An apparatus for manufacturing integrated circuits on a wafer includes a polish pad; a rinse arm movable over the polish pad; and a post-polish cleaner. The post-polish cleaner includes a brush for brushing the wafer; and a nozzle aiming at the wafer. The apparatus further includes a mixer configured to mix an additive and de-ionized water; and a pipe connecting the mixer to at least one of the rinse arm and the nozzle.