Ferroelectric la-sr-co-o/pb-la-zr-ti-o/la-sr-co-o heterostructures on silicon

Ferroelectric Pb0.9, La0.1, Zr0.2 Ti0.8 O,(PLZT) thin film capacitors with symmetrical La-Sr-Co-0 top and hottom electrodes have been grown on [Ol] Si with a Yttria stabilized zirconia (YSZ) huffer layer and on SiOJSi substrates. A layered perovskite “template” layer (300–500 A thick), grown between the YSZ buffer layer or the SiO, layer and the bottom La-Sr-Co-0 electrode, is critical for obtaining the required orientation of the subsequent layers. The fatigue, retention and aging characteristics of these new structures are quite desirable for nonvolatile memory operation. Preliminary studies show that this ferroelectric performance obtained in large (SO- 100 pm diameter) capacitors can be replicated in smaller capacitors (down to 4 pm diameter) processed by ion milling. © 1994, Taylor & Francis Group, LLC. All rights reserved.