An improved trench capacitor structure is disclosed that allows for the formation of narrower capacitors. An example capacitor structure includes a first conductive layer on the sidewalls of an opening through a thickness of a dielectric layer, a capacitor dielectric layer on the first conductive layer, a second conductive layer on the capacitor dielectric layer, and a conductive fill material on the second conductive layer. The capacitor dielectric layer laterally extends above the opening and along a top surface of the dielectric layer, and the conductive fill material fills a remaining portion of the opening.