Abstract: 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.

Abstract: A tubing connection provides a unique nut assembly that does not loosen or leak when exposed to the initial heat/cool cycles of a chemistry setup. The nut assembly includes a outer housing portion, and a concentric inner locking ferrule. A cavity defined between the inner and outer portion houses a stainless steel spring secured therein by a snap-engaged spring retainer. As the outer nut is rotated on the threads of the fitting, it drives the spring retainer toward the ferrule, thereby compressing the spring and causing it to maintain the engagement of the tubing end on the connector fitting.

Abstract: A method and apparatus for megasonic bath cleaning of wafers employs a megasonic resonator that is directed obliquely toward the front, active surface of the wafer, so that higher acoustic energy levels may be used without causing structural damage to the wafer. In one embodiment four transducers are coupled to a resonating plate, the four transducers being spaced apart to uniformly radiate separate portions of the wafer that total a ¼ portion of the wafer surface. When the wafer is rotated, the wafer receives equal megasonic power across the entire surface. In a further embodiment, a resonating plate is driven by an acoustic transducer at an angle to the wafer and coupled to a refracting plate to result in an off-normal axis impingement angle. In another embodiment, a resonating plate is translated radially with respect to a wafer. The radiating surface of the plate may be rotated 0°-10° from normal to radiate obliquely to the wafer surface.