MEGASONIC CLEANING METHOD AND APPARATUS

摘要

A method and apparatus for megasonic cleaning of substrates by placing the wafers in the far-field megasonic zone to eliminate sonic-induced damage to highly sensitive small-scale device structures that occurs in the near-field megasonic zone. Folded acoustic beam paths are defined by at least one reflector to achieve sufficient path length to the wafers. A reciprocally rotating reflector may be used to sweep the acoustic beam across the substrate surfaces.