Purification of CuCI₂by anion-exchange separation using multi-column method

The demand for high purity Cu is growing because it has an advantage to reduce the resistivity of the interconnect in ultra large-scale integration. Anion-exchange separation with the multi-column method was proposed and its separation efficiency was investigated in this work. The recoveries of anion-exchange separation for Cu purification in the previous studies are relatively low. Whole separation efficiency would be improved if the yield could be increased. Prior to the separation tests, the target impurities were determined from thermodynamic consideration of the process for preparation of high purity Cu. As a result, anion-exchange separation with the multi-column method proposed in this paper successfully eliminated the possible impurities, which should be removed in order to obtain a ultra high purity Cu. Thus, the purified CuCl₂-HCl solution is ready for preparation of the ultra high purity Cu.