Recent advances in electroless copper deposition-A review

This article reviews the recent advances in electroless copper plating and discusses the role of complexing agents, reducing agents and the role of additives in the rate of deposition. Environmental concerns have led to interest in developing cyanide and EDTA-free methanesulphonate baths for electroless deposition of copper. Eco-friendly polyhydroxy compounds has found more importance as an complexing agent replacing EDTA and other common chelators. The role of different reducing agent in the electroless copper deposition has been studied and summarised. The effect of bath operating conditions (temperature, pH and agitation) and bath additives on plating rate, bath stability, morphology and etching rate of the coating has been discussed. Lone pair of electron bearing elements like Nitrogen and Sulphur containing organic compounds are generally used as additives. The additives were found to modify the crystal structure with the production of small grain size, dense, tightly adherent and etching resistant copper deposits.