Nonvolatile memory devices, operating methods thereof and memory systems including the same
Nonvolatile memory device, operating methods thereof, and memory systems including the same. In the operating method, a ground select line of a first string connected to a bit line may be floated. An erase prohibition voltage may be applied to a ground select line of a second string connected to the bit line. An erase operation voltage may be applied to the first and second strings.
1. An operating method, comprising:
floating a first ground select line connected to a first string connected to a bit line;
applying an erase prohibition voltage to a second ground select line connected to a second string connected to the bit line,
the first and second strings each including a plurality of memory cells stacked on top of each other in a direction normal to a substrate;
applying an erase operation voltage to the first and second strings; and
applying a ground voltage to a plurality of word lines connected to the first and second strings during the applying the erase operation voltage to the first and second strings.
2. The operating method of claim 1 , wherein the erase prohibition voltage is greater than a threshold voltage of a ground select transistor connected to the second ground select line of the second string.
3. The operating method of claim 1 , wherein the applying of the erase operation voltage includes
applying an erase voltage to a common source line connected to the first and second strings.
4. The operating method of claim 1 , wherein the applying the erase operation voltage includes,
floating a plurality of word lines connected to the first and second strings,
applying a pre-voltage to a common source line connected to the first and second strings, and
applying an erase voltage to the common source line.
5. The operating method of claim 1 , further comprising:
applying a second erase prohibition voltage to a third ground select line connected to the second string.
6. The operating method of claim 5 , wherein the second erase prohibition voltage is less than the erase prohibition voltage.
7. The operating method of claim 5 , wherein the second erase prohibition voltage is greater than a threshold voltage of a second ground select transistor connected to the second ground select line of the second string.
8. The operating method of claim 5 , further comprising:
applying a third erase prohibition voltage to a string select line connected to the second string.
9. A nonvolatile memory device, comprising:
a memory cell array including first and second strings of memory cells connected between a bit line and a common source line, the strings each connected to at least one word line, at least one select line, and at least one ground select line;
a driver configured to apply voltages to the word lines, select lines, ground select lines and the common source line,
the driver configured to, during an erase operation, apply a same voltage to a first word line of the first string and a second word line of the second string, and to apply different voltages to a first ground select line of the first string and a second ground select line of the second string; and
a read & write circuit configured to write data to and read data from the memory cells of the first and second strings.
10. The nonvolatile memory device of claim 9 , wherein the driver is configured to, during the erase operation, float the first ground select line, apply an erase prohibition voltage to the second ground select line, and apply erase operation voltages to the first and second word lines and the common source line.
11. The nonvolatile memory device of claim 10 , wherein the driver is configured to, during the erase operation, apply a second erase prohibition voltage to a third ground select line connected to the second string.
12. The nonvolatile memory device of claim 11 , wherein the second ground select line is between the third ground select line and the common source line, and the second erase prohibition voltage is less than the erase prohibition voltage.
13. The nonvolatile memory device of claim 9 , wherein the driver is configured to, during the erase operation, apply a ground voltage to the first and second word lines, and apply an erase voltage to the common source line.
14. The nonvolatile memory device of claim 9 , wherein the driver is configured to, during the erase operation, vary the voltage of the first and second word lines from a floating state to a ground voltage, and vary the voltage of the common source line from a pre-voltage to an erase voltage.
15. The nonvolatile memory device of claim 9 , wherein the memory cells of the first and second strings are stacked in a direction normal to a substrate.
16. The nonvolatile memory device of claim 9 , wherein the first and second word lines are electrically connected.
17. A memory system, comprising:
a nonvolatile memory device including,
a memory cell array with first and second strings of memory cells connected between a bit line and a common source line, the strings each connected to at least one word line, at least one select line, and at least one ground select line,
a driver configured to apply voltages to the word lines, select lines, ground select lines and the common source line, the driver configured to, during an erase operation, apply a same voltage to a first word line of the first string and a second word line of the second string, and to apply different voltages to a first ground select line of the first string and a second ground select line of the second string, and
a read & write circuit configured to write data to and read data from the memory cells of the first and second strings; and
a controller configured to control the nonvolatile memory device.
18. A semiconductor drive (Solid State Drive), comprising the memory system of claim 17 .
19. A memory card, comprising the memory system of claim 17 .