Since the early days of copper CMP much research and development effort was put into formulation of new copper and barrier CMP slurries. Two major motivations for this effort are the improvement of process performance for currently used integration schemes and the preparation for new integration schemes using low-k and ultra low-k dielectric materials. In this paper a systematic procedure for topography investigation after copper and barrier CMP is presented. The procedure is applied to four different copper slurries in order to compare after copper and after barrier CMP topography performance. As a result of the post copper CMP topography investigations, a discussion of advantages and disadvantages of non-selective and selective barrier polish processes will be presented. To complete the discussion of potential topography correction during barrier CMP, an investigation of an observed pronounced dielectric erosion close to large metal features or within high metal density arrays with medium or high selective barrier CMP processes will be presented.