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:
Jun. 01, 2004
Filed:
Jul. 14, 2000
Julie Segal, Palo Alto, CA (US);
David Lepejian, Palo Alto, CA (US);
John Caywood, Sunnyvale, CA (US);
Heuristics Physics Laboratories, Inc., San Jose, CA (US);
Abstract
A method for determining the number of redundancy units to employ in a memory integrated circuit. The critical areas for faults on each process layer in the integrated circuit for a range of defect sizes, and the signatures of the electrical responses of faulted circuits to input test stimuli are determined. A statistical frequency distribution for both the signatures for a ratio of defect sizes on each of the process layers, and for the occurrences of selected combinations of the signatures are determined. A ratio of the signature distribution for different numbers of redundancy units, and the die area for each of the different numbers of redundancy units are determined. The number of usable die per wafer is determined from the signature distribution and the die area. A level of redundancy that maximizes the number of usable die per wafer is selected.