Polycrystalline La0.5Sr0.5CoO3/PbZr0.53Ti0.47O3/ La0.5Sr0.5CoO3 ferroelectric capacitors on platinized silicon with no polarization fatigue

Abstract
Pulsed laser ablation-deposition is used to produce fatigue-free La0.5Sr0.5CoO3(LSC)/ PbZr0.53Ti0.47O3 (PZT)/LSC ferroelectric capacitors on oxidized (100) Si substrates coated with a bilayer of Pt/Ti. These capacitors utilize a unique bottom electrode combination of LSC on Pt, where the LSC (a conducting oxide) acts as a template to promote the ferroelectric perovskite phase of PZT and to minimize polarization fatigue, while Pt is used for its high electrical conductivity and high temperature stability. We have used the hybrid Pt/LSC electrode discussed in this letter to integrate PZT-based capacitors with Si substrates. X-ray diffraction analysis shows that the PZT film is polycrystalline and is entirely perovskite phase. Devices show no significant degradation of the switchable polarization after 3×1010 switching cycles. Aging tests show that the rate of loss of switchable polarization may allow useful memory retention for times up to 1010 s.