US 2021/0240345 A1 · NONVOLATILE SEMICONDUCTOR MEMORY DEVICE

Abstract

A nonvolatile semiconductor memory device comprises a cell unit including a first and a second selection gate transistor and a memory string provided between the first and second selection gate transistors and composed of a plurality of serially connected electrically erasable programmable memory cells operative to store effective data; and a data write circuit operative to write data into the memory cell, wherein the number of program stages for at least one of memory cells on both ends of the memory string is lower than the number of program stages for other memory cells, and the data write circuit executes the first stage program to the memory cell having the number of program stages lower than the number of program stages for the other memory cells after the first stage program to the other memory cells.

Claims25

Dependent claims

(canceled)

A method for controlling a nonvolatile semiconductor memory device,

the nonvolatile semiconductor memory device comprising:
a memory cell array including:
a first selection gate transistor,
a second selection gate transistor, and
a plurality of serially-connected memory cells provided between the first selection gate transistor and the second selection gate transistor,
the memory cells including:
a first memory cell connected with a first word line and capable of being programmed in one stage and storing data of one bit,
a second memory cell connected with a second word line and capable of being programmed in multi stages and storing data of three bits, the second memory cell being closer to the first selection gate transistor as compared with the first memory cell,
a third memory cell connected with a third word line and capable of being programmed in the multi stages and storing data of three bits, the third memory cell being closer to the first selection gate transistor as compared with the second memory cell, and
a fourth memory cell connected with a fourth word line and capable of being programmed in the multi stages and storing data of three bits, the fourth memory cell being closer to the first selection gate transistor as compared with the third memory cell,
the method comprising:
performing a first program on the third memory cell as a non-final stage of the multi stages;
performing a second program on the fourth memory cell as a final stage of the multi stages, after performing the first program;
performing a third program on the second memory cell as the non-final stage of the multi stages, after performing the second program;
performing a fourth program on the third memory cell as the final stage of the multi stages, after performing the third program;
performing a fifth program on the first memory cell as the non-final stage of the multi stages, after performing the fourth program;
and
performing a sixth program on the second memory cell as the final stage of the multi stages, after performing the fifth program.

15 more elements

A method for controlling a nonvolatile semiconductor memory device,

the nonvolatile semiconductor memory device comprising:
a memory cell array including:
a first selection gate transistor,
a second selection gate transistor, and
a plurality of serially-connected memory cells provided between the first selection gate transistor and the second selection gate transistor,
the memory cells including:
a first memory cell connected with a first word line and capable of being storing data of two bits,
a second memory cell connected with a second word line and capable of storing data of three bits, the second memory cell being closer to the first selection gate transistor as compared with the first memory cell,
a third memory cell connected with a third word line and capable of storing data of three bits, the third memory cell being closer to the first selection gate transistor as compared with the second memory cell,
a fourth memory cell connected with a fourth word line and capable of storing data of three bits, the fourth memory cell being closer to the first selection gate transistor as compared with the third memory cell, and
a fifth memory cell connected with a fifth word line and capable of storing data of three bits, the fifth memory cell being closer to the first selection gate transistor as compared with the fourth memory cell,
the method comprising:
performing a first program on the fourth memory cell as a non-final one of stages for writing three bits;
performing a second program on the fifth memory cell as a final one of stages for writing three bits, after performing the first program;
performing a third program on the third memory cell as the non-final one of stages for writing three bits, after performing the second program;
performing a fourth program on the fourth memory cell as the final one of stages for writing three bits, after performing the third program;
performing a fifth program on the second memory cell as the non-final one of stages for writing three bits, after performing the fourth program;
performing a sixth program on the first memory cell as a final one of stages for writing two bits, after performing the fifth program;
and
performing a seventh program on the second memory cell as the final one of stages for writing three bits, after performing the sixth program.

17 more elements

A method for controlling a nonvolatile semiconductor memory device,

the nonvolatile semiconductor memory device comprising:
a memory cell array including:
a first selection gate transistor,
a second selection gate transistor, and
a plurality of serially-connected memory cells provided between the first selection gate transistor and the second selection gate transistor,
the memory cells including:
a first memory cell connected with a first word line and capable of being programmable in D1 stages to thereby store data of D1 bits, D1 being an integer of 1 or more,
a second memory cell connected with a second word line and capable of being programmable in D2 stages to thereby store data of D2 bits, D2 being an integer of 3 or more and greater than D1, the second memory cell being closer to the first selection gate transistor than the first memory cell,
a third memory cell connected with a third word line and capable of being programmable in D3 stages to thereby store data of D3 bits, D3 being an integer of 3 or more and greater than D1, the third memory cell being closer to the first selection gate transistor than the second memory cell, and
a fourth memory cell connected with a fourth word line and capable of being programmable in D4 stages to thereby store data of D4 bits, D4 being an integer of 3 or more and greater than D1, the fourth memory cell being closer to the first selection gate transistor than the third memory cell,
the method comprising:
performing a first program on the third memory cell as a first one of the D3 stages;
performing a second program on the fourth memory cell as a second or higher one of the D4 stages, after performing the first program;
performing a third program on the second memory cell as a first one of the D2 stages, after performing the second program,
performing a fourth program on the third memory cell as a second or higher one of the D3 stages, after performing the third program;
performing a fifth program on the first memory cell as a first one of the D1 stages, after performing the fourth program;
and
performing a sixth program on the second memory cell as a second or higher one of the D2 stages, after performing the fifth program.

15 more elements

A method for controlling a nonvolatile semiconductor memory device, comprising:

a memory cell array including:
a first selection gate transistor,
a second selection gate transistor, and
a plurality of serially-connected memory cells provided between the first selection gate transistor and the second selection gate transistor,
the memory cells including:
a first memory cell connected with a first word line and capable of being programmable in D1 stages to thereby store data of D1 bits, D1 being an integer of 1 or more,
a second memory cell connected with a second word line and capable of being programmable in D2 stages to thereby store data of D2 bits, D2 being an integer of 3 or more and greater than D1, the second memory cell being closer to the first selection gate transistor than the first memory cell,
a third memory cell connected with a third word line and capable of being programmable in D3 stages to thereby store data of D3 bits, D3 being an integer of 3 or more and greater than D1, the third memory cell being closer to the first selection gate transistor than the second memory cell, and
a fourth memory cell connected with a fourth word line and capable of being programmable in D4 stages to thereby store data of D4 bits, D4 being an integer of 3 or more and greater than D1, the fourth memory cell being closer to the first selection gate transistor than the third memory cell,
the method comprising:
performing a first program on the third memory cell as a second or lower one of the D3 stages;
performing a second program on the fourth memory cell as a final one of the D4 stages, after performing the first program;
performing a third program on the second memory cell as a second or lower one of the D2 stages, after performing the second program;
performing a fourth program on the third memory cell as a final one of the D3 stages, after performing the third program;
performing a fifth program on the first memory cell as a first or higher one of the D1 stages, after performing the fourth program;
and
performing a sixth program on the second memory cell as a final one of the D2 stages, after performing the fifth program.

14 more elements

Dependencies are inferred from the claim text.

Nonvolatile semiconductor memory device

Life of this patent

Nonvolatile semiconductor memory device

Life of this patent

Abstract

Claims25