Studies of hydrogen-induced degradation processes in SrBi{sub 2}Ta{sub 2}O{sub 9} ferroelectric film-based capacitors

Journal Article · Mon Feb 01 00:00:00 EST 1999 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.123474· OSTI ID:324900

Im, J ^[1]; Auciello, O ^[2]; Krauss, A R; Gruen, D M ^[1]; Chang, R P ^[3]; Kim, S H; Kingon, A I ^[4]

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1. Materials Science and Chemistry Divisions, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
2. Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
3. Materials Science and Engineering Department, Northwestern University, Evanston, Illinois 60208 (United States)
4. Materials Science and Engineering Department, North Carolina State University, Raleigh, North Carolina 27695 (United States)

It is known that the forming gas (N{sub 2}{endash}H{sub 2} mixture) annealing process required for microcircuit fabrication results in an unacceptable electrical degradation of SrBi{sub 2}Ta{sub 2}O{sub 9} (SBT) ferroelectric capacitors due mainly to the interaction of H{sub 2} with the ferroelectric layer of the capacitor. We have found a strong relationship between changes in the surface composition of the ferroelectric layer and the electrical properties of SBT capacitors as a result of hydrogen annealing. Mass spectroscopy of recoiled ions (MSRI) analysis revealed a strong reduction in the Bi signal as a function of exposure to hydrogen at high temperatures ({approximately}500{degree}C). The Bi signal reduction correlates with Bi depletion in the SBT surface region. Subsequent annealing in oxygen at temperatures in the range of 700{endash}800{degree}C resulted in the recovery of the MSRI Bi signal, corresponding to the replenishment of Bi in the previously Bi-depleted surface region. X-ray diffraction (XRD) analysis (probing the whole SBT film thickness) showed little difference in the XRD spectra of the SBT films before and after hydrogen and oxygen-recovery annealing. The combined results of the MSRI and XRD analyses can be interpreted as an indication that the degradation of the electrical properties of the SBT capacitors, after hydrogen annealing, is mainly due to the degradation of the near surface region of the SBT layer. {copyright} {ital 1999 American Institute of Physics.}

• OSTI ID: 324900
• Journal Information: Applied Physics Letters, Vol. 74, Issue 8; Other Information: PBD: Feb 1999
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES
STRONTIUM COMPOUNDS
BISMUTH COMPOUNDS
STRONTIUM OXIDES
BISMUTH OXIDES
TANTALUM OXIDES
FERROELECTRIC MATERIALS
CAPACITORS
HYDROGEN
INTEGRATED CIRCUITS
ANNEALING
SURFACE PROPERTIES
X-RAY DIFFRACTION
MASS SPECTRA
STRUCTURAL CHEMICAL ANALYSIS