Potential-dependence of additives distribution in copper electrodeposition via filling

Abstract

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.