Influence of Chloride Ion on the Synergistic Interaction and Adsorption Behavior of SPS, PEG and TPM-1 during Copper Electrodeposition

In this study, the influence of chloride ion on the synergistic interaction and adsorption behavior of bis-(3-sulfopropyl) disulfide (SPS), polyethylene glycol (PEG) and TPM-1 in acidic electrolyte were investigated by the electrochemical measurements at different rotating speeds. TPM-1 is a triphenylmethane based leveler with saturated tertiary amines. The galvanostatic measurements (GMs) show that when the electroplating solution only containing SPS, PEG and TPM-1, the potential difference was negative. While, the potential difference was positive in the presence of chloride ion. These results indicated that chloride ion play a key role in induced the convection dependent adsorption (CDA). In addition, the synergistic interaction between chloride ion and TPM-1 can obviously increase the adsorption strength of TPM-1 and leading to the copper deposition rate decreased on the cathodic surface. The result from cyclic voltammetry stripping (CVS) measurements indicated that increasing the concentration of chloride ion is beneficial to enhance the adsorption strength of PEG and TPM-1 on the cathode surface.