WORKING METHOD BY HYDROXIDE ION IN ULTRA-PURE WATER

摘要

PROBLEM TO BE SOLVED: To provide an ideal and realistic working method by hydroxide ions in ultra-pure water enabling clean working without leaving impurities on a working face of a workpiece using hydroxide ions in ultra-pure water by further increasing hydroxide ion density on the working face of the workpiece and removing atoms of the workpiece bonded to the hydroxide ions from the working face speedily to increase working rate. SOLUTION: A workpiece 2 and a high pressure nozzle 1 are arranged at a predetermined interval in a working tank containing ultra-pure water only, and an ion exchange material 4 which increases hydroxide ions or a catalyst material is provided around a tip of the high pressure nozzle facing a working face of a workpiece. A voltage is applied using the high pressure nozzle as cathode and the workpiece as anode to generate high speed shearing steam of ultra-pure water injected from the high pressure nozzle in the vicinity of a surface of the workpiece and supply hydroxide ion produced from ultra-pure water to a surface of the workpiece so that removing work of the workpiece or oxide film formation work is done by chemical elution reaction or oxidation reaction by means of hydroxide ions.