Molecular dynamics study of damage nearby silicon surface bombarded by energetic carbon ions

Journal Pre-proof Molecular dynamics study of damage nearby silicon surface bombarded by energetic carbon ions

Guoying Liang, Haowen Zhong, Shijian Zhang, Mofei Xu, Shicheng Kuang, Jianhui Ren, Nan Zhang, Sha Yan, Xiao Yu, Gennady Efimovich Remnev, Xiaoyun Le PII:

S0257-8972(20)30019-0

DOI:

https://doi.org/10.1016/j.surfcoat.2020.125350

Reference:

SCT 125350

To appear in:

Surface & Coatings Technology

Received date:

18 November 2019

Revised date:

4 January 2020

Accepted date:

6 January 2020

Please cite this article as: G. Liang, H. Zhong, S. Zhang, et al., Molecular dynamics study of damage nearby silicon surface bombarded by energetic carbon ions, Surface & Coatings Technology (2020), https://doi.org/10.1016/j.surfcoat.2020.125350

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

© 2020 Published by Elsevier.

Journal Pre-proof

Molecular dynamics study of damage nearby silicon surface bombarded by energetic carbon ions

Guoying Lianga,b,c,d, Haowen Zhonga,b,c, Shijian Zhanga,b,c, Mofei Xua,b,c, Shicheng Kuanga,b,c, Jianhui Rena,b,c, Nan Zhanga,b,c, Sha Yane, Xiao Yua,b,c, Gennady Efimovich Remneva,f, Xiaoyun Lea,b,c* a

Beijing Key Laboratory of Advanced Nuclear Energy Materials and Physics, Beihang University, Beijing

of

b

School of Physics, Beihang University, Beijing 100191, P.R. China

Beijing Advanced Innovation Center for Big Date-based Precision Medicine, Beihang University, Beijing

-p

c

ro

100191, P. R. China

e

Institute of Biophysics, Dezhou University, Dezhou 253023, P.R. China

lP

d

re

100191, P. R. China

Institute of Heavy Ion Physics, Peking University, Beijing 100871, P.R. China National Research Tomsk Polytechnic University, Tomsk 634050, Russia

na

f

Jo ur

*Corresponding author. E-mail address: [email protected]; Tel.: +86-010-82315038

Abstract: This paper investigates damage generation and evolution nearby silicon surface bombarded by energetic carbon ions by using molecular dynamics simulations. We experimentally measured elementary composition in defect regions based on energy dispersive spectrometer analysis. Using molecular dynamics simulations, point defects generation and evolution in monocrystalline silicon were illustrated. The percentage of carbon in defect regions is significantly more than that in non-irradiated regions of monocrystalline silicon. Point defects rapidly generate at the beginning of collision cascades between projective carbon ions and silicon atoms. The radial straggling and penetration along the 1

Journal Pre-proof depth direction are respectively dominant when projective ions with different kinetic energies implant into silicon target. These results can be used to better understand the interaction between projective energetic ions and target.

Jo ur

na

lP

re

-p

ro

of

Keywords: damage, point defect, molecular dynamics, vacancy, interstitial atom

2

Journal Pre-proof 1. Introduction Intense pulsed ion beam (IPIB) technique [1, 2], which is an effective tool in the field of material modification, has been rapidly developed in the past decades [3-8]. However, it is inevitable that defects generate in material modification by using IPIB [9]. Therefore, a major challenge in the application of IPIB is how to maintain structural integrity in material. The integrity is crucial to semi-conductive material such as crystalline silicon, which has been a

of

base material used in the semiconductor industry owing to its electronic and mechanical

ro

properties [10]. However, because of the limits of experimental facilities and conditions, it is

-p

difficult to directly observe damage evolution during IPIB irradiation. The mechanisms

re

governing defects formation induced by projective energetic ions remain unclear.

lP

To understand the mechanisms of the interaction between projective ions and target, researchers investigated atomistic structure deformation by using numerical methods as the

na

first step. Molecular dynamics (MD) simulation is a useful tool to illustrate crystal structure

Jo ur

and dynamics at the atomic scale. Based on MD simulations, Aoki et al. [11] studied damage formation induced by argon gas clusters ions impact on silicon substrate and illustrated the relationship between average damage depth, incident energy and cluster size. Liu et al. [12] studied helium ion implantation into silicon by using MD simulations, indicating that the damage was positively correlated with ion doses. Tian et al. [13] calculated C60 impact on carbon materials and studied sputtering based on MD simulations. They found that the sputtering yield on graphite was much smaller compared to that on diamond. Lehtinen et al. [14] studied the implantation process of nitrogen and silicon ions into diamond by using MD simulations, indicating that ion channeling was an important effect with an onset energy depending on the crystal orientation. Insepov et al. [15] investigated the mechanism of crater 3

Journal Pre-proof formation near silicon surfaces irradiated by cluster ion impacts, they predicted that carters were nearly triangular in cross-section of silicon target with the facets directed along the close-packed {111} planes. However, few researchers explained the mechanisms of damage formation near crystalline silicon surface during IPIB irradiation. It is necessary to study the interaction between projective energetic ions and silicon target. In this work, we investigated damage formation induced by energetic carbon ions nearby

of

monocrystalline silicon surface by using experimental method and MD simulations. The

ro

elements of defect regions, silicon target deformation and defects distribution were discussed.

-p

2. Method

re

2.1 IPIB irradiation experiment

lP

Monocrystalline silicon target (100) surface was irradiated with the TIA-450 accelerator at College of Materials Science, Shenyang Ligong University. The beams from the accelerator

na

were composed of 70% Cn+ and 30% H+, the ion source was provided by magnetically

Jo ur

insulated diode of graphite anode. The pulse duration was 60 ns. Typically, the peak values of accelerating voltage and current density were 350 kV and 130 A/cm2, respectively [16]. It was implied that the projective ions fluence is ~1012-1013cm-2 per pulse [17, 18]. Fig. 1 shows scanning electron microscope (SEM, Hitachi S-4800) image of monocrystalline silicon target surface irradiated by IPIB. Craters can be easily found on target surface. A lot of defects generate nearby silicon target surface after IPIB irradiation. We firstly chose black and white regions on silicon target surface, which were indicated with A and B in Fig. 1, respectively. Then, the elementary compositions in A and B were illustrated by using energy dispersive spectrometer (EDS) analysis. 2.2 Simulation method and model 4

Journal Pre-proof In this work, the classical molecular dynamics simulations of projective ions impact on monocrystalline silicon surface were performed by using the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) [19]. The three dimensional MD model of projective ions impact on monocrystalline silicon target surface is constructed as shown in Fig. 2. The cubic block represents silicon target which has diamond lattice structure and contains 1,640,000 atoms. The edge lengths of the block are the same as 20a along X, Y axis and 500a

of

along Z axis. The lattice constant a is given as 5.431 Å. The blue spots represent projective

ro

carbon ions and contain 280 carbon ions. Periodic boundary conditions are applied in X, Y

-p

axis direction, free boundary conditions are imposed in Z axis direction. According to periodic

re

symmetry, the fluence of projective carbon ions is ~2×1014 cm-2. The fixed layers that have 2a

lP

thickness at the bottom of the silicon target avoid projective carbon ions penetration target. The boundary layers that include 2a thickness above the fixed layers and 2a thickness at four

na

lateral boundaries of the target are imitated to decrease energy dissipation with the Berendsen

Jo ur

method. The mobile layers which contain 1,637,000 silicon atoms and obey the classical Newton’s second law are bombarded by projective carbon ions. The interatomic interaction in materials during collision cascades can be briefly described by an empirical potential function. The Tersoff potential [20] is used to describe the long-range interactions among covalent systems. It is applied to describe the interaction between silicon atoms and carbon atoms. A short-range of repulsive Ziegler-BiersackLittmark (ZBL) potential [21] is used to describe the binary collision between silicon atoms and carbon ions at short interatomic distances. Considering the distinctive application of the Tersoff potential and the ZBL potential in covalent systems, the Tersoff/ZBL complex potential that is the Tersoff potential splined smoothly to the ZBL potential by a transition 5

