INTERCONNECTION STRUCTURE

摘要

An interconnection structure includes an inter-layer dielectric; a topmost copper metal layer inlaid into the inter-layer dielectric; an insulating layer disposed on the inter-layer dielectric and the topmost copper metal layer; a via opening in the insulating layer for exposing a top surface of the topmost copper metal layer, wherein the via opening consists of an inwardly tapered upper via portion and a lower via portion having a substantially vertical sidewall profile; and an aluminum layer filling into the via opening.