A method for chemical mechanical planarization of a semiconductor structure comprised of a conductive metal interconnect layer, a barrier or liner film, and an underlying dielectric layer using a two-step polishing process is provided. In the first step, the conducting metal overburden is substantially removed with little removal of the barrier or liner layer or the underlying dielectric structure. In the second step, the barrier layer is removed with little removal of the underlying dielectric layer. Five different methods and associated slurry compositions are described for the second polishing step, each adjusted to the state of the wafer following the first step of polishing. By using the appropriate method, the integrity of the remaining semiconductor structure can be substantially retained.