Nonlinear stepped programming voltage

摘要

A voltage control circuit that narrows the distribution of threshold voltages of memory cells by using nonlinearly incremented programming voltages. To do so, the voltage control circuit applies to the memory cells a first program pulse of a first voltage, a second program pulse of a second voltage to the memory cell, and a third program pulse of a third voltage, where the difference between the third voltage and the second voltage is less than the difference between the second voltage and the first voltage.