Synthesis and characterization of Pb(Zr0.54Ti0.46)O3 thin films on (100)Si using textured YBa2Cu3O7−δ and yttria-stabilized zirconia buffer layers by laser physical vapor deposition technique

Abstract

We have fabricated high-quality textured Pb(Zr0.54Ti0.46)O3 (PZT) thin films on (00l)Si with interposing textured YBa2Cu3O7−δ (YBCO) and yttria-stabilized zirconia (YSZ) buffer layers using pulsed laser deposition (KrF excimer laser, λ, = 248 nm, τ = 20 nanosecs). The YBCO layer provides a seed for PZT growth and can also act as an electrode for the PZT films, whereas YSZ provides a diffusion barrier as well as a seed for the growth of YBCO films on (001)Si. These heterostructures were characterized using x-ray diffraction, high-resolution transmission electron microscopy, and Rutherford backscattering techniques. The YSZ films were deposited in oxygen ambient (∼9 × 10−4 Torr) at 775°C on (001)Si substrate having YSZ // Si texture. The YBCO thin films were deposited in-situ in oxygen ambient (200 mTorr) at 650°C. The temperature and oxygen ambient for the PZT deposition were optimized to be 530°C and 0.4-0.6 Torr, respectively. The laser fluence to deposit this multilayer structure was 2.5-5.0 J/cm2. The textured perovskite PZT films showed a dielectric constant of 800-1000, a saturation polarization of 37.81 µC/cm2, remnant polarization of 24.38 µC/cm2 and a coercive field of 125 kV/cm. The effects of processing parameters on microstructure and ferroelectric properties of PZT films and device implications of these structures are discussed.