Influence of 3-N,N-Dimethyldithiocarbamoyl-1-Propanesulphonic Acid on the Kinetics and Morphology During Copper Deposition

摘要

The influence of 3-N,N-dimethyldithiocarbamoyl-1-propanesulphonic acid(DPS),one of the common additives in commercial acid copper electroplating bath,on the cathodic reduction of cupric ions has been studied by rotating disc voltammetry,cyclic voltammetry and potential step techniques.The DPS additive [(CH_3)_2NC(S)S(CH_2)_3SO_3H] added as a sodium salt was not reducible in 1.8M H_2SO_4 at a Cu cathode.A mass transport controlled oxidation wave was observed at approx 1.2 V vs.SCE at a Pt anode.The interaction of DPS with Cu(I)and Cu(II)ions in aqueous-acidic media was studied by UV-VIS spectroscopy.The results suggest the formation of a Cu(I)DPS type complex,but the similar interaction with copper(II)ions was not observed.