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:
Feb. 26, 2019
Filed:
Dec. 15, 2016
Asml Netherlands B.v., Veldhoven, NL;
Gerbrand Van Der Zouw, Waalre, NL;
ASML Netherlands B.V., Veldhoven, NL;
Abstract
A focus monitoring arrangement () is provided for a scatterometer or other optical system. A first focus sensor () provides a first focus signal (S-S) indicating focus relative to a first reference distance (z). A second focus sensor () for providing a second focus signal (C-C) indicating focus relative to a second reference distance (z). A processor () calculates a third focus signal by combining the first focus signal and the second focus signal. By varying the proportions of the first and second focus signals in calculating the third focus signal, an effective focus offset can be varied electronically, without moving elements.