journal-opt - abstr156-172

https://doi.org/10.15407/iopt.2020.55.156

Optoelectron. Semicond. Tech. 55, 156-172 (2020)

A.A. Efremov, O.S. Oberemok, O.V. Kosulya

INFLUENCE OF LOCAL MECHANICAL STRESSES ON THE SILICON SPUTTERING YIELD BY ION BEAM

A review of scientific publications and modeling of the effect of mechanical stresses on the sputtering

yield of silicon by an ion beam is carried out. It is shown that the flux of atoms (from the depth to the surface) through

interstitial or vacancy mechanisms due to the stress gradient caused by the limiting bending of the plate is insufficient to

explain the increase in the sputtering coefficient. Calculations show that even the limiting elastic deformations do not

significantly change the energy of atom detachment from the site, and an increase in the drift velocity of atoms due to

the enrichment of the near-surface region with vacancies is insufficient to increase the sputtering rate. Consequently, it

is necessary that the elastic deformation is transformed into plastic with the formation of mobile weakly bound atoms.

The calculated stress distribution in a loaded silicon wafer using the COMSOL Multiphysics software package showed

that the key driving force behind the increase in the silicon sputtering coefficient is the concentration of compressive

and tensile stresses in the vicinity of the simulated crater during sputtering. The created crater is a stress concentrator,

the gradients of which significantly exceed the values obtained by bending a plate without a crater. It is demonstrated

that the generated stresses exceed the ultimate strength of the material in the vicinity of the crater, which begins to relax

due to the expulsion of "excess" atoms in the tension region. The appearance of additional deformation-stimulated

fluxes of weakly bound surface atoms at the bottom and walls of the crater provides an increase in the concentration of

knocked-out atoms in the process of ion sputtering. Simulations predict an increase in sputtering yield of up to 40%. It

is also shown that closely spaced craters, due to elastic interaction with each other, compensate each other's elastic

fields, which has an effect on the value of the sputtering coefficient.

Keywords: atomic sputtering yield, deformation, stress gradient, stress and strain concentrator.

PDF

References

1. K.A. Tolpin, K.F. Minnebaev, V.E. Yurasova. Detection by sputtering of deformed areas hidden under a surface. Vacuum. V. 138. R. 139-145, 2017.

https://doi.org/10.1016/j.vacuum.2016.11.002

2. V. E. Yurasova and A. F. Aleksandrov. Ion Diagnostics of Deformed Regions in Solids. Journal of Surface Investigation. Xray, Synchrotron and Neutron Techniques. 2012. Vol. 6, No. 4. R. 699-711.

https://doi.org/10.1134/S1027451012080186

3. Oleksii Liubchenko, Tomash Sabov, Vasyl Kladko, Viktor Melnik and other. Modification of elastic deformations and analysis of structural and optical changes in Ar+-implanted AlN/GaN superlattices. Applied Nanoscience. 2019. № 8. S. 2479-2487

https://doi.org/10.1007/s13204-019-01000-w

4. Pranyavichyus L., Dudonis Yu. Modifikaciya svojstv tverdyh tel ionnymi puchkami, Vilnyus: Molyuslas. 1980. 242 s.

5. P. Sigmund. Theory of Sputtering. I. Sputtering Yield of Amorphous and Polycrystalline Targets. Phys. Rev. 1969. V. 184. R. 383.

https://doi.org/10.1103/PhysRev.184.383

6. Y. Yamamura, H. Tawara. Ion-Induced Sputtering Yields. Atomic Data and Nuclear Data Tables. 1996. V. 62, № 2. R. 149-253.

https://doi.org/10.1006/adnd.1996.0005

7. J. Bohdansky. A Universal Relation For The Sputtering Yield Of Monatomic Solids At Normal Ion Incidence. Nuclear Instruments and Methods in Physics Research. 1984. B2. R. 587-591.

https://doi.org/10.1016/0168-583X(84)90271-4

8. C. Steinbruechel. A Simple Formula for Low-Energy Sputtering Yields. Appl. Phys. 1985. V. A 36, R. 37-42.

https://doi.org/10.1007/BF00616458

9. D. Falkone. Teoriya raspyleniya. UFN. 1992. T. 162, № 1. R. 71-117.

https://doi.org/10.3367/UFNr.0162.199201c.0071

10. Raspylenie ionnoj bombardirovkoj, obshie teoreticheskie predstavleniya v «Raspylenie tverdyh tel ionnoj bombardirovkoj: Fizicheskoe raspylenie odnoelementnyh tverdyh tel». Per. s angl.Pod red. R. Berisha. M.: Mir. 1984. 336 s.

