Fourier filters, inspection systems, and systems for fabricating fourier filters

摘要

Fourier filters, inspection systems, and systems for fabricating Fourier filters are provided. One Fourier filter configured for use in an inspection system includes a substrate that is substantially transparent to light from a specimen illuminated by the inspection system. The Fourier filter also includes an array of patterned features formed on the substrate. The patterned features are formed of one or more pigments on the substrate. The patterned features are configured to block light reflected and diffracted from structures on the specimen and to allow light scattered from defects on the specimen to pass through the substrate.