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. An interconnect structure comprising:
an interlevel dielectric layer on an electrically conductive feature; an opening in the interlevel dielectric layer, the opening including a first width at a first depth into the interlevel dielectric layer, and a second width at a second depth that is greater than the first depth, wherein the second width is less than the first width of the opening and includes a portion of the opening that extends through the entirety of the interlevel dielectric layer into contact with the electrically conductive feature; a contact extending through the opening into contact with the electrically conductive feature, wherein a gouge is present at the interface of the contact and the electrically conductive feature; and a shield liner present on vertical sidewalls of the opening between the interlevel dielectric layer and the contact.