Giant tunnel electroresistance for non-destructive readout of ferroelectric states

Abstract

Ferroelectrics possess a polarization that is spontaneous, stable and electrically switchable1, and submicrometre-thick ferroelectric films are currently used as non-volatile memory elements with destructive capacitive readout2. Memories based on tunnel junctions with ultrathin ferroelectric barriers would enable non-destructive resistive readout3. However, the achievement of room-temperature polarization stability and switching at very low thickness is challenging4,5. Here we use piezoresponse force microscopy at room temperature to show robust ferroelectricity down to 1 nm in highly strained BaTiO3 films; we also use room-temperature conductive-tip atomic force microscopy to demonstrate resistive readout of the polarization state through its influence on the tunnel current6,7. The resulting electroresistance effect scales exponentially with ferroelectric film thickness, reaching 75,000% at 3 nm. Our approach exploits the otherwise undesirable leakage current—dominated by tunnelling at these very low thicknesses—to read the polarization state without destroying it. We demonstrate scalability down to 70 nm, corresponding to potential densities of >16 Gbit inch-2. These results pave the way towards ferroelectric memories with simplified architectures, higher densities and faster operation, and should inspire further exploration of the interplay between quantum tunnelling and ferroelectricity at the nanoscale.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Figure 1: Structural properties of BaTiO 3 (BTO) thin films.
Figure 2: Ferroelectricity of BTO ultrathin films.
Figure 3: Direct evidence for ferroelectricity-related giant TER with ultrathin strained BTO films.
Figure 4: Resistive readout of polarization state in high-density nanoscale ferroelectric dot arrays.

References

  1. 1

    Dawber, M., Rabe, K. M. & Scott, J. F. Physics of thin-film ferroelectric oxides. Rev. Mod. Phys. 77, 1083–1130 (2005)

    ADS  CAS  Article  Google Scholar 

  2. 2

    Scott, J. F. & Paz de Araujo, C. A. Ferroelectric memories. Science 246, 1400–1405 (1989)

    ADS  CAS  Article  Google Scholar 

  3. 3

    Tsymbal, E. Y. & Kohlstedt, H. Tunneling across a ferroelectric. Science 313, 181–183 (2006)

    CAS  Article  Google Scholar 

  4. 4

    Junquera, J. & Ghosez, P. Critical thickness for ferroelectricity in perovskite ultrathin films. Nature 422, 506–509 (2003)

    ADS  CAS  Article  Google Scholar 

  5. 5

    Despont, L. et al. Direct evidence for ferroelectric polar distortion in ultrathin lead titanate perovskite films. Phys. Rev. B 73, 094110 (2006)

    ADS  Article  Google Scholar 

  6. 6

    Zhuravlev, M. Y., Sabirianov, R. F., Jaswal, S. S. & Tsymbal, E. Y. Giant electroresistance in ferroelectric tunnel junctions. Phys. Rev. Lett. 94, 246802 (2005)

    ADS  Article  Google Scholar 

  7. 7

    Kohlstedt, H., Pertsev, N. A., Rodriguez Contreras, J. & Waser, R. Theoretical current-voltage characteristics of ferroelectric tunnel junctions. Phys. Rev. B 72, 125341 (2005)

    ADS  Article  Google Scholar 

  8. 8

    Kohlstedt, H., Pertsev, N. A. & Waser, R. Size effects on polarization in epitaxial ferroelectric films and the concept of ferroelectric tunnel junctions including first results. Mater. Res. Soc. Symp. Proc. 688, C6.5 (2002)

    Google Scholar 

  9. 9

    Ghosez, P. & Junquera, J. in Handbook of Theoretical and Computational Nanotechnology Vol. 7 (Rieth, M. & Schommers, W.) 623–728 (American Scientific Publishers, 2006)

    Google Scholar 

  10. 10

    Despont, L. et al. Direct evidence for ferroelectric polar distortion in ultrathin lead titanate perovskite films. Phys. Rev. B 73, 094110 (2006)

    ADS  Article  Google Scholar 

  11. 11

    Fong, D. D. et al. Ferroelectricity in ultrathin perovskite films. Science 304, 1650–1653 (2004)

    ADS  CAS  Article  Google Scholar 

  12. 12

    Lichtensteiger, C. et al. Monodomain to polydomain transition in ferroelectric PbTiO3 thin films with La0. 67Sr0. 33MnO3 electrodes. Appl. Phys. Lett. 90, 052907 (2007)

    ADS  Article  Google Scholar 

  13. 13

    Béa, H. et al. Ferroelectricity down to at least 2 nm in multiferroic BiFeO3 epitaxial thin films. Jpn. J. Appl. Phys. 45, L187–L189 (2006)

