NONVOLATILE SEMICONDUCTOR MEMORY DEVICE AND METHOD OF CONTROLLING SAME

摘要

According to an embodiment, a semiconductor memory device includes a memory cell array and a control circuit. The memory cell array comprises a plurality of memory cells that each include a control gate and a charge accumulation layer and that each are configured to have a threshold set to be included in any of a plurality of threshold distributions, the memory cell being connected between a bit line and a source line. The control circuit, in at least one of a write verify operation and a read operation on a selected memory cell, applies to the control gate a control gate voltage to determine the threshold of the selected memory cell, the control gate voltage having a plurality of values respectively corresponded to the plurality of threshold distributions, and sets a voltage between the bit line and the source line based on the control gate voltage.

主权项

1. A nonvolatile semiconductor memory device, comprising:
a memory cell array comprising a plurality of memory cells that each include a control gate and a charge accumulation layer and that each are configured to have a threshold set to be included in any of a plurality of threshold distributions and thereby store multiple bits of data, the memory cell being connected between a bit line and a source line, and the control gate of the memory cell being connected to a word line; and a control circuit that, in at least one of a write verify operation and a read operation on a selected memory cell, applies to the word line a control gate voltage to determine the threshold of the selected memory cell, the control gate voltage having a plurality of values respectively corresponded to the plurality of threshold distributions, and sets a voltage between the bit line and the source line to which the selected memory cell is connected, based on the control gate voltage.