Preparation of Pb(Zr<sub>0.54</sub>Ti<sub>0.46</sub>)O<sub>3</sub> Thin Films on (100)Si Using Textured YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7−δ</sub> and Yttria-Stabilized Zirconia Buffer Layers by Laser Physical Vapor Deposition Technique
Tiwari, P.; Zheleva, T.; Morimoto, A.; Shukla, V.N.; Narayan, J.; Tiwari P.; Department of Materials Science and Engineering North Carolina State University; Zheleva T.; Department of Materials Science and Engineering North Carolina State University; Morimoto A.; Department of Materials Science and Engineering North Carolina State University; Shukla V.N.; Department of Materials Science and Engineering North Carolina State University; Narayan J.; Department of Materials Science and Engineering North Carolina State University
Журнал:
MRS Proceedings
Аннотация:
ABSTRACTWe have fabricated high-quality <001> textured Pb(Zr<sub>0.54</sub>Ti<sub>0.46</sub>)O<sub>3</sub> (PZT) thin films on (001)Si with interposing <001> textured YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7−δ</sub> (YBCO) and yttria-stabilized zirconia (YSZ) buffer layers using pulsed laser deposition (KrF excimer laser, λ=248 nm, τ=20 nanoseconds). 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 (∼9X10<sup>−4</sup> 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 2.5–5.0 J/cm<sup>2</sup>. The <001> textured perovskite PZT films showed a dielectric constant of 800–1000, a saturation polarization of 37.81 μC/cm<sup>2</sup>, remnant polarization of 24.38 μC/cm<sup>2</sup> and a coersive 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.
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