Journal Pre-proof function was carried out in this work. 1

𝐸 = 2 ∑𝑖 ∑𝑗≠𝑖 𝑉𝑖𝑗

(1) 𝑇𝑒𝑟𝑠𝑜𝑓𝑓

𝑉𝑖𝑗 = [1 − 𝑓𝐹 (𝑟𝑖𝑗 )]𝑉𝑖𝑗𝑍𝐵𝐿 + 𝑓𝐹 (𝑟𝑖𝑗 )𝑉𝑖𝑗 𝑓𝐹 (𝑟𝑖𝑗 ) = 𝑇𝑒𝑟𝑠𝑜𝑓𝑓

where 𝑉𝑖𝑗𝑍𝐵𝐿 and 𝑉𝑖𝑗

1 −𝐴 (𝑟 −𝑟 ) 1+𝑒 𝐹 𝑖𝑗 𝑐

(2) (3)

indicate the ZBL interatomic potential portion and the Tersoff

interatomic potential portion, respectively. 𝑟𝑖𝑗 is the distance between i atom and j atom. 𝑟𝑐

of

is the cutoff radius for the ZBL potential. 𝑓𝐹 (𝑟𝑖𝑗 ) is a transition function that controls the

ro

smoothness of the transition between the ZBL potential and the Tersoff potential. 𝑓𝐹 (𝑟𝑖𝑗 ) is

-p

controlled by the parameter of 𝐴𝐹 , the larger 𝐴𝐹 is, the sharper the transition function is,

re

vice versa.

lP

Before performing collision events, we relaxed the whole system by using a conjugate gradient energy minimization algorithm. Then, projective carbon ions bombarded silicon

na

target at 7o off the normal direction of the target top surface to minimize channel effect.

Jo ur

Finally, the system was calculated 100,000 timesteps during collision cascades between carbon ions and silicon atoms. The MD timestep was kept at a value of 0.1 fs, which was sufficient for energetic ions irradiation on silicon target [22]. The open visualization tool (OVITO) [23] code was used to quantitatively measure the microscopic morphology in monocrystalline silicon. 3. Results and discussion 3.1 Element analysis In order to illustrate the interaction between projective carbon ions and silicon atoms, we firstly studied the elementary compositions of target surface after energetic ions irradiation. Fig. 3(a) and Fig. 3(b) show elementary compositions of A and B by means of EDS line 6

Journal Pre-proof scanning pattern and spot scanning pattern, where Wt% is weight ratio and At% is atom ratio. The element carbon is observed in A and B regions. Its atom percentage is up to 65.75% and more than the percentage of silicon in A region. Meanwhile, the atom percentage of carbon is up to 18.93% and less than that of silicon in B region. The element carbon is not found in non-irradiated silicon sample as shown in Fig. 3(c). The percentage of carbon in A region is more than that in B region. These results indicate that carbon distribution on monocrystalline

of

silicon surface is nonuniform. The sources of carbon atoms include two portions: the first is

ro

the impurity atoms from the residual atmosphere of the working chamber; the second is the

-p

explosive plasma formed on the surface of graphite anode [24]. Carbon ions mainly deposit

re

nearby target surface via elastic collision with silicon atoms, while protons transfer deeper

lP

levels in target [25]. Compared with protons less energy loss, most energy loss of carbon ions generates nearby target surface. Hence, the interaction between carbon ions and silicon atoms

na

is mainly studied in this paper. One of factors that affect projective ions deposition is

Jo ur

projective ion beams nonuniform reported by our previous results [26]. However, other factors are still unclear during projective carbon ions deposition in monocrystalline silicon at atomic level. Therefore, the behavior of target morphology evolution during energetic ions deposition may be firstly studied. Due to lack of direct observational method to investigate the interaction between projective carbon ions and silicon atoms, MD simulations were carried out in this work. 3.2 Target surface damage during energetic ions irradiation To investigate monocrystalline silicon target damage, radial distribution function (RDF) was studied by using MD simulations. RDF is a common analytical method to investigate structural changes [27, 28], it has the following form: 7

Journal Pre-proof 𝑑𝑁

𝑔(𝑟) = 𝜌4𝜋𝑟 2 𝑑𝑟

(4)

where g(r) is the probability of finding an atom within a distance r from the center atom, 𝜌 is the average number density of atoms in system, dN is the average number of atoms found in the spherical shell dr around the position r. Incident carbon ions bombarded target surface with initial kinetic energy of 100 keV, 200 keV and 300 keV nearby the peak value of IPIB accelerating voltage, while other irradiation

of

conditions were kept constant for each energy. Fig. 4 shows the RDF g(r) of monocrystalline

ro

silicon target under energetic carbon ions with 100 keV irradiation. Silicon target appears

-p

perfect diamond lattice structure and has a long-range order before irradiation at 0 ps. Then,

re

projective carbon ions start to bombard silicon target surface. Elastic collisions generate

lP

between carbon ions and silicon atoms, forming lots of Frankel pairs, which are composed of vacancies and interstitial atoms. Due to formation of lots of vacancies, the peak value of RDF

na

decreases at every neighbor distance from 0.1ps to 10 ps. Compared 1.5 ps with 10 ps, the

Jo ur

RDF curves almost never change and show that damage has been formed stable structure since 1.5 ps. This result is in agreement with ~ 2 ps in previous study [29]. After that, interstitial atoms only process local rearrangement, without much change in their positions. Fig. 5 shows the RDF comparison of silicon target irradiated by projective carbon ions with different energies. The peak value of RDF at every neighbor distance decreases with increasing the kinetic energy of projective carbon ions. More silicon atoms migrate from their initial lattice sites when their obtained kinetic energies exceed the threshold displacement energy via elastic collision with carbon ions. It is suggested that projective carbon ions with larger kinetic energy can induce more vacancies and interstitial atoms. 3.3 Point defects distribution during energetic ions irradiation 8

Journal Pre-proof In order to study local damage in target during energetic ions irradiation, Wigner-Seitz cell analysis [30] was applied in this work. Wigner-Seitz cell is a primitive cell, which is enclosed with perpendicular planes at the midpoint of the lines between a center atom and nearest atoms. Fig. 6 shows point defects distribution in silicon target at different times. Point defects including vacancies and interstitial atoms in silicon target increase rapidly after 100 keV-300 keV carbon ions irradiation. In this stage, a lot of silicon atoms rapidly obtain kinetic energies

of

that exceed the threshold displacement energy, migrate to new places and form vacancies at

ro

original lattice sites. Vacancies and interstitial atoms quickly increase because of increasing of

-p

collision cascades in the first 3 ps as shown in Fig. 6(a), (b) and (c). Because of accumulation

re

of lots of vacancies, an obvious cavity can be found in this stage as shown in the inset of 1 ps.

lP

Then, the number of vacancies is up to its peak value at 1~3 ps, meanwhile the cavity increases up to its maximal volume. Afterward, the recombination of vacancies and interstitial

na

atoms is more than generation, and silicon atoms only vibrate at their equilibrium positions.

Jo ur

Finally, a conical cavity forms nearby target surface. Fig. 6(d) shows the profiles of vacancies generation versus annealing time under 100-500 keV ions irradiation. In cases of 100-300 keV, the projective ions predominantly present radial straggling rather than penetration along the depth direction. By comparing with 200 keV and 300 keV, it is found that latter produce slightly more vacancies than the former before 4.2 ps, but after 4.2 ps the correlation is reversed. It is suggested that at beginning of annealing the higher kinetic energy ions produce more vacancies in silicon target, while after maximum vacancy peak the vacancies produced by higher kinetic energy ions decreases more sharply due to increased penetration of ions. The phenomenon can be easily found in cases of 400 keV and 500 keV. The higher the kinetic energy of projective ions is, the more the ions penetration along the depth direction is, 9

Journal Pre-proof inducing lower vacancies generation. The results are approximately consistent with the description of Lehtinen et al. [14], where nitrogen and silicon ions with different kinetic energies implant into diamond target. 4. Conclusion In this work, damage nearby silicon surface bombarded by energetic carbon ions were studied by using experiments and MD simulations. The percentages of carbon and silicon in

of

defect regions were inspected by using EDS analysis. Based on MD simulations, the

ro

generation and evolution of point defects were analyzed at atomic level. The element carbon

-p

percentage in defect regions is significantly more than that in non-irradiated regions of

re

monocrystalline silicon target. Carbon ions have obviously nonuniform distribution and

lP

induce point defects generation in monocrystalline silicon target. Point defects including vacancies and interstitial atoms increase rapidly at the beginning of collision cascades

na

between projective carbon ions and silicon atoms. The radial straggling and penetration along

Jo ur

the depth direction are respectively dominant when projective ions with different kinetic energies implant into silicon target. These results provide more insight in material surface modification via ions irradiation. Acknowledgments

This work is supported by National Natural Science Foundation of China (Grant No. 11875084) and National Magnetic Confinement Fusion Program (Grant No. 2013GB109004).

