Resistance change memory
View Patent ↗According to one embodiment, a memory includes memory cells between first conductive lines and second conductive lines. A control circuit is configured to apply a first potential to a first end of a selected first conductive line connected to the selected memory cell among the first conductive lines and first ends of unselected second conductive lines not connected to the selected memory cell among the second conductive lines, apply a second potential larger than the first potential to a first end of a selected second conductive line connected to the selected memory cell among the second conductive lines, apply third potentials smaller than the second potential to first ends of unselected first conductive lines not connected to the selected memory cell among the first conductive lines respectively, and change values of the third potentials based on an address of the selected first conductive line.
1. A resistance change memory comprising:
a plurality of first conductive lines extending in a first direction, and arranged side by side in a second direction which intersects the first direction;
a plurality of second conductive lines extending in the second direction, and arranged side by side in the first direction;
memory cells connected between the first conductive lines and the second conductive lines, at respective intersections of the first conductive lines and the second conductive lines;
a first driver/decoder connected to first ends of the first conductive lines;
a second driver/decoder connected to first ends of the second conductive lines;
a potential generating circuit generating a potential which is applied to the first ends of the first conductive lines and the first ends of the second conductive lines; and
a control circuit controlling an operation mode which applies a voltage or a current to a selected memory cell among the memory cells,
wherein each of the memory cells comprises a rectifying element and a resistance change element connected in series, and
the control circuit is configured, in the operation mode, to:
apply a first potential to a first end of a selected first conductive line connected to the selected memory cell among the first conductive lines and first ends of unselected second conductive lines not connected to the selected memory cell among the second conductive lines,
apply a second potential larger than the first potential to a first end of a selected second conductive line connected to the selected memory cell among the second conductive lines,
apply third potentials smaller than the second potential to first ends of unselected first conductive lines not connected to the selected memory cell among the first conductive lines respectively, and
change the third potentials to a plurality of values based on an address of the selected first conductive line.
2. The memory of claim 1 ,
wherein the third potentials are equal to or higher than a fourth potential of the selected second conductive line at a position where the selected memory cell connected to the selected first conductive line.
3. The memory of claim 1 ,
wherein the third potentials applied to the first ends of the unselected first conductive lines placed on a side of the selected memory cell opposite to the second decoder/driver.
4. The memory of claim 3 ,
wherein the value of the third potentials applied to the first ends of the unselected first conductive lines placed on a side of the selected memory cell opposite to the second decoder/driver is lowered in accordance with an increment in the address of the selected first conductive line.
5. The memory of claim 3 ,
wherein the first conductive lines are divided into blocks, and
the value of the third potentials applied to the first ends of the unselected first conductive lines placed on a side of the selected memory cell opposite to the second decoder/driver varies in accordance with the block including the selected memory cell.
6. The memory of claim 1 ,
wherein the third potentials applied to the first ends of the unselected first conductive lines placed on a side of the selected memory cell facing the second decoder/driver have values that differ depending on each of the unselected first conductive lines.
7. The memory of claim 1 ,
wherein the third potentials applied to the first ends of the unselected first conductive lines placed on a side of the selected memory cell facing the second decoder/driver have the same value.
8. The memory of claim 7 ,
wherein the first conductive lines are divided into blocks, and
the value of the third potentials applied to the first ends of the unselected first conductive lines placed on a side of the selected memory cell facing the second decoder/driver varies in accordance with the block including the selected memory cell.
9. The memory of claim 1 ,
wherein the first conductive lines are divided into blocks, and
the third potentials applied to the first ends of the unselected first conductive lines placed on a side of the selected memory cell facing the second decoder/driver have values that differ in accordance with each of the blocks.
10. The memory of claim 1 , further comprising:
a memory portion which stores a relationship between the address of the selected memory cell and values of the third potentials applied to the first ends of the unselected first conductive lines,
wherein the control circuit determines the values of the third potentials applied to the first ends of the unselected first conductive lines based on the address of the selected memory cell in the operation mode.
11. A resistance change memory comprising:
a plurality of first conductive lines extending in a first direction, and arranged side by side in a second direction which intersects the first direction;
a plurality of second conductive lines extending in the second direction, and arranged side by side in the first direction;
memory cells connected between the first conductive lines and the second conductive lines at respective intersections of the first conductive lines and the second conductive lines;
a first driver/decoder connected to first ends of the first conductive lines;
a second driver/decoder connected to first ends of the second conductive lines;
a potential generating circuit generating a potential which is applied to the first ends of the first conductive lines and the first ends of the second conductive lines; and
a control circuit controlling an operation mode which applies a voltage or a current to a selected memory cell among the memory cells,
wherein each of the memory cells comprises a rectifying element and a resistance change element connected in series, and
the control circuit is configured, in the operation mode, to:
apply a first potential to a first end of a selected first conductive line connected to the selected memory cell among the first conductive lines,
apply a second potential larger than the first potential to first ends of unselected first conductive lines not connected to the selected memory cell among the first conductive lines and a first end of a selected second conductive line connected to the selected memory cell among the second conductive lines,
apply third potentials larger than the first potential to first ends of unselected second conductive lines not connected to the selected memory cell among the second conductive lines respectively, and
change the third potentials to a plurality of values based on an address of the selected second conductive line.
