RECYCLING OF WAFER CLEANING SUBSTANCES

摘要

A method of recycling and purifying cleaning chemicals used in the production of semiconductor circuits and containing hydrofluoric acid and or hydrochloric acid. Recycling of such chemicals is accomplished using separation and reconstitution steps Hydrofluoric acid and hydrochloric acid cannot be distilled directly from a chemical solution as they form azeotropes with water. A low vapor pressure substance such as sulfuric acid or phosphoric acid is used to break the azeotrope while increasing the purity of the recovered chemicals and decreasing disposal problems. The method is useable at the point of use of the chemicals.