An integrated circuit includes a substrate, a dielectric layer, an etch stop layer, a bottom electrode, a resistance switching element, and a top electrode. The dielectric layer is over the substrate. The etch stop layer is over the dielectric layer, in which the dielectric layer has a first portion directly under the etch stop layer. The bottom electrode penetrates through the etch stop layer and the dielectric layer, in which the dielectric layer has a second portion directly under the bottom electrode, and a top of the first portion of the dielectric layer is lower than a top of the second portion of the dielectric layer. The resistance switching element is over the bottom electrode. The top electrode is over the resistance switching element.