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Surface effects in quasiatomic layer etching of silicon

Danielsson, Oscar ; Karimi, Amin ; Ilarionova, Yoana ; Garnæs, Jørgen ; Khan, Sabbir A. and Maximov, Ivan LU orcid (2025) In Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films 43(4).
Abstract

The current investigation explores the surface effects of quasiatomic layer etching (Q-ALE) of silicon (Si), focusing on the interplay of process parameters, such as Ar+ ion energy, and their impact on etch rate, surface roughness, and material damage. Using a chlorine-based reactive ion etching tool at varying radio frequency bias voltages, the ion energy distribution and etching characteristics were systematically analyzed. Experimental results demonstrate the existence of an ALE process window at 50-70 eV Ar+ peak ion energy, achieving an etch-per-cycle of ∼0.12 nm with minimum surface roughness and damage. Outside this window, higher ion energies led to increased surface roughness of the etched Si. Ellipsometry... (More)

The current investigation explores the surface effects of quasiatomic layer etching (Q-ALE) of silicon (Si), focusing on the interplay of process parameters, such as Ar+ ion energy, and their impact on etch rate, surface roughness, and material damage. Using a chlorine-based reactive ion etching tool at varying radio frequency bias voltages, the ion energy distribution and etching characteristics were systematically analyzed. Experimental results demonstrate the existence of an ALE process window at 50-70 eV Ar+ peak ion energy, achieving an etch-per-cycle of ∼0.12 nm with minimum surface roughness and damage. Outside this window, higher ion energies led to increased surface roughness of the etched Si. Ellipsometry and atomic force microscopy revealed that the amorphous Si layer resulting from Ar+ ion bombardment was limited to ∼0.6 nm under optimal conditions. These findings provide insights into optimizing Q-ALE processes for precise and controlled Si etching, enabling advancements in nanoscale device fabrication.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
volume
43
issue
4
article number
042601
publisher
American Institute of Physics (AIP)
external identifiers
  • scopus:105005493785
ISSN
0734-2101
DOI
10.1116/6.0004257
language
English
LU publication?
yes
id
b37310b1-2da2-42dc-ac8f-f6a106f43da5
date added to LUP
2025-07-17 10:22:39
date last changed
2025-07-17 10:22:57
@article{b37310b1-2da2-42dc-ac8f-f6a106f43da5,
  abstract     = {{<p>The current investigation explores the surface effects of quasiatomic layer etching (Q-ALE) of silicon (Si), focusing on the interplay of process parameters, such as Ar<sup>+</sup> ion energy, and their impact on etch rate, surface roughness, and material damage. Using a chlorine-based reactive ion etching tool at varying radio frequency bias voltages, the ion energy distribution and etching characteristics were systematically analyzed. Experimental results demonstrate the existence of an ALE process window at 50-70 eV Ar<sup>+</sup> peak ion energy, achieving an etch-per-cycle of ∼0.12 nm with minimum surface roughness and damage. Outside this window, higher ion energies led to increased surface roughness of the etched Si. Ellipsometry and atomic force microscopy revealed that the amorphous Si layer resulting from Ar<sup>+</sup> ion bombardment was limited to ∼0.6 nm under optimal conditions. These findings provide insights into optimizing Q-ALE processes for precise and controlled Si etching, enabling advancements in nanoscale device fabrication.</p>}},
  author       = {{Danielsson, Oscar and Karimi, Amin and Ilarionova, Yoana and Garnæs, Jørgen and Khan, Sabbir A. and Maximov, Ivan}},
  issn         = {{0734-2101}},
  language     = {{eng}},
  number       = {{4}},
  publisher    = {{American Institute of Physics (AIP)}},
  series       = {{Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films}},
  title        = {{Surface effects in quasiatomic layer etching of silicon}},
  url          = {{http://dx.doi.org/10.1116/6.0004257}},
  doi          = {{10.1116/6.0004257}},
  volume       = {{43}},
  year         = {{2025}},
}