Ferroelectric memory cell and method of sensing and writing the polarization state thereof

摘要

A memory cell containing a ferroelectric capacitor the memory state of which is sensed by cycling the potential across the capacitor from zero, through an upper electric field point and back to zero. If the cell was residing in the upper permanent remnant polarization point, a low change in charge flow occurs and if the cell was residing in the lower permanent remnant polarization point, a low (near zero) change in charge flow occurs. This change in charge flow from a near zero value to a large amount allows a very accurate reference capacitor to be used for the comparison or sensing process.