THREE-DIMENSIONAL NONVOLATILE MEMORY AND RELATED READ METHOD DESIGNED TO REDUCE READ DISTURBANCE

摘要

A nonvolatile memory device performs a read operation comprising first and second intervals. In the first interval the device applies a turn-on voltage to string selection lines and ground selection lines connected to the string selection transistors and the ground selection transistors, respectively. In the second interval, the device applies a turn-off voltage to unselected string selection lines and unselected ground selection lines while continuing to apply the turn-on voltage to a selected string selection line and a selected ground selection line. In both the first and second intervals, the device applies a first read voltage to a selected wordline connected to memory cells to be read by the read operation and applying a second read voltage to unselected wordlines among connected to memory cells not to be read by the read operation.

主权项

1. A method of operating a nonvolatile memory device, the nonvolatile memory device comprising a plurality of cell strings, each cell string including a ground selection transistor, a plurality of memory cells and a string selection transistor serially-connected and stacked on a direction perpendicular to a substrate, the method comprising:
applying first, second, third and fourth voltages to first, second, third and fourth string selection lines connected to string selection transistors of first, second, third and fourth cell strings respectively; applying a fifth voltage to a selected word line connected to selected memory cell of the first cell string; and applying sixth voltage to at least one of unselected word lines connected to unselected memory cells of the first, second, third and third cell strings, wherein the second voltage is different from the third voltage and the fourth voltage.