Parametric study of sputtered Sr-deficient SrBi{sub 2}Ta{sub 2}O{sub 9} thin films

Journal Article · Wed Nov 15 00:00:00 EST 2006 · Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films

DOI:https://doi.org/10.1116/1.2338560· OSTI ID:20853789

Zhang, Sam; Yibin, Li; Weidong, Fei; Zhenghao, Gan; Mhaisalkar, Subodh; Li, X M ^[1]

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1. School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

Sr-deficient SrBi{sub 2}Ta{sub 2}O{sub 9} (SBT) thin films for nonvolatile ferroelectric random access memory applications were deposited by radio-frequency magnetron sputtering on Pt/Ta/SiO{sub 2}/Si substrates. The effect of deposition parameters on microstructures and chemical composition were studied using x-ray diffraction (XRD), field emission scanning electron microscopy, and x-ray photoelectron spectroscopy (XPS). The composition of the films was dependent on the sputtering conditions. The undesirable pyrochlore phase could be eliminated by adjusting process pressure, target power density, and target-to-substrate distance. The evolution of microstructures at various deposition conditions was attributed to changes in the Bi/Ta and Sr/Ta ratios. When Sr became deficient and Bi excessive (Sr{sub 0.74}Bi{sub 2.2}Ta{sub 2}O{sub 9+x} as determined by XPS), no pyrochlore phase was detected with XRD. Under an electric field of 240 kV/cm, the Sr-deficient SBT film demonstrated a remnant polarization (2P{sub r}) of 11.6 {mu}C/cm{sup 2} and a coercive field (2E{sub c}) of 96 kV/cm.

• OSTI ID: 20853789
• Journal Information: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films, Vol. 24, Issue 6; Other Information: DOI: 10.1116/1.2338560; (c) 2006 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1553-1813
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BISMUTH COMPOUNDS
CHEMICAL COMPOSITION
DEPOSITION
ELECTRIC FIELDS
FERROELECTRIC MATERIALS
FIELD EMISSION
MAGNETRONS
MICROSTRUCTURE
PARAMETRIC ANALYSIS
POLARIZATION
POWER DENSITY
PYROCHLORE
RADIOWAVE RADIATION
SCANNING ELECTRON MICROSCOPY
SILICON OXIDES
SPUTTERING
STRONTIUM COMPOUNDS
SUBSTRATES
THIN FILMS
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY