A semiconductor device with an embedded capacitor structure. A dielectric layer is disposed on a substrate, having a contact opening exposing the substrate and a trench opening above the contact opening. A first metal electrode layer is conformally disposed over the sidewalls and bottoms of the contact and trench openings. A second metal electrode layer is conformally disposed over the sidewalls and bottoms of the contact and trench openings. A capacitor dielectric layer is interposed between the first and second metal electrode layers. A method for fabricating the semiconductor device is also disclosed.