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, 2025
Filed:
Aug. 11, 2022
Kla Corporation, Milpitas, CA (US);
KLA Corporation, Milpitas, CA (US);
Abstract
An overlay metrology target may include grating-over-grating structures formed from a lower grating structure with a first coarse pitch in a first sample layer and an upper grating structure with a second coarse pitch in a second sample layer, where the upper and lower grating structures overlap on the sample. At least one of the upper grating structure or the lower grating structure may include features with a fine pitch smaller than a wavelength of an illumination beam and arranged to rotate first-order diffraction of the illumination beam associated with at least one of the first or second coarse pitches with respect to at least one of specular reflection from a top surface of the sample or zero-order diffraction from the one or more grating structures. Overlay between the first and second layers of the sample is determinable from an image of the grating structures based on the first-order diffraction.