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. 07, 2018
Filed:
Nov. 04, 2014
Asml Netherlands B.v., Veldhoven, NL;
Hendrik Jan Hidde Smilde, Veldhoven, NL;
Arie Jeffrey Den Boef, Veldhoven, NL;
Omer Abubaker Omer Adam, Veldhoven, NL;
Martin Jacobus Johan Jak, Veldhoven, NL;
ASML Netherlands B.V., Veldhoven, NL;
Abstract
A substrate has three or more overlay gratings formed thereon by a lithographic process. Each overlay grating has a known overlay bias. The values of overlay bias include for example two values in a region centered on zero and two values in a region centered on P/2, where P is the pitch of the gratings. Overlay is calculated from asymmetry measurements for the gratings using knowledge of the different overlay bias values and an assumed non-linear relationship between overlay and target asymmetry, thereby to correct for feature asymmetry. The periodic relationship in the region of zero bias and P/2 has gradients of opposite sign. The calculation allows said gradients to have different magnitudes as well as opposite sign. The calculation also provides information on feature asymmetry and other processing effects. This information is used to improve subsequent performance of the measurement process, and/or the lithographic process.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile