Patent ID: 9441289
Filing Date: 2016-09-13
CPC Classification: C22C,C23C

Claim Text:
1. A process for manufacturing a high-purity copper or high-purity copper alloy sputtering target, comprising the steps of: providing a high purity copper anode and an aqueous nitric acid or hydrochloric acid solution as an electrolyte in an electrolytic cell for an electrolytic refining process, wherein an anode side of the electrolytic cell is separated from a cathode side with a diaphragm; performing electrolysis in the electrolytic cell, extracting anolyte formed by the electrolysis, and filtering the extracted anolyte through an activated carbon filter immediately before supplying the filtered anolyte to the cathode side; obtaining a high purity electrodeposited copper on the cathode as a raw material having a purity of 6N or higher, a content of 1 ppm or less of each of P, S, O and C impurity elements, and a structure containing nonmetal inclusions dispersed therein of a number of 30,000 inclusions/g or less for nonmetal inclusions having a size of 0.5 to 20 μm; and melting the high purity electrodeposited copper with a cold crucible melting process or a vacuum arc remelting process and casting the molten copper to obtain a cast ingot of copper having a purity of 6N or higher, a content of 1 ppm or less for each of P, S, O and C impurity elements, and a structure containing nonmetal inclusions dispersed therein of a number of 30,000 inclusions/g or less for nonmetal inclusions having a size of 0.5 to 20 μm; or melting the high purity electrodeposited copper with addition of at least one alloying element in a cold crucible melting process or a vacuum arc remelting process and casting the molten copper alloy to obtain a cast ingot of the high-purity copper alloy having a purity of a purity of 6N or higher, a content of 1 ppm or less for each of P, S, O and C impurity elements, and a structure containing nonmetal inclusions dispersed therein of a number of 30,000 inclusions/g or less for nonmetal inclusions having a size of 0.5 to 20 μm.