ELECTROCHEMICAL DEPOSITION AND STRIPPING OF COPPER, NICKEL AND COPPER-NICKEL ALLOY THIN-FILMS AT A POLYCRYSTALLINE GOLD SURFACE - A COMBINED VOLTAMMETRY-COULOMETRY-ELECTROCHEMICAL QUARTZ-CRYSTAL MICROGRAVIMETRY STUDY

Cyclic voltammetry, anodic stripping voltammetry (ASV) and coulometry were used in conjunction with electrochemical quartz crystal microgravimetry (EQCM) and ex situ X-ray photoelectron spectroscopy (XPS) for a study of the electrodeposition and stripping of Cu, Ni and Cu-Ni alloy thin films at a polycrystalline Au surface. A deaerated Watts bath was employed for the electrodeposition of Ni and Cu-Ni thin films, the bath containing Cu2+ ions (Ni:Cu = 200:1 mole ratio) in the latter case. These films showed the most satisfactory stripping in either 0.1 M HCl or 0.1 M H2SO4. Coulometry was used in conjunction with EQCM data for mapping the (potentiostatic) plating efficiency as a function of deposition potential in the Cu and Ni systems. For the Cu-Ni alloy, similar data were acquired by additionally utilizing XPS compositional information and assuming current additivity in the (non-interactive) co deposition of Cu and Ni. Finally, the feasibility of employing the combined ASV-EQCM technique for analysis of Cu-Ni/Ni bilayers is presented.