A dark field surface inspection tool and system are disclosed herein. The
tool includes an illumination source capable of scanning a light beam
onto an inspection surface. Light scattered by each inspection point is
captured as image data by a photo detector array arranged at a fourier
plane. The images captured are adaptively filtered to remove a portion of
the bright pixels from the images to generate filtered images. The
filtered images are then analyzed to detect defects in the inspection
surface. Methods of the invention include using die-to-die comparison to
identify bright portions of scattering patterns and generate unique image
filters associated with those patterns. The associated images are then
filtered to generate filtered images which are then used to detect
defects. Also, data models of light scattering behavior can be used to
generate filters.