Low-temperature growth and characterization of epitaxial La0.5Sr0.5CoO3/Pb(Zr0.52 Ti0.48)O3/ La0.5Sr0.5 CoO3 capacitors on SrTiO3/TiN buffered Si(001) substrates

We report on the low-temperature growth and characterization of epitaxial all-oxide ferroelectric thin film capacitors, La0.5Sr0.5CoO3/Pb(Zr0.52 Ti0.48)O3/ La0.5Sr0.5 CoO3 on Si(001) substrates by use of SrTiO3/TiN as buffer layers. The capacitor and the buffer layer stack were grown sequentially at 540°C by in situ pulsed laser deposition. Structural characterization using three-axis x-ray diffraction (specular and off-specular θ-2θ scan, ω-scan rocking curve, and φ scan) reveals a parallel growth for all layers. Scanning electron micrographs show that the epitaxial heterostructures have a smooth and crack-free surface. The sharp characteristic optical absorption bands of the SrTiO3 and Pb(Zr0.52Ti0.48)O3 layers also imply good crystallinity in the as-grown films. Resistivity versus temperature measurements show that both the bottom and top oxide electrodes are highly conductive with resistivity at 300 K of 170 and 140 μΩ cm, respectively. Remanent polarization of 19 μC cm-2, coercive field of 45 kV cm-1 and negligible fatigue after 109 cycles at 8 V indicate good electric performance of the integrated capacitor structure.