Comparison of forming gas effects on the ferroelectric properties between more-oriented and less-oriented Pb(Zr0.52Ti0.48)O3 thin films

Abstract

More-oriented and less-oriented Pb(Zr0.52Ti0.48)O3 (PZT) thin films were deposited by using a pulsed-laser deposition method on a Pt∕Ti∕SiO2∕Si substrate with (Pb0.72La0.28)Ti0.93O3 buffer and on a Pt∕Ti∕SiO2∕Si substrate without buffer, respectively, which were observed by x-ray diffraction patterns. These films were annealed in H2-contained ambient for 30 min at the substrate temperature of 400 °C to evaluate the forming gas annealing effects. The comparative studies on the ferroelectric properties of these two films were carried out that showed that ferroelectric properties such as remanent polarization did not change in the case of the more-oriented PZT film, whereas the remanent polarization value of the less-oriented lead zirconate titanate (PZT) film degraded from 20.8 to 7.3μC∕cm2. The leakage current became higher in both cases, but that of the more-oriented PZT film had the moderate value of the 10−6 order of A∕cm2. This is mainly because the hydrogen atoms that cause the degradation of PZT films cannot infiltrate into the more-oriented PZT film as well as into the less-oriented PZT film.