Pattern Effects on Planarization Efficiency of Cu Electropolishing

Cu electropolishing has recently been introduced to replace Cu-chemical mechanical polishing (CMP). In this work, we found that when the space width is fixed, the planarization efficiency (PE) decreases with increasing line width. When line width is fixed, the PE value decreases as space width increases. Furthermore, the average roughness ( R a ) of blanket Cu films decreases as polishing time increases. After electropolishing, the resistivity of polished films is not obviously changed.