Structural and chemical composition investigation of thin lead zirconate titanate films

Journal Article · Wed Jul 01 04:00:00 EDT 1992 · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States)

DOI:https://doi.org/10.1116/1.578048· OSTI ID:7292327

Huffman, M ^[1]; Goral, J P; Al-Jassim, M M ^[2]; Echer, C ^[3]

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1. Ramtron Corporation, 1850 Ramtron Drive, Colorado Springs, Colorado 80921 (United States)
2. National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401 (United States)
3. National Center for Electron Microscopy, Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720 (United States)

Thin lead zirconate titanate (PZT) ferroelectric films are currently being used in a variety of applications. One of the more novel uses is in nonvolatile random access memory devices. As part of such a memory device, these PZT films undergo a significant amount of thermal cycling during standard semiconductor processing. Therefore, it is of considerable importance to understand the evolution of the PZT film morphology and composition as a function of temperature. The ferroelectric domain and PZT grain boundary evolution in sputtered and sol-gel deposited PZT films has been recorded. Hot stage transmission electron microscopy has been used for this investigation between room temperature and 600 {degree}C. The ferroelectric domains in all the samples are very distinct. The transition from the tetragonal to the cubic paraelectric phase was observed at Curie temperatures ({ital T}{sub {ital C}}) close to those expected for the various compositions analyzed. Zr/Ti ratios in these films ranged from 48/52 to 30/70. Since the films are polycrystalline and some compositional inhomogeneity exists from crystallite to crystallite, a distribution of transition temperatures has been observed throughout a single PZT film. This result fits very well with electrically measured values of {ital T}{sub {ital C}}, which exhibit very broad maxima. Nanoprobe analysis of the composition of these films was performed before and after heating to see if there are any significant changes. Line scans were used to analyze grain and grain boundary composition in both plan view and cross section. The difficulties of obtaining reliable analytical results are explored in detail.

• OSTI ID: 7292327
• Journal Information: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States), Journal Name: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States) Vol. 10:4; ISSN 0734-2101; ISSN JVTAD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606* -- Other Materials-- Physical Properties-- (1992-)
CHEMICAL COMPOSITION
CRYSTAL STRUCTURE
FERROELECTRIC MATERIALS
FILMS
GRAIN BOUNDARIES
LEAD COMPOUNDS
MICROSTRUCTURE
OXYGEN COMPOUNDS
PZT
TEMPERATURE RANGE
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
THERMAL DEGRADATION
THIN FILMS
TITANATES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
ZIRCONATES
ZIRCONIUM COMPOUNDS