Epitaxial integration of tetragonal BiFeO3 with silicon for nonvolatile memory applications

Publication date: 1 February 2017
Source:Journal of Crystal Growth, Volume 459
Author(s): Jingbin Zhu, Zhigang Yin, Zhen Fu, Yajuan Zhao, Xingwang Zhang, Xin Liu, Jingbi You, Xingxing Li, Junhua Meng, Heng Liu, Jinliang Wu
Ferroelectric field-effect transistor has long been considered as a promising nonvolatile memory technology, but its application is limited by the poor scalability. Here we show that this problem can be solved by epitaxially integrating tetragonal BiFeO3, a stress-induced metastable phase which exhibits remarkably low dielectric permittivity and high coercive field, on the silicon platform. Tetragonal BiFeO3 was stabilized on (001)-oriented silicon by using Bi2SiO5, which is chemically and structurally compatible with both silicon and tetragonal BiFeO3, as the buffer layer. Unlike the commonly observed M C structure, the obtained BiFeO3 layer exhibits a true tetragonal symmetry. An unprecedented high memory window of 6.5V was observed for the Au/BiFeO3/Bi2SiO5/Si capacitor with BiFeO3 thickness of 135nm. The epitaxial integration of tetragonal BiFeO3 with silicon may pave a possible avenue for nanosized, power-efficient ferroelectric nonvolatile memories.