Thin oxide films were grown at temperatures from 373 to 1073 K in plasma and in air on commercially pure titanium substrates. It was determined that the color, thickness, composition, phase, and polarization behavior in a copper electrolyte varied with operating conditions: temperature, oxygen partial pressure, and plasma composition. High-temperature and high oxygen partial pressure plasma produced a thick oxide film. The surface film structure transformed from TiO 2 (anatase) to TiO 2 (rutile) at a temperature of 600 ЊC. A lower oxide of the form Ti n O 2nϪ1 , such as Ti 2 O 3 (which may be porous) or possibly Ti 3 O 5 , was formed on a thermally treated sample (400 ЊC, 80 mtorr O 2 , 3 hours). This sample exhibited the lowest potential for copper nucleation and gave a very uniform, smooth, and hole-free copper foil.