Memory system and method of operating the same
A memory system may include performing a first read operation on first data stored in first memory cells coupled to a first word line, performing an error correction operation on the first data, performing an interference program operation on second memory cells coupled to a second word line when the error correction operation fails, and performing a second read operation on the first data stored in the first memory cells after performing the interference program operation.
1. A method of operating a memory system, comprising:
performing a first read operation on first data stored in first memory cells coupled to a first word line;
performing an error correction operation on the first data;
performing an interference program operation on second memory cells coupled to a second word line in response to failure of the error correction operation; and
performing a second read operation on the first data stored in the first memory cells after performing the interference program operation,
wherein the interference program operation is configured to increase threshold voltages of memory cells in an erase threshold voltage distribution by a first threshold voltage, and increase threshold voltages of memory cells in a second program threshold voltage distribution by a second threshold voltage, and
wherein the first threshold voltage is greater than the second threshold voltage.
2. The method according to claim 1 , wherein the second word line is adjacent to the first word line.
3. The method according to claim 2 , wherein:
stored data in each of the first and second memory cells includes a least significant bit (LSB) and a most significant bit (MSB), and
an MSB program operation is performed on the second memory cells after an MSB program operation has been performed on the first memory cells.
4. The method according to claim 2 , further comprising, before performing the interference program operation,
reading second data stored in the second memory cells; and
backing up the second data.
5. The method according to claim 4 , further comprising copying and programming the first data and the second data to another location.
6. The method according to claim 2 , wherein:
threshold voltages of the second memory cells form the erase threshold voltage distribution, a first program threshold voltage distribution, the second program threshold voltage distribution, and a third program threshold voltage distribution in ascending order of magnitudes of their threshold voltages.
7. The method according to claim 6 , wherein:
the interference program operation is configured to increase threshold voltages of memory cells in the third program threshold voltage distribution by a third threshold voltage, and
the second threshold voltage is greater than the third threshold voltage.
8. The method according to claim 6 , wherein, during the interference program operation, memory cells in the first program threshold voltage distribution are program-inhibited.
9. The method according to claim 6 , wherein read voltages used in performing the second read operation are greater than respective read voltages used in performing the first read operation.
10. The method according to claim 2 , wherein the interference program operation causes respective widths of program threshold voltage distributions of the first memory cells to decrease.
11. A method of operating a memory device, comprising:
performing a first read operation on first data stored in first memory cells coupled to a first word line;
performing a read operation on second data stored in second memory cells coupled to a second word line that is adjacent to the first word line;
performing an interference program operation on the second memory cells; and
performing a second read operation on the first data stored in the first memory cells after performing the interference program operation,
wherein the interference program operation causes widths of one or more of program threshold voltage distributions formed by the first memory cells to decrease, and
wherein the performing the interference program operation comprises:
applying a first program bias to the second word line; and
applying a second program bias greater than the first program bias to the second word line.
12. The method according to claim 11 , further comprising:
storing the second data in a page buffer group;
changing data corresponding to an erase threshold voltage distribution, of the second data stored in the page buffer group, to data corresponding to a first program threshold voltage distribution; and
changing data corresponding to a second program threshold voltage distribution, of the second data stored in the page buffer group, to data corresponding to a third program threshold voltage distribution,
wherein threshold voltages of the second memory cells form the erase threshold voltage distribution, the first program threshold voltage distribution, the second program threshold voltage distribution, and the third program threshold voltage distribution in ascending order of magnitudes of their threshold voltages.
13. The method according to claim 12 , wherein the interference program operation is performed based on the changed data.
14. The method according to claim 11 , wherein:
during the applying of the second program bias, memory cells corresponding to the erase threshold voltage distribution or the first program threshold voltage distribution are program-inhibited, and
threshold voltages of the second memory cells form the erase threshold voltage distribution, the first program threshold voltage distribution, the second program threshold voltage distribution, and the third program threshold voltage distribution in ascending order of magnitudes of their threshold voltages.
15. The method according to claim 11 , further comprising programming the first data to the first memory cells and programming the second data to the second memory cells, and
wherein the programming is performed based on a shadow program algorithm.
16. A memory system, comprising:
a first physical page configured to store data;
a second physical page arranged adjacent to the first physical page;
a control logic configured to control a read operation and a program operation on the first and second physical pages; and
an error checking and correction unit configured to perform an error correction operation on data read from the first and second physical pages,
wherein, in response to failure of the error checking and correction unit in an error correction operation performed on data read from the first physical page, the control logic performs a program operation on the second physical page, and
wherein the program operation is configured to shift threshold voltages of memory cells in an erase threshold voltage distribution to a first program threshold voltage distribution.
17. The memory system according to claim 16 , wherein the control logic performs another read operation on the first physical page after performing the program operation on the second physical page.
18. The memory system according to claim 16 , wherein:
threshold voltages of the second physical page form the erase threshold voltage distribution, the first program threshold voltage distribution, a second program threshold voltage distribution, and a third program threshold voltage distribution in ascending order of magnitudes of their threshold voltages.
19. The memory system according to claim 18 , wherein the program operation performed on the second physical page causes threshold voltages of memory cells in the second program threshold voltage distribution and memory cells in the third program threshold voltage distribution to be shifted to a fourth program threshold voltage distribution having threshold voltages greater than those of the third program threshold voltage distribution.
20. The memory system according to claim 18 , wherein the control logic is configured such that, during the program operation, memory cells in the first program threshold voltage distribution are program-inhibited.