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 journalArticlepeer-review

12 Citations (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

Bibliographical note

Funding Information:
This work was supported by the Ministry of Trade, Industry & Energy (MoTIE, Korea) under the Industrial Strategic Technology Development Program (Grant no. 10068075) and the Brain Korea 21 plus projects (BK21 plus).

Publisher Copyright:
© 2019 IOP Publishing Ltd.

All Science Journal Classification (ASJC) codes

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

Fingerprint

Dive into the research topics of 'Ovonic threshold switching in polycrystalline zinc telluride thin films deposited by RF sputtering'. Together they form a unique fingerprint.

Cite this