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Time evolution of surface species during the ALD of high-k oxide on InAs

D'Acunto, Giulio LU ; Shayesteh, Payam LU ; Kokkonen, Esko LU orcid ; Boix de la Cruz, Virginia LU ; Rehman, Foqia LU ; Mosahebfard, Zohreh ; Lind, Erik LU ; Schnadt, Joachim LU orcid and Timm, Rainer LU orcid (2023) In Surfaces and Interfaces 39(102927).
Abstract

Understanding the reaction mechanisms involved during the early stage of atomic layer deposition (ALD) of HfO2 on InAs is a key requirement for improving interfaces in III-V semiconductor-based devices. InAs is an excellent candidate to outperform silicon regarding speed and power consumption, and combined with HfO2, it gives promise for a new generation of ultra-fast MOSFETs. However, an improved interface quality and in-depth understanding of the involved surface species are needed. Here, we use in situ and operando ambient pressure XPS to follow in real-time the reaction mechanisms which control the ALD chemistry. Besides the removal of all unwanted oxide from the III-V, the same oxygen atoms are found to form... (More)

Understanding the reaction mechanisms involved during the early stage of atomic layer deposition (ALD) of HfO2 on InAs is a key requirement for improving interfaces in III-V semiconductor-based devices. InAs is an excellent candidate to outperform silicon regarding speed and power consumption, and combined with HfO2, it gives promise for a new generation of ultra-fast MOSFETs. However, an improved interface quality and in-depth understanding of the involved surface species are needed. Here, we use in situ and operando ambient pressure XPS to follow in real-time the reaction mechanisms which control the ALD chemistry. Besides the removal of all unwanted oxide from the III-V, the same oxygen atoms are found to form HfOx already from the first half-cycle. In contrast to the standard ALD model, no hydroxyl groups are needed on the InAs surface. Furthermore, we observe an insertion reaction forming unexpected surface species. The second ALD half-cycle allows the immediate removal of all organic species leaving behind a uniform HfO2 layer partially terminated by hydroxyl groups. We find that prolonged exposure times upon both half-cycles guarantee a sharp InAs/HfO2 interface. Such an improved interface is an important step towards fast and sustainable III-V semiconductor-based electronics.

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author
; ; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Atomic layer deposition, HfO, III-V semiconductors, Time-resolved APXPS
in
Surfaces and Interfaces
volume
39
issue
102927
article number
102927
publisher
Elsevier
external identifiers
  • scopus:85160299783
ISSN
2468-0230
DOI
10.1016/j.surfin.2023.102927
language
English
LU publication?
yes
additional info
Publisher Copyright: © 2023 The Author(s)
id
48b9d37b-ed4e-4b27-9a58-f3c3d849fe28
date added to LUP
2023-06-12 14:17:08
date last changed
2024-02-05 11:38:20
@article{48b9d37b-ed4e-4b27-9a58-f3c3d849fe28,
  abstract     = {{<p>Understanding the reaction mechanisms involved during the early stage of atomic layer deposition (ALD) of HfO<sub>2</sub> on InAs is a key requirement for improving interfaces in III-V semiconductor-based devices. InAs is an excellent candidate to outperform silicon regarding speed and power consumption, and combined with HfO<sub>2</sub>, it gives promise for a new generation of ultra-fast MOSFETs. However, an improved interface quality and in-depth understanding of the involved surface species are needed. Here, we use in situ and operando ambient pressure XPS to follow in real-time the reaction mechanisms which control the ALD chemistry. Besides the removal of all unwanted oxide from the III-V, the same oxygen atoms are found to form HfO<sub>x</sub> already from the first half-cycle. In contrast to the standard ALD model, no hydroxyl groups are needed on the InAs surface. Furthermore, we observe an insertion reaction forming unexpected surface species. The second ALD half-cycle allows the immediate removal of all organic species leaving behind a uniform HfO<sub>2</sub> layer partially terminated by hydroxyl groups. We find that prolonged exposure times upon both half-cycles guarantee a sharp InAs/HfO<sub>2</sub> interface. Such an improved interface is an important step towards fast and sustainable III-V semiconductor-based electronics.</p>}},
  author       = {{D'Acunto, Giulio and Shayesteh, Payam and Kokkonen, Esko and Boix de la Cruz, Virginia and Rehman, Foqia and Mosahebfard, Zohreh and Lind, Erik and Schnadt, Joachim and Timm, Rainer}},
  issn         = {{2468-0230}},
  keywords     = {{Atomic layer deposition; HfO; III-V semiconductors; Time-resolved APXPS}},
  language     = {{eng}},
  number       = {{102927}},
  publisher    = {{Elsevier}},
  series       = {{Surfaces and Interfaces}},
  title        = {{Time evolution of surface species during the ALD of high-k oxide on InAs}},
  url          = {{http://dx.doi.org/10.1016/j.surfin.2023.102927}},
  doi          = {{10.1016/j.surfin.2023.102927}},
  volume       = {{39}},
  year         = {{2023}},
}