ABSTRACT
Principles of light scattering are used in many instruments that measure the presence and properties of particles in air, in liquids, and on surfaces. For particles with sizes of interest in the microelectronics industry, theory that describes light scattering is complex. This chapter introduces the important concepts of light-scattering theory in a way that represents the principles that govern the light scattering theory. The intensity of the scattered light is proportional to the intensity of the incident light, and depends strongly on the size of the particle. Instruments that size particles by light scattering combine the intensities from a range of scattering angles. Scanners used to detect or size particles on a silicon wafer rely on detecting the light scattered by these particles. The size of a nonspherical particle can be expressed as that of a sphere that scatters light in the same way as the particle of interest.
