Control of removal rates in CMP

摘要

A two-step method for chemical mechanical polishing of a semiconductor substrate having successive layers, comprised of, a metal layer, an underlying barrier film and an underlying dielectric layer. The first polishing step is performed utilizing a slurry composition selective to the metal in the metal layer, to remove the metal at a high removal rate during polishing, and the second polishing step is performed utilizing a slurry composition selective to the barrier film and least selective to the metal layer and the underlying dielectric layer. In an alternate embodiment, the second polishing step is performed with a slurry equally selective to the barrier layer and the underlying dielectric layer and least selective to the metal of the metal layer, to remove the barrier layer at a high removal rate during polishing, and level a surface of the dielectric layer to the surface of the metal interconnection structure in the underlying dielectric layer.