| 摘要 |
PROBLEM TO BE SOLVED: To prevent ionized amines from flowing into ultrapure water in a step of manufacturing the ultrapure water for use in a step of manufacturing semiconductor device. SOLUTION: When an UF (ultrafilteration) module UFM (UF module) to be newly input is cleaned, an aqueous solution of acid is first supplied from acids supply equipment ASPE so that higher amines in the UF module UFM react with the aqueous solution of acid to form an aqueous higher amine salt. Next, after the aqueous solution of acid is discharged, pure water is supplied from a pure water supply equipment PWPE to clean the UF module UFM therewith. The treatment using the aqueous solution of acid and the pure water cleaning are repeated until an amine concentration in the cleaning solution (pure water) discharged from the UF module UFM during the pure water cleaning becomes a prescribed value or smaller. A gas is supplied from a gas supply equipment GPE between the treatment using the aqueous solution of acid and the pure water cleaning to be subject to gas blow. Consequently, cleaned residue in the UF module UFM is reduced. COPYRIGHT: (C)2004,JPO&NCIPI
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