Semiconductor memory device and method for operating the same
Provided herein is a semiconductor memory device and a method for operating the same. The semiconductor memory device may include a memory cell array including a plurality of memory blocks, each including dummy cells coupled to dummy word lines and normal memory cells coupled to normal word lines, a peripheral circuit configured to perform an erase operation on a memory block selected from among the plurality of memory blocks and control logic configured to control the peripheral circuit, during the erase operation, to apply a pre-program voltage pulse to the dummy word lines and the normal word lines, and to control application of dummy word line voltages to the dummy word lines based on Erase-Write (EW) cycling information while applying an erase voltage to a common source line of the selected memory block, wherein the EW cycling information indicates a number of erase-write cycles of the selected memory block.
1. A semiconductor memory device, comprising:
a memory cell array including a plurality of memory blocks, each including dummy cells coupled to dummy word lines and normal memory cells coupled to normal word lines;
a peripheral circuit configured to perform an erase operation on a memory block selected from among the plurality of memory blocks; and
a control logic configured to control the peripheral circuit, during the erase operation, to apply an erase permission voltage to the dummy word lines and the normal word lines for a preset time and to apply an erase prohibition voltage to the dummy word lines after the preset time,
wherein the preset time is determined based on Erase-Write (EW) cycling information and is determined regardless of a time for the erase operation, and
wherein the EW cycling information indicates a number of erase-write cycles of the selected memory block.
2. The semiconductor memory device according to claim 1 ,
wherein the control logic applies the erase permission voltage to the dummy word lines and the normal word lines while applying an erase voltage to a common source line, and applies a pre-program voltage pulse to the dummy word lines and the normal word lines before the erase permission voltage is applied to the dummy word lines and the normal word lines.
3. The semiconductor memory device according to claim 2 , wherein the erase permission voltage is a ground voltage.
4. The semiconductor memory device according to claim 2 , wherein the control logic includes an erase operation control unit configured to store the EW cycling information for each of the plurality of memory blocks.
5. The semiconductor memory device according to claim 2 , wherein a length of the preset time becomes shorter as the number of erase-write cycles of the selected memory block becomes greater.
6. The semiconductor memory device according to claim 1 , wherein the control logic receives respective pieces of the EW cycling information for each of the plurality of memory blocks from an external controller either periodically or randomly.
7. The semiconductor memory device according to claim 6 , wherein the control logic receives the EW cycling information from the external controller in response to a set parameter command.
8. The semiconductor memory device according to claim 6 , wherein the control logic receives the EW cycling information from the external controller in response to a set feature command.
9. A method for operating a semiconductor memory device, the semiconductor memory device including a plurality of memory blocks, each including dummy cells coupled to dummy word lines and normal memory cells coupled to normal word lines, the method comprising:
applying a pre-program voltage pulse to dummy word lines and to normal word lines that are coupled to a memory block selected from among the plurality of memory blocks;
applying an erase permission voltage to the dummy word lines and the normal word lines for a preset time; and
applying an erase prohibition voltage to the dummy word lines after the preset time,
wherein the preset time is determined based on Erase-Write (EW) cycling information, and is determined regardless of a time for an erase operation, and
wherein the EW cycling information indicates a number of erase-write cycles of the selected memory block.
10. The method according to claim 9 , wherein applying the erase permission voltage comprises:
applying the erase permission voltage to the dummy word lines and the normal word lines while applying an erase voltage to a common source line.
11. The method according to claim 10 , wherein applying the erase permission voltage includes applying a ground voltage to the dummy word lines and the normal word lines.
12. The method according to claim 10 , wherein a length of the preset time becomes shorter as the number of erase-write cycles of the selected memory block becomes greater.
13. The method according to claim 9 , further comprising receiving respective pieces of the EW cycling information for each of the plurality of memory blocks from an external controller either periodically or randomly.
14. The method according to claim 13 , wherein receiving the respective pieces of the EW cycling information is performed in response to a set parameter command.
15. The method according to claim 13 , wherein receiving the respective pieces of the EW cycling information is performed in response to a set feature command.