Via and metal line interface capable of reducing the incidence of electro-migration induced voids

摘要

Embodiments of the invention include a method for forming copper interconnect structure. The method involves providing a substrate having a copper conductive layer formed thereon. An insulating layer having openings is formed on the conductive layer so that the openings expose portions of the underlying conductive layer at the bottom of the openings. A barrier layer is formed on the surface of the substrate. A portion of the barrier layer is removed at the bottom of the opening to expose the underlying conductive layer. A copper plug is formed in the opening such that the bottom of the plug is in contact with the exposed conductive layer. The substrate can be subjected to further processing if desired. The invention also includes a copper interconnect structure having increased resistance to electromigration.