12. The memory of claim 11 ,
wherein the third potentials are equal to or higher than a fourth potential of the selected first conductive line at a position where the selected memory cell is connected to the selected first conductive line.
13. The memory of claim 11 ,
wherein the third potentials applied to the first ends of the unselected second conductive lines placed on a side of the selected memory cell opposite to the first decoder/driver side of the selected memory cell have the same value.
14. The memory of claim 13 ,
wherein the value of the third potentials applied to the first ends of the unselected second conductive lines placed on a side of the selected memory cell opposite to the first decoder/driver is increased in accordance with an increment in the address of the selected second conductive line.
15. The memory of claim 13 ,
wherein the second conductive lines are divided into blocks, and
the value of the third potentials applied to the first ends of the unselected second conductive lines placed on a side of the selected memory cell opposite to the first decoder/driver varies in accordance with the block including the selected memory cell.
16. The memory of claim 11 ,
wherein the third potentials applied to the first ends of the unselected second conductive lines placed on a side of the selected memory cell facing the first decoder/driver have values that differ depending on each of the unselected second conductive lines.
17. The memory of claim 11 ,
wherein the third potentials applied to the first ends of the unselected second conductive lines placed on a side of the selected memory cell facing the first decoder/driver have the same value.
18. The memory of claim 17 ,
wherein the second conductive lines are divided into blocks, and
the value of the third potentials applied to the first ends of the unselected second conductive lines placed on a side of the selected memory cell facing the first decoder/driver varies in accordance with the block including the selected memory cell.
19. The memory of claim 11 ,
wherein the second conductive lines are divided into blocks, and
the third potentials applied to the first ends of the unselected second conductive lines placed on a side of the selected memory cell facing the first decoder/driver have values that differ in accordance with each of the blocks.
20. The memory of claim 11 , further comprising:
a memory portion which stores a relationship between the address of the selected memory cell and values of the third potentials applied to the first ends of the unselected second conductive lines,
wherein the control circuit determines the values of the third potentials applied to the first ends of the unselected second conductive lines based on the address of the selected memory cell in the operation mode.
21. The memory of claim 1 , further comprising:
a memory portion which stores a table showing a relationship between the address of the selected memory cell and the values of the third potentials applied to the first ends of the unselected first conductive lines,
wherein the control circuit determines the values of the third potentials applied to the first ends of the unselected first conductive lines based on the address of the selected memory cell and the table in the operation mode.
22. The memory of claim 1 ,
wherein the values of the third potentials applied to the first ends of the unselected first conductive lines are determined based on an nth-order function (n is a natural number) by fitting a relationship between the address of the selected memory cell and adjustment values of the third potentials applied to the first ends of the unselected first conductive lines with respect to the nth-order function.
23. The memory of claim 1 ,
wherein second ends on an opposite side of the first ends of the first conductive lines and second ends on an opposite side of the first ends of the second conductive lines are opened (an opened state).
24. The memory of claim 1 ,
wherein the operation mode is a mode that one of a write operation and a read operation of data relative to the selected memory cell is performed.
25. The memory of claim 1 , further comprising:
a semiconductor substrate; and
memory cell arrays stacked on the semiconductor substrate,
wherein each of the memory cell arrays comprises the first conductive lines, the second conductive lines, and the memory cells, and
the first driver/decoder, the second driver/decoder, the potential generating circuit, and the control circuit are arranged on the semiconductor substrate.
26. The memory of claim 11 , further comprising:
a memory portion which stores a table showing a relationship between the address of the selected memory cell and the values of the third potentials applied to the first ends of the unselected second conductive lines,
wherein the control circuit determines the values of the third potentials applied to the first ends of the unselected second conductive lines based on the address of the selected memory cell and the table in the operation mode.
27. The memory of claim 11 ,
wherein the values of the third potentials applied to the first ends of the unselected second conductive lines are determined based on an nth-order function (n is a natural number) by fitting a relationship between the address of the selected memory cell and adjustment values of the third potentials applied to the first ends of the unselected second conductive lines with respect to the nth-order function.
28. The memory of claim 11 ,
wherein second ends on the opposite side of the first ends of the first conductive lines and second ends on the opposite side of the first ends of the second conductive lines are opened (an opened state).
29. The memory of claim 11 ,
wherein the operation mode is a mode that one of a write operation and a read operation of data relative to the selected memory cell is performed.
30. The memory of claim 11 , further comprising:
a semiconductor substrate; and
memory cell arrays stacked on the semiconductor substrate,
wherein each of the memory cell arrays comprises the first conductive lines, the second conductive lines, and the memory cells, and
the first driver/decoder, the second driver/decoder, the potential generating circuit, and the control circuit are arranged on the semiconductor substrate.