The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 29, 2012
Filed:
Oct. 05, 2009
Yevgeniy Konstantinovich Shmarev, Lagrangeville, NY (US);
Eric Brian Catey, Danbury, CT (US);
Robert Albert Tharaldsen, Sherman, CT (US);
Richard David Jacobs, Brookfield, CT (US);
Yevgeniy Konstantinovich Shmarev, Lagrangeville, NY (US);
Eric Brian Catey, Danbury, CT (US);
Robert Albert Tharaldsen, Sherman, CT (US);
Richard David Jacobs, Brookfield, CT (US);
ASML Holding N.V., Veldhoven, NL;
Abstract
A method and systems for reticle inspection. The method includes coherently illuminating surfaces of an inspection reticle and a reference reticle, applying a Fourier transform to scattered light from the illuminated surfaces, shifting the phase of the transformed light from the reference reticle such that a phase difference between the transformed light from the inspection reticle and the transformed light from the reference reticle is 180 degrees, combining the transformed light as an image subtraction, applying an inverse Fourier transform to the combined light, and detecting the combined light at a detector. An optical path length difference between two optical paths from the illumination source to the detector is less than a coherence length of the illumination source. The image detected by the detector represents a difference in amplitude and phase distributions of the reticles allowing foreign particles, defects, or the like, to be easily distinguished.