Abstract: A cleaning method for peeling and removing photoresists from a semiconductor by applying ultrasound to a cleaning solution comprising a mixture of an organic solvent diluted with pure water and halogenated alkali metal salts, hydrofluoric acid, or ammonium fluoride. The cleaning method removes organic film such as a photoresist or the like at room temperature, not by dissolving, but rather by peeling. The cleaning liquid does not degrade over a long period of time and, moreover, has a strong cleaning effect yet chemical vapors and water vapors are essentially not generated.

Abstract: An apparatus for the treatment of a low-concentration organic waste water for relaim a low-concentration organic waste water having a TOC concentration of from 0.5 to 3 ppm and obtaining an ultra pure water having a TOC concentration of not more than 1 ppb is characterized by the fact that a first treating system comprising a reverse osmosis unit for transforming a low-concentration organic waste water having a TOC concentration of from 0.5 to 3 ppm into a low-concentration organic waste water having a TOC concentration of from 60 to 200 ppb and a vacuum degasifier adapted to admit an inert gas at a volumetric feed flow rate in the range of from 0.001 to 1.0 based on the volume of the waste water under treatment at a vacuum rate of not more than 35 Torrs and a second treating system comprising a low-pressure ultraviolet decomposition unit for emitting an ultraviolet light of a wavelength of 184.