Researchers have developed a method to grow ultrathin films (1 nanometer thick) that have enhanced ferroelectricity.
Significance and Impact
This is the first demonstration of ferroelectricity in a material that is not limited by thickness. The new material paves the way towards new types of memory storage devices and advanced transistors.
- Ultrathin films of doped hafnium oxide (HZO) were grown on silicon using low-temperature atomic layer deposition. Several characterization techniques confirmed robust ferroelectricity in films as thin as 1 nm.
- Ferroelectricity is not only stabilized in ultrathin HZO but also shows enhanced polar distortion in the ultrathin regime, effects that do not occur in comparable perovskites.
- Ultrathin film thickness was confirmed using X-ray reflectivity and transmission electron microscopy.
S.S. Cheema, D. Kwon, N. Shanker, R. dos Reis, S-L. Hsu, J. Xiao, H. Zhang, R. Wagner, A. Datar, M.R. McCarter, C.R. Serrao, A.K. Yadav, G. Karbasian, C-H Hsu, A. J Tan, L-C. Wang, V. Thakare, X. Zhang, A. Mehta, E. Karapetrova, R. V. Chopdekar, P. Shafer, E. Arenholz, C. Hu, R. Proksch, R. Ramesh, J. Ciston, S. Salahuddin, Nature 2020 580. 479-482 DOI: 10.1038/s41586-020-2208-x.
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