Ferroelectric Al0.85Sc0.15N and Hf0.5Zr0.5O2 Domain Switching Dynamics

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Roberto Guido - , NaMLab - Nanoelectronic materials laboratory gGmbH (Author)
  • Xuetao Wang - , NaMLab - Nanoelectronic materials laboratory gGmbH (Author)
  • Bohan Xu - , NaMLab - Nanoelectronic materials laboratory gGmbH (Author)
  • Ruben Alcala - , NaMLab - Nanoelectronic materials laboratory gGmbH (Author)
  • Thomas Mikolajick - , Chair of Nanoelectronics, NaMLab - Nanoelectronic materials laboratory gGmbH, TUD Dresden University of Technology (Author)
  • Uwe Schroeder - , NaMLab - Nanoelectronic materials laboratory gGmbH (Author)
  • Patrick D. Lomenzo - , NaMLab - Nanoelectronic materials laboratory gGmbH (Author)

Abstract

The capability to reliably program partial polarization states with nanosecond programming speed and femtojoule energies per bit in ferroelectrics makes them an ideal candidate to realize multibit memory elements for high-density crossbar arrays, which could enable neural network models with a large number of parameters at the edge. However, a thorough understanding of the domain switching dynamics involved in the polarization reversal is required to achieve full control of the multibit capability. Transient current integration measurements are adopted to investigate the domain dynamics in aluminum scandium nitride (Al0.85Sc0.15N) and hafnium zirconium oxide (Hf0.5Zr0.5O2). The switching dynamics are correlated to the crystal structure of the films. The contributions of domain nucleation and domain wall motion are decoupled by analyzing the rate of change of the time-dependent normalized switched polarization. Thermally activated creep domain wall motion characterizes the Al0.85Sc0.15N switching dynamics. The statistics of independently nucleating domains and the domain wall creep motion in Hf0.5Zr0.5O2 are associated with the spatially inhomogeneous distribution of local switching field due to polymorphism, absence of preferential crystallite orientation, as well as defects and charges that can be located at the grain boundaries. The c-axis texture, single-phase nature, and strong likelihood of less fabrication process-induced defects contribute to the homogeneity of the local switching field in Al0.85Sc0.15N. Nonetheless, defects generated and redistributed upon bipolar electric field switching cycling result in Al0.85Sc0.15N domain wall pinning. The wake-up effect in Hf0.5Zr0.5O2 is explained thorough the continuous addition of switchable regions associated with two independent distributions of characteristic switching times.

Details

Original languageEnglish
Pages (from-to)42415-42425
Number of pages11
JournalACS Applied Materials and Interfaces
Volume16
Issue number32
Publication statusPublished - 14 Aug 2024
Peer-reviewedYes

External IDs

ORCID /0000-0003-3814-0378/work/166326517

Keywords

ASJC Scopus subject areas

Keywords

  • aluminum scandium nitride, domain nucleation, domain wall motion, ferroelectrics, hafnium zirconium oxide, switching kinetics