Effects of polymer additives such as gelatin and polyethylene glycol (PEG) on Cu electrodeposition behavior have been investigated by measuring the polarization curves for Cu deposition and the amount of additive adsorbed on Cu powder. Gelatin and PEG act as a polarizer for Cu deposition to shift the cathode potential in a less noble direction. The degree of polarization increased with an increase in the concentration and the molecular weight of additives, while the polarization effect of PEG was decreased when the molecular weight exceeded 103. Since the amount of gelatin adsorbed on Cu powder increased with increasing the molecular weight, the polarization effect of gelatin appears to depend on its adsorptive activity on the cathode. The morphology of deposited Cu showed the compacted surface composed of fine grains with an increase in the polarization of cathode potential by the additives.
