Frontiers in Materials (Aug 2022)

Large remnant polarization and great reliability characteristics in W/HZO/W ferroelectric capacitors

  • Shiva Asapu,
  • James Nicolas Pagaduan,
  • Ye Zhuo,
  • Taehwan Moon,
  • Rivu Midya,
  • Dawei Gao,
  • Jungmin Lee,
  • Qing Wu,
  • Mark Barnell,
  • Sabyasachi Ganguli,
  • Reika Katsumata,
  • Yong Chen,
  • Qiangfei Xia,
  • J. Joshua Yang,
  • J. Joshua Yang

DOI
https://doi.org/10.3389/fmats.2022.969188
Journal volume & issue
Vol. 9

Abstract

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In this work, the effect of rapid thermal annealing (RTA) temperature on the ferroelectric polarization in zirconium-doped hafnium oxide (HZO) was studied. To maximize remnant polarization (2Pr), in-plane tensile stress was induced by tungsten electrodes under optimal RTA temperatures. We observed an increase in 2Pr with RTA temperature, likely due to an increased proportion of the polar ferroelectric phase in HZO. The HZO capacitors annealed at 400°C did not exhibit any ferroelectric behavior, whereas the HZO capacitors annealed at 800°C became highly leaky and shorted for voltages above 1 V. On the other hand, annealing at 700 °C produced HZO capacitors with a record-high 2Pr of ∼ 64 μC cm−2 at a relatively high frequency of 111 kHz. These ferroelectric capacitors have also demonstrated impressive endurance and retention characteristics, which will greatly benefit neuromorphic computing applications.

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