    Article  Google Scholar 

  14. 14

    Chu, Y. H. et al. Ferroelectric size effects in multiferroic BiFeO3 thin films. Appl. Phys. Lett. 90, 252906 (2007)

    ADS  Article  Google Scholar 

  15. 15

    Gajek, M. et al. Tunnel junctions with multiferroic barriers. Nature Mater. 6, 296–302 (2007)

    ADS  CAS  Article  Google Scholar 

  16. 16

    Kim, Y. S. et al. Critical thickness of ultrathin ferroelectric BaTiO3 films. Appl. Phys. Lett. 86, 102907 (2005)

    ADS  Article  Google Scholar 

  17. 17

    Petraru, A. et al. Wedgelike ultrathin epitaxial BaTiO3 films for studies of scaling effects in ferroelectrics. Appl. Phys. Lett. 93, 072902 (2008)

    ADS  Article  Google Scholar 

  18. 18

    Takahashi, R., Grepstad, J. K., Tybell, T. & Matsumoto, Y. Photochemical switching of ultrathin PbTiO3 films. Appl. Phys. Lett. 92, 112901 (2008)

    ADS  Article  Google Scholar 

  19. 19

    Thompson, C. et al. Imaging and alignment of nanoscale 180° stripe domains in ferroelectric thin films. Appl. Phys. Lett. 93, 182901 (2008)

    ADS  Article  Google Scholar 

  20. 20

    Choi, K. J. et al. Enhancement of ferroelectricity in strained BaTiO3 thin films. Science 306, 1005–1009 (2004)

    ADS  CAS  Article  Google Scholar 

  21. 21

    Tybell, T., Ahn, C. H. & Triscone, J.-M. Ferroelectricity in thin perovskite films. Appl. Phys. Lett. 75, 856–858 (1999)

    ADS  CAS  Article  Google Scholar 

  22. 22

    Houzé, F., Meyer, R., Schneegans, O. & Boyer, L. Imaging the local electrical properties of metal surfaces by atomic force microscopy with conducting probes. Appl. Phys. Lett. 69, 1975–1977 (1996)

    ADS  Article  Google Scholar 

  23. 23

    Velev, J. P. et al. Magnetic tunnel junctions with ferroelectric barriers: predictions of four resistance states from first principles. Nano Lett. 9, 427–432 (2009)

    ADS  CAS  Article  Google Scholar 

  24. 24

    Rodriguez-Contreras, J. et al. Resistive switching in metal-ferroelectric-metal junctions. Appl. Phys. Lett. 83, 4595–4597 (2003)

    ADS  CAS  Article  Google Scholar 

  25. 25

    Velev, J. P., Duan, C.-G., Belashchenko, K. D., Jaswal, S. S. & Tsymbal, E. Y. Effect of ferroelectricity on electron transport in Pt/BaTiO3/Pt tunnel junctions. Phys. Rev. Lett. 98, 137201 (2007)

    ADS  CAS  Article  Google Scholar 

  26. 26

    Paruch, P., Tybell, T. & Triscone, J.-M. Nanoscale control of ferroelectric polarization and domain size in epitaxial Pb(Zr0. 2Ti0. 8)O3 thin films. Appl. Phys. Lett. 79, 530–532 (2001)

    ADS  CAS  Article  Google Scholar 

  27. 27

    Planès, J., Houzé, F., Chrétien, P. & Schneegans, O. Conducting probe atomic force microscopy applied to organic conducting blends. Appl. Phys. Lett. 79, 2993–2995 (2001)

    ADS  Article  Google Scholar 

Download references

Acknowledgements

We thank H. Béa, C. Israel, M. Vickers and B. Warot-Fonrose for technical support, and H. Kohlstedt for discussions. This work was supported by the France-UK PMC Alliance programme, the French RTRA Triangle de la Physique, EU STRP Macomufi, EU STRP CoMePhS, UK EPSRC EP/E026206/I, the French ANR Femmes and the French ANR Alicante.

Author information

Affiliations

Authors

Corresponding author

Correspondence to M. Bibes.

Supplementary information

Supplementary Information

This file contains Supplementary Data, Supplementary Figures S1-S5 with Legends and a Supplementary Reference. (PDF 451 kb)

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Garcia, V., Fusil, S., Bouzehouane, K. et al. Giant tunnel electroresistance for non-destructive readout of ferroelectric states. Nature 460, 81–84 (2009). https://doi.org/10.1038/nature08128

Download citation

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing