Mechanical effects of polishing pad in copper electrochemical mechanical deposition for planarization

ECMD (electrochemical mechanical deposition) process consists of a traditional ECP (electrochemical plating) mechanism and a mechanical component. That is, this technique involves both electrochemical plating and mechanical sweeping of the material surface by the polishing pad. The mechanism of the ECMD process may be achieved through two mechanisms. The first mechanism may be the electrochemical plating on the surface where mechanical sweeping of polishing pad does not reach, and the second mechanism may be that the plating rate in the area that is mechanically swept may be reduced by the polishing pad. In this study, the effects of the mechanical component were investigated through various polishing pad types and hole ratios. In comparison to various polishing pad types using the manufactured the ECMD system, the plating rate and WIWNU (within wafer non-uniformity) using the experimental non-pore polishing pad were better than those of the experiments using other polishing pads.