Properties of ferroelectric Pb(Zr,Ti)O3 thin films on ZnO/Al2O3 (0001) epilayers

Thin films of Pb(Zr0.52Ti0.48)O3 (PZT) were deposited by pulsed laser deposition on ZnO/Al2O3 (0001) layers grown by molecular beam epitaxy, and Pt/SiO2/Si substrates. The ZnO epilayers serve as a crystalline oxide template for PZT deposition, and a conducting material that may be used for electrodes in thin film ferroelectric capacitors. The PZT thin films (thickness ∼300 nm) deposited on the ZnO epilayers were determined to be crystalline with preferential (110) orientation based on X-ray diffraction measurements. In comparison, PZT thin films deposited on Pt/SiO2/Si possess a random crystalline orientation with reduced crystalline quality. Capacitors fabricated from the PZT thin films deposited on ZnO/Al2O3 demonstrate ferroelectric hysteresis behavior with a remenant polarization of 15 μC/cm2 and coercive field of 55 kV/cm. The crystalline properties and ferroelectric behavior of the PZT suggest that ZnO/Al2O3 may provide a desirable platform for future ferroelectric devices.