Capacitance–voltage characteristics of Pt/Bi₂VO_5.5/p-Si structures

Abstract

Ferroelectric Bi₂VO_5.5 thin films were fabricated on p-type (100) Si substrates by sol–gel method and then annealed at different temperatures. The microstructures and surface morphologies of the Bi₂VO_5.5 thin films were examined by X-ray diffraction and atomic force microscope, respectively. The results indicate that the Bi₂VO_5.5 thin films show high c-axis preferred orientation and are compatible well with p-type Si substrates. The capacitance–voltage characteristics of Pt/Bi₂VO_5.5/Si capacitors measured at 1 MHz shows a clockwise hysteresis loop. The memory window of the hysteresis loop is 0.42 V with the gate voltage from −4 to 4 V. It is found that the memory window may be determined by the competition between ferroelectric polarization and charge injection.