The ferroelectric and optical properties of (Pb_(0.92)La_(0.08))(Zr_(0.65)Ti_(0.35))O_(3) thin films deposited by radio-frequency magnetron sputtering

摘要

Ferroelectric (Pb_(0.92)La_(0.08))(Zr_(0.65)Ti_(0.35))O_(3) (PLZT) films have been prepared on Pt/Ti/SiO_(2)/Si and fused quartz substrates using radio-frequency (rf) magnetron sputtering at a deposition temperature of 650 deg C. X-ray diffraction analysis shows that the PLZT thin films on platinized silicon are polycrystalline with (100)-preferential orientation. A Al/PLZT/Pt capacitor has been fabricated and it shows that the films have excellent ferroelectric character, with saturation polarization (P_(s)), remanent polarization (P_(r)) and coercive field (E_(c)) of 32.8(mu)C/cm~(2), 24.3(mu)C/cm~(2) and 142 kV/cm, respectively. The PLZT thin films exhibit good insulating property and the leakage current density of the films on platinized silicon is only about 0.86 X 10~(-7) A/cm~(2) at 200 kV/cm. By the optical transmission spectra measurements, the energy gap (E_(g)) of the PLZT films on fused quartz is found to be about 3.54 eV. The optical constants (n and k) of the films in the wavelength range of 250-900 nm are obtained by a Filmetrics F20 reflectance spectrometer.