THRESHOLD VOLTAGE GROUPING OF MEMORY CELLS IN SAME THRESHOLD VOLTAGE RANGE

摘要

A memory cell undergoing programming is determined as belonging to a particular one of a plurality of second threshold voltage ranges that divide a present threshold voltage range of the particular memory cell. Programming pulses are applied to program the particular memory cell to within the target threshold voltage range. At least one of a program voltage and a total duration of the programming pulses applied to the particular memory cell is varied, depending on the particular second threshold voltage range of the memory cell.

主权项

1. A memory device, comprising:
a memory array including a plurality of memory cells storing a same data value; and control circuitry programming the plurality of memory cells, the plurality of memory cells storing the same data value prior to said programming by the control circuitry, said programming by the control circuitry including:
regarding the plurality of memory cells occupying a first threshold voltage range, characterizing memory cells in the plurality of memory cells as belonging to one of a plurality of threshold voltage subranges that divide the first threshold voltage range; andapplying programming pulses to program the plurality of memory cells, and varying the programming pulses, depending on the particular ones of the plurality of threshold voltage subranges to which the memory cells in the plurality of memory cells belong.