Patent attributes
An apparatus for cleaning a wafer includes a plurality of holders for contacting and securing peripheral portions of a wafer, and for rotating the wafer, a first plate disposed to face a first surface of the wafer, the first plate having a plurality of first nozzles for spraying a first cleaning solution onto the first surface of the wafer, and a second plate disposed to face a second surface of the wafer that is opposite to the first surface, the second plate having a plurality of second nozzles for spraying a second cleaning solution onto the second surface of the wafer. In operation, the first and second plates and the wafer are rotated in opposite directions. The opposite rotation causes the cleaning solutions to flow abruptly thereby increasing a frictional force between the surfaces on the wafer and the cleaning solutions to improve the efficiency of the cleaning process.