METHOD FOR ERASING AND PROGRAM OPERATING A FLASH DEVICE, FOR OBTAINING A PROPERTY OF A THRESHOLD VOLTAGE DISTRIBUTION IN AN ERASED STATE

摘要

PURPOSE: A method for erasing and program operating a flash device is provided to improve a property of a threshold voltage distribution in an erased state by implementing an erasing operation with the threshold voltage distribution of the lowest program state.;CONSTITUTION: Threshold voltage distributions in different program states are lowered to a first state of the threshold voltage distribution close to an erased state of the threshold voltage distribution. The threshold voltage distribution of a cell in which a soft erasing operation is implemented is lower to the erased state(102). The threshold voltage distribution of a cell in which a soft erasing operation is implemented is as same as the first state of threshold voltage distribution. A ground voltage is applied to a channel by applying an erasing pulse to a word line. An erasing voltage is applied to the channel by applying the ground voltage to the word line.;COPYRIGHT KIPO 2010