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:
Aug. 03, 1999
Filed:
Aug. 20, 1997
Masaaki Sugimoto, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An object of the present invention is to provide a device for and a method of searching a really defective cell by removing influence of poor accuracy of a stage shifting mechanism or a numerical operation error of the device. The method of the present invention is a method of searching a specific cell of memory LSI, said method being employed in performing analysis, processing and observation operation with reference to a part of a physical address which corresponds to a logical address outputted as a result of an electrical test performed on memory LSI of array structure in which a plurality of memory cells are repeatedly arranged. Further, position coordinates are continuously observed with reference to an area including the end point of the array structure of said memory cell, the memory cells and a part between the memory cells; the number of memory cells on memory cell LSI is counted according to changes in brightness or luminosity; and a part in which said counted value and the value shown by said physical address coincide with each other is selected as the part of said logical address.