Accession Number : ADA294517

Title :   Novel Ferroelectric Heterostructures for High-Density DRAMS.

Descriptive Note : Final rept. 1-30 Apr 95,

Corporate Author : ADVANCED FUEL RESEARCH INC EAST HARTFORD CT

Personal Author(s) : Kung, Pang-Jen ; Fenner, David B.

PDF Url : ADA294517

Report Date : 25 MAY 1995

Pagination or Media Count : 25

Abstract : In pursuit of oxide ferroelectric materials in perovskite phases with high dielectric constants used as storage capacitor dielectrics in new-generation dynamic random access memories (DRAMs), development of the process for fabricating film capacitors in planar structures of small dimensions is a central issue of great importance. From the point of view of device performance, such effort includes not only the deposition of epitaxial ferroelectric films but also the integration of associated top and bottom electrodes. The objective of the present study is, therefore, to explore the feasibility of a process based on all oxide materials for dielectrics and electrodes. As such, thin, epitaxial ferroelectric films (FE) including BaTiO3, (Ba, Sr)TiO3, and Pb(Zr, Ti)O3 stacked in a multilayer structure of M/FE/M/B, where M is the conducting oxide electrode and B is the oxide buffer layer, have been successfully grown in this work by pulsed laser deposition on Si(100) wafers. Scanning electron microscopy, X-ray diffractometry, and transmission electron microscopy were employed to characterize these multilayer films for their morphology, crystallinity, and microstructure, respectively. Dielectric constants, leakage, hysteresis loops, remanent polarization, saturation voltage, and fatigue were measured to study the device potential. Our findings have provided valuable information on the realization of oxide ferroelectric film capacitors applied in DRAMs, but more work is still needed to improve the fatigue behavior and understand the microstructure-related device physics. (AN)

Descriptors :   *FERROELECTRIC MATERIALS, BUFFERS, POLARIZATION, SCANNING ELECTRON MICROSCOPES, MICROSTRUCTURE, LAYERS, THIN FILMS, DIELECTRICS, FABRICATION, VOLTAGE, EPITAXIAL GROWTH, INTEGRATED CIRCUITS, PULSED LASERS, SEMICONDUCTORS, SATURATION, RANDOM ACCESS COMPUTER STORAGE, DEPOSITION, DIELECTRIC PROPERTIES, FEASIBILITY STUDIES, OXIDES, ELECTRODES, SILICON, PLANAR STRUCTURES, HIGH DENSITY, FATIGUE(MECHANICS), WAFERS, LEAKAGE(ELECTRICAL), BARIUM TITANATES, HYSTERESIS, PEROVSKITES, THIN FILM CAPACITORS, DIFFRACTOMETERS.

Subject Categories : Electricity and Magnetism
      Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE