Method of erasing data in nonvolatile memory device, nonvolatile memory device performing the same and memory system including the same
A method of operating a memory device includes performing a data read operation on at least one victim sub-block within a memory block containing a plurality of sub-blocks therein, in response to an erase command directed to a selected sub-block within the plurality of sub-blocks. Next, a soft program operation is performed on the at least one victim sub-block. This soft programming operation is then followed by an operation to erase the selected sub-block within the plurality of sub-blocks. This operation to erase the selected sub-block may include providing an erase voltage to a bulk region of a substrate on which the memory block extends, and the at least one victim sub-block may be disposed between the selected sub-block and the substrate.
1. A method of operating a nonvolatile memory device, comprising:
performing a data read operation on at least one victim sub-block within a memory block containing a plurality of sub-blocks, in response to an erase command directed to a selected sub-block within the plurality of sub-blocks; then
performing a soft program operation on the at least one victim sub-block; and then
performing a data erase operation on the selected sub-block within the plurality of sub-blocks.
2. The method of claim 1 , wherein said performing a data erase operation comprises providing an erase voltage to a bulk region of a substrate on which the memory block extends; and wherein the at least one victim sub-block is disposed between the selected sub-block and the substrate.
3. The method of claim 1 , wherein the memory block comprises a common source line; and wherein the at least one victim sub-block extends closer to the common source line relative to the selected sub-block.
4. The method of claim 1 , wherein said performing a data read operation on the at least one victim sub-block comprises reading first victim memory cells among a plurality of victim memory cells included in the at least one victim sub-block, using a first read voltage; and wherein the first victim memory cells are commonly connected to a first word line within the memory block.
5. The method of claim 4 , wherein the soft program operation is a one-shot program operation during which at least a plurality of the first victim memory cells are simultaneously programmed.
6. The method of claim 1 , wherein the soft program operation is a one-shot program operation during which at least a plurality of memory cells within the at least one victim sub-block are simultaneously programmed to thereby increase their respective threshold voltages.
7. A method of erasing data in a nonvolatile memory device that includes a memory block including memory cells stacked in a direction intersecting a substrate, the memory block being divided into a plurality of sub-blocks configured to be erased independently, the method comprising:
receiving a data erase command for a selected sub-block among the plurality of sub-blocks;
performing a data read operation on at least one victim sub-block among the plurality of sub-blocks, in response to the data erase command; then
selectively performing a soft program operation on the at least one victim sub-block based on a result of the data read operation; and then
performing a data erase operation on the selected sub-block after the data read operation is performed and the soft program operation is selectively performed.
8. The method of claim 7 , wherein the at least one victim sub-block is disposed closer to an erase source used in the data erase operation than the selected sub-block.
9. The method of claim 8 , wherein:
in the data erase operation, an erase voltage is provided to a bulk region in the substrate on which the memory block is formed, and
the at least one victim sub-block is disposed lower than the selected sub-block such that the at least one victim sub-block is closer to the substrate than the selected sub-block.
10. The method of claim 8 , wherein the at least one victim sub-block is disposed closer to a common source line than the selected sub-block.
11. The method of claim 7 , wherein performing the data read operation on the at least one victim sub-block includes:
reading first victim memory cells among a plurality of victim memory cells included in the at least one victim sub-block based on a first read voltage, the first victim memory cells being connected to one wordline.
12. The method of claim 11 , wherein selectively performing the soft program operation on the at least one victim sub-block includes:
when a number of first memory cells among the first victim memory cells is greater than a reference number, performing the soft program operation on the plurality of victim memory cells, each of the first memory cells having a threshold voltage lower than the first read voltage.
13. The method of claim 12 , wherein the soft program operation is a one-shot program operation in which all of the plurality of victim memory cells are simultaneously programmed.
14. The method of claim 12 , wherein the first read voltage is a voltage for determining an erase state of each of the first victim memory cells.
15. The method of claim 12 , wherein:
after the soft program operation is performed on the plurality of victim memory cells, threshold voltages of all of erase memory cells among the plurality of victim memory cells increase, and
each of the erase memory cells is a memory cell having an erase state.
16. The method of claim 12 , wherein, when the number of the first memory cells among the first victim memory cells is smaller than or equal to the reference number, the soft program operation on the plurality of victim memory cells is omitted.
17. The method of claim 7 , wherein performing the data read operation on the at least one victim sub-block includes:
reading first victim memory cells among a plurality of victim memory cells included in the at least one victim sub-block based on a first read voltage, the first victim memory cells being connected to two or more wordlines.
18. The method of claim 7 , wherein performing the data read operation on the at least one victim sub-block includes:
sequentially reading first through N-th victim memory cells among a plurality of victim memory cells included in the at least one victim sub-block based on a first read voltage, where N is a natural number greater than or equal to two, the first through N-th victim memory cells being connected to first through N-th wordlines, respectively.
19. The method of claim 18 , wherein selectively performing the soft program operation on the at least one victim sub-block includes:
when a number of first memory cells among K-th victim memory cells is greater than a reference number, selectively performing the soft program operation on the K-th victim memory cells, where K is a natural number greater than or equal to one and smaller than or equal to N, each of the first memory cells having a threshold voltage lower than the first read voltage.
20. A method of operating a nonvolatile memory device, comprising:
performing a data read operation on at least one victim sub-block within a memory block containing a plurality of sub-blocks, in response to an erase command directed to a selected sub-block within the plurality of sub-blocks; then
performing a soft program operation on the at least one victim sub-block to inhibit an over-erase condition in a plurality of the memory cells within the at least one victim sub-block, in response to the erase command; and then
performing a data erase operation on the selected sub-block within the plurality of sub-blocks, in response to the erase command.