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:
Nov. 10, 2020
Filed:
Dec. 12, 2017
Asml Netherlands B.v., Veldhoven, NL;
Martin Jacobus Johan Jak, 's-Hertogenbosch, NL;
Kaustuve Bhattacharyya, Veldhoven, NL;
ASML Netherlands B.V., Veldhoven, NL;
Abstract
An overlay metrology target (T) is formed by a lithographic process. A first image (()) of the target structure is obtained using with illuminating radiation having a first angular distribution, the first image being formed using radiation diffracted in a first direction (X) and radiation diffracted in a second direction (Y). A second image ((R)) of the target structure using illuminating radiation having a second angular illumination distribution which the same as the first angular distribution, but rotated 90 degrees. The first image and the second image can be used together so as to discriminate between radiation diffracted in the first direction and radiation diffracted in the second direction by the same part of the target structure. This discrimination allows overlay and other asymmetry-related properties to be measured independently in X and Y, even in the presence of two-dimensional structures within the same part of the target structure.