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:
Apr. 09, 2002
Filed:
May. 13, 1999
Leonardo Ravazzi, Dalmine, IT;
Lorenzo Fratin, Buccinasco, IT;
STMicroelectronics S.r.l., Agrate Brianza, IT;
Abstract
Method for localizing point defects causing column leakage currents in a non-volatile memory device including a plurality of memory cells arranged in rows and columns in a matrix structure, source diffusions, and metal lines which connect said source diffusions to each other. Such a method includes the steps of: modifying the memory device in order to make source diffusions independent of each other and each one electrically connected to a respective row; sequentially biasing the single columns of the matrix; localizing the column to which at least one defective cell belongs, as soon as the leakage current flow occurs in the biased column; by keeping biased the localized column, biasing sequentially the single rows of the matrix to the same potential as that of the localized column; localizing a couple of cells, wherein at least one of them involves the point defects, as soon as the leakage current flow does not occur.