REDUCING CONTACT RESISTANCE IN VIAS FOR COPPER INTERCONNECTS

摘要

A method of forming an electrical transmission structure that includes forming an opening through an interlevel dielectric layer to expose at least one electrically conductive feature and forming a shield layer on the opening. A gouge is formed in the electrically conductive feature through the opening using a subtractive method during which the shield layer protects the interlevel dielectric layer from being damaged by the subtractive method. A contact is formed within the opening in electrical communication with the at least one electrically conductive feature.

主权项

1. A method of forming an electrical transmission structure comprising:
forming an interlevel dielectric layer atop a substrate including at least one electrically conductive feature; forming an opening through the interlevel dielectric layer to expose a portion of the at least one electrically conductive feature; forming a shield layer on the opening, wherein the shield layer is formed with a non-conformal process to provide a greater thickness of the shield material on horizontal surfaces of the opening in comparison to vertical surfaces of the opening; forming a gouge in the electrically conductive feature through the opening using a subtractive method, the shield layer protecting the interlevel dielectric layer from being damaged by the subtractive method; and forming a contact within the opening in electrical communication with the at least one electrically conductive feature.