US Patent 7539052 Non-volatile multilevel memory cell programming

Embodiments of the present disclosure provide methods, devices, modules, and systems for programming an array of non-volatile multilevel memory cells to a number of threshold voltage ranges. One method includes programming a lower page of a first wordline cell to increase a threshold voltage (Vt) of the first wordline cell to a first Vt within a lowermost Vt range. The method includes programming a lower page of a second wordline cell prior to programming an upper page of the first wordline cell. The method includes programming the upper page of the first wordline cell such that the first Vt is increased to a second Vt, wherein the second Vt is within a Vt range which is then a lowermost Vt range and is positive.