Semiconductor device and methods of formation

Abstract

A layer of conductive material is formed above a bottom-most layer of interconnect structures in an interconnect layer of a semiconductor device, and the layer of conductive material is etched to define the bottom-most layer of metallization structures from the layer of conductive material. To reduce contact resistance between the bottom-most layer of interconnect structures and the bottom-most layer of metallization structures in the interconnect layer, an adhesion layer may be formed in a selective manner so that the adhesion layer is formed only on an underlying dielectric layer and not on the bottom-most layer of interconnect structures. Selective deposition of the adhesion layer may be achieved using a blocking layer that is selectively formed on the bottom-most layer of interconnect structures.

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