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.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Dawber, M., Rabe, K. M. & Scott, J. F. Physics of thin-film ferroelectric oxides. Rev. Mod. Phys. 77, 1083–1130 (2005)
Scott, J. F. & Paz de Araujo, C. A. Ferroelectric memories. Science 246, 1400–1405 (1989)
Tsymbal, E. Y. & Kohlstedt, H. Tunneling across a ferroelectric. Science 313, 181–183 (2006)
Junquera, J. & Ghosez, P. Critical thickness for ferroelectricity in perovskite ultrathin films. Nature 422, 506–509 (2003)
Despont, L. et al. Direct evidence for ferroelectric polar distortion in ultrathin lead titanate perovskite films. Phys. Rev. B 73, 094110 (2006)
Zhuravlev, M. Y., Sabirianov, R. F., Jaswal, S. S. & Tsymbal, E. Y. Giant electroresistance in ferroelectric tunnel junctions. Phys. Rev. Lett. 94, 246802 (2005)
Kohlstedt, H., Pertsev, N. A., Rodriguez Contreras, J. & Waser, R. Theoretical current-voltage characteristics of ferroelectric tunnel junctions. Phys. Rev. B 72, 125341 (2005)
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)
Ghosez, P. & Junquera, J. in Handbook of Theoretical and Computational Nanotechnology Vol. 7 (Rieth, M. & Schommers, W.) 623–728 (American Scientific Publishers, 2006)
Despont, L. et al. Direct evidence for ferroelectric polar distortion in ultrathin lead titanate perovskite films. Phys. Rev. B 73, 094110 (2006)
Fong, D. D. et al. Ferroelectricity in ultrathin perovskite films. Science 304, 1650–1653 (2004)
Lichtensteiger, C. et al. Monodomain to polydomain transition in ferroelectric PbTiO3 thin films with La0. 67Sr0. 33MnO3 electrodes. Appl. Phys. Lett. 90, 052907 (2007)
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)
Chu, Y. H. et al. Ferroelectric size effects in multiferroic BiFeO3 thin films. Appl. Phys. Lett. 90, 252906 (2007)
Gajek, M. et al. Tunnel junctions with multiferroic barriers. Nature Mater. 6, 296–302 (2007)
Kim, Y. S. et al. Critical thickness of ultrathin ferroelectric BaTiO3 films. Appl. Phys. Lett. 86, 102907 (2005)
Petraru, A. et al. Wedgelike ultrathin epitaxial BaTiO3 films for studies of scaling effects in ferroelectrics. Appl. Phys. Lett. 93, 072902 (2008)
Takahashi, R., Grepstad, J. K., Tybell, T. & Matsumoto, Y. Photochemical switching of ultrathin PbTiO3 films. Appl. Phys. Lett. 92, 112901 (2008)
Thompson, C. et al. Imaging and alignment of nanoscale 180° stripe domains in ferroelectric thin films. Appl. Phys. Lett. 93, 182901 (2008)
Choi, K. J. et al. Enhancement of ferroelectricity in strained BaTiO3 thin films. Science 306, 1005–1009 (2004)
Tybell, T., Ahn, C. H. & Triscone, J.-M. Ferroelectricity in thin perovskite films. Appl. Phys. Lett. 75, 856–858 (1999)
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)
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)
Rodriguez-Contreras, J. et al. Resistive switching in metal-ferroelectric-metal junctions. Appl. Phys. Lett. 83, 4595–4597 (2003)
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)
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)
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)
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
Authors and Affiliations
Corresponding author
Supplementary information
Supplementary Information
This file contains Supplementary Data, Supplementary Figures S1-S5 with Legends and a Supplementary Reference. (PDF 451 kb)
Rights 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
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/nature08128
This article is cited by
-
Stoner instability-mediated large magnetoelectric effects in 2D stacking electrides
npj Computational Materials (2024)
-
Giant tunnelling electroresistance in atomic-scale ferroelectric tunnel junctions
Nature Communications (2024)
-
Stripe noise removal in conductive atomic force microscopy
Scientific Reports (2024)
-
Unsupervised character recognition with graphene memristive synapses
Neural Computing and Applications (2024)
-
Ferromagnetic order controlled by the magnetic interface of LaNiO3/La2/3Ca1/3MnO3 superlattices
Scientific Reports (2023)
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.