Effect of H2O2 on the planarization efficiency of the copper pattern wafer in the copper clearing step

The alkaline copper slurry which was made by out own, diluted (X50) as the copper clearing slurry and add different concentration H2O2 into the slurry before used. Experiment results show that as the H2O2 concentration increase, the dissolution rate and polish rate of copper, also the barrier films such as Ta/TaN removal rate have small decrease. But the experiment on the MIT854 pattern wafer in copper clearing step results, the dishing values reduce with the H2O2 concentration increase. The copper clearing slurry with 5vol% H2O2, after achieved initial planarization, follow the copper clearing step for copper residue removal, the pattern wafer can achieved completely planarization of different linewidths, the dishing values can meet the industrial requirements. These rules paly an important role to achieve global planarization of CMP.