Ferroelectric properties and reliability of La-Sr-Co-O/Pb-La-Zr-Ti-O/La-Sr-Co-O heterostructures on si for non-volatile memory applications

Abstract

Highly oriented La-Sr-Co-O(LSCO)/Pb-La-Zr-Ti-O(PLZT)/La-Sr-Co-O heterostructures have been successfully grown on a highly oriented Pt film which was grown on a thermally oxidized Si (SiO₂/Si) substrate. The growth of oriented Pt film on the SiO₂/Si substrate was made possible through the use of a thin bismuth titanate template layer which is c-axis oriented on the SiO₂/Si substrate. The hybrid LSCO/Pt structure effectively reduced the sheet resistance of the electrodes by at least 3–5 times compared with a single LSCO electrode. These ferroelectric PLZT capacitors on Si exhibited symmetric hysteresis loops with very desirable ferroelectric properties. The test capacitors showed reliable performance at both room and high (100°C) temperatures with respect to fatigue, retention, aging, and imprint, suggesting that they can be used as reliable, nonvolatile memory elements.