Deep dishing and erosion are serious problems in conventional chemical mechanical planarization (CMP) of copper/barrier layer, specifically when a hard barrier layer is used as the polishing stopper. This paper describes the reduction of the dishing in the CMP with lower removal rate ratio. This CMP can be achieved by following procedures. (i) Increase of removal rate in barrier layer; removal rate is 1.5 nm/min in polycrystalline tantalum nitride barrier layer. This rate increases to 77 nm/min in TaSiN barrier layer when polished by MnO2 slurry with hard pad. (ii) Reduction of the removal rate of copper layer; removal rate of electroplated copper layer decreases to 210 nm/min by MnO2 Slurry. This rate decreases to 77 nm/min when additive is doped into this slurry by 10%. Because thin antioxide layer is formed at the copper surface during the polishing by this additive, removal rate ratio of Cu/barrier layer reduces to unity by this doping, Dishing free CMP can be developed by this process.