallel to an upper surface of the substrate and contact parts extending from the line part toward the substrate. The contact parts are separated from each other with an insulating pattern therebetween. The insulating pattern includes a portion of each of the first upper insulating interlayer, the protection insulating layer, and the first lower insulating interlayer. At least a portion of the insulating pattern has a stepped profile.