The Effects of Aromatic Surfactants on the Electrodeposition of Tin

The suppression effect of polyoxyethylene surfactants on the electrochemical deposition of tin (Sn) was systematically studied using cyclic voltammetry and chronopotentiometry methods for future applications for superconducting interconnects in quantum devices. Two types of surfactants, igepal with a phenyl group and ENSA with a naphthalene group, were used in conjunction with two simple additives, polyethylene glycol and naphthalene sulfonic acid, to dissect the effects of the aromatic ring and the oxyethylene chain. The suppression effect was found to be a result of a synergistic action between aromatic ring and oxyethylene chain. Furthermore, the fused naphthalene ring structure in ENSA results in a stronger adherence to the Sn surface than the single benzene ring in igepal, relating to a stronger and faster suppression that is also more resistant to agitation.