Patent ID: 8085592

Claim:
A method of operating a charge-trap flash memory device including a memory cell array with a plurality of unused memory cells that are unused for data storage and a plurality of normal memory cells that are used for data storage, the method comprising: selecting one of the normal memory cells to be pre-programmed; after selecting one of the normal memory cells to be pre-programmed, selecting one of the unused memory cells wherein the plurality of unused memory cells comprise a plurality of dummy or redundant memory cells, and wherein selecting one of the unused memory cells comprises selecting one of the unused memory cells sharing a word line with the selected normal memory cell; and programming the selected unused memory cell to have a programmed threshold voltage that is different than an erased threshold voltage wherein programming the unused memory cell comprises simultaneously pre-programming the selected unused memory cell and the selected normal memory cell to have the programmed threshold voltage that is different than the erased threshold voltage.