Nonvolatile semiconductor memory

摘要

A nonvolatile semiconductor memory includes a memory cell string containing a selection transistor and at least one cell transistor which is connected to the selection transistor and has a floating gate. Cell transistors are arranged in a memory cell array. The transistors each have a charge accumulation layer. A potential supply circuit supplies a potential different from a ground potential to gates of the cell transistor at least read operation and when the memory cell array is unselected.