| 摘要 |
PURPOSE:To eliminate generation of static electricity in wafer by using a gas-liquid contact device using an ultrafilter membrane, reverse osmotic membrane, etc. to bring ultrapure water into contact with gaseous carbon dioxide and to decrease the specific resistance of the ultrapure water and spraying said water from a spray nozzle. CONSTITUTION:Gaseous carbon dioxide is supplied from a cylinder 7 and after fine particles are removed from the same in a membrane filter 8, the gaseous carbon dioxide is fed through a pressure regulating valve 9 and a gas feed pipe 6 into the block 3b in an intermediate chamber 1c. The gaseous carbon dioxide supplied into the chamber 1c and the ultrapure water flowing in each hollow yarn type permeable membrane 2 contact with each other through the surface of the permeable membranes and the gaseous carbon dioxide is dissolved in the ultrapure water. The ultrapure water having a decreased specific resistance is discharged from an outlet chamber 1b into a discharging pipe 5 but the control of the specific resistance value thereof is accomplished by providing a measuring means 10 such as a conductivity meter or the like to the pipe 5, and adjusting the supply pressure of the gaseous carbon dioxide by regulating the opening degree of the regulating valve 9 by the signal thereof.
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