Encapsulated-metal vertical-interdigitated capacitor and damascene method of manufacturing same

Abstract

An integrated circuit includes a vertical-interdigitated capacitor located between an upper interconnect layer and a lower interconnect layer. Both interconnect layers include conductors formed of a metal capable of atom diffusion or ion migration, such as copper. The capacitor plates contact an interconnect layer conductor to create barrier layers to prevent atom diffusion or ion migration from the conductors at the contact locations. Additional barrier layers contact the conductors at locations other than where the capacitor plate portions contact the conductors, and the additional barrier layers are preferably formed of the same material and at the same time that one of the plates is formed. The integrated circuit may include a via plug interconnect extending between conductors of upper and lower interconnect layers, with a plug barrier layer surrounding the plug material to prevent atom diffusion or ion migration from the plug material.