Issue 40, 2023

Effect of interfacial SiO2 layer thickness on the memory performances in the HfAlOx-based ferroelectric tunnel junction for a neuromorphic system

Abstract

In recent years, research on ferroelectric materials based on hafnium oxide has increased because of promising advantages such as fast operating speeds and CMOS process compatibility. In the case of Al-doped HfO2 (HAO), the remnant polarization (Pr), switching endurance, and high ON/OFF ratio can induce better ferroelectricity. In this work, three metal–ferroelectric–(insulator)–semiconductor MF(I)S devices with TiN/HAO/n+ Si and 1 nm and 2 nm thick SiO2 insulators inserted between the ferroelectric layer and the semiconductor have been studied. Doping Al2O3 results in enhanced ferroelectric properties such as switching voltage and higher polarization compared to that of undoped HfO2. It is because the stabilization of tetragonal phases results in a high dielectric constant. The MFIS (1 nm) device's high remnant polarization value of 37.8 μC cm−2 was measured using polarization-switching PUND (positive-up–negative-down). Additionally, with DC dual sweeping, IV characteristics exhibited a wide memory window and a large tunneling electro-resistance (TER) ratio. Furthermore, it has shown improvement in current and energy performance because of the stronger bond between the ferroelectric layer and the bottom electrical material and high charge transfer efficiency. Finally, we have successfully demonstrated the properties of the interfacial SiO2 layer and found the thickness of the optimal interlayer for the MFIS structure. Various experiments were conducted to study the synaptic characteristics of FTJ devices, including the long-term potentiation and depression, paired-pulse facilitation (PPF), spike-timing-dependent plasticity (STDP), and the recognition and prediction ability of the device using reservoir computing (RC) technology. Through these experiments, the fabricated device is suitable as an ideal device for implementing energy-efficient and high-speed artificial neural network applications.

Graphical abstract: Effect of interfacial SiO2 layer thickness on the memory performances in the HfAlOx-based ferroelectric tunnel junction for a neuromorphic system

  • This article is part of the themed collection: #MyFirstJMCC

Supplementary files

Article information

Article type
Paper
Submitted
19 Jun 2023
Accepted
11 Sep 2023
First published
13 Sep 2023

J. Mater. Chem. C, 2023,11, 13886-13896

Effect of interfacial SiO2 layer thickness on the memory performances in the HfAlOx-based ferroelectric tunnel junction for a neuromorphic system

Y. Park, J. Kim, S. Kim, D. Kim, W. Shim and S. Kim, J. Mater. Chem. C, 2023, 11, 13886 DOI: 10.1039/D3TC02137H

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements