The dual role of PZT in metal-PZT-Al2O3 structure for nonvolatile memory cell

We have shown that the metal-PZT-Al₂O₃ memory stack exhibits much larger than usual memory window, in the direction of charge-trapping effect (which is opposite to the polarization switching effect) which we attribute to the enhanced charge injection due to the large polarization field of the PZT. Other attractive properties such as excellent endurance characteristics and good retention make the metalPZT-Al₂O₃ memory stack a promising candidate for nonvolatile memory technology. Although the memory stack used in this study contains relatively thick PZT that necessitates high P/E voltages, our preliminary results have shown much lower P/E voltages for thinner PZT, and results for such scaled memory stacks will be reported at the conference.