| 摘要 |
In a nonvolatile semiconductor memory device including a memory cell array obtained by arranging, in a matrix manner, electrically programmable memory cells, each of which comprises stacking a charge storage layer and a control gate on a semiconductor layer through an insulating film, the threshold voltages of the memory cells are detected after erasing, and data are programmed in a fast programmable cell at a relatively low voltage and in a slow programmable cell at a relatively high voltage, thereby suppressing variations in threshold voltages after programming within the same period of programming time.
|
