Cladded metal interconnects

Abstract

Techniques are disclosed for providing cladded metal interconnects. Given an interconnect trench, a barrier layer is conformally deposited onto the bottom and sidewalls of the trench. A first layer of a bilayer adhesion liner is selectively deposited on the barrier layer, and a second layer of the bilayer adhesion liner is selectively deposited on the first layer. An interconnect metal is deposited into the trench above the bilayer adhesion liner. Any excess interconnect metal is recessed to get the top surface of the interconnect metal to a proper plane. Recessing the excess interconnect metal may include recessing previously deposited excess adhesion liner and barrier layer materials. The exposed top surface of the interconnect metal in the trench is then capped with the bilayer adhesion liner materials to provide a cladded metal interconnect core. In some embodiments, the adhesion liner is a single layer adhesion liner.