The invention is directed to unique high-surface area BEOL capacitor structures with high-k dielectric layers and methods for fabricating the same. These high-surface area BEOL capacitor structures may be used in analog and mixed signal applications. The capacitor is formed within a trench with pedestals within the trench to provide additional surface area. The top and bottom electrodes are created using damascene integration scheme. The dielectric layer is created as a multilayer dielectric film comprising for instance Al₂O₃, Al₂O₃/Ta₂O₅, Al₂O₃/Ta₂O₅/Al₂O₃ and the like. The dielectric layer may be deposited by methods like atomic layer deposition or chemical vapor deposition. The dielectric layer used in the capacitor may also be produced by anodic oxidation of a metallic precursor to yield a high dielectric constant oxide layer.