Abstract: A surface inspection system, as well as related components and methods, are provided. The surface inspection system includes a beam source subsystem, a beam scanning subsystem, a workpiece movement subsystem, an optical collection and detection subsystem, and a processing subsystem. The system features a variable polarization a polarizing relay assembly arranged to selectively permit the scattered light having a selected polarization orientation to pass along a detector optical axis to a light detection unit in the detection subsystem. They system also features a collector output width varying subsystem for varying the width of an output slit in response to changes in the location of the location scanned on the workpiece.

Abstract: The composition of a particle occurring on the surface of a smooth substrate is identified by impinging the surface with a light beam having a strong P-polarized component at an oblique angle of incidence to the surface, and collecting light scattered from the surface at forward, center, and back locations relative to the portion of the surface impinged by the incident beam. The intensities of the light collected at these locations are measured by detectors and converted into signals, and the magnitudes of the signals are compared to correlations of particle material as a function of the relative magnitudes of the forward-, center-, and back-scatter signals so as to identify the material whose correlation most nearly matches the measured detector signals. Preferably, a ratio of the back detector signal magnitude to forward detector signal magnitude is correlated with particle material and back detector signal magnitude.