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:
May. 03, 2005
Filed:
Apr. 17, 2003
Applicants:
Enio Carpi, Fishkill, NY (US);
Shoaib Hasan Zaidi, Poughkeepsie, NY (US);
Inventors:
Enio Carpi, Fishkill, NY (US);
Shoaib Hasan Zaidi, Poughkeepsie, NY (US);
Assignee:
Infineon Technologies Aktiengesellschaft, Munich, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L023/544 ;
U.S. Cl.
CPC ...
Abstract
An alignment or overlay mark with improved signal to noise ratio is disclosed. Improved signal-to-noise ratio results in greater depth of focus, thus improving the performance of the alignment mark. The alignment mark comprises a zone plate having n concentric alternating opaque and non-opaque rings. Light diffracted by either the odd or even rings are cancelled while light diffracted by the other of the odd or even rings are added.