STRONTIUM BISMUTH NIOBATE TANTALATE FERROELECTRIC THIN FILM

摘要

The thin film ferroelectric material 500 for use in the integrated memory circuits 300 and 400, such as FERAM 300, has strontium bismuth niobium tantalate having the empirical formula SrBi _{2 + E} (Nb _x Ta _2-x ) O _{9 + 3E / 2} . Wherein E is a number representing an excess of bismuth in the range of 0 to 2; X is a number indicating an excess amount of niobium in the range of 0.01 to 0.9. An operating method of the ferroelectric memory cell 400 includes the steps of providing a first polarization state to the material having the above-described formula; Applying a plurality of unidirectional voltage pulses to the thin film ferroelectric material in a first polarization state; And then switching the ferroelectric material from the plurality of unidirectional voltage pulses to a second polarization state essentially free of imprint.