10

Journal Pre-proof References

[1] S. Humphries, Intense pulsed ion beams for fusion applications, Nucl. Fusion 20 (1980) 1549-1612. https://doi.org/10.1088/0029-5515/20/12/006.

[2] G.E. Remnev, V.A. Shulov, Application of high-power ion beams for technology, Laser Part. Beams, 11 (1993) 707-731. https://doi.org/10.1017/S0263034600006467.

ro

of

[3] H.A. Davis, G.P. Johnston, J.C. Olson, D.J. Rej, W.J. Waganaar, C.L. Ruiz, F.A. Schmidlapp, M.O. Thompson, Characterization and modeling of the ablation plumes formed by intense-pulsed ion beam impact on solid targets, J. Appl. Phys. 85 (1999) 713-721. https://doi.org /10.1063/ 1.369151.

re

-p

[4] X.X. Mei, W.F. Sun, S.Z. Hao, T.C. Ma, C. Dong, Surface modification of high-speed steel by intense pulsed ion beam irradiation, Surf. Coat. Technol. 201 (2007) 5072-5076. https://doi.org/10.1016/j.surfcoat.2006.07.085.

na

lP

[5] V.K. Struts, A.N. Zakoutaev, V.M. Matvienko, A.V. Petrov, A.S. Shlapakovski, Formation of protective coatings on metals by intense pulsed ion beam, Surf. Coat. Technol. 158-159 (2002) 494-497. https://doi.org/10.1016/S0257-8972(02)00302-X.

Jo ur

[6] X.P. Zhu, H. Suematsu, W.H. Jiang, K. Yatsui, Structures and photoluminescence properties of silicon thin films prepared by pulsed ion-beam evaporation, Mater. Sci. Eng. B 149 (2008) 105-110. https://doi.org/10.1016/j.mseb.2008.01.001.

[7] W.J. Zhao, G.E. Remnev, S. Yan, M.S. Opekounov, X.Y. Le, V.M. Matvienko, B.X. Han, J.M. Xue, Y.G. Wang, Intense pulsed ion beam sources for industrial applications, Rev. Sci. Instrum. 71 (2000) 1045-1048. https://doi.org/10.1063/1.1150382.

[8] V.N. Popok, Energetic cluster ion beams: Modification of surfaces and shallow layers, Mater. Sci. Eng. R 72 (2011) 137–157. https://doi.org/10.1016/ j.mser.2011.03.001.

[9] M. Köntges, I. Kunze, S. Kajari-Schröder, X. Breitenmoser, B. Bjørneklett, The risk of power loss in crystalline silicon based photovoltaic modules due to micro-cracks, Sol. Energy Mater. Sol. Cells 95 (2011) 1131–1137. https://doi.org/10.1016/j.solmat.2010.10.034.

11

Journal Pre-proof [10] W. Heywang, K.H. Zaininger, Silicon: Evolution and Future of a Technology, in: P. Siffert, E.F. Krimmel (Eds.), Silicon: The Semiconductor Material, Springer Verlag, Berlin Heideberg, 2004, pp. 25-42.

[11] T. Aoki, T. Seki, J. Matsuo, Molecular dynamics simulation study of damage formation and sputtering with huge fluorine cluster impact on silicon, Nucl. Instrum. Methods Phys. Res. sect. B 303 (2013) 170–173. https://doi.org/10.1016/j.nimb.2012.10.040.

of

[12] L. Liu, Z.W. Xu, R.R. Li, R. Zhu, J. Xu, J.L Zhao, C. Wang, K. Nordlund, X. Fu, F.Z. Fang, Molecular dynamics simulation of helium ion implantation into silicon and its migration, Nucl. Instrum. Methods Phys. Res. sect. B 456 (2019) 53-59. https://doi.org/10.1016/j.nimb.2019.06.034.

-p

ro

[13] J.T. Tian, T. Zheng, J.Y. Yang, S.Y. Kong, J.M. Xue, Y.G. Wang,K. Nordlund, Capacity of graphite’s layered structure to suppress the sputtering yield: A molecular dynamics study, Appl. Surf. Sci. 337 (2015) 6–11. https://doi.org/10.1016/j.apsusc.2015.01.241.

lP

re

[14] O. Lehtinen, B. Naydenov, P. Borner, K. Melentjevic, C. Muller, L. P. McGuinness, S. Pezzagna, J. Meijer, U. Kaiser, F. Jelezko, Molecular dynamics simulations of shallow nitrogen and silicon implantation into diamond, Phys. Rev. B 93 (2016) 035202. https://doi.org/10.1103/PhysRevB.93.035202.

