Evolution of the Morphology of Electrodeposited Copper at the Early Stage of Dendritic Growth

The morphological evolution at the onset of dendritic growth of Cu electrodeposited from unsupported CuSO4 solution under high current density was observed by Scanning Electron Microscopy (SEM). SEM observation was conducted for three stages of the Cu electrodeposition process; i) just before, ii) at and iii) soon after depletion of the Cu2+ ion at the cathode surface. A deposit consisting in microcrystals was observed at all stages, with size ranging from 20 nm to 2 μm. This size was shown to increase with Cu concentration and decrease with overpotential. At stage iii) the early stage of dendritic growth was observed.