NONVOLATILE MEMORY DEVICE AND PROGRAM METHOD THEREOF

摘要

According to example embodiments of inventive concepts, a nonvolatile memory device includes at least two strings that are vertically stacked on a substrate and share one bit line. A program method of the nonvolatile memory device includes setting a pre-charge condition on the basis of a disturb environment between the at least two cell strings, pre-charging or not pre-charging an unselected cell string among the at least two cell strings in response to the pre-charge condition and programming memory cells in a selected cell string among the at least two cell strings.

主权项

1. A nonvolatile memory device comprising:
a memory cell array comprising a plurality of cell strings that include a selected cell string and an unselected cell string that are connected to a first bit-line in common, each of the plurality of cell strings including a string selection transistor (SST) and a plurality of serially-connected nonvolatile memory cells that are stacked on or above a substrate in a direction that is perpendicular to the substrate, the SST of the selected cell string being connected to a selected string selection line (SSL), the SST of the unselected cell string being connected to an unselected SSL, a first memory cell among the plurality of serially-connected nonvolatile memory cells of the selected cell string and a second memory cell among the plurality of serially-connected nonvolatile memory cells of the unselected cell string being connected to a first word-line in common; an address decoder configured to apply a program voltage to the first word-line, and configured to apply a selected SSL voltage to the selected SSL and an unselected SSL voltage to the unselected SSL; a control circuit configured to control a plurality of program loops to program the first memory cell, configured to determine whether to perform a pre-charge operation for each of the plurality of program loops based on a loop number of the program loop or a level of the program voltage corresponding to the program loop, the level of the program voltage corresponding to the program loop becoming higher as the loop number of the program loop becomes greater; and a read and write circuit configured to apply a pre-charge voltage, wherein when the control circuit determines to perform the pre-charge operation for a first program loop among the plurality of program loops, the address decoder applies the unselected SSL voltage to turn-on the SST of the unselected cell string to the unselected SSL during the first program loop, while the read and write circuit applies the pre-charge voltage to the first bit-line before the address decoder applies the program voltage corresponding to the first program loop to the first word-line during the first program loop.