Obtaining of Copper Coatings on Dielectrics from Non-Formaldehyde Electroless Copper Plating Bath

摘要

Commercial electroless copper plating solution often use formaldehyde or its derivatives as reducing agent and are operated at pH values above 11. The high pH is not compatible with some dielectric or photoresist materials. In this work the non-formaldehyde electroless copper plating solution with weakly alkaline pH was developed. The influence of pH value and adding of nickel ions to the solution on deposition rate was investigated. The morphology, structure and the surface chemistry of the obtained copper layers was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS).