a multiple wafer cleaning apparatus comprising a first module , having a first spaced - apart brush assembly having an inner brush and an outer brush , each brush having a brush pad and a platen , and a second module having a second spaced - apart brush assembly having an inner brush and an outer brush , each brush having a brush pad and a platen , each pair of spaced - apart , opposing , vertically disposed brushes and for scrubbing vertically disposed semiconductor wafers , in tanks . the two modularized sets of motorized , rotating , opposed , pancake shaped brushes and , grip the freely rotating wafers causing the wafers to rotate in the same direction as the brushes . the size of the brushes relative to the wafer radius is selected so that at any given instant a first portion of the offset vertically disposed wafers are positioned between the contacts of the brushes while the second remaining portion of the wafers extend outwardly downward from between the brushes . the peripheral second remaining portions of the wafers are supported by the vertical rotating support members . the tanks can contain a cleaning solution and a megasonic transducer allowing the support member to support the workpiece in a partially submerged position .