Ferroelectric Tunneling Junctions Based on Aluminum Oxide/ Zirconium-Doped Hafnium Oxide for Neuromorphic Computing
| Autor: | Haonan Wu, Fubo Rao, Wenjuan Zhu, Hojoon Ryu |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Silicon lcsh:Medicine chemistry.chemical_element 02 engineering and technology Substrate (electronics) 01 natural sciences Article 0103 physical sciences lcsh:Science Polarization (electrochemistry) Quantum tunnelling 010302 applied physics Multidisciplinary business.industry lcsh:R Doping Conductance 021001 nanoscience & nanotechnology Ferroelectricity Electrical and electronic engineering Nanoscale devices chemistry Optoelectronics lcsh:Q 0210 nano-technology business Voltage |
| Zdroj: | Scientific Reports Scientific Reports, Vol 9, Iss 1, Pp 1-8 (2019) |
| ISSN: | 2045-2322 |
| DOI: | 10.1038/s41598-019-56816-x |
| Popis: | Ferroelectric tunneling junctions (FTJs) with tunable tunneling electroresistance (TER) are promising for many emerging applications, including non-volatile memories and neurosynaptic computing. One of the key challenges in FTJs is the balance between the polarization value and the tunneling current. In order to achieve a sizable on-current, the thickness of the ferroelectric layer needs to be scaled down below 5 nm. However, the polarization in these ultra-thin ferroelectric layers is very small, which leads to a low tunneling electroresistance (TER) ratio. In this paper, we propose and demonstrate a new type of FTJ based on metal/Al2O3/Zr-doped HfO2/Si structure. The interfacial Al2O3 layer and silicon substrate enable sizable TERs even when the thickness of Zr-doped HfO2 (HZO) is above 10 nm. We found that F-N tunneling dominates at read voltages and that the polarization switching in HZO can alter the effective tunneling barrier height and tune the tunneling resistance. The FTJ synapses based on Al2O3/HZO stacks show symmetric potentiation/depression characteristics and widely tunable conductance. We also show that spike-timing-dependent plasticity (STDP) can be harnessed from HZO based FTJs. These novel FTJs will have high potential in non-volatile memories and neural network applications. |
| Databáze: | OpenAIRE |
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