New Method to Generate the High Concentration Ozonated Water by Using the Ultrapure Water of the Semiconductor Factory

摘要

A new method has been developed to generate highly ozonated ultrapure for semiconductors manufacturing, using hollow fibers modules. In this method, the decomposition of ozone due to the streaming electrification which occurs at the fibers wall and the high resistivity ultrapure water's interface could be prevented by two procedures; namely: 1) Addition of some electrolytes (i.e.CO_2, HCl) to the ultrapure water. 2) Addition of CO_2 gas in small quantities to the oxygen fed electric discharge-type ozone gas generator. According to the experimental results obtained, it was observed that more than two times larger dissolved ozone concentrations within high resistivity ultrapure water could be achieved following the application of the above mentioned measures. Furthermore, it could be found out as well that, in the case of CO_2 addition, a dissolved ozone concentration as high as that predicted from mass-balance was maintained constant for more than 2 hours even after the suspension of the CO_2 supply.