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Atomic Layer Deposition of Hafnium Oxide on InAs : Insight from Time-Resolved in Situ Studies

D'Acunto, Giulio LU ; Troian, Andrea LU ; Kokkonen, Esko LU orcid ; Rehman, Foqia LU ; Liu, Yen Po LU ; Yngman, Sofie LU ; Yong, Zhihua LU ; McKibbin, Sarah R. LU orcid ; Gallo, Tamires LU and Lind, Erik LU , et al. (2020) In ACS Applied Electronic Materials 2(12). p.3915-3922
Abstract

III-V semiconductors, such as InAs, with an ultrathin high-κ oxide layer have attracted a lot of interests in recent years as potential next-generation metal-oxide-semiconductor field-effect transistors, with increased speed and reduced power consumption. The deposition of the high-κ oxides is nowadays based on atomic layer deposition (ALD), which guarantees atomic precision and control over the dimensions. However, the chemistry and the reaction mechanism involved are still partially unknown. This study reports a detailed time-resolved analysis of the ALD of high-κ hafnium oxide (HfOx) on InAs(100). We use ambient pressure X-ray photoemission spectroscopy and monitor the surface chemistry during the first ALD half-cycle, i.e., during... (More)

III-V semiconductors, such as InAs, with an ultrathin high-κ oxide layer have attracted a lot of interests in recent years as potential next-generation metal-oxide-semiconductor field-effect transistors, with increased speed and reduced power consumption. The deposition of the high-κ oxides is nowadays based on atomic layer deposition (ALD), which guarantees atomic precision and control over the dimensions. However, the chemistry and the reaction mechanism involved are still partially unknown. This study reports a detailed time-resolved analysis of the ALD of high-κ hafnium oxide (HfOx) on InAs(100). We use ambient pressure X-ray photoemission spectroscopy and monitor the surface chemistry during the first ALD half-cycle, i.e., during the deposition of the metalorganic precursor. The removal of In and As native oxides, the adsorption of the Hf-containing precursor molecule, and the formation of HfOx are investigated simultaneously and quantitatively. In particular, we find that the generally used ligand exchange model has to be extended to a two-step model to properly describe the first half-cycle in ALD, which is crucial for the whole process. The observed reactions lead to a complete removal of the native oxide and the formation of a full monolayer of HfOx already during the first ALD half-cycle, with an interface consisting of In-O bonds. We demonstrate that a sufficiently long duration of the first half-cycle is essential for obtaining a high-quality InAs/HfO2 interface.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
ambient pressure XPS, atomic layer deposition, HfO, InAs, ligand exchange, self-cleaning, TDMA-Hf
in
ACS Applied Electronic Materials
volume
2
issue
12
pages
8 pages
publisher
The American Chemical Society (ACS)
external identifiers
  • scopus:85096566513
ISSN
2637-6113
DOI
10.1021/acsaelm.0c00775
language
English
LU publication?
yes
id
9d9cb874-1e7f-4f25-8e3a-a0d5b436ace8
date added to LUP
2020-12-07 15:01:37
date last changed
2024-01-17 16:16:26
@article{9d9cb874-1e7f-4f25-8e3a-a0d5b436ace8,
  abstract     = {{<p>III-V semiconductors, such as InAs, with an ultrathin high-κ oxide layer have attracted a lot of interests in recent years as potential next-generation metal-oxide-semiconductor field-effect transistors, with increased speed and reduced power consumption. The deposition of the high-κ oxides is nowadays based on atomic layer deposition (ALD), which guarantees atomic precision and control over the dimensions. However, the chemistry and the reaction mechanism involved are still partially unknown. This study reports a detailed time-resolved analysis of the ALD of high-κ hafnium oxide (HfOx) on InAs(100). We use ambient pressure X-ray photoemission spectroscopy and monitor the surface chemistry during the first ALD half-cycle, i.e., during the deposition of the metalorganic precursor. The removal of In and As native oxides, the adsorption of the Hf-containing precursor molecule, and the formation of HfOx are investigated simultaneously and quantitatively. In particular, we find that the generally used ligand exchange model has to be extended to a two-step model to properly describe the first half-cycle in ALD, which is crucial for the whole process. The observed reactions lead to a complete removal of the native oxide and the formation of a full monolayer of HfOx already during the first ALD half-cycle, with an interface consisting of In-O bonds. We demonstrate that a sufficiently long duration of the first half-cycle is essential for obtaining a high-quality InAs/HfO2 interface. </p>}},
  author       = {{D'Acunto, Giulio and Troian, Andrea and Kokkonen, Esko and Rehman, Foqia and Liu, Yen Po and Yngman, Sofie and Yong, Zhihua and McKibbin, Sarah R. and Gallo, Tamires and Lind, Erik and Schnadt, Joachim and Timm, Rainer}},
  issn         = {{2637-6113}},
  keywords     = {{ambient pressure XPS; atomic layer deposition; HfO; InAs; ligand exchange; self-cleaning; TDMA-Hf}},
  language     = {{eng}},
  month        = {{12}},
  number       = {{12}},
  pages        = {{3915--3922}},
  publisher    = {{The American Chemical Society (ACS)}},
  series       = {{ACS Applied Electronic Materials}},
  title        = {{Atomic Layer Deposition of Hafnium Oxide on InAs : Insight from Time-Resolved in Situ Studies}},
  url          = {{http://dx.doi.org/10.1021/acsaelm.0c00775}},
  doi          = {{10.1021/acsaelm.0c00775}},
  volume       = {{2}},
  year         = {{2020}},
}