Interconnect structure having enhanced electromigration reliability and a method of fabricating same

An interconnect structure comprising:

• a dielectric material having at least one conductively filled feature located therein;
• a diffusion barrier separating the at least on conductively filled feature from said dielectric material;
• and
• a horizontal electromigration (EM) preventing liner that separates a lower conductive material from an upper conductive material, wherein said at least one conductively filled feature, said diffusion barrier and said EM preventing liner are confined in an opening that is formed within said dielectric material, said lower conductive material and said upper conductive material are comprised of a same conductive material, and wherein no portion of the horizontal EM preventing liner is in contact with said dielectric material and said horizontal EM preventing liner is vertically offset from a horizontal surface of said diffusion barrier.

A method of fabricating an interconnect structure comprising:

• providing at least one opening in a dielectric material, said at least one opening is lined with a diffusion barrier;
• forming a first conductive region partially within said at least one opening;
• forming an electromigration (EM) preventing liner on at least a surface of said first conductive region within said at least one opening, wherein no portion of the EM preventing liner contacts said dielectric material, and said EM preventing liner is selected from the group consisting of an U-shaped EM preventing liner that is in direct contact only with an upper portion of a vertical sidewall of said diffusion barrier, and a horizontal EM liner that has a horizontal surface that is vertically offset from a horizontal surface of the diffusion barrier;
• and
• forming a second conductive region on said EM preventing liner filling a remaining portion of said at least one opening, said first and second conductive regions form a conductive feature within said dielectric material, and wherein said first conductive region and said second conductive region are comprised of a same conductive material.