Method for producing aqueous solution of purified orthoperiodic acid, method for producing semiconductor device, and aqueous solution of orthoperiodic acid

Abstract

A method for producing an aqueous solution of purified orthoperiodic acid with a reduced Cr content; a method for producing a semiconductor device that includes etching a Ru layer on a semiconductor substrate with an etchant obtained by the method; and an aqueous solution of orthoperiodic acid with a reduced Cr content. The method includes bringing an aqueous solution of crude orthoperiodic acid into contact with a metal removing agent including a chelating resin, the aqueous solution of crude orthoperiodic acid containing orthoperiodic acid and water and having an orthoperiodic acid content of 15% by mass or less and a Cr content of 1 ppb by mass or more based on the total mass of the aqueous solution of crude orthoperiodic acid.

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