THE ROLE OF THE MICROSTRUCTURE OF COPPER-DEPOSITS DURING ELECTROLESS PLATING IN FORMALDEHYDE CONTAINING ALKALINE BATHS - COMPARISON OF FOURIER-TRANSFORM IMPEDANCE SPECTROSCOPY AND SURFACE ENHANCED RAMAN-SPECTROSCOPY

The microstructure of copper deposits was in-situ investigated by impedance measurements and by surface enhanced Raman scattering, The simultaneous determination of the copper deposition rate with a quartz microbalance and the mixed potential under electroless plating conditions allows to separate the two partial processes copper deposition and formaldehyde oxidation. Due to this combination of investigation techniques we are able to correlate responses of the partial processes e.g. caused by variation of the bath components on changes of the surface microstructure of the copper deposit. A microstructure with amplitudes of an atomic scale is only maintained during the electroless deposition process and is a specific catalyst for formaldehyde oxidation. The overall process is found to be a complex heterogeneously catalyzed system, which can be understood in synergetic terms as a selforganizing process.