R. Dat et al., POLYCRYSTALLINE LA0.5SR0.5COO3 PBZR0.53TI0.47O3 LA0.5SR0.5COO3 FERROELECTRIC CAPACITORS ON PLATINIZED SILICON WITH NO POLARIZATION FATIGUE, Applied physics letters, 64(20), 1994, pp. 2673-2675
Pulsed laser ablation-deposition is used to produce fatigue-free La0.5
Sr0.5CoO3(LSC)/PbZr0.53Ti0.47O3 (PZT)/LSC ferroelectric capacitors on
oxidized (100) Si substrates coated with a bilayer of Pt/Ti. These cap
acitors utilize a unique bottom electrode combination of LSC on Pt, wh
ere the LSC (a conducting oxide) acts as a template to promote the fer
roelectric perovskite phase of PZT and to minimize polarization fatigu
e, while Pt is used for its high electrical conductivity and high temp
erature 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 a
nd is entirely perovskite phase. Devices show no significant degradati
on of the switchable polarization after 3X10(10) switching cycles. Agi
ng tests show that the rate of loss of switchable polarization may all
ow useful memory retention for times up to 10(10)s.