Interconnect structures including liner layers that are non-planar with at
least the adjacent insulating layer and at least one capping layer on
conductive features embedded in the insulating layer. The interconnect
structure includes an insulating layer of a dielectric material having a
top surface and a bottom surface between the top surface and a substrate.
An opening, such as a trench, has sidewalls extending from the top
surface of the insulating layer toward the bottom surface and is at least
partially filled by a conductive feature. A capping layer is disposed on
at least a top surface of the conductive feature. A conductive liner
layer is disposed between the insulating layer and the conductive feature
along at least the sidewalls of the opening. The conductive liner layer
has sidewall portions projecting above the top surface of the insulating
layer adjacent to the sidewalls of the opening.