Time evolution of surface species during the ALD of high-k oxide on InAs
(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.
(Less)
- author
- D'Acunto, Giulio LU ; Shayesteh, Payam LU ; Kokkonen, Esko LU ; Boix de la Cruz, Virginia LU ; Rehman, Foqia LU ; Mosahebfard, Zohreh ; Lind, Erik LU ; Schnadt, Joachim LU and Timm, Rainer LU
- organization
-
- LTH Profile Area: Nanoscience and Semiconductor Technology
- Synchrotron Radiation Research
- NanoLund: Centre for Nanoscience
- Department of Physics
- MAX IV Laboratory
- LTH Profile Area: AI and Digitalization
- Department of Electrical and Information Technology
- MAX IV, APXPS
- LU Profile Area: Light and Materials
- LTH Profile Area: Photon Science and Technology
- publishing date
- 2023-07
- 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
- 2024-08-10 08:44:34
@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}}, }