TY - JOUR

T1 - Influence of the active TaN/ZrOx/Ni memristor layer oxygen content on forming and resistive switching behavior

AU - Voronkovskii, V. A.

AU - Aliev, V. S.

AU - Gerasimova, A. K.

AU - Perevalov, T. V.

AU - Prosvirin, I. P.

AU - Islamov, D. R.

N1 - Funding Information: This work was partially funded by the Ministry of Science and Higher Education of Russia under project #0242-2019-0002 (sample synthesis and analysis of experimental data) and by the Russian Science Foundation under project #16-19-00002 (XPS, charge transport experiments). The authors are grateful to Yuri Zhivodkov for his assistance in the measurements at the 'Nanostructures' Collective Use Center (ISP SB RAS, Novosibirsk) and to Dr Vladimir Gritsenko for his valuable discussions. The VB XPS spectra simulation study was performed using Siberian Supercomputer Center (ICMMG SB RAS) resources. Publisher Copyright: © 2021 IOP Publishing Ltd Printed in the UK Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/4/30

Y1 - 2021/4/30

N2 - The influence of oxygen content in active zirconium oxide layers on the electrophysical properties of TaN/ZrOx/Ni memristors is investigated. The [O]/[Zr] atomic ratio (x) in the oxide layers was varied in the range from 1.56 to 2.0 by changing the partial oxygen pressure during their deposition by ion-beam sputtering deposition. The ZrOx film compositions were analyzed using x-ray photoelectron spectroscopy and density functional theory simulations. The multiple resistive switching phenomenon in TaN/ZrOx/Ni memristors was found to occur in a certain range of x 1.78. With the x value decreasing in the oxide layers, the forming voltage of memristors decreased. Furthermore, at the lower edge of x values the switchable range, they no longer required forming. At the same time, as the x value decreased, the memory window (ION/IOFF ratio) also decreased from 5 to 1 order of magnitude due to an increase in the memristor conductivity in the high resistance state. In order to identify the underlying conduction mechanism of TaN/ZrOx/Ni memristors, their current-voltage curves in low and high resistance states were analyzed in the temperature range from 250 to 400 K for the samples with x = 1.78 (forming-free) and 1.97 (which required forming). It was found that, for both samples, the conductivity in the low-resistance state is characterized by the trap-free space-charge-limited current (SCLC) model, whereas the conductivity in the high-resistance state is characterized by the trap-mediated SCLC model. The possible origins of structural defects involved in the memristor conductivity and resistive switching are discussed based on the obtained results.

AB - The influence of oxygen content in active zirconium oxide layers on the electrophysical properties of TaN/ZrOx/Ni memristors is investigated. The [O]/[Zr] atomic ratio (x) in the oxide layers was varied in the range from 1.56 to 2.0 by changing the partial oxygen pressure during their deposition by ion-beam sputtering deposition. The ZrOx film compositions were analyzed using x-ray photoelectron spectroscopy and density functional theory simulations. The multiple resistive switching phenomenon in TaN/ZrOx/Ni memristors was found to occur in a certain range of x 1.78. With the x value decreasing in the oxide layers, the forming voltage of memristors decreased. Furthermore, at the lower edge of x values the switchable range, they no longer required forming. At the same time, as the x value decreased, the memory window (ION/IOFF ratio) also decreased from 5 to 1 order of magnitude due to an increase in the memristor conductivity in the high resistance state. In order to identify the underlying conduction mechanism of TaN/ZrOx/Ni memristors, their current-voltage curves in low and high resistance states were analyzed in the temperature range from 250 to 400 K for the samples with x = 1.78 (forming-free) and 1.97 (which required forming). It was found that, for both samples, the conductivity in the low-resistance state is characterized by the trap-free space-charge-limited current (SCLC) model, whereas the conductivity in the high-resistance state is characterized by the trap-mediated SCLC model. The possible origins of structural defects involved in the memristor conductivity and resistive switching are discussed based on the obtained results.

KW - Forming-free

KW - Memristor

KW - ReRAM

KW - SCLC

KW - XPS

KW - Zirconium oxide

UR - http://www.scopus.com/inward/record.url?scp=85102711733&partnerID=8YFLogxK

U2 - 10.1088/1361-6528/abce7b

DO - 10.1088/1361-6528/abce7b

M3 - Article

C2 - 33620032

AN - SCOPUS:85102711733

VL - 32

JO - Nanotechnology

JF - Nanotechnology

SN - 0957-4484

IS - 18

M1 - 185205

ER -