Temperature dependence of the current conduction mechanisms in ferroelectric Pb(Zr0.53,Ti0.47)O3 thin films

The temperature dependence of the current conduction mechanisms in Au/Pb(Zr-0.53,Ti-0.47)O-3/Pt (Au/PZT/Pt) metal-insulator-metal thin-film capacitors was investigated. The dominant current conduction mechanism from 300 to 375 K is space-charge-limited current (SCLC) due to holes and changes to Schottky emission in the temperature range of 400 to 500 K above the electric field of 0.2 MV/cm. It is observed that the transition voltage (V-tr) of SCLC conduction decreases with increasing temperature. Shallow hole trap levels vary from 0.3 to 0.19 eV above the valence-band edge as the temperature varies from 300 to 375 K. The trap-filled-limited voltage (V-TFL) increases with increasing temperature. The deep trap level extracted from V-TFL is positioned at 0.39 eV above the valence-band edge. The Au/PZT barrier height extracted from Schottky emission is 0.85 eV. An energy band diagram of the Au/PZT/Pt system is proposed to explain the current-voltage characteristics. (C) 2004 American Institute of Physics.