Potential-dependence of additives distribution in copper electrodeposition via filling

Via filling by copper electrodeposition is of great interest for industry to realize 3D packaging and reduce cost. To achieve “bottom-up” filling with no voids and seams, numerous studies on additives mechanism have been conducted. The organic sulful-containing accelerator, bis(3-sulfopropyl) disulfide (SPS) and the inhibitor (e.g., poly(ethylene glycol) (PEG) ), are common additives in “bottom-up” filling of vias. This work investigates a straightforward method for “bottom-up” filling simulation of SPS-PEG additive system. In this method, the potential dependence of additives adsorption behavior was summarized and employed in further simulation. A model estimation method was applied to estimate the precision. This model was then utilized in Finite Element Method (FEM) simulation, and the results gave a glimpse of the defect formation in via filling.