Preparation 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 〈00l〉 textured Pb(Zr0.54Ti0.46)O3 (PZT) thin films on (001)Si by interposing 〈00l〉 textured YBa2Cu3O7−δ (YBCO) and yttria-stabilized zirconia (YSZ) buffer layers using pulsed laser deposition (KrF excimer laser, λ=248 nm, τ=20 ns). 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 〈001〉 YSZ//〈001〉Si texture. The YBCO thin films were deposited in situ in oxygen ambient (200 mTorr) at 650 °C. 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 multistructure was 2.5–5 J/cm2. The 〈00l〉 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.