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:
Oct. 29, 2013
Filed:
Oct. 26, 2010
Matthew R. Arnison, Umina, AU;
Tuan Quang Pham, North Ryde, AU;
Matthew R. Arnison, Umina, AU;
Tuan Quang Pham, North Ryde, AU;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A method of determining a focus parameter for aligning a water in an exposure tool within a measurement tolerance required for the exposure tool, the exposure tool using a lens system for alignment. A test chart is provided having a sharp auto-correlation associated with the wafer. An image of the test chart is captured using a lens pupil mask having at least two phase ramps that are non-parallel. The captured image of the test charge is auto-correlated to determine the position of the test chart relative to a focal position of the lens system. The focus parameter for alignment of the wafer is determined using the determined position of the test chart, whereby the focus parameter is determined within the measurement tolerance required by the exposure tool.