Method for producing treatment liquid

Abstract

An object of the present invention is to provide a method for producing a treatment liquid, having excellent filterability. The method for producing a treatment liquid of an embodiment of the present invention is a method for producing a treatment liquid, the method including filtering an object to be purified including a surfactant, using a first filter having a first filter medium, to produce a treatment liquid for a semiconductor substrate, in which the first filter medium includes at least one selected from the group consisting of a nylon, a polyallyl sulfonic acid, a perfluoroalkoxy alkane which has been subjected to a hydrophilization treatment, a polytetrafluoroethylene which has been subjected to a hydrophilization treatment, a polyolefin which has been subjected to a hydrophilization treatment, and a polyvinylidene fluoride which has been subjected to a hydrophilization treatment, and the surfactant includes at least one selected from the group consisting of a nonionic surfactant including a group represented by Formula (1) and an anionic surfactant including a group represented by Formula (1). (LO)n  Formula (1) L represents an alkylene group, and n represents 3 to 55.

Dependencies are inferred from the claim text.