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:
Aug. 30, 2022
Filed:
Dec. 17, 2019
Kla Corporation, Milpitas, CA (US);
John Hench, Los Gatos, CA (US);
Andrei V. Shchegrov, Cambell, CA (US);
Michael S. Bakeman, San Jose, CA (US);
KLA Corporation, Milpitas, CA (US);
Abstract
Methods and systems for performing overlay and edge placement errors of device structures based on x-ray diffraction measurement data are presented. Overlay error between different layers of a metrology target is estimated based on the intensity variation within each x-ray diffraction order measured at multiple, different angles of incidence and azimuth angles. The estimation of overlay involves a parameterization of the intensity modulations of common orders such that a low frequency shape modulation is described by a set of basis functions and a high frequency overlay modulation is described by an affine-circular function including a parameter indicative of overlay. In addition to overlay, a shape parameter of the metrology target is estimated based on a fitting analysis of a measurement model to the intensities of the measured diffraction orders. In some examples, the estimation of overlay and the estimation of one or more shape parameter values are performed simultaneously.