A surface analysis system is described that uses an unconventional illumination approach. The system uses two orthogonally polarized lasers that may have different frequencies (colors). The lasers used are both He-Ne devices, with either both operating at 633 nm (red), or one at 633 nm and one at 543 nm (green). The system is capable of sizing polystyrene latex (PSL) particles on bare silicon wafers as small as 0.1 μm and provides first-order differentiation between particles and defects. The scanning function is most similar to that used in optical disk drives. The optical system is modeled after a dark-field microscope and thus is capable of analyzing particles on transparent materials, as well as highly reflective materials such as silicon and dielectric mirrors. The instrument can also be configured to analyze polished memory disks, optical elements, and ring laser gyro mirrors.

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