Adherent Cu films were electrodeposited on polycrystalline W foils from a purged 0.05 M CuSO4 solution in H2SO4 supporting electrolyte at pH 1. Films were deposited under constant potential conditions at voltages between -0.6 and -0.2 V vs. Ag/AgCl. The films produced by pulses of 10 s duration were visible to the eye, copper colored, and survived the Scotch tape test. Characterization by scanning electron microscopy and X-ray photoelectron spectroscopy (XPS) confirmed the presence of Cu, with apparent dendritic growth. No sulfur impurity was observable by XPS. Kinetics measurements indicated that the Cu nucleation process is slow compared to recently reported kinetics for Cu electrodeposition on TiN. The adhesion of the deposited Cu strongly suggests the absence of an interfacial oxide. (C) 2002 The Electrochemical Society.