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:
Sep. 23, 2008
Filed:
Nov. 16, 2006
Vi Vuong, Fremont, CA (US);
Yan Chen, Santa Clara, CA (US);
Holger Tuitje, Fremont, CA (US);
Tokyo Electron Limited, Tokyo, JP;
Abstract
Drift in an optical metrology tool is compensated for by obtaining a first measured diffraction signal and a second measured diffraction signal of a first calibration structure mounted on the optical metrology tool. The first and second measured diffraction signals were measured using the optical metrology tool. The second measured diffraction signal was measured later in time than the first measured diffraction signal. A first drift function is generated based on the difference between the first and second measured diffraction signals. A third measured diffraction signal is obtained of a first structure formed on a first wafer using the optical metrology tool. A first adjusted diffraction signal is generated by adjusting the third measured diffraction signal using the first drift function.