Studies on the patterning effect of copper deposits in magnetic gradient fields

Electrochemical Cu deposition was performed from electrolytes containing 0.1 M to 1 M CuSO4 in a well-defined magnetic gradient field. Patterned deposits resulted in all cases showing a strong correlation to this gradient field. It was observed that with increasing Cu2+ concentration the structuring effect decreases in terms of differences in topography and morphology. An explanation of this effect is presented based on local convection induced by the magnetic field gradient force which is dependent on the concentration gradient established during the deposition. Superimposed effects of Lorentz force driven convection were observed for high Cu2+ concentrations, and their influence on the deposition process is discussed.