Semiconductor storage device and controller
View Patent ↗A semiconductor storage device includes memory cells, select transistors, memory strings, a block, word lines, and select gate lines. In the memory string, the current paths of plural memory cells are connected in series. When data are written in the block, after a word line connected to the control gates of memory cells of different memory strings in the second block is selected, the data are sequentially written in the memory cells of the different memory strings in the block which have their control gates connected to the selected word line.
1. A semiconductor storage device comprising:
first, second, third, and fourth memory strings, each memory string including a serial connection of a select transistor, a first memory cell, and a second memory cell;
a bit line electrically connected to the first, second, third, and fourth memory strings, in common;
first, second, third, and fourth select gate lines that are electrically connected to gates of the select transistors of the first, second, third, and fourth memory strings, respectively;
a first word line electrically connected to gates of the first memory cells of the first, second, third, and fourth memory strings, in common; and
a second word line electrically connected to gates of the second memory cells of the first, second, third, and fourth memory strings, in common,
wherein during a write operation, data are written in the first memory cells of the first, second, third, and fourth memory strings in this order, and thereafter in the second memory cells of the first, second, third, and fourth memory strings in this order.
2. The semiconductor memory device according to claim 1 , wherein the data are written sequentially.
3. The semiconductor memory device according to claim 1 , wherein
the first memory cells of the first, second, third, and fourth memory strings are located farther from a substrate than the second memory cells of the first, second, third, and fourth memory strings.
4. The semiconductor memory device according to claim 1 , wherein
the first memory cells of the first, second, third, and fourth memory strings are located closer to a substrate than the second memory cells of the first, second, third, and fourth memory strings.
5. The semiconductor memory device according to claim 1 , wherein
during an erase operation, data stored in the first and second memory cells of the first, second, third, and fourth memory strings are erased collectively.
6. The semiconductor memory device according to claim 1 , wherein
during an erase operation, data stored in the first, second, third, and fourth memory strings are erased separately.
7. The semiconductor memory device according to claim 1 , wherein
each of the serial connections of the first, second, third, and fourth memory strings includes a dummy transistor between the select transistor and the first memory cell thereof.
8. The semiconductor memory device according to claim 1 , wherein
the data are written in the first and second memory cells of the first, second, third, and fourth memory strings in a multi-bits per cell manner.
9. A semiconductor memory device, comprising:
first and second memory strings, each memory string including a serial connection of a select transistor, a first memory cell, and a second memory cell;
a bit line electrically connected to the first and second memory strings in common;
first and second select gate lines that are electrically connected to gates of the select transistors of the first and second memory strings, respectively;
a first word line electrically connected to gates of the first memory cells of the first and second memory strings, in common;
a second word line electrically connected to gates of the second memory cells of the first and second memory strings, in common; and
a control circuit configured to carry out a write operation, during which data are written in the first memory cells of the first and second memory strings in this order, and thereafter in the second memory cells of the first and second memory strings in this order.
10. The semiconductor memory device according to claim 9 , further comprising:
a third memory string including a serial connection of a select transistor, a first memory cell, and a second memory cell; and
a third select gate line electrically connected to a gate of a the select transistor of the third memory string, wherein
the bit line is electrically connected to the third memory string,
the first word line is electrically connected to a gate of the first memory cell of the third memory string, and
the second word line is electrically connected to a gate of the second memory cell of the fourth memory string.
11. The semiconductor memory device according to claim 10 , wherein
during the write operation, data are written in the first memory cells of the first, third, and second memory strings in this order, and thereafter, in the second memory cells of the first, third, and second memory strings in this order.
12. The semiconductor memory device according to claim 9 , wherein the data are written sequentially.
13. The semiconductor memory device according to claim 9 , wherein
the first memory cells of the first and second memory strings are located farther from a substrate than the second memory cells of the first and second memory strings.
14. The semiconductor memory device according to claim 9 , wherein
the first memory cells of the first and second memory strings are located closer to a substrate than the second memory cells of the first and second memory strings.
15. The semiconductor memory device according to claim 9 , wherein
the control circuit is further configured to carry out an erase operation, during which data stored in the first and second memory cells of the first and second memory strings are erased collectively.
16. The semiconductor memory device according to claim 9 , wherein
the control circuit is further configured to carry out an erase operation, during which data stored in the first, second, third, and fourth memory strings are erased separately.
17. The semiconductor memory device according to claim 9 , wherein
each of the serial connections of the first and second memory strings includes a dummy transistor between the select transistor and the first memory cell thereof.
18. The semiconductor memory device according to claim 9 , wherein
the data are written in the first and second memory cells of the first and second memory strings in a multi-bits per cell manner.
19. A semiconductor memory device, comprising:
a plurality of memory strings connected to a common bit line, each of the memory strings including a select transistor and a plurality of memory cells connected in series, gates of the select transistors of the memory strings being connected to different select gate lines, and a gate of one of the memory cells in each of the memory strings being connected to a common word line; and
a control circuit configured to sequentially write data in the memory cells connected to the common word line, before writing data in other memory cells of the memory strings.