The present invention provides a capacitor structure, comprising a substrate, a TSV, a dielectric layer and a doped region. The substrate includes a first surface and a second surface, which are disposed oppositely to each other. The TSV penetrates through the first surface and the second surface. The dielectric layer is disposed in the substrate and encompasses the TSV. The doped region is disposed between the dielectric layer and the substrate. The present invention further provides a method of forming the same.