Wet etch system with overflow particle removing feature

Abstract

A wet etch system including a process tank having an inner etch bath chamber and an outer overflow chamber surrounding the etch bath chamber. A frame which is removably mounted on the process tank defines a diversion channel between the upper ends of the etch bath chamber and overflow chamber. The etch bath chamber receives a wafer-containing cassette, which displaces etchant from the etch bath chamber, through the diversion channel and into the overflow chamber, where the etchant is drained from the process tank. Particulate impurities leave the etch bath chamber, enter the overflow chamber and drain from the process tank with the overflow etchant. Fresh etchant is poured into the etch bath chamber prior to a subsequent etch cycle. A water spray loop may be provided in the overflow chamber for removing etch particles from the interior wall surfaces of the overflow chamber.