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. 09, 2006
Filed:
Mar. 24, 2003
Adam Weiss, Pickering, CA;
Afsar Saranli, Toronto, CA;
Oleksiy Lopatin, Scarborough, CA;
Alexandre Obotnine, Toronto, CA;
Adam Weiss, Pickering, CA;
Afsar Saranli, Toronto, CA;
Oleksiy Lopatin, Scarborough, CA;
Alexandre Obotnine, Toronto, CA;
Photon Dynamics, Inc., San Jose, CA (US);
Abstract
In an inspection system for planar objects having periodic structures, programmable optical Fourier filtering in the focal plane of a telecentric lens system is used to directly identify physical phenomena indicative of non-periodic defects. Lens assemblies and a coherent optical source are used to generate and observe a spatial Fourier transform of a periodic structure in the Fourier plane. Optical Fourier filtering (OFF) is performed in the focal plane using an electrically programmable and electrically alignable spatial light modulator. The spatial light modulator with high signal to noise ratio is electrically reconfigurable according to a feedback-driven, filter construction and alignment algorithm. The OFF enhances any non-periodic components present in the Fourier plane and final image plane of the object. A system having a plurality of inspection channels provides high-throughput inspection of objects with small non-periodic defects while maintaining high detection sensitivity.