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:
Dec. 29, 2015
Filed:
Jan. 30, 2012
Kaustuve Bhattacharyya, Veldhoven, NL;
Arie Jeffrey Den Boef, Waalre, NL;
Stefan Carolus Jacobus Antonius Keij, Breda, NL;
Peter Clement Paul Vanoppen, Hechtel-Eksel, BE;
Kaustuve Bhattacharyya, Veldhoven, NL;
Arie Jeffrey Den Boef, Waalre, NL;
Stefan Carolus Jacobus Antonius Keij, Breda, NL;
Peter Clement Paul Vanoppen, Hechtel-Eksel, BE;
ASML Netherlands B.V., Veldhoven, NL;
Abstract
Asymmetry properties of a periodic target on a substrate, such as a grating on a wafer, are determined. An inspection apparatus has a broadband illumination source with illumination beams point mirrored in the pupil plane of a high numerical aperture objective lens. The substrate and target are illuminated via the objective lens from a first direction and a second direction mirror reflected with respect to the plane of the substrate. A quad wedge optical device separately redirects diffraction orders of radiation scattered from the substrate and separates diffraction orders from illumination along each of the first and second directions. For example the zeroth and first orders are separated for each incident direction. After capture in multimode fibers, spectrometers are used to measure the intensity of the separately redirected diffraction orders as a function of wavelength.