Growth and electrical properties of highly (0 0 1)-oriented Pb(Zr 0.52Ti0.48)O3 thin films on amorphous TiN buffered Si(1 0 0)

Abstract

Pb(Zr0.52Ti0.48)O3 (PZT) ferroelectric thin films with LaNiO3 (LNO) as bottom electrodes have been grown on amorphous TiN buffered Si(1 0 0) substrates by pulsed laser deposition. It was found that highly (0 0 1)-oriented LNO films could be obtained even if TiN underlayers were amorphous. XRD analyses showed that the subsequently deposited PZT films were also preferentially (0 0 1)-oriented due to the template effect of the perovskite structured LNO films. Dielectric constant of the PZT thin films remained almost constant with frequency in the range from 103 to 106 Hz, and tangent loss was as small as 0.02 at high frequencies. The remnant polarization and coercive field of an Au/PZT/LNO capacitor were typically 20 μC/cm2 and 30 kV/cm, respectively. C-V and I-V characteristics revealed the capacitance and leakage current variations with applied voltage were asymmetric when the bottom electrode was negatively as well as positively biased, indicating that ferroelectric/electrode interfaces and space charges play an important role in the electrical properties of ferroelectric capacitors. © 2005 Elsevier B.V. All rights reserved.