Patent ID: 7466598

Claim:
A method of programming a NAND flash memory device, the method comprising: providing a flash memory device where N word lines are disposed between a drain selecting line and a source selecting line, each word line being assigned with a first bit line and a second bit line; performing an LSB program operation for storing a lower rank data bit from a first word line adjacent to the source selecting line to an Nth word line adjacent to the drain selecting line; and performing a MSB program operation for storing a higher rank data bit from the first word line adjacent to the source selecting line to the Nth word line adjacent to the drain selecting line, wherein the LSB program operation includes: selecting a given word line, and programming first memory cells coupled to the first bit line of the selected word line and then second memory cells coupled to the second bit line of the select word line, wherein the selecting-a-given-word-line step and the programming-first-memory-cells step are repeated until the Nth word line has been processed.