An integrated circuit includes a substrate, a bottom electrode, a dielectric layer, a metal-containing compound layer, a resistance switching element, and a top electrode. The bottom electrode is over the substrate, the bottom electrode having a bottom portion and a top portion over the bottom portion. The bottom portion of the bottom electrode has a sidewall slanted with respect to a sidewall of the top portion of the bottom electrode. The dielectric layer surrounds the bottom portion of the bottom electrode. The metal-containing compound layer surrounds the top portion of the bottom electrode. A top end of the sidewall of the bottom portion of the bottom electrode is higher than a bottom surface of the metal-containing compound layer. The resistance switching element is over the bottom electrode. The top electrode is over the resistance switching element.