Patent ID: 7619920

Claim:
A NAND type flash memory comprising: a first selection transistor; a second selection transistor; a first memory cell transistor, a second memory cell transistor, and a third memory cell transistor having current paths connected in series between one end of a current path of the first selection transistor and one end of a current path of the second selection transistor, and each having a control gate and a charge storage layer; the first memory cell transistor being adjacent to the first selection transistor; the second memory cell transistor being adjacent to the second selection transistor; the third memory cell transistor being not adjacent to the first selection transistor and the second selection transistor and being positioned between the first memory cell transistor and the second memory cell transistor; the third memory cell transistor holding data having not less than three bits; the first memory cell transistor holding 2-bit data in which a middle page and an upper page is written by skipping a lower page; and a lower page verify voltage being set when writing the middle page, and a middle page verify voltage is set when writing the upper page, changing a position of a threshold distribution of the first memory cell transistor.