Method for reducing wettability of interconnect material at corner interface and device incorporating same

摘要

A method for forming an interconnect structure includes forming a recess in a dielectric layer of a substrate, forming a first transition metal layer in the recess on corner portions of the recess, and forming a second transition metal layer in the recess over the first transition metal layer to line the recess. The method further includes filling the recess with a fill layer and annealing the substrate so that the first transition metal layer and the second transition metal layer form an alloy portion proximate the corner portions during the annealing, the alloy portion having a reduced wettability for a material of the fill layer than the second transition metal. Additionally, the method includes polishing the substrate to remove portions of the fill layer extending above the recess.