A semiconductor device including a substrate; a bottom electrode on the substrate; a first dielectric layer on the bottom electrode, the first dielectric layer including a first metal oxide including at least one of Hf, Al, Zr, La, Ba, Sr, Ti, and Pb; a second dielectric layer on the first dielectric layer, the second dielectric layer including a second metal oxide including at least one of Hf, Al, Zr, La, Ba, Sr, Ti, and Pb, wherein the first metal oxide and the second metal oxide are different materials; a third dielectric layer on the second dielectric layer, the third dielectric layer including a metal carbon oxynitride; and an upper electrode on the third dielectric layer.