Eastman-kodak Company

Lightforce Technology, Inc.

Peter M Hammond

Joachim Bunkenburg

Kevin J Kearney

A process for detachment and removal of microscopic contaminant particles from a surface includes a pulsed detach light directed at the surface to excite a contaminant particle thereon at or near its resonant frequency, to thereby detach the particle from the surface; and a photophoresis light directed at the particle to move it by photophoresis, to thereby prevent its reattachment to the surface. A thermal gradient may also be applied to control the velocity and direction of particle movement by thermophoresis. Detach light is of variable pulse frequency and angle of incidence.

Detachment and removal of microscopic surface contaminants using a

Apparatus for treating the surfaces of a plurality of wafers, such as semiconductor wafers, which comprises a container of treatment fluid having an open upper side for accepting a cassette containing a plurality of vertically disposed wafers. The cassette is supported in the fluid in said container and a transducer carrier is mounted in the lower portion of the container. The carrier has at least one megasonic transducer arranged to project a beam of ultrasonic energy upwardly over the vertical surfaces of the wafers. The transducer carrier is moved parallel with the wafer surfaces transversely of the container whereby the ultrasonic energy beam contacts and treats the entire surface of all of the wafers therein.

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Rochester, NY, United States of America

Peter M Hammond