A semiconductor device includes an interlayer dielectric layer on a substrate, the interlayer dielectric layer having an upper surface, a lower plug extending down into the interlayer dielectric layer from the upper surface of the interlayer dielectric layer, the lower plug having an upper surface, a first dielectric layer pattern on the upper surface of the lower plug, at least a portion of the first dielectric layer pattern being directly connected to the upper surface of the lower plug, a first metal electrode pattern on the first dielectric layer pattern, a first upper plug electrically connected to the first metal electrode pattern, and a second upper plug on the lower plug, the second upper plug being spaced apart from the first upper plug.