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:
Jan. 11, 2005
Filed:
Dec. 28, 2001
Christopher P. Ausschnitt, Lexington, MA (US);
Timothy A. Brunner, Ridgefield, CT (US);
Joseph P. Kirk, Chelsea, NY (US);
Nakgeuon Seong, Wappingers Falls, NY (US);
Christopher P. Ausschnitt, Lexington, MA (US);
Timothy A. Brunner, Ridgefield, CT (US);
Joseph P. Kirk, Chelsea, NY (US);
Nakgeuon Seong, Wappingers Falls, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method is described for determining lens aberrations using a test reticle and a standard metrology tool. The method provides test patterns, preferably in the form of standard overlay metrology test patterns, that include blazed gratings having orientation and pitch selected to sample desired portions of the lens pupil. The method measures relative shifts in the imaged test patterns using standard metrology tools to provide both magnitude and sign of the aberrations. The metrology tools need not be modified if standard test patterns are used, but can be adapted to obtain additional information. The test reticles may be formed with multiple test patterns having a range of orientations and pitch in order to compute any desired order of lens aberration. Alternatively, single test patterns may be used to determine both the magnitude and sign of lower order lens aberrations, such as defocus or coma.