Control of bismuth volatility in SBT by vanadium doping

Robert Barz, Deborah A. Neumayer, Prashant Majhi, Changgong Wang, Sandwip Dey

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Scopus citations


The volatility of bismuth (Bi) presents difficulty in the integration of ferroelectric strontium bismuth tantalate (SrBi2Ta2O9 or SBT) thin films for FeRAM applications. This paper presents preliminary results indicating that the Bi volatility problem may be controlled by the addition of vanadium (V) to SBT. A series of V-doped SBT films (150 nm), of a nominal composition SrBi2.2(Ta1-xVx)2O9 with x = 0, 0.01, and 0.07, were deposited on Pt/SiO2/Si wafers by sol-gel processing. XRD and SEM revealed a polycrystalline morphology and a vanadium solubility in SBT of at least 7%. SBT with 7% V-doping exhibited little structural damage from a forming gas anneal. 7% V-doping also limited Bi diffusion into Pt bottom electrodes and increased the surface Bi 4f7/2 electron binding energies. The ferroelectric and polarization fatigue properties did not improve with V-doping, which was attributed to oxygen vacancy formation due to acceptor doping. Vanadium stabilized Bi in the SBT matrix by reducing from the pentavalent to the tetravalent state, which provided the free energy to either oxidize bismuth or prevent the reduction of bismuth.

Original languageEnglish (US)
Title of host publicationIntegrated Ferroelectrics
Number of pages11
StatePublished - 2001
Event13th International Symposium on Integrated Ferroelectrics - Colorado Springs, CO, United States
Duration: Mar 11 2006Mar 14 2006


Other13th International Symposium on Integrated Ferroelectrics
Country/TerritoryUnited States
CityColorado Springs, CO


  • Bi volatility
  • Forming gas anneal
  • SBT

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Physics and Astronomy (miscellaneous)
  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials


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