Effect of the abnormal electric field induced by the passive layer on imprint failures of ferroelectric capacitors

The polarization and electric field versus time (P-t and E-t) curves of ferroelectric and passive layers were simulated for different thickness ratios based on the Landau-Khalatnikov theory, and the corresponding hysteresis loops of the ferroelectric capacitor placed in a Sawyer-Tower circuit were obtained via the polarization and electric fields at each time point on the P-t and E-t curves. The results show that the larger the thickness ratio is, the more remarkable the abnormal electric field in the ferroelectric layer and the horizontal shift of hysteresis loops are. The imprint failure may be attributed to the abnormal electric field induced by the passive layer. It is expected to predicate the imprint failure of ferroelectric thin films in a metal-ferroelectric-metal structure. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim