Liner and barrier layer in dual damascene cu interconnect for enhanced em and process

Abstract

A Cu interconnect and a method of forming a Cu interconnect of damascene process is provided. A barrier layer is formed at a sidewall and a bottom of a through hole and a groove, constructing a Cu interconnecting line. The barrier layer comprises a metal crystal adhesion layer or a graphene layer. The metal crystal adhesion layer may be a Co, Ru or Os crystal layer. The metal crystal adhesion layer may enhance adhesion of Cu, inhibit diffusion of Cu toward a dielectric layer efficiently, and promoting electro-migration of Cu. The graphene layer may be an Carbon allotrope/graphene complex layer. The graphene layer may provide lower resistance for the Cu interconnect and increase adhesion between barrier and dielectric layer to improve EM. Both the metal crystal adhesion layer and the graphene layer may efficiently reduce the total thickness of the barrier layer and the first barrier layer to efficiently decrease resistance of the through hole.