Investigation into Electrical Conduction Mechanisms of Pb(Zr,Ti)O₃ Thin-Film Capacitors with Pt, IrO₂ and SrRuO₃ Top Electrodes

Abstract

The conduction mechanisms of Pb(Zr,Ti)O3 (PZT) thin-film capacitors with Pt bottom electrodes and Pt, IrO2 and SrRuO3 (SRO) top electrodes were investigated. In the case of SRO top electrode prepared by pulsed laser deposition, the Schottky barrier was not formed at the interface due to the interdiffusion and the space-charge-limited current with a trap energy of 2.1 eV was dominant. On the other hand, for the Pt and IrO2 top electrodes prepared by sputtering, the capacitors showed the Schottky emission current at low electric field and the Fowler-Nordheim current at a high electric field. The Schottky barrier heights for Pt/PZT and IrO2/PZT interfaces were estimated to be 0.93 and 0.67 eV, respectively. An ultra thin alteration layer between the Pt top electrodes and PZT films seems to degrade the barrier height of the Pt/PZT interface. Furthermore, the Pt/PZT/Pt capacitor showed negative resistance at room temperature. We concluded that the potential well formed near the top interface by band bending is the origin of this negative resistance.

Stability of photovoltage and trap of light-induced charges in ferroelectric WO3-doped (Pb0.97La0.03)(Zr0.52Ti0.48)O3 thin films

“…For the Au/PLWZT/Pt capacitor, the I-V curves measured at different temperatures under forward and reverse biases were found to follow the thermionic Schottky emission equation 19,20 …”

Effect of bottom electrode and resistive layer on the dielectric and ferroelectric properties of sol–gel derived BiFeO3 thin films

“…Therefore, at higher electric fields (>80 kV/cm), Fowler-Nordheim, a surface-limit conduction is the dominant conduction mechanism in all the films. The effect of injecting charge carriers from the electrodes into an insulator layer usually occurs at high electric fields in BFO, PZT, and BST films [34,38,44].…”

Interface Effects of Pb(Zr,Ti)O3Thin Film Capacitors with Pt, IrO2and SrRuO3Top Electrodes

“…After calculating the Schottky barrier from the I-V characteristics of these PZT thin film capacitors, results of 0.93 eV for the Pt/PZT interface and 0.67 eV for the IrO 2 /PZT PZT interface are obtained. However, the Schottky barrier did not form at the SRO/PZT interface, and SCLC-type electrical conduction characteristics were observed [7]. Figure 5 shows the ε-V characteristics and tan δ-V characteristics of each sample at 1 kHz.…”