Processed high-purity copper material having uniform and fine crystalline structure, and process for production thereof

Abstract

Disclosed is a processed high-purity copper material which comprises Cu having a purity of 99.9999 mass% or more and has an average crystal particle diameter of 20 [mu]m or less, wherein the ratio of an area occupied by crystal particles having particle diameters more than 2.5 times higher than the average crystal particle diameter is less than 10% of the total area occupied by all of the crystal particles in the particle size distribution of the crystal particles. Also disclosed is a process for producing the processed high-purity copper material, which comprises carrying out the hot forging of a mass of a cast comprising high-purity copper having a Cu purity of 99.9999 mass% or more at an initial temperature of 550 DEG C or higher, cooling the hot-forged product with water, carrying out the warm forging of the cooled product at an initial temperature of 350 DEG C or higher, cooling the warm-forged product with water, carrying out the cold cross-rolling of the cooled product at a total reduction of 50% or more, and carrying out the stress relief annealing of the rolled product at 200 DEG C or higher.

Description

technical field [0001] The present invention relates to a high-purity copper processed material having a uniform and fine crystal structure suitable for use as a sputtering target, for example, and a method for producing the same. [0002] This application claims priority based on Japanese Patent Application No. 2010-48516 for which it applied in Japan on March 5, 2010, and uses the content here. Background technique [0003] As a method of forming a conductive film or the like when manufacturing semiconductor devices such as ICs, LSIs, and ULSIs, sputtering using a high-purity copper target with fine crystal grains, electrolysis in a plating bath using a high-purity copper anode, etc. are known. . The high-purity copper preferably has a purity of 99.9999% by mass or more and fine crystal grains with an average crystal grain size of 200 μm or less. [0004] For example, as shown in Patent Documents 1 and 2, high-purity copper having fine crystal grains is produced as follo...

AI Technical Summary

Problems solved by technology

However, there is a problem that it is difficult to stably obtain fine grains with an average grain size of 200 μm or less industrially

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