Jo ur

na

[15] Z. Insepov, L.P. Allen, C. Santeufemio, K.S. Jones, I. Yamada, Computer modeling and electron microscopy of silicon surfaces irradiated by cluster ion impacts, Nucl. Instrum. Methods Phys. Res. sect. B 202 (2003) 261–268. https://doi.org/10.1016/ S0168-583X (02)01867-0.

[16] J. Shen, X. Yu, J. Zhang, H.W. Zhong, X.J. Cui, G.Y. Liang, X. Yu,W.Y. Huang, I. Shahid, X.F. Zhang, S. Yan, X.Y. Le, Anisotropy effect of crater formation on single crystal silicon surface under intense pulsed ion beam irradiation, Nucl. Instrum. Methods Phys. Res. sect. B 421 (2018) 7–12. https://doi.org/10.1016/j.nimb.2018.02.011

[17] G.E. Remnev, I.F. Isakov, M.S. Opekounov, V.M. Matvienko, V.A. Ryzhkov, V.K. Struts, I.I. Grushin, A.N. Zakoutayev, A.V. Potyomkin, V.A. Tarbokov, A.N. Pushkaryov, V.L. Kutuzov, M.Yu. Ovsyannikov, High intensity pulsed ion beam sources and their industrial applications, Surf. Coat. Technol. 114 (1999) 206–212. https://doi.org/10.1016/S0257-8972(99)00058-4.

[18] G.E. Remnev, V.V. Uglov, V.I. Shymanski, S.K. Pavlov, A.K. Kuleshov, Formation of nanoscale carbon structures in the surface layer of metals under the impact of high intensity ion beam, Appl. Surf. Sci. 310 (2014) 204–209. https://doi.org/10.1016/j.apsusc.2014.04.068.

12

Journal Pre-proof [19] S. Plimpton, Fast parallel algorithms for short-range molecular dynamics, J. Comput. Phys. 117 (1995) 1-19. https://doi.org/10.1006/jcph.1995.1039.

[20] J. Tersoff, Modeling solid-state chemistry: interatomic potential for multicomponent systems, Phys. Rev. B 39 (1989) 5566–5568. https://doi.org/10.1103/PhysRevB.39.5566.

[21] J. Ziegler, J. Biersack, U. Littmark, The Stopping and Range of Ions in Solids, Pergamon Press, New York, 1985.

ro

of

[22] Y.J. Xiao, F.Z. Fang, Z.W. Xu, X.T. Hu, Annealing recovery of nanoscale silicon surface damage caused by Ga focused ion beam, Appl. Surf. Sci. 343 (2015) 56–69. http://doi.org/10.1016/j.apsusc.2015.03.059.

re

-p

[23] A. Stukowski, Visualization and analysis of atomistic simulation data with OVITO - the Open Visualization Tool, Model. Simul. Mater. Sci. Eng. 18 (2010) 1-7. https://doi.org/10.1088/0965-0393/18/1/015012.

na

lP

[24] N. E. Aktaev, G. E. Remnev, Modeling of carbon penetration into silicon structure under the action of pulsed high-intensity ion beam, Surf. Coat. Technol. 306 (2016) 54-57. https://doi.org/10.1016/j.surfcoat.2016.04.050

Jo ur

[25] X.J. Cui, L.L. Wang, J. Shen, H.W. Zhong, J. Zhang, G.Y. Liang, X. Yu, X.F. Zhang, X.Y. Le, Lattice damage and expansion in RbTiOPO4 crystals induced by carbon ion implantation, Surf. Coat. Technol. 348 (2018) 142–149. https://doi.org/10.1016/j.surfcoat.2019.06.037.

[26] X. Yu, J. Shen, Y.I. Isakova, H.W. Zhong, J. Zhang, S. Yan, G.L. Zhang, X.F. Zhang, X.Y. Le, Study of energy deposition of intense pulsed ion beam in metal target, Vacuum 122 (2015) 12-16. https://doi.org/10.1016/j.vacuum.2015.09.006.

