ELECTROCHEMICAL CHARACTERIZATION OF COPPER DEPOSITED ON PLASMA AND THERMALLY MODIFIED TITANIUM SURFACES

Thin oxide films were grown at temperatures from 373 to 1073 K in plas ma and in air on commercially pure titanium substrates. It was determi ned that the color, thickness, composition, phase, and polarization be havior in a copper electrolyte varied with operating conditions: tempe rature, oxygen partial pressure, and plasma composition. High-temperat ure and high oxygen partial pressure plasma produced a thick oxide fil m. The surface film structure transformed from TiO2 (anatase) to TiO2 (rutile) at a temperature of 600 degrees C. A lower oxide of the form TinO2n-1, such as Ti2O3 (which may be porous) or possibly Ti3O5, was f ormed on a thermally treated sample (400 degrees C, 80 mtorr O-2, 3 ho urs). This sample exhibited the lowest potential for copper nucleation and gave a very uniform, smooth, and hole-free copper foil.