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 SiO2 (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 SiO2 for identical incident ion conditions.

1.
S.
Subramanian
et al., “First monolithic integration of 3D complementary FET (CFET) on 300 mm wafers,” in 2020 IEEE Symposium on VLSI Technology, Honolulu, Hawaii (IEEE, New York, 2020), pp. 1–2.
2.
H.
Kim
,
S.-J.
Ahn
,
Y. G.
Shin
,
K.
Lee
, and
E.
Jung
, “Evolution of NAND flash memory: From 2D to 3D as a storage market leader,” in 2017 IEEE International Memory Workshop (IMW), Monterey, California (IEEE, New York, 2017), pp. 1–4.
3.
C. G.
Lee
,
K. J.
Kanarik
, and
R. A.
Gottscho
,
J. Phys. D: Appl. Phys.
47
,
273001
(
2014
).
4.
K. J.
Kanarik
,
J. Vac. Sci. Technol. A
38
,
031004
(
2020
).
5.
H.
Conrads
and
M.
Schmidt
,
Plasma Sources Sci. Technol.
9
,
441
(
2000
).
6.
V. M.
Donnelly
and
A.
Kornblit
,
J. Vac. Sci. Technol. A
31
,
050825
(
2013
).
7.
Y.
Zhang
,
M. J.
Kushner
,
S.
Sriraman
,
A.
Marakhtanov
,
J.
Holland
, and
A.
Paterson
,
J. Vac. Sci. Technol. A
33
,
031302
(
2015
).
8.
S.
Huang
,
C.
Huard
,
S.
Shim
,
S. K.
Nam
,
I.-C.
Song
,
S.
Lu
, and
M. J.
Kushner
,
J. Vac. Sci. Technol.
37
,
031304
(
2019
).
9.
D.
Ruixue
,
Y.
Yintang
, and
H.
Ru
,
J. Semicond.
30
,
016001
(
2009
).
10.
J.-H.
Min
,
G.-R.
Lee
,
J.-K.
Lee
,
S. H.
Moon
, and
C.-K.
Kim
,
J. Vac. Sci. Technol. B
23
,
425
(
2005
).
11.
W.
Jin
and
H. H.
Sawin
,
J. Vac. Sci. Technol. A
21
,
911
(
2003
).
12.
J.-K.
Lee
,
I.-Y.
Jang
,
S.-H.
Lee
,
C.-K.
Kim
, and
S. H.
Moon
,
J. Electrochem. Soc.
157
,
D142
(
2010
).
13.
K.
Eriguchi
,
Y.
Takao
, and
K.
Ono
, “A new aspect of plasma-induced physical damage in three-dimensional scaled structures—sidewall damage by stochastic straggling and sputtering,” in 2014 IEEE International Conference on IC Design & Technology (IEEE, New York, 2014), pp. 1–5.
14.
A.
Sarkar
,
J.
Eapen
,
A.
Raj
,
K.
Murty
, and
T. D.
Burchell
,
J. Nucl. Mater.
473
,
197
(
2016
).
15.
L. V.
Zhigilei
,
Y. G.
Yingling
,
T. E.
Itina
,
T. A.
Schoolcraft
, and
B. J.
Garrison
,
Int. J. Mass Spectrom.
226
,
85
(
2003
).
16.
G. S.
Oehrlein
,
R. J.
Phaneuf
, and
D. B.
Graves
,
J. Vac. Sci. Technol. B
29
,
010801
(
2011
).
17.
B.
Helmer
and
D.
Graves
,
J. Vac. Sci. Technol. A
16
,
3502
(
1998
).
18.
E. J. C.
Tinacba
,
M.
Isobe
,
K.
Karahashi
, and
S.
Hamaguchi
,
Surf. Coat. Technol.
380
,
125032
(
2019
).
19.
F.
Gou
,
A.
Kleyn
, and
M.
Gleeson
,
Int. Rev. Phys. Chem.
27
,
229
(
2008
).
20.
E. J. C.
Tinacba
,
T.
Ito
,
K.
Karahashi
,
M.
Isobe
, and
S.
Hamaguchi
,
J. Vac. Sci. Technol. B
39
,
043203
(
2021
).
21.
J.
Vegh
et al.,
Appl. Phys. Lett.
91
,
233113
(
2007
).
22.
N.
Nakazaki
,
Y.
Takao
,
K.
Eriguchi
, and
K.
Ono
,
Jpn. J. Appl. Phys.
53
,
056201
(
2014
).
23.
X.
Hua
,
S.
Engelmann
,
G.
Oehrlein
,
P.
Jiang
,
P.
Lazzeri
,
E.
Iacob
, and
M.
Anderle
,
J. Vac. Sci. Technol. B
24
,
1850
(
2006
).
24.
M.
Armacost
et al.,
IBM J. Res. Dev.
43
,
39
(
1999
).
25.
C.
Cardinaud
,
M.-C.
Peignon
, and
P.-Y.
Tessier
,
Appl. Surf. Sci.
164
,
72
(
2000
).
26.
C. Y.
Ho
,
C.
Lien
,
Y.
Sakamoto
,
R. J.
Yang
,
H.
Fijita
,
C.
Liu
,
Y.
Lin
,
S.
Pittikoun
, and
S.
Aritome
,
IEEE Electron Device Lett.
29
,
1199
(
2008
).
27.
