Optimizing Ferroelectric and Interface Layers in HZO-Based FTJs for Neuromorphic Applications

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Ayse Sünbül - , Fraunhofer Institute for Electronic Nano Systems (Author)
  • Tarek Ali - , Fraunhofer Institute for Electronic Nano Systems (Author)
  • Konstantin Mertens - , Fraunhofer Institute for Electronic Nano Systems (Author)
  • Ricardo Revello - , Fraunhofer Institute for Electronic Nano Systems (Author)
  • David Lehninger - , Fraunhofer Institute for Electronic Nano Systems (Author)
  • Franz Müller - , Fraunhofer Institute for Electronic Nano Systems (Author)
  • Maximilian Lederer - , Chair of Experimental Physics / Photophysics, Institute of Applied Physics, Fraunhofer Institute for Electronic Nano Systems (Author)
  • Kati Kühnel - , Fraunhofer Institute for Electronic Nano Systems (Author)
  • Matthias Rudolph - , Fraunhofer Institute for Electronic Nano Systems (Author)
  • Sebastian Oehler - , Fraunhofer Institute for Electronic Nano Systems (Author)
  • Raik Hoffmann - , Fraunhofer Institute for Electronic Nano Systems (Author)
  • Katrin Zimmermann - , Fraunhofer Institute for Electronic Nano Systems (Author)
  • Kati Biedermann - , Fraunhofer Institute for Electronic Nano Systems (Author)
  • Philipp Schramm - , Fraunhofer Institute for Electronic Nano Systems (Author)
  • Malte Czernohorsky - , Fraunhofer Institute for Electronic Nano Systems (Author)
  • Konrad Seidel - , Fraunhofer Institute for Electronic Nano Systems (Author)
  • Thomas Kämpfe - , Fraunhofer Institute for Electronic Nano Systems (Author)
  • Lukas M. Eng - , Carus Center for Teaching Excellence (CarL), Chair of Experimental Physics / Photophysics, TUD Dresden University of Technology (Author)

Abstract

Nonvolatile memories especially the ferroelectric (FE)-based ones such as ferroelectric tunnel junctions (FTJs) and ferroelectric field-effect transistors (FeFETs) have recently attracted a lot of attention. FTJs have been intensively researched for the last decade and found to be very promising memory devices due to their significant nondestructive readout advantage as compared to conventional ferroelectric random access memory (FRAM). However, more research is needed on FTJ devices to obtain reliable endurance and retention behavior. In this article, we demonstrate the characteristics and performance of zirconium-doped hafnium oxide-based FTJ devices in terms of FE switching and reliability. This is investigated for FTJ stack structure tuning as well as for the FE switching process in FTJ devices. The FTJ memory switching characteristics, the effects of polarization switching on the write conditions, and the impact of pulse width and pulse amplitude on switching are investigated. The impact of FE layer thickness and interface layer type/thickness are reported to obtain a maximum FTJ ION/IOFF ratio (memory window) and reliable performance. The maximum ION/IOFF ratio changes depending on the FE layer (zirconium-doped HfO2 layer) thickness (12, 8, 6, and 4 nm), the interface layer type (SiO2, Al2O3), and thickness(1 and 2nm), indicating the maximum value of ION/IOFF ratio for a 1 nm SiO2 interface layer stack. Moreover, a stable endurance of 104 cycles is reported and extrapolated measurements suggest stable retention for more than ten years. Time-dependent breakdown analysis was performed to investigate the reliability of devices indicating a lifetime of ten years.

Details

Original languageEnglish
Pages (from-to)808-815
Number of pages8
JournalIEEE Transactions on Electron Devices
Volume69
Issue number2
Publication statusPublished - 1 Feb 2022
Peer-reviewedYes

External IDs

ORCID /0000-0002-2484-4158/work/142257562

Keywords

Keywords

  • Ferroelectric tunnel junction (FTJ), Hafnium zirconium oxide, Metal-ferroelectric-insulator-semiconductor (MFIS)