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:
Jan. 17, 2023
Filed:
Apr. 14, 2021
Kla Corporation, Milpitas, CA (US);
Asaf Granot, Lotem, IL;
KLA Corporation, Milpitas, CA (US);
Abstract
An optical inspection apparatus includes an illumination assembly, configured to direct optical radiation to illuminate a semiconductor wafer on which first and second patterned layers have been deposited in succession, including a first target feature in the first patterned layer and a second target feature in the second patterned layer, such that at least one of the first and second target features has at least one dimension in the plane of the wafer that is less than an optical diffraction limit of the apparatus. An imaging assembly is configured to capture at least one image of the wafer, and a controller is configured to process the at least one image in order to identify respective locations of the first and second target features in the at least one image and to measure an overlay error between the first and second patterned layers responsively to a displacement between the respective locations.