Effect of parameters of pulsating current (PC) regimes on morphology of electrodeposited copper in hydrogen co-deposition range

Abstract

The most often employed electrolytes for the electrodeposition of copper are those based on aqueous solutions of sulfuric acid (H2SO4) and cupric sulfate (CuSO4). There is an ionic equilibrium of a lot of species in the CuSO4-H2SO4-H2O system. Electrodeposition processes at high current densities and overpotentials are very suitable for experimental verification of this ionic equilibrium, because there is parallelism between copper electrodeposition and hydrogen evolution reaction at high current densities and overpotentials. In this study, it is shown that effects attained by the choice of appropriate parameters of square-waves pulsating current (PC) on morphology of electrodeposited copper were equivalent to those obtained by electrodepositions at the constant overpotential in the hydrogen co-deposition range from six solutions of different concentrations of CuSO4 and H2SO4. In this way, it was clear that it is possible to simulate the ionic equilibrium of the species in the CuSO4-H2SO4-H2O system using the only one electroplating solution if the appropriate parameters of PC regimes are used.