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. 05, 2002
Filed:
Feb. 22, 1999
Roger Lawrence Barr, Milton, VT (US);
Robert Truman Froebel, Fairfax, VT (US);
Paul Sonntag, Colchester, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Robust alignment marks which are substantially resistant to degradation caused by semiconductor device fabrication steps are disclosed. The new alignment marks use a series of geometrical shapes that are staggered in respect to each other to achieve more left and right edges providing a checkerboard alignment mark. The geometrical shapes have a size that is selected so as to be within the resolving capability of the exposure tool, yet smaller than the resolving capability of the alignment system. The small staggered geometrical shapes provide a more symmetrical signal which is more resistant to variability in prior processing steps than the standard mark design.