Effect of electrode configurations on the process-induced imprint behavior of epitaxial Pb(Zr0.52Ti0.48)O3 capacitors

By using La0.7Sr0.3MnO3 (L) and SrRuO3 (S) electrodes, epitaxial Pb(Zr0.52Ti0.48)O3 (PZT) capacitors with different electrode configurations, i.e., L/PZT/L (from top to bottom) (a), S/PZT/S (b), S/PZT/L (c), and L/PZT/S (d), have been fabricated and the process-induced imprint was investigated. All as-grown capacitors are nearly imprint-free; however, after being annealed at 10−5 Torr of O2 the capacitors a (b) show a large negative (positive) imprinted polarization (P) state at zero electric-field (E), the capacitors c give strongly pinched P-E hysteresis loops, and the capacitors d are highly resistant to imprint failure. We show evidence that the internal fields could be attributed to the various oxygen-loss-related strain gradients at PZT top and bottom interfaces, induced during the annealing.