Ovonic threshold switching in polycrystalline zinc telluride thin films deposited by RF sputtering

Taeho Kim, Youngjae Kim, Ingwan Lee, Dayoon Lee, Hyunchul Sohn

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Chalcogenide materials of the amorphous phase with low band gaps were reported to show Ovonic threshold switching (OTS), making them suitable for selection devices in cross-point memory arrays. Herein, we report that ZnTe films with polycrystalline structures show OTS behavior. Nearly stoichiometric ZnTe thin films were deposited by an RF sputtering method. X-ray diffraction analysis indicated that the films were polycrystalline. The optical band gaps of the ZnTe films were estimated as 2.2 eV from UV-visible spectroscopy transmittance measurements. Photoluminescence measurements indicated the existence of deep-level defects in the ZnTe thin films. Although these ZnTe films have a polycrystalline structure with a relatively high band gap, I-V profiles show OTS characteristics, with a selectivity of over 104, fast threshold switching time in the sub-10 ns scale, and thermal stability up to 400 °C. ZnTe also shows switching endurance for more than 109 cycles without Vth drift, maintaining its selectivity of 104. Thus, we improved the threshold switching characteristics by using a wide band-gap and polycrystalline-structured ZnTe-based chalcogenide material. Post-annealing experiments indicated that the thermal budget of the ZnTe thin film was sufficient for stacked cross-point array structures, thereby overcoming a previous limitation of chalcogenide switching materials. This material is promising for application in high-density cross-point memory arrays as the selection device.

Original languageEnglish
Article number13LT01
JournalNanotechnology
Volume30
Issue number13
DOIs
Publication statusPublished - 2019 Feb 5

Fingerprint

Sputtering
Zinc
Thin films
Energy gap
Data storage equipment
Optical band gaps
X ray diffraction analysis
Photoluminescence
Durability
Thermodynamic stability
Spectroscopy
Annealing
Defects
Experiments

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering
  • Electrical and Electronic Engineering

Cite this

Kim, Taeho ; Kim, Youngjae ; Lee, Ingwan ; Lee, Dayoon ; Sohn, Hyunchul. / Ovonic threshold switching in polycrystalline zinc telluride thin films deposited by RF sputtering. In: Nanotechnology. 2019 ; Vol. 30, No. 13.
@article{024fb44ffee54ce7b0cc23cceff895f3,
title = "Ovonic threshold switching in polycrystalline zinc telluride thin films deposited by RF sputtering",
abstract = "Chalcogenide materials of the amorphous phase with low band gaps were reported to show Ovonic threshold switching (OTS), making them suitable for selection devices in cross-point memory arrays. Herein, we report that ZnTe films with polycrystalline structures show OTS behavior. Nearly stoichiometric ZnTe thin films were deposited by an RF sputtering method. X-ray diffraction analysis indicated that the films were polycrystalline. The optical band gaps of the ZnTe films were estimated as 2.2 eV from UV-visible spectroscopy transmittance measurements. Photoluminescence measurements indicated the existence of deep-level defects in the ZnTe thin films. Although these ZnTe films have a polycrystalline structure with a relatively high band gap, I-V profiles show OTS characteristics, with a selectivity of over 104, fast threshold switching time in the sub-10 ns scale, and thermal stability up to 400 °C. ZnTe also shows switching endurance for more than 109 cycles without Vth drift, maintaining its selectivity of 104. Thus, we improved the threshold switching characteristics by using a wide band-gap and polycrystalline-structured ZnTe-based chalcogenide material. Post-annealing experiments indicated that the thermal budget of the ZnTe thin film was sufficient for stacked cross-point array structures, thereby overcoming a previous limitation of chalcogenide switching materials. This material is promising for application in high-density cross-point memory arrays as the selection device.",
author = "Taeho Kim and Youngjae Kim and Ingwan Lee and Dayoon Lee and Hyunchul Sohn",
year = "2019",
month = "2",
day = "5",
doi = "10.1088/1361-6528/aafe13",
language = "English",
volume = "30",
journal = "Nanotechnology",
issn = "0957-4484",
publisher = "IOP Publishing Ltd.",
number = "13",

}

Ovonic threshold switching in polycrystalline zinc telluride thin films deposited by RF sputtering. / Kim, Taeho; Kim, Youngjae; Lee, Ingwan; Lee, Dayoon; Sohn, Hyunchul.