[27] S.D. Liu , H. Li, Y.Z. He, X.Y. Li, Y.F. Li, X. Wang, Pathway into the silicon nucleation on silicene substrate at nanoscale, Mater. Des. 85 (2015) 60–66. http://doi.org/10.1016/j.matdes.2015.07.002.

[28] K.C. Fang, C.I. Weng, S.P Ju, An investigation into the structural features and thermal conductivity of silicon nanoparticles using molecular dynamics simulations, Nanotechnology 17 (2006) 3909–3914. https://doi.org/10.1088/0957-4484/17/15/049.

13

Journal Pre-proof [29] Q. Peng, F.J. Meng, Y.Z. Yang, C.Y. Lu, H.Q. Deng, L.M. Wang, S. De, F. Gao, Shockwave generates < 100 > dislocation loops in bcc iron, Nature Communications 9 (2018):4880. http://doi.org/10.1038/s41467-018-07102-3

Jo ur

na

lP

re

-p

ro

of

[30] E. Wigner, F. Seitz, On the constitution of metallic sodium, Phys. Rev. 43 (1933) 804-810. http://doi.org/10.1103/PhysRev.43.804.

14

Journal Pre-proof Figure captions Fig. 1 SEM image of monocrystalline silicon (100) surface under one pulse IPIB irradiation. One radial shape of crater can be found on the target surface. A indicates the circular region and B indicates the rectangular region. (1-column image) Fig. 2 The three-dimensional MD model for projective carbon ions impact on monocrystalline silicon target. Blue spots, red spots, green spots and yellow spots represent projective carbon ions, mobile silicon atoms,

of

boundary silicon atoms and fixed silicon atoms, respectively. (1-column image)

ro

Fig. 3 EDS photographs of monocrystalline silicon surface with line and spot scanning pattern. (a) black

-p

region (A region in Fig. 1), (b) white region (B region in Fig. 1), (c) non-irradiated sample (polished

re

surface). The inset is element ratio of carbon and silicon, defining Wt% and At%. (1-column image)

lP

Fig. 4 Radial distribution function of silicon target during collision cascades between 100 keV projective carbon ions and silicon atoms at different times. (1-column image)

na

Fig. 5 Radial distribution function of silicon target irradiated by projective carbon ions with different

Jo ur

kinetic energies. (1-column image)

Fig. 6 Vacancies evolution in silicon target irradiated by projective carbon ions with different kinetic energies (a) 100 keV, (b) 200 keV, (c) 300 keV, (d) comparison. The inset is the distribution of vacancy in Y-Z cross-section at different times. Red spots represent silicon interstitial atoms. The blank areas made up of vacancies indicate the cavities in silicon target (a and b inserted in one 2-column image, c and d inserted in one 2-column image)

15

Journal Pre-proof

Jo ur

na

lP

re

-p

ro

Fig. 1

of

Figures

Fig. 2

16

Fig. 3

Jo ur

na

lP

re

-p

ro

of

Journal Pre-proof

Fig 4

17

Journal Pre-proof

lP

re

-p

ro

of

Fig. 5

Jo ur

na

Fig. 6(a)

Fig. 6(b)

18

Journal Pre-proof

Fig. 6(d)

Jo ur

na

lP

re

-p

ro

of

Fig. 6(c)

19

Journal Pre-proof Declaration of interests ☒ The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Jo ur

na

lP

re

-p

ro

of

☐The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:

20

Journal Pre-proof CRediT Author Statement

Guoying Liang: Conceptualization, methodology, writing-original draft preparation Haowen Zhong: Conceptualization, writing-review and edition Shijian Zhang: software, Visualization Mofei Xu: software, Visualization

of

Shicheng Kuang: software, Visualization

ro

Jianhui Ren: formal analysis

-p

Nan Zhang: formal analysis

re

Sha Yan: Supervision

lP

Xiao Yu: methodology, writing-original draft preparation, writing-review and edition Gennady Efimovich Remnev: funding acquisition, Supervision

Jo ur

na

Xiaoyun Le: funding acquisition, Supervision

21

Journal Pre-proof

Highlights 

Point defects rapidly generate at the beginning of cascade collision



Carbon in defect regions is significantly more than in nonirradiated regions



The radial straggling and penetration along the depth direction are respectively dominant

Jo ur

na

lP

re

-p

ro

of

when projective ions with different kinetic energies implant into silicon target

22

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6