Buried metal dual damascene plate capacitor

摘要

A metal capacitor formed as part of metal dual damascene process in the BEOL, of a wafer. A lower plate (27) of the capacitor is sandwiched between an insulating layer (25) and a dielectric layer (29). The insulating layer on an opposite side abuts a layer of metalization (23, 24) and the dielectric layer separates the lower plate of the capacitor from an upper plate (59) of the capacitor. A portion (27A) of the lower plate projects into a via (37) adjacent to it that is filled with copper (63). The via projects up to a common surface with the upper plate but is electrically isolated form the upper plate. The via also extends down to the layer of metalization.