Patent ID: 8450204

Claim:
A method of fabricating a semiconductor structure comprising: providing a structure including at least one semiconductor device located on a surface of a semiconductor substrate, said at least one semiconductor device including at least a material stack having an upper surface that is comprised of a metal semiconductor alloy; forming a dielectric material on said surface of said semiconductor substrate, said dielectric material including a contact opening that extends to the upper surface of said material stack, said contact opening having an aspect ratio of greater than 3:1; filling said contact opening with at least a metal-containing material, said metal-containing material is present at least within a lower region of said contact opening and is in direct contact with said upper surface of said material stack, wherein said metal-containing material is void of any key-hole seam defects; and forming at least a U-shaped diffusion barrier and a conductive metal-containing material within said contact opening, said conductive metal-containing material is located within an upper portion of said contact opening and is separated from said metal-containing material by a bottom wall portion of at least said U-shaped diffusion barrier, and wherein said conductive metal-containing material has an uppermost surface that is coplanar with an uppermost surface of said dielectric material.