Patent ID: 7338878

Claim:
A method for forming a capacitor, comprising: providing a substrate with an insulator layer; forming a hole in the insulator layer, the hole having an opening, a side surface and a bottom surface, the side surface having a bowing shape in a plane perpendicular to the substrate; forming a film of a conductive material on the insulator layer and on the side surface and the bottom surface of the hole; exposing the film and the insulator layer to a chemical-mechanical polishing process to remove the film and the insulator in part in a direction perpendicular to the substrate so as to form a lower electrode of the conductive material and a polished insulator, the polished insulator defining a widened opening larger in size than the opening; forming a capacitor dielectric on the lower electrode; and forming an upper electrode on the capacitor dielectric, wherein forming the hole comprises: forming a hardmask with a patterned aperture on the insulator layer; and exposing the insulator layer to an anisotropic etch process by using the hardmask, wherein the hardmask is removed by the chemical-mechanical polishing process, and wherein the exposing the insulator layer to an anisotropic etch process is carried out so that the hole is provided with a particular vase-shaped profile; the particular vase-shaped profile has an upper section extending downwardly from the opening to a predetermined level and a lower section extending downwardly from the predetermined level to the bottom surface; the upper section has larger sizes with increased depths; and the lower section has smaller sizes with increased depths.