Effect of Film Thickness on Electrical Properties of Chemical Solution Deposition-Derived Pb(Zr_xTi_1-x)O₃/LaNiO₃/Si

Abstract

Pb(Zr x Ti 1Àx )O 3 (PZT) thin films with different thicknesses and compositions near the morphotropic phase boundary (MPB) were deposited on a pseudocubic LaNiO 3 (LNO) thin film electrode by chemical solution deposition (CSD) in order to elucidate effect of film thickness on the electrical properties of the resultant PZT thin films. The crystal symmetry of the resultant PZT thin films changed from tetragonal to rhombohedral with increasing PbZrO 3 concentration as well as with increasing film thickness or decreasing residual stress in the film. The residual stress and the lattice constants were measured by Raman spectroscopy and from X-ray diffraction patterns of the PZT thin films with different thicknesses and compositions, respectively. As a result, compressive residual stress was confirmed from the change in the lattice constants along a-and c-axes. In addition, residual stress increased with decreasing film thickness, which shifted the MPB composition toward the Zr-rich composition, depending on the film thickness.

Dependence of lattice distortion of monoclinic phase on film thickness in Pb(Zr0.58Ti0.42)O3 thin films

“…Generally speaking, the residual stress decreases with the film thickness increasing [30]. If the diffraction peak displacements are only caused by residual stress, the peak displacement directions for all diffractions should be the same.…”

Influence of the substrate on the phase composition and electrical properties of 0.65PMN–0.35PT thick films

“…According to these experimental results, the compressive residual stress in PZT thin films shifts the MPB region towards the Zr-rich composition side, i.e., towards the rhombohedral phase. 7,12,13 In other words, the stress enhances the thermodynamic stability of the tetragonal phase, as would be expected under a two-dimensional compressive stress, according to the thermodynamic formalism based on the Landau-Devonshire phenomenological theory. Of course, the authors are aware that the 0.65PMN-0.35PT films are thick in comparison with the PZT thin films and that the phase diagrams for the PMN-PT and PZT materials are not similar.…”

“…Compositions of the so-called morphotropic phase boundary (MPB) region, where the properties are the highest, in PZT for both bulk ceramics and thin films were studied theoretically and experimentally. [7][8][9][10][11][12][13][14] A great deal of effort was made to understand the differences in the behaviour between bulk PZT and thin films. [2][3][4] However, although films with thicknesses below 1 m were frequently investigated, thick films with thicknesses of a few tens of microns have received much less attention.…”

Effect of bottom electrode structure on electrical properties of BaTiO3 thin films fabricated by CSD method

“…The lattice parameters, a and c, increased with increasing LNO layer numbers which might be caused by the compressive stress applied from LNO to the film due to the difference of the thermal expansion coefficient between the BT, LNO, and substrate. 35), 36) Dielectric and ferroelectric properties of the BT film with various LNO layer number were shown in Fig. 4 and Fig.…”