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:
Mar. 18, 2008
Filed:
Sep. 16, 2005
Guoheng Zhao, Milpitas, CA (US);
Mehdi Vaez-iravani, Los Gatos, CA (US);
Andrew V. Hill, San Jose, CA (US);
Avijit K. Ray-chaudhuri, San Ramon, CA (US);
Guoheng Zhao, Milpitas, CA (US);
Mehdi Vaez-Iravani, Los Gatos, CA (US);
Andrew V. Hill, San Jose, CA (US);
Avijit K. Ray-Chaudhuri, San Ramon, CA (US);
KLA-Tencor Technologies Corp., Milpitas, CA (US);
Abstract
Fourier filters and wafer inspection systems are provided. One embodiment relates to a one-dimensional Fourier filter configured to be included in a bright field inspection system such that the bright field inspection system can be used for broadband dark field inspection of a wafer. The Fourier filter includes an asymmetric illumination aperture configured to be positioned in an illumination path of the inspection system. The Fourier filter also includes an asymmetric imaging aperture complementary to the illumination aperture. The imaging aperture is configured to be positioned in a light collection path of the inspection system such that the imaging aperture blocks light reflected and diffracted from structures on the wafer and allows light scattered from defects on the wafer to pass through the imaging aperture.