A semiconductor structure includes a substrate, at least one dielectric layer and a capacitor structure. The at least one dielectric layer is disposed over the substrate, and the at least one dielectric layer includes a step edge profile. The capacitor structure is disposed over the substrate. The capacitor structure includes a bottom electrode, a capacitor dielectric layer and a top electrode. The bottom electrode covers the step edge profile of the at least one dielectric layer and has a first step profile substantially conformal to the step edge profile of the at least one dielectric layer. The capacitor dielectric layer covers the bottom electrode and has a second step profile substantially conformal to the first step profile. The top electrode covers the capacitor dielectric layer.