Growth of (001) oriented La-Sr-Co-O/Pb-La-Zr-Ti-O/La-Sr-Co-O ferroelectric capacitors on (001) GaAs with a MgO buffer layer

Thin film La0.5Sr0.5CoO3Pb0.9La 0.1Zr0.2Ti0.3O3/La 0.5Sr0.5CoO3 capacitor structures (LSCO/PLZT/LSCO) have been grown on (001) GaAs substrates with MgO as a buffer layer. The MgO films on GaAs were grown by pulsed laser deposition and electron-beam evaporation and the capacitor heterostructures were grown using pulsed laser deposition. X-ray diffraction (XRD) showed all films to be (001) oriented. Ferroelectric capacitors were fabricated to determine their electrical behavior: the films showed resistivity above 1010 ohms/cm2, a typical saturation polarization of 20-30 μC/cm2, minimum retention loss, low time-dependent imprint and negligible fatigue up to 1011 cycles. These characteristics indicate that high-quality (001) oriented PLZT can be easily integrated with GaAs substrates, and could be used to produce GaAs-based electrical and, more importantly, optical devices.