Structural and Electrical Properties of EOT HfO2 (<1 nm) Grown on InAs by Atomic Layer Deposition and Its Thermal Stability

Yu Seon Kang, Hang Kyu Kang, Dae Kyoung Kim, Kwang Sik Jeong, Min Baik, Youngseo An, Hyoungsub Kim, Jin Dong Song, Mann Ho Cho

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19 Citations (Scopus)


We report on changes in the structural, interfacial, and electrical characteristics of sub-1 nm equivalent oxide thickness (EOT) HfO2 grown on InAs by atomic layer deposition. When the HfO2 film was deposited on an InAs substrate at a temperature of 300°C, the HfO2 was in an amorphous phase with an sharp interface, an EOT of 0.9 nm, and low preexisting interfacial defect states. During post deposition annealing (PDA) at 600°C, the HfO2 was transformed from an amorphous to a single crystalline orthorhombic phase, which minimizes the interfacial lattice mismatch below 0.8%. Accordingly, the HfO2 dielectric after the PDA had a dielectric constant of ∼24 because of the permittivity of the well-ordered orthorhombic HfO2 structure. Moreover, border traps were reduced by half than the as-grown sample due to a reduction in bulk defects in HfO2 dielectric during the PDA. However, in terms of other electrical properties, the characteristics of the PDA-treated sample were degraded compared to the as-grown sample, with EOT values of 1.0 nm and larger interfacial defect states (Dit) above 1 × 1014 cm-2 eV-1. X-ray photoelectron spectroscopy data indicated that the diffusion of In atoms from the InAs substrate into the HfO2 dielectric during the PDA at 600°C resulted in the development of substantial midgap states.

Original languageEnglish
Pages (from-to)7489-7498
Number of pages10
JournalACS Applied Materials and Interfaces
Issue number11
Publication statusPublished - 2016 Mar 30

Bibliographical note

Funding Information:
This work was partially supported by an Industry-Academy joint research program between Samsung Electronics and Yonsei University; J.-D.S. acknowledges the support from KIST institutional programs of flag-ship.

Publisher Copyright:
© 2016 American Chemical Society.

All Science Journal Classification (ASJC) codes

  • Materials Science(all)


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