Semiconductor memory device
According to one embodiment, a semiconductor memory device includes: a first memory cell; a second memory cell; a first word line; a second word line; and a first bit line. The device is configured to execute a first operation, a second operation, and a third operation to write data into the first memory cell. In the first operation, a first voltage is applied to the second word line. In the second operation, after the first operation, a second voltage higher than the first voltage is applied to the second word line. In the third operation, after the second operation, a third voltage higher than the second voltage is applied to the first word line, and a fourth voltage lower than both the second voltage and the third voltage is applied to the second word line.
1. A semiconductor memory device comprising:
a first memory cell capable of holding data;
a second memory cell capable of holding data;
a first word line coupled to the first memory cell;
a second word line coupled to the second memory cell; and
a first bit line capable of being electrically coupled to both the first memory cell and the second memory cell,
wherein the first memory cell shares a semiconductor layer with the second memory cell, and faces the second memory cell across the semiconductor layer,
the device is configured to execute a first operation, a second operation, and a third operation to write data into the first memory cell, wherein
in the first operation, a first voltage is applied to the second word line,
in the second operation, after the first operation, a second voltage higher than the first voltage is applied to the second word line, and
in the third operation, after the second operation, a third voltage higher than the second voltage is applied to the first word line, and a fourth voltage lower than both the second voltage and the third voltage is applied to the second word line.
2. The device according to claim 1 , wherein the first voltage is applied to the second word line when data is read from the first memory cell, and
the fourth voltage turns on a memory cell.
3. The device according to claim 1 , wherein the first operation is executed to verify the second memory cell,
the second operation includes a first program operation to increase a threshold value of the second memory cell based on a result of the first operation, and
the third operation includes a second program operation to write data received from a controller configured to control the device, into the first memory cell.
4. The device according to claim 3 , wherein the second program operation includes:
a first write operation using a first program verify voltage; and
a second write operation after the first write operation and using a second program verify voltage higher than the first program verify voltage, and
wherein the first write operation in the third operation is executed with the first operation and the second operation, and
the second write operation in the third operation is executed without the first operation and the second operation.
5. The device according to claim 3 , wherein the second operation includes an operation of programming a memory cell which is determined in the first operation that a threshold value is lower than or equal to the first voltage.
6. The device according to claim 1 , wherein the device is further configured to execute a fourth operation after the second operation,
in the fourth operation, the first voltage is applied to the second word line, and
the third operation is executed after the fourth operation.
7. The device according to claim 6 , wherein the first operation is executed to verify the second memory cell,
the second operation includes a first program operation to increase a threshold value of the second memory cell based on a result of the first operation,
the fourth operation includes an operation to verify the second memory cell to confirm a result of the second operation, and
the third operation includes a second program operation to write data received from a controller configured to control the device, into the first memory cell.
8. The device according to claim 3 , wherein the second program operation includes:
a first write operation using a first program verify voltage; and
a second write operation executed after the first write operation and using a second program verify voltage higher than the first program verify voltage, and
wherein the first write operation in the third operation is executed with the first operation and the second operation, and
the second write operation in the third operation is executed without the first operation and the second operation.
9. The device according to claim 8 , wherein the second operation includes an operation of programming a memory cell which is determined in the first operation that a threshold value is lower than or equal to the first voltage.
10. The device according to claim 1 , wherein the device is further configured to execute a fourth operation before the first operation,
in the fourth operation, the third voltage is applied to the second word line.
11. The device according to claim 10 , wherein the fourth operation includes a third program operation to increase a threshold value of the second memory cell,
the first operation includes an operation to verify the second memory cell,
the second operation includes a first program operation to increase a threshold value of the second memory cell based on a result of the first operation, and
the third operation includes a second program operation to write data received from a controller configured to control the device, into the first memory cell.
12. The device according to claim 11 , wherein the second program operation includes:
a first write operation using a first program verify voltage; and
a second write operation after the first write operation and using a second program verify voltage higher than the first program verify voltage, and
wherein the first write operation in the third operation is executed with the first operation and the second operation, and
the second write operation in the third operation is executed without the first operation and the second operation.
13. The device according to claim 11 , wherein the second operation includes an operation of programming a memory cell which is determined in the first operation that a threshold value is lower than or equal to the first voltage.
14. The device according to claim 1 , wherein the first voltage is a negative voltage.
15. A semiconductor memory device comprising:
a first memory cell capable of holding data;
a second memory cell capable of holding data;
a first word line coupled to the first memory cell;
a second word line coupled to the second memory cell; and
a first bit line capable of being electrically coupled to both the first memory cell and the second memory cell,
wherein the first memory cell shares a semiconductor layer with the second memory cell, and faces the second memory cell across the semiconductor layer,
wherein the device is configured to execute a first operation, a second operation, and a third operation, wherein
in the first operation, a first voltage is applied to a word line corresponding to a non-selected memory cell,
in the second operation, after the first operation, a second voltage higher than the first voltage is applied to the word line corresponding to the non-selected memory cell,
in the third operation, after the second operation, a third voltage higher than the second voltage is applied to the word line corresponding to the non-selected memory cell, and a fourth voltage lower than both the third voltage and the second voltage is applied to a word line corresponding to a selected memory cell,
the device is further configured to:
execute the first operation, the second operation, and the third operation when receiving a write command for the first memory cell, and
execute the third operation without the first and second operations executed during a period between the device entering to a busy state and returning to a ready state when receiving a write command for the second memory cell.
16. The device according to claim 15 , wherein, the first voltage is applied to the second word line when data is read from the first memory cell,
the fourth voltage turns on a memory cell, and
the first voltage is a negative voltage.
17. The device according to claim 15 , further comprising:
a third memory cell capable of holding data; and
a third word line coupled to the third memory cell,
wherein the second word line is positioned between the first word line and the third word line, and
the device is further configured to write data into the second memory cell after data is written into the first memory cell and the third memory cell.
18. The device according to claim 15 , wherein the first operation is executed to verify the non-selected memory cell,
the second operation includes a first program operation to increase a threshold value of the non-selected memory cell based on a result of the first operation, and
the third operation includes a second program operation to write data received from a controller configured to control the device, into the selected memory cell.
19. The device according to claim 18 , wherein the second program operation includes:
a first write operation using a first program verify voltage; and
a second write operation after the first write operation and using a second program verify voltage higher than the first program verify voltage,
wherein the first write operation in the third operation is executed with the first operation and the second operation, and
the second write operation in the third operation is executed without the first operation and the second operation.
20. The device according to claim 18 , wherein the second operation includes an operation of programming a memory cell which is determined in the first operation that a threshold value is lower than or equal to the first voltage.