High density non-volatile flash memory without adverse effects of electric field coupling between adjacent floating gates

摘要

Electric field coupling between floating gates of a high density flash EEPROM cell array has been found to produce errors in reading the states of the cells, particularly when being operated with more than two storage states per cell. The effect of this coupling is overcome by placing a conductive shield or insulating material with a low dielectric constant between adjacent floating gates, and/or by compensating for the coupling when reading the states of the cells.