In plasma etching for microelectronics fabrication, one of the objectives is to produce a high aspect ratio (HAR) via and trench structures. A principal contributor to the HAR feature shape is the manner in which energetic ions interact with sidewalls inside the feature. The scattering angle and energy loss of ions reflecting from sidewalls determine the sidewall slope and can lead to defects such as microtrenching and bowing. Understanding how ions interact with sidewalls can improve our control of the critical dimensions of HAR features. Ions accelerated in the plasma sheath arrive in the feature with energies as large as a few keV and initially strike the sidewalls at glancing angles. These scattering events extend to the photolithographic mask. Scattering from the mask at glancing angles can produce ions incident into the underlying feature with a broader angular distribution, leading to less desirable feature properties. In this work, results are discussed from Molecular Dynamics (MD) simulations of glancing-angle scattering of argon ions from three materials common to HAR etch: polystyrene (as a photoresist surrogate), amorphous carbon (a hard mask material), and (a common insulating material used in microelectronics devices). Results from simulations reveal a transition from specular scattering to diffuse scattering as the angle of the incident ion decreases (90 being glancing incidence) and incident energy increases. Scattering from polystyrene is more diffuse compared to amorphous carbon and for identical incident ion conditions.
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September 2022
Research Article|
September 01 2022
Comparison of glancing-angle scatterings on different materials in a high aspect ratio plasma etching process using molecular dynamics simulation
Yao Du
;
Yao Du
a)
(Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Resources, Software, Validation, Visualization, Writing – original draft)
1
Department of Nuclear Engineering, North Carolina State University
, Raleigh, North Carolina 27695-7909a)Electronic mail: ydu9@ncsu.edu
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Florian Krüger
;
Florian Krüger
(Resources, Software, Writing – review & editing)
2
Department of Electrical Engineering and Computer Science, University of Michigan
, 1301 Beal Ave., Ann Arbor, Michigan 48109-2122
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Sang Ki Nam;
Sang Ki Nam
(Project administration, Resources, Writing – review & editing)
3
Mechatronics Research Division, Samsung Electronics Co., Ltd.
, Suwon 443-742, South Korea
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Hoki Lee;
Hoki Lee
(Project administration, Resources, Writing – review & editing)
3
Mechatronics Research Division, Samsung Electronics Co., Ltd.
, Suwon 443-742, South Korea
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Suyoung Yoo;
Suyoung Yoo
(Project administration, Resources, Writing – review & editing)
3
Mechatronics Research Division, Samsung Electronics Co., Ltd.
, Suwon 443-742, South Korea
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Jacob Eapen
;
Jacob Eapen
(Formal analysis, Methodology, Validation, Writing – review & editing)
1
Department of Nuclear Engineering, North Carolina State University
, Raleigh, North Carolina 27695-7909
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Mark J. Kushner
;
Mark J. Kushner
(Conceptualization, Investigation, Methodology, Supervision, Writing – review & editing)
2
Department of Electrical Engineering and Computer Science, University of Michigan
, 1301 Beal Ave., Ann Arbor, Michigan 48109-2122
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Steven Shannon
Steven Shannon
b)
(Conceptualization, Funding acquisition, Project administration, Resources, Supervision, Writing – review & editing)
1
Department of Nuclear Engineering, North Carolina State University
, Raleigh, North Carolina 27695-7909b)Author to whom correspondence should be addressed: scshanno@ncsu.edu
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a)Electronic mail: ydu9@ncsu.edu
b)Author to whom correspondence should be addressed: scshanno@ncsu.edu
J. Vac. Sci. Technol. A 40, 053007 (2022)
Article history
Received:
June 07 2022
Accepted:
July 28 2022
Citation
Yao Du, Florian Krüger, Sang Ki Nam, Hoki Lee, Suyoung Yoo, Jacob Eapen, Mark J. Kushner, Steven Shannon; Comparison of glancing-angle scatterings on different materials in a high aspect ratio plasma etching process using molecular dynamics simulation. J. Vac. Sci. Technol. A 1 September 2022; 40 (5): 053007. https://doi.org/10.1116/6.0002008
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