Interconnect structure and method of making same

A method of manufacturing a structure, comprising:

• forming a layered structure of a first dielectric material with a first metal wire in a first trench of the first dielectric material and a second dielectric material with a second metal wire;
• exposing a top surface of the second metal wire in a second trench formed in the second dielectric material, wherein the forming the second trench removes a portion of an upper surface of the second dielectric layer and extends down to and contacts the first metal wire;
• selectively depositing a sacrificial material on a remaining portion of the upper surface of the second dielectric material;
• depositing a metal capping layer over the second metal wire, which causes a plurality of isolated unwanted depositing and/or nucleation of the metal capping layer on the sacrificial material;
• and
• undercutting the sacrificial material and the unwanted deposited and/or nucleated metal capping layer.

A method of manufacturing a structure, comprising:

• forming a trench in a portion of a top surface of a planarized dielectric layer, wherein the forming the trench removes the portion of the top surface of the planarized dielectric layer;
• forming a conductive layer in the trench of the planarized dielectric layer, wherein a top surface of the conductive layer is formed at a coplanar level as a remaining portion of the top surface of the planarized dielectric layer;
• forming a liner completely lining sidewalls and a bottom of the trench;
• selectively depositing a sacrificial layer on the remaining portion of the top surface of the planarized dielectric layer;
• forming a cap layer on the conductive layer to prevent migration, wherein the forming the cap layer results in a plurality of isolated deposits of unwanted deposited and/or rogue nucleated metal capping layer being formed on the sacrificial layer;
• and
• removing the sacrificial layer including the plurality of isolated deposits of the unwanted deposited and/or rogue nucleated metal capping layer deposited on the sacrificial layer during the forming of the cap layer, such that the planarized dielectric layer is devoid of the plurality of isolated deposits of the unwanted deposited and/or rogue nucleated metal capping layer.