Electrochemical Mechanical Planarization (eCMP) of Copper Thin Films

Abstract

A novel Electrochemical Mechanical Planarization (eCMP) process was developed and integrated on the copper plating platform to meet the stringent technical requirements including higher planarization efficiency, higher throughput at lower down force and lower defectivity for the manufacture of devices at 65 nm and beyond technology nodes. In the integrated system, following the electroplating process, the wafer is transferred to the planarization module where the bulk of copper is polished and planarized at a high rate, leaving a thin, planar copper film. It was determined that the resulting planar thin film enables conventional chemical mechanical polishing to clear the remaining copper and barrier with low dishing and erosion. The planarization mechanism of the eCMP process was explained on the basis of electrochemical experimental results.