Systems and methods for particle detection

Abstract

The present invention discloses a dark field inspection system, which may include: an illumination source for generating an illumination beam; one or more illumination optics for directing the illumination beam along an illumination direction at an off-axis angle to a sample; a detector; one or more collection optics for producing a dark field image of the sample on the detector based on light collected from the sample in response to the illumination beam; and radial polarization a polarizer positioned at a pupil plane of the one or more collection optics, wherein the radial polarizer repels specular reflections from the sample in the pupil plane corresponding to the illumination beam The reference point has radially polarized light.

Description

[0001] Cross-references to related applications

[0002] This application claims under 35 U.S.C. §119(e) the names of Jenn-Kuen Leong, Daniel Kavaldjiev, John Fielden, and Guoheng Zhao US Provisional Application Serial No. 62 / 767,246, entitled "PARTICLE DETECTION WITH IMPROVED RESOLUTION ON WAFER INSPECTION SYSTEM," filed November 14, 2018 by the inventor of Zhao) the rights of the case, the entire contents of which are incorporated herein by reference. technical field

[0003] The present invention relates generally to particle inspection, and more particularly, to dark field particle inspection. Background technique

[0004] Particle inspection systems are commonly used in semiconductor processing lines to identify defects or particles on wafers such as, but not limited to, unpatterned wafers. As semiconductor devices continue to shrink, particle detection systems require corresponding increases in sensitivity and resolution. An obvious source of noise that can limit m...

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