Na2SO4-assisted shift in the nucleation mechanism of copper-electrocrystallization from an acidic bath

In this study, the effect of sodium sulphate (Na₂SO₄) on the nucleation mechanism of copper films during electrodeposition was investigated. Voltammetric and chronoamperometric studies were employed to analyze the kinetics of electrochemical nucleation. Phase analysis of the nucleated copper was performed via X-ray diffraction, while morphological and topographical studies were conducted using scanning electron microscopy (SEM) and atomic force microscopy (AFM) to further validate the electrochemical findings. The deposits obtained in the presence of Na₂SO₄ were finer and more closely packed compared to those formed without Na₂SO₄. Additionally, the roughness of the deposits varied between the two conditions, with films formed in the presence of Na₂SO₄ being slightly smoother. The results indicate that the addition of Na₂SO₄ changed the nucleation mechanism from charge transfer controlled to mass transfer controlled.