In ferroelectric materials, spontaneous symmetry breaking leads to a switchable electric polarization, which offers significant promise for nonvolatile memories. In particular, ferroelectric tunnel junctions (FTJs) have emerged as a new resistive switching memory which exploit polarization-dependent tunnel current across a thin ferroelectric barrier. Here we demonstrate FTJs with CMOS-compatible Zr-doped HfO2 (Zr:HfO2) ferroelectric barriers of just 1 nm thickness, grown by atomic layer deposition on silicon. These 1 nm Zr:HfO2 tunnel junctions exhibit large polarization-driven electroresistance (19000%), the largest value reported for HfO2-based FTJs. In addition, due to just a 1 nm ferroelectric barrier, these junctions provide large tunnel current (> 1 A/cm2) at low read voltage, orders of magnitude larger than reported thicker HfO2-based FTJs. Therefore, our proof-of-principle demonstration provides an approach to simultaneously overcome three major drawbacks of prototypical FTJs: a Si-compatible ultrathin ferroelectric, large electroresistance, and large read current for high-speed operation.
@article{arxiv.2007.06182,
title = {One nanometer HfO$_2$-based ferroelectric tunnel junctions on silicon},
author = {Suraj S. Cheema and Nirmaan Shanker and Cheng-Hsiang Hsu and Adhiraj Datar and Jongho Bae and Daewoong Kwon and Sayeef Salahuddin},
journal= {arXiv preprint arXiv:2007.06182},
year = {2020}
}