2011 Volume 127 Issue 10_11 Pages 662-666
Electrodeposition of Cu was conducted at a current density of 260 A/m2 for 48 h in a Cu electrorefining solution at 60°C to investigate the effect of glue, thiourea, and chloride ions on the morphology and texture of the deposited Cu. The texture was evaluated using electron back scatter diffraction patterns. The chloride ions promoted growth in the <110> direction of the deposited Cu, and glue and thiourea maintained the field-oriented texture type of the crystals. In a solution containing the appropriate amount of glue, thiourea, and chloride ions, the deposited Cu showed a smooth surface without salient edges due to anomalous deposition. However, an increase in the concentration of glue and chloride ions in the solution caused a locally anomalous salient. With an increase in the concentration of thiourea, the surface became smooth and the concentration of current at the edge was suppressed. In an additive-free solution or in a solution containing two or less additives, the deposited Cu initially showed unoriented dispersed or field-oriented texture type of crystals, and with increasing deposition duration, it showed epitaxial growth. This is attributed to the decrease in the actual current density due to an increase in the surface roughness of the deposited Cu with deposition time. The continuous epitaxial growth increased the grain size of the deposited Cu, resulting in an increase in the asperity.