11. V. Samul. Osnovy teorii uprugosti i plastichnosti. M.: Vyssh. Shkola. 1982. 264 c.

12. Timoshenko S. P., Guder Dzh., Teoriya uprugosti: Per. s angl. Pod red. G. S. Shapiro. M.: Nauka. 1979.

13. O'Mara W. C., Herring R. B., Hunt L. P. Handbook of Semiconductor Silicon Technology Park Ridge. New Jersey: Noyes Publications. 1990.

14. A. Polyakova. Deformaciya poluprovodnikov i poluprovodnikovyh priborov. M.: Energiya, 1979.168 s.

15. I. F. Chervonyj (red.). Poluprovodnikovyj kremnij: teoriya i tehnologiya. Zaporozhe: ZGIA. 2004. 344 s.

16. V. Eremeev. Diffuziya i napryazheniya. M.: Energoatomizdat. 1984. S. 384.

17. D. E. Laughlin, K. Hono (Eds.). Physical Metallurgy. V. I. Fifth Edition. Amsterdam. Elsevier B.V. 2014.

18. P. Pichler. Intrinsic Point Defects, Impurities, and Their Diffusion in Silicon. Wien: Springer-Verlag, 2004.

https://doi.org/10.1007/978-3-7091-0597-9

19. Geguzin Ya. E., Krivoglaz M. A.Dvizhenie makroskopicheskih vklyuchenij v tverdyh telah. M.: Metallurgiya. 1971. 344 s.

20. Tetelbaum D.I., Mendeleva Yu.A. Nanostrukturirovanie kremniya ionnymi puchkami. Nizhnij Novgorod: NNGU. 2007. 81 s.

21. M. Greenspan. Effect of a small hole on the stresses. Q. J. Appl. Math. 1944. V. 2, № 1. R. 60-71.

https://doi.org/10.1090/qam/10101

22. H. Gerqek. Calculation of Elastic Boundary Stresses for Rectangular Underground Openings. Mining Scienceand Technology. 1988. V. 7. R. 173-182.

https://doi.org/10.1016/S0167-9031(88)90574-9

24. S. P. Timoshenko, S. Vojnovskij-Kriger. Plastinki i obolochki. M.: Nauka. 1966.

25. S. P. Timoshenko. Soprotivlenie materialov. T. II. M.: Nauka. 1965. 480 s.

26. S. Onaka, M. Kato. A Free Energy Approach for Deriving Rate Equations for Diffusion-controlled Sintering. ISIJ International. 1989. V. 29, № 10. R. 852-861.

https://doi.org/10.2355/isijinternational.29.852

27. S. Onaka, M. Kato. Unified Analysis for Various Diffusion-controlled Deformation and Fracture Processes. ISIJ International. 1991.V. 31, № 4. R. 331 -341.

https://doi.org/10.2355/isijinternational.31.331

28. J. D. Hoffman. Numerical Methods for Engineers and Scientists. NEW-YORK. BASEL: Marcel Dekker Inc., 2001.

29. G. Xu, GPS: Theory, Algorithms and Applications, 2-nd edition. Berlin Heidelberg: Springer-Verlag. 2007.

О.О. Єфремов, О.С. Оберемок, О.В. Косуля

ВПЛИВ ЛОКАЛЬНИХ МЕХАНІЧНИХ НАПРУЖЕНЬ НА КОЕФІЦІЄНТ РОЗПИЛЕННЯ КРЕМНІЮ ІОННИМ ПУЧКОМ

Проведено огляд та моделювання впливу механічних напружень на коефіцієнт розпилення

кремнію іонним пучком. Показано, що утворюваний при іонному розпиленні кратер є концентратором

напружень, які можуть досягати екстремальних величин. Моделювання прогнозує збільшення коефіцієнта

розпилення до 40%, що пов'язано з інтенсивною деформаційно-стимульованою міграцією слабозв’язаних

поверхневих атомів по поверхні стінок і дна кратера, яка відбувається в процесі іонного розпилення.

Ключові слова: коефіцієнт розпилення, деформація, градієнт напруження, концентратор напруження.

Back / Повернутися