Patent ID: 6240023
Filing Date: 2001-05-29
Classification: G11C

Abstract:
A method of soft programming a block of memory cells, comprising:measuring a leakage current in a bit line of a column in the block without accessing any memory cells in the column to produce a measured bit line leakage current; andif the measured bit line leakage current exceeds a predetermined current level, sequentially soft programming each of the memory cells coupled to the bit line for approximately a predetermined period of time so non-over erased memory cells are undisturbed, and until the measured bit line leakage current is less than or equal to the predetermined current level, wherein soft programming comprises applying fixed repair voltages to a source, a drain and a control gate of the memory cells, the predetermined period of time is less than 100 microseconds and is substantially less than a time period required to repair an average over erased memory cell.