Method of writing data to a semiconductor memory device

1. A method of writing data to a semiconductor memory device with memory cells, each of which stores data defined by threshold voltage thereof in a non-volatile manner, the device having first and second memory cells disposed adjacent to each other to be sequentially written in this order, the method comprising:

performing a first data write operation for writing data defined by a threshold voltage lower than a desired threshold voltage into the first memory cell;

performing a second data write operation for writing data into the second memory cell; and

performing a third data writing operation for writing data defined by the desired threshold voltage into the first memory cell.

2. The method according to claim 1 , wherein

the first and second memory cells are coupled to adjacent two word lines, respectively.

3. The method according to claim 1 , wherein

the first and second memory cells are coupled to adjacent two bit lines, respectively.

4. The method according to claim 1 , wherein

each of the first to third data write operations is performed by repeat of write voltage application and write-verify, the write voltage being boosted in accordance with write cycle increase, and wherein

a write voltage step-up in the third data write operation is set to be lower than that in the first data write operation.

5. The method according to claim 1 , wherein

the third data write operation is performed as an independent write sequence based on command input, or performed in a sequence of the second data operation as following the write completion detection therein.

6. The method according to claim 1 , wherein

the third data write operation is performed by use of write data, which are written into the first memory cell in accordance with the first data write operation and then read out as the write data.

7. The method according to claim 1 , wherein

the device has a memory cell array in which NAND cell units are arranged, each NAND cell unit including a plurality of memory cells connected in series.

8. The method according to claim 1 , wherein

the device is configured to store multi-value data.

9. A method of writing data to a semiconductor memory device, the device comprising word lines and bit lines which are arranged as crossing each other and electrically rewritable and non-volatile memory cells disposed at the respective crossings of the word lines and bit lines, the method comprising:

performing a first data write operation for selectively writing a threshold voltage state lower than a desired threshold voltage into a first set of memory cells;

performing, after the first data write operation, a second data write operation for selectively writing data into a second set of memory cells disposed adjacent to the first set of memory cells; and

performing, after the second data write operation, a third data write operation for writing the desired threshold voltage state into the first set of memory cells with the same data pattern as in the first data write operation.

10. The method according to claim 9 , wherein

the first data write operation is for preliminarily writing data into the first set of memory cells arranged along a first word line;

the second data write operation is for preliminarily writing data into the second set of memory cells arranged along a second word line disposed adjacent to the first word line and selected as following the first word line; and

the third data write operation is a finishing write operation for writing the desired threshold state into the first set of memory cells.

11. The method according to claim 9 , wherein

the first data write operation is for preliminarily writing data into the first set of memory cells selected by a certain word line and even numbered bit lines;

the second data write operation is for preliminarily writing data into the second set of memory cells selected by the certain word line and odd numbered bit lines; and

the third data write operation is a finishing write operation for writing the desired threshold state into the first set of memory cells.

12. The method according to claim 9 , wherein

the first set of memory cells is a first sector X, which includes memory cells selected by a first word line and even numbered bit lines;

the second set of memory cells includes a second sector Y containing memory cells selected by the first word line and odd numbered bit lines, a third sector Z containing memory cells selected by the first word line and the even numbered bit lines, and a fourth sector W containing memory cells selected by the second word line and the odd numbered bit lines; and wherein

the first data write operation Is for preliminarily writing data into the first sector;

the second data write operation is for preliminarily writing data sequentially into the second to fourth sectors; and

the third data write operation is a finishing write operation for writing the desired threshold state into the first sector.

13. The method according to claim 9 , wherein

the third data write operation is performed as an independent write sequence based on command input, or performed in a sequence of the second data operation as following the write completion detection therein.

14. The method according to claim 9 , wherein

the third data write operation is performed by use of write data, which are written into the first memory cell in accordance with the first data write operation and then read out as the write data.

15. The method according to claim 9 , wherein

the device has a memory cell array in which NAND cell units are arranged, each NAND cell unit including a plurality of memory cells connected in series.

16. The method according to claim 9 , wherein

the device is configured to store multi-value data.

17. The method according to claim 9 wherein

each memory cell stores four-value data defined by lower page data and upper page data, and wherein

the first data write operation is a first preliminary write operation for writing upper page data with threshold voltages lower than desired threshold voltages into the first set of memory cells, in which lower page data have already been written;

the second data write operation is a second preliminary write operation for writing upper page data with threshold voltages lower than the desired threshold voltages into the second set of memory cells, in which lower page data have already been written; and

the third data write operation is a finishing data write operation for writing upper page data with the desired threshold voltages into the first set of memory cells for which the first preliminary data write has been performed.

18. A method of writing data to a semiconductor memory device with memory cells, each of which stores data defined by threshold voltage thereof in a non-volatile manner, the device having first and second memory cells disposed adjacent to each other to be sequentially written in this order, the method being to write data with a desired threshold voltage into the first memory cell, wherein

in case data to be written into the second memory cell is a first threshold voltage state, a first write-verify voltage equal to the desired threshold voltage is used at the data write time for the first memory cell; and

in case data to be written into the second memory cell is a second threshold voltage state higher than the first threshold voltage, a second write-verify voltage lower than the desired threshold voltage is used at the data write time for the first memory cell.

19. A method of writing data to a semiconductor memory device, the device comprising word lines and bit lines which are arranged as crossing each other and electrically rewritable and non-volatile memory cells disposed at the respective crossings of the word lines and bit lines, the method comprising:

applying a write voltage to at least two, first and second, memory cells arranged along a word line for writing data defined by a desired threshold voltage state;

in case data to be written into a third memory cell disposed adjacent to the first memory cell has no influence on the first memory cell's threshold voltage, the third memory cell being selected by a second word line selected as following the first word line, performing write-verify with a first verify-voltage equal to the desired threshold voltage; and

in case data to be written into a fourth memory cell disposed adjacent to the second memory cell has influence on the second memory cell's threshold voltage, the fourth memory cell being selected by the second word line, performing write-verify with a second verify-voltage lower than the desired threshold voltage.

20. The method according to claim 19 , wherein

data to be written into the third and fourth memory cells are loaded in a sense amplifier circuit at the data write time for the first and second memory cells, and write-verify operations with the first and second verify-voltages are sequentially executed in accordance with the data loaded in the sense amplifier circuit.