| 摘要 |
A method is provided for erasing data from a non-volatile semiconductor memory device including a matrix of memory cells grouped into one or more blocks in which data can be electrically written to or erased from the memory cells being formed by a field effect transistor including a drain, a source, a floating gate and a control gate, each block including a first well of a first conductivity type provided on a substrate of a second conductivity type, a second well or second conductivity type provided on the first well electrically isolated from the substrate by the first well, and a plurality of memory cells provided on the second well, the sources of the memory cells in each block commonly connected to one another. The method includes steps of: withdrawing electrons from each floating gate through a Fowler-Nordheim tunnel phenomenon to perform a batch erase operation, on all memory cells in each block; and prior to the batch erase operation, performing a pro-erase write operation in which a first voltage, a second voltage of an opposite polarity to the first voltage and a third voltage of the same polarity an the first voltage are respectively applied to the control gates, the second wells and the first wells of all of the memory cells in the block to be erased so that electrons are injected into the floating gates of each memory cell through a Fowler-Nordheim tunnel phenomenon.
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