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

Abstract

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.

Processing Optimization of Lead Magnesium Niobate‐Lead Titanate Thin Films for Piezoelectric MEMS Application

“…), confirming that electrode asymmetry enhances the built‐in electric field in the films . This enhancement is attributed mainly to the difference in work function between the electrodes and the ferroelectric layer, resulting in different built‐in voltages at the film‐electrode interface . Other mechanisms reported to cause an internal bias in ferroelectric films are aligned V O ‐ V Pb defect dipoles, and strain gradient formation through thickness .…”

“…This enhancement is attributed mainly to the difference in work function between the electrodes and the ferroelectric layer, resulting in different built‐in voltages at the film‐electrode interface . Other mechanisms reported to cause an internal bias in ferroelectric films are aligned V O ‐ V Pb defect dipoles, and strain gradient formation through thickness . Due to PbO cover‐coat in the films’ processing, low concentrations of surface Pb vacancies (and consequently defect dipoles) are expected.…”

Effect of thickness on dielectric, ferroelectric, and optical properties of Ni substituted Pb(Zr0.2Ti0.8)O3 thin films

“…A clear shift in P-E loops was seen towards the negative voltage side, which is due to high in-built electric field. The observed imprint behavior is due to different work functions of dissimilar top and bottom electrodes (Pt and LSMO) 36 or the presence of extra stress at the interface originating during high temperature annealing process. 33 It may also arise from space charge at the ferroelectric/electrode interface.…”

Tunable photovoltaic effects in transparent Pb(Zr0.53,Ti0.47)O3 capacitors

“…The total internal electric field, E, in ferroelectric capacitors consists of two independent components, the built-in field, E bi , and the depolarization field, E p . The E bi in ferroelectric capacitors originates from various factors, including the oxygen-related strain gradient 24 and the effect of interfacial layer between the ferroelectric thin films and the substrates. 25 In the present ITO/PZT/ITO capacitors, E bi may result from the effect of the interface layer between PZT films and ITO electrode.…”