Copper electrocrystallization from acidic sulfate electrolyte containing MPS additive

Abstract

Copper electrodeposition and nucleation on a glassy carbon electrode from acid sulfate electrolytes in the presence of 3-mercapto-1-propanesulfonate sodium salt (MPS) and its combinations with chloride ions (Cl) or/and polyethylene glycol (PEG) were investigated by utilizing cyclic voltammetry (CV), chronoamperometry (CA) and scanning electron microscopy (SEM). CV results indicate that MPS and MPS–PEG inhibit whereas MPS–Cl and MPS–PEG–Cl accelerate copper deposition. CA and SEM results suggest that copper nucleation follows an instantaneous nucleation mechanism with three-dimensional growth from all baths at the studied deposition potentials. The copper nucleation rate and nuclei number density are increased greatly in the MPS–Cl and MPS–PEG–Cl baths.