Pattern dependence study of copper planarization using linear polisher for 0.13 /spl mu/m applications

In this work, the dependency of Cu planarization process upon local metal pattern density over a wide density range for 0.13 /spl mu/m applications has been evaluated using a linear polisher. Results show that the amount of metal dishing and erosion strongly depend on metal density with worse planarization observed for higher metal density. The impact of the planarization result on electrical leakage of the upper metal is also studied. Various approaches have been experimented to resolve this issue. We found that the most effective solution is to implement oxide slot and polish time control. The effect of the layout of the oxide slot is also reported.