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:
Jul. 21, 2009
Filed:
Jun. 30, 2006
Martin N. Weiss, Portland, OR (US);
Martin N. Weiss, Portland, OR (US);
Intel Corporation, Santa Clara, CA (US);
Abstract
Pattern recognition targets including regions of one or more layers of gratings are used for semiconductor fabrication wafer alignment. Grates of the gratings are below the resolution limit of the alignment microscopes, and have dimensions compatible with design rules applied to actual device circuitry. Targets may be located by the contrast of light reflected and diffracted back from the regions and through a numerical aperture of the microscope. Target contrast may be achieved by controlling the diffractive properties of the regions. A grating with a pitch that causes a significant amount light to diffract out of the numerical aperture will appear darker, while a grating with a pitch that produces minimal diffraction with appear much brighter. Moreover, for a darker causing pitch, a region of layers gratings having grates stacked on each other can appear even darker, while a region having layers of grates interleaved can appear even brighter.