ABSTRACT
A principal motivation for developing interrogation techniques for characterizing the attraction of particles to surfaces is the need of the semiconductor industry to remove contaminants from wafers. When focused to provide high acoustic energy densities over regions comparable to the cross-sectional area of a contaminant particle, acoustic waves can provide particle accelerations as high as 105g. This chapter describes the development of the focused acoustic wave as a tool for selectively interrogating the behavior of contaminant particles of the scale of one micrometer and some tests of its abilities. A prototype system has been developed successfully to focus acoustic waves on fine particles on surfaces and examine their response. Features such as the pulse-modulated transducer operation and its focusing capabilities enable delivery of sufficient acoustic energy to the surface to allow controlled manipulation, displacement, and removal of individual particles as small as one micrometer in diameter.
