Method of erasing flash memory cells

Abstract

The present invention relates to a method of erasing flash memory cells. In the flash memory cell having a substrate, a source, a drain, a tunnel oxide film, a floating gate, a dielectric film and a control gate, the method of erasing the flash memory cell comprises the steps of performing an erase operation for the cell, by applying a negative voltage being an erase voltage to the control gate and a positive voltage being an erase voltage to the substrate, discharging the control gate by making the control gate grounded, discharging the source by making the source grounded, and simultaneously performing a discharge operation and a recovery operation by making the substrate grounded. Therefore, the threshold voltages of the cells can be converted to have a constant voltage even though additional recovery operation is not performed.

Dependencies are inferred from the claim text.