In: Nanotechnology, Vol. 30, No. 13, 13LT01, 05.02.2019.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Ovonic threshold switching in polycrystalline zinc telluride thin films deposited by RF sputtering

AU - Kim, Taeho

AU - Kim, Youngjae

AU - Lee, Ingwan

AU - Lee, Dayoon

AU - Sohn, Hyunchul

PY - 2019/2/5

Y1 - 2019/2/5

N2 - Chalcogenide materials of the amorphous phase with low band gaps were reported to show Ovonic threshold switching (OTS), making them suitable for selection devices in cross-point memory arrays. Herein, we report that ZnTe films with polycrystalline structures show OTS behavior. Nearly stoichiometric ZnTe thin films were deposited by an RF sputtering method. X-ray diffraction analysis indicated that the films were polycrystalline. The optical band gaps of the ZnTe films were estimated as 2.2 eV from UV-visible spectroscopy transmittance measurements. Photoluminescence measurements indicated the existence of deep-level defects in the ZnTe thin films. Although these ZnTe films have a polycrystalline structure with a relatively high band gap, I-V profiles show OTS characteristics, with a selectivity of over 104, fast threshold switching time in the sub-10 ns scale, and thermal stability up to 400 °C. ZnTe also shows switching endurance for more than 109 cycles without Vth drift, maintaining its selectivity of 104. Thus, we improved the threshold switching characteristics by using a wide band-gap and polycrystalline-structured ZnTe-based chalcogenide material. Post-annealing experiments indicated that the thermal budget of the ZnTe thin film was sufficient for stacked cross-point array structures, thereby overcoming a previous limitation of chalcogenide switching materials. This material is promising for application in high-density cross-point memory arrays as the selection device.

AB - Chalcogenide materials of the amorphous phase with low band gaps were reported to show Ovonic threshold switching (OTS), making them suitable for selection devices in cross-point memory arrays. Herein, we report that ZnTe films with polycrystalline structures show OTS behavior. Nearly stoichiometric ZnTe thin films were deposited by an RF sputtering method. X-ray diffraction analysis indicated that the films were polycrystalline. The optical band gaps of the ZnTe films were estimated as 2.2 eV from UV-visible spectroscopy transmittance measurements. Photoluminescence measurements indicated the existence of deep-level defects in the ZnTe thin films. Although these ZnTe films have a polycrystalline structure with a relatively high band gap, I-V profiles show OTS characteristics, with a selectivity of over 104, fast threshold switching time in the sub-10 ns scale, and thermal stability up to 400 °C. ZnTe also shows switching endurance for more than 109 cycles without Vth drift, maintaining its selectivity of 104. Thus, we improved the threshold switching characteristics by using a wide band-gap and polycrystalline-structured ZnTe-based chalcogenide material. Post-annealing experiments indicated that the thermal budget of the ZnTe thin film was sufficient for stacked cross-point array structures, thereby overcoming a previous limitation of chalcogenide switching materials. This material is promising for application in high-density cross-point memory arrays as the selection device.

UR - http://www.scopus.com/inward/record.url?scp=85061138919&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85061138919&partnerID=8YFLogxK

U2 - 10.1088/1361-6528/aafe13

DO - 10.1088/1361-6528/aafe13

M3 - Article

C2 - 30641500

AN - SCOPUS:85061138919

VL - 30

JO - Nanotechnology

JF - Nanotechnology

SN - 0957-4484

IS - 13

M1 - 13LT01

ER -