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. 07, 2020
Filed:
Oct. 24, 2017
Kla-tencor Corporation, Milpitas, CA (US);
KLA-Tencor Corporation, Milpitas, CA (US);
Abstract
Scatterometry overlay targets and measurement methods are provided, which are configured to detect and eliminate process-related errors and illumination-related errors from overlay measurements of the targets. Targets comprise at least three cells associated with a measurement direction, wherein at least two of the cells comprise periodic structures at different target layers, having a same pitch and opposite offsets between the two cells, and at least an additional cell comprises a periodic structure with the same pitch at only one of the target layers. The additional cell(s) are used to detect irregularities in the respective periodic structure(s), enable estimation of process quality, provide reference images, enhance metrology simulations and provide mitigation of errors in critical process steps. Measurement methods incorporate scatterometry measurements ion the additional cell(s) for these purposes.