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. 14, 2023
Filed:
Sep. 28, 2021
Kla Corporation, Milpitas, CA (US);
Stilian Pandev, Santa Clara, CA (US);
Min-Yeong Moon, Ann Arbor, MI (US);
Andrei V. Shchegrov, Campbell, CA (US);
Jonathan Madsen, Los Altos, CA (US);
Dimitry Sanko, Vallejo, CA (US);
Liran Yerushalmi, Zicron Yaacob, IL;
Alexander Kuznetsov, Austin, TX (US);
Mahendra Dubey, Milpitas, CA (US);
KLA Corporation, Milpitas, CA (US);
Abstract
A self-calibrating overlay metrology system may receive device overlay data from device targets on a sample, determine preliminary device overlay measurements for the device targets including device-scale features using an overlay recipe with the device overlay data as inputs, receive assist overlay data from sets of assist targets on the sample including device-scale features, where a particular set of assist targets includes one or more target pairs formed with two overlay targets having programmed overlay offsets of a selected value with opposite signs along a particular measurement direction. The system may further determine self-calibrating assist overlay measurements for the sets of assist targets based on the assist overlay data, where the self-calibrating assist overlay measurements are linearly proportional to overlay on the sample, and generate corrected overlay measurements for the device targets by adjusting the preliminary device overlay measurements based on the self-calibrating assist overlay measurements.