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. 23, 2010
Filed:
Apr. 11, 2008
Bernd Schulz, Radebeul, DE;
Bernd Schulz, Radebeul, DE;
GlobalFoundries, Inc., Grand Caymand, KY;
Abstract
An enhanced technique for determination of an alignment accuracy involves an overlay target assembly which comprises at least two targets, each target having a first sub-structure of a first layer and a second sub-structure of a second layer, wherein, when the first layer and the second layer are correctly aligned, the first sub-structure and the second sub-structure of at least one of the targets are offset with respect to each other by a programmed offset and the overlay target assembly is invariant to at least one geometric transformation. If the offset vectors which describe the offset between the first sub-structure and the second sub-structure all have the same norm, the overlay error may be determined without calibration. Redundancy may be increased by providing each target with two or more programmed offsets between elements of the first sub-structure and elements of the second sub-structure.