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arXiv · 2007.06182

One nanometer HfO$_2$-based ferroelectric tunnel junctions on silicon

Suraj S. Cheema·Nirmaan Shanker·Cheng-Hsiang Hsu·Adhiraj Datar·Jongho Bae·Daewoong Kwon·Sayeef Salahuddin
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Abstract

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 HfO$_2$ (Zr:HfO$_2$) ferroelectric barriers of just 1 nm thickness, grown by atomic layer deposition on silicon. These 1 nm Zr:HfO$_2$ tunnel junctions exhibit large polarization-driven electroresistance (19000$\%$), the largest value reported for HfO$_2$-based FTJs. In addition, due to just a 1 nm ferroelectric barrier, these junctions provide large tunnel current (> 1 A/cm$^2$) at low read voltage, orders of magnitude larger than reported thicker HfO$_2$-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.

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Suraj S. Cheema, Nirmaan Shanker, Cheng-Hsiang Hsu, Adhiraj Datar, Jongho Bae, Daewoong Kwon, Sayeef Salahuddin. 2020-07-13. One nanometer HfO$_2$-based ferroelectric tunnel junctions on silicon. https://arxiv.org/abs/2007.06182

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