The effects of “green” complexing agents on electroless deposition of copper from methanesulfonate baths

• These four different complexing agents have strong metal binding properties.
• Biodegradable Bronsted acid, methanesulfonic acid (MSA) as the bath liquid
• The deposition of copper at pH values from 12.50 to 13.25 with 0.25 pH jumps.
• Enhanced stability and optimized Cu deposition at room temperature.

We study the effect of environmentally-friendly complexing agents on the electroless deposition of copper from methanesulfonate baths. Four different complexing agents, viz. Ethylenediaminedithiocarbamate (EDADTC), saccharose, diethanolaminedithiocarbamate (DEADTC) and xylitol are added to a methanesulfonate bath that uses paraformaldehyde as the reducing agent, and their effects on morphology of deposits and rate of deposition are studied. All complexing agents show optimum deposition rates when the pH of the bath is above 12.0. The baths are stable at pH as high as 12.75, and the four chelators show optimum deposition at different pH values in this range (12.0–12.75). The physical parameters are calculated by weight gain and gravimetric methods. Crystallite size, roughness, quality and quantity of the deposits are determined by AFM, CV and XRD. The effects of the various complexing agents on the nature of deposits are discussed.