Reliability studies of polycrystalline La-Sr-Co-O/Pb-La-Zr-Ti-O/La-Sr-Co-O capacitors on silicon

Polycrystalline LSCO/PLZT/LSCO heterostructures have been grown on Pt/Ti/SiO2/Si substrates by Pulsed Laser Deposition (PLD). Combined Pt/LSCO electrodes were formed using photolithography lift off processes to fabricate the heterostructures into prototype ferroelectric memory capacitors. Ferroelectric properties and reliability, characteristics (fatigue, logic state retention and imprint) of the polycrystalline LSCO/PLZT/LSCO capacitors were evaluated both at room temperature and 100°C. and were compared with that of epitaxial and oriented LSCO/PLZT/LSCO heterostructure capacitors. Fatigue free results were achieved up to 1011 switching cycles at both temperatures, and the retention and imprint tests also show that the polycrystalline LSCO/PLZT/LSCO heterostructure is suitable for nonvolatile random access memory applications.