Apparatus and process for separation and recovery of liquid and slurry abrasives used for polishing

Abstract

Abrasive components and clear fluids are separated from an aqueous chemical mechanical slurry used for planarization of semiconductor materials, to permit the reuse of the clear liquid effluent in non-process applications as well as for gray water for irrigation, process cooling water, or as make-up water for a reverse osmosis system, or safe disposal in the industrial waste stream, as desired. A solids detection device determines the concentration of abrasive solids in the aqueous waste effluent stream, and a diverter valve receives and diverts the entire aqueous waste effluent stream to at least one reuse water collection tank when the abrasive solids concentration is below a desired threshold, and diverts the entire aqueous waste effluent stream to at least one concentrate water collection tank when the abrasive solids concentration is greater than or equal to the threshold. With the additional use of ion exchange, the resulting water stream can be reused in high purity water applications.

Dependencies are inferred from the claim text.