AIP Advances (Aug 2020)

Thermal stability of interface dipole modulation in atomic layer-deposited HfO2/SiO2 multi-stack structures

  • Shutaro Asanuma,
  • Kyoko Sumita,
  • Yusuke Miyaguchi,
  • Kazumasa Horita,
  • Takehito Jimbo,
  • Kazuya Saito,
  • Noriyuki Miyata

DOI
https://doi.org/10.1063/5.0015348
Journal volume & issue
Vol. 10, no. 8
pp. 085114 – 085114-5

Abstract

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In this paper, we report on an interface dipole modulation (IDM) loss occurring in HfO2/atomically thin TiO2/SiO2 stack structures prepared by atomic layer deposition (ALD). The IDM characteristic, which is observed as a capacitance–voltage (C–V) hysteresis curve, disappears when the temperature during ALD or post-deposition annealing exceeds its respective critical temperatures, even though the HfO2/SiO2 stack structure is maintained. We found a correlation between Ti suboxide formation and IDM loss and speculated the effect of impurities and defects introduced during the ALD process on IDM operation.