Patent ID: 6067250
Filing Date: 2000-05-23
Classification: G11C,H01L

Abstract:
Method for localizing point defects causing column leakage currents in a non-volatile memory device, said device comprising a plurality of memory cells arranged in rows and columns in a matrix structure, said columns being connected to drain regions by means of first contacts, source diffusions, and metal lines which connect said source diffusions to each other by means of second contacts, comprising the steps of:modifying said memory device in order to eliminate a part of said first contacts and all the second contacts, and to form third contacts, which connect said metal lines to drain regions in rows wherein said first contacts have been eliminated, making said source diffusions independent of each other and halving the initial number of said memory cells;sequentially biasing the single columns of said matrix;sequentially biasing said single rows of said matrix, keeping biased one column;localizing a memory cell which presents said point defects, when said leakage current flow occurs.