Recycling method and device for recycling waste water containing slurry from a semi-conductor treatment process, in particular from a chemico-mechanical polishing process

Abstract

A recycling device for recycling slurry wastewater from a semiconductor processing process is provided. The recycling device includes a circulation vessel for receiving slurry-containing wastewater; a wastewater feed line connected to the circulation vessel; an ultrafilter device connected via an ultrafilter feed line to the circulation vessel for concentrating mixed wastewater continuously removed from the circulation vessel by means of fluid removal; a wastewater return line for passing the concentrated wastewater into the circulation vessel; and a control device which carries out after one another in time filtration, in which, during a continuous removal of mixed wastewater and concentration thereof by the ultrafilter device, fresh wastewater is continuously fed to the circulation vessel, and concentration, in which, during the continuous removal of mixed wastewater and concentration thereof by the ultrafilter device, the feed of the fresh wastewater to the circulation vessel is reduced or substantially shut off.

1 . A recycling device for recycling slurry wastewater from a chemical-mechanical semiconductor polishing process, the recycling device comprising:
 a circulation vessel for receiving fresh slurry-containing wastewater;   a wastewater feed line connected to the circulation vessel;   an ultrafilter device connected via an ultrafilter feed line to the circulation vessel and removing fluid from mixed wastewater continuously removed from the circulation vessel to concentrate the mixed wastewater to produce concentrated wastewater;   a wastewater return line for passing the concentrated wastewater into the circulation vessel; and   a control device which switches between a filtration step, in which the fresh slurry-containing wastewater is continuously fed to a circulation vessel, while the mixed wastewater is continuously removed from the circulation vessel, the mixed wastewater being passed through the ultrafilter device in which the fluid is removed from the mixed wastewater to obtain the concentrated wastewater and the concentrated wastewater being passed into the circulation vessel to mix with the contents of the circulation vessel in order to obtain the mixed wastewater; and   a concentration step, following the filtration step in time, in which the feed of the fresh slurry-containing wastewater to the circulation vessel is decreased, while the mixed wastewater is continuously removed from the circulation vessel, the mixed wastewater that is removed from the circulation vessel being passed through the ultrafilter device in which fluid is removed from the mixed wastewater to obtain concentrated wastewater, and the concentrated wastewater is passed into the circulation vessel.