International Business Machines Corporation
Bottom barrier free interconnects without voids

Abstract:

Techniques to enable bottom barrier free interconnects without voids. In one aspect, a method of forming interconnects includes: forming metal lines embedded in a dielectric; depositing a sacrificial dielectric over the metal lines; patterning vias and trenches in the sacrificial dielectric down to the metal lines, with the trenches positioned over the vias; lining the vias and trenches with a barrier layer; depositing a conductor into the vias and trenches over the barrier layer to form the interconnects; forming a selective capping layer on the interconnects; removing the sacrificial dielectric in its entirety; and depositing an interlayer dielectric (ILD) to replace the sacrificial dielectric. An interconnect structure is also provided.