New environmentally friendly noncyanide alkaline electrolyte for copper electroplating

This article presents a novel noncyanide alkaline bath for electroplating thin copper films on stainless steel substrate. A detailed study was made about the effect of the operating parameters (current density and temperature), concentration of complexing agent on cathodic current efficiency (CCE %) and the characteristics of the deposited layers. The addition of sorbitol as complexing agent to the plating bath assists in the formation of fine-grained and highly adherent copper film. The phase structure and surface morphology of the deposited films were examined by using X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The analysis of XRD patterns showed that the crystallographic orientation of copper deposits is independent on the current density while the bath efficiency is function of the applied current density, operating bath temperature and sorbitol concentration. The corrosion rate of copper films depends on the current density and the films deposited at 2 A dm(-2) exhibited the best corrosion performance. (c) 2008 Elsevier B.V. All rights reserved.