Method of forming metal interconnect structures in ultra low-k dielectrics

Abstract

A metal interconnect structure in ultra low-k dielectrics is described having a capped interconnect layer; an interconnect feature with a contact via and a contact line formed in a dielectric layer, where the via is partially embedded into the interconnect layer; and a thin film formed on the dielectric layer and separating the dielectric layer from the contact line. A method of fabricating the interconnect structure is also described and includes forming a first dielectric on a capped interconnect element; forming a thin film over the first dielectric; forming a second dielectric on the thin film; forming a via opening on the second dielectric, the thin film and extending into the first dielectric; forming a line trench on a portion of the second dielectric; and filling the via opening and the line trench with a conductive material for forming a contact via and a contact line, where the contact via is partially embedded in the interconnect element.