Materials Compatibility and Organic Build-Up during Ozone-Based Cleaning of Semiconductor Devices

摘要

The pH of deionized water (DI-water) was found to decrease when ozone was bubbled through the solution. This phenomenon was investigated by monitoring the change in chemical composition of the ozonated solution by means of Ion Chromatography (IC). It was found that nitrate, sulfate, formiate, acetate and oxalate ions were generated in the DI-water whereby these organic acids are responsible for the pH-decrease. These species are reaction products of the gas phase reaction between ozone and the Teflon tubing connecting the ozone generator to the reaction vessel.