Observation of the behavior of additives in copper electroplating using a microfluidic device

Nowadays, high performance of integrated circuits is owing its interconnections and packaging technologies, and copper electroplating is widely used for the fabrication of wirings since 1997, so called The IBM shock . IBM announced chips with copper interconnects in 1997. The copper wirings were made by filling copper into vias in an insulating layer. Surprisingly, wet electroplating in acid copper sulfate was employed for the copper filling because preferential deposition from via bottoms, i.e. superfilling, was available by addition of several organic additives into the copper sulfate bath. However, at that time, the mechanism of superfilling was not clarified. Then, CEAC (Curvature Enhanced Accelerator Coverage) mechanism was proposed by Moffat et al. and the accelerator based theory is widely recognized as the principle of the superfilling for the sub-micron scale vias. Please click Additional Files below to see the full abstract