Effect of Additives in the Electrolyte on the Physical Properties of Electrodeposited Copper

Abstract

Copper deposited using bath additives added to the bath such as brighteners like Bis-(3-sulfopropyl)-disulfide (SPS) shows physical property changes when kept even at room temperature. In this research, the elements or groups contained in 2-Mercapto-5-benzimidazole (2M-5S), which have effects in preventing the property changes, are investigated. From this, Mercapto groups and Nitrogen atoms are thought to be essential and Benzene rings are thought to assist these effects. 2M-5S is thought to produce a strong union with the Cu(I) complex and coexisting additives using δ-polarized Nitrogen atoms and increases the amount of impurities incorporated into the deposits at the time of reduction.