H.-C.
Scheer
,
N.
Bogdanski
, and
M.
Wissen
,
Jpn. J. Appl. Phys.
44
,
5609
(
2005
).
28.
J. K.
Kim
,
S. I.
Cho
,
N. G.
Kim
,
M. S.
Jhon
,
K. S.
Min
,
C. K.
Kim
, and
G. Y.
Yeom
,
J. Vac. Sci. Technol. A
31
,
021301
(
2013
).
29.
J.
Robertson
,
Mater. Sci. Eng. R. Rep.
37
,
129
(
2002
).
30.
A.
Nakano
,
R. K.
Kalia
, and
P.
Vashishta
,
Phys. Rev. Lett.
75
,
3138
(
1995
).
31.
A. P.
Thompson
et al.,
Comput. Phys. Commun.
271
,
108171
(
2021
).
32.
S.
Munetoh
,
T.
Motooka
,
K.
Moriguchi
, and
A.
Shintani
,
Comput. Mater. Sci.
39
,
334
(
2007
).
33.
D. J.
Evans
and
B. L.
Holian
,
J. Chem. Phys.
83
,
4069
(
1985
).
34.
S.
Nose
,
J. Phys.: Condens. Matter
2
,
SA115
(
1990
).
35.
G. J.
Martyna
,
D. J.
Tobias
, and
M. L.
Klein
,
J. Chem. Phys.
101
,
4177
(
1994
).
36.
J.
Tersoff
,
Phys. Rev. B
37
,
6991
(
1988
).
37.
S.
Wang
and
K.
Komvopoulos
,
Sci. Rep.
10
,
8089
(
2020
).
38.
P.
Erhart
and
K.
Albe
,
Phys. Rev. B
71
,
035211
(
2005
).
39.
C. D.
Wick
,
M. G.
Martin
, and
J. I.
Siepmann
,
J. Phys. Chem. B
104
,
8008
(
2000
).
40.
A.
Srivastava
, “A molecular dynamics based study of bulk and finite polystyrene-carbon dioxide binary systems,” Ph.D. thesis (The Ohio State University, 2010).
41.
V.
Harmandaris
,
N.
Adhikari
,
N. F.
van der Vegt
, and
K.
Kremer
,
Macromolecules
39
,
6708
(
2006
).
42.
J.
Han
and
R. H.
Boyd
,
Polymer
37
,
1797
(
1996
).
43.
M.
Kim
,
J.
Moon
,
J.
Choi
,
S.
Park
,
B.
Lee
, and
M.
Cho
,
Macromolecules
51
,
6922
(
2018
).
44.
B. P.
Haley
,
N.
Wilson
,
C.
Li
,
A.
Arguelles
,
E.
Jaramillo
, and
A.
Strachan
, “Polymer Modeler,”
nanoHUB
(2022).
45.
J. F.
Ziegler
and
J. P.
Biersack
, “The stopping and range of ions in matter,” in Treatise on Heavy-Ion Science, Austin, Texas (Springer, Boston, Massachusetts, 1985), pp. 93–129.
46.
K. K.
Kammara
,
R.
Kumar
, and
F. S.
Donbosco
,
Comput. Particle Mech.
3
,
3
(
2016
).
47.
A. A.
Sycheva
,
E. N.
Voronina
,
T. V.
Rakhimova
, and
A. T.
Rakhimov
,
J. Vac. Sci. Technol. A
36
,
061303
(
2018
).
48.
A.-P.
Prskalo
,
S.
Schmauder
,
C.
Ziebert
,
J.
Ye
, and
S.
Ulrich
,
Surf. Coat. Technol.
204
,
2081
(
2010
).
49.
D. B.
Graves
and
P.
Brault
,
J. Phys. D: Appl. Phys.
42
,
194011
(
2009
).
50.
P. A.
Johnson
,
A. C.
Wright
, and
R. N.
Sinclair
,
J. Non-Cryst. Solids
58
,
109
(
1983
).
51.
B.
Bhattarai
and
D.
Drabold
,
Carbon
115
,
532
(
2017
).
52.
D.
McCulloch
,
D.
McKenzie
, and
C.
Goringe
,
Phys. Rev. B
61
,
2349
(
2000
).
53.
B.
O’Malley
,
I.
Snook
, and
D.
McCulloch
,
Phys. Rev. B
57
,
14148
(
1998
).
54.
G. Inc., see http://www.goodfellow.com/E/Polystyrene.html for “Polystyrene material information” (2021), accessed: 2021-09-12.
55.
C. F.
Abrams
and
D. B.
Graves
,
J. Vac. Sci. Technol. A
16
,
3006
(
1998
).
56.
A.
Stukowski
,
Modell. Simul. Mater. Sci. Eng.
18
,
015012
(
2009
).
57.
J. D.
Hunter
,
Comput. Sci. Eng.
9
,
90
(
2007
).
58.
M.
Mitchell
,
B.
Muftakhidinov
,
T.
Winchen
,
A.
Wilms
,
B.
van Schaik
, badshah400, Mo-Gul, T. G. Badger, Z. Jędrzejewski-Szmek, kensington, and kylesower:
markummitchell/engauge-digitizer: Nonrelease
(
2020
).
59.
X.
Mei
,
W.
Mohamed
, and
J.
Eapen
,
Philos. Mag.
98
,
2701
(
2018
).
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