METHOD OF REPAIRING OVERERASED CELLS IN A FLASH MEMORY

摘要

A method of repairing overerased cells in a flash memory array including a column having a first cell and a second cell is described. Repair begins by determining whether a first cell is overerased and applying a programming pulse if so. Next, the second cell is examined to determine whether it is overerased. A programming pulse is applied to the second cell if it is overerased. Afterward, if either of the cells was overerased then the repair pulse voltage level is incremented. These steps are repeated until none of the cells on the column is identified as overerased.