An electrically conductive interconnect is provided through an opening in a dielectric layer, electrically connecting two conductive layers. In one embodiment, the interconnect is formed by ruthenium entirely filling the opening in the dielectric layer. In another embodiment, an adhesion layer of titanium is provided in the opening prior to providing the ruthenium. In using this approach, an aspect ratio (i.e., the ratio of the length of the interconnect to the width thereof) of 20:1 or greater is achievable.