COMPARATIVE STUDY OF PLASMA PARAMETERS AND COMPOSITIONS IN CF4, Cl2 AND HBr + Ar GAS MIXTURES

DOI: 
10.6060/tcct.20165910.5431

Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2016. V. 59. N 10. P. 11-18

This work discusses the plasma characteristics and chemistry in CF4 + Ar, Cl2 + Ar and HBr + Ar gas systems under one and the same operating condition. The investigation was carried out using the combination of plasma diagnostics by Langmuir probes and 0-dimensional plasma modeling in the planar inductively coupled plasma reactor at constant gas pressure (10 mTorr), input power (800 W) and bias power (300 W), but with variable (0–80%) Ar fraction in a feed gas.The main attention was attracted to the parameters influenc-ing the steady-state densities of plasma active species (electron temperature, electron density, electron-impact rate coefficients) and the kinetics of ion-assisted chemical reaction (fluxes of halogen atoms, ion bombardment energy, ion energy flux).

Key words: CF4, Cl2, HBr, plasma, rate coefficient, reaction rate, halogen atom flux, ion energy flux

REFERENCES
1. Sugano T. Applications of plasma processes to VLSI technology. New York: Wiley. 1990. 567 p.
2. Rooth J.R. Industrial Plasma Engineering. Philadelphia: IOP Publishing LTD. 1995. 620 р. DOI: 10.1201/ 9781420050868.
3. Roosmalen A.J., Baggerman J.A.G., Brader S.J.H. Dry etching for VLSI. New-York: Plenum Press. 1991. 490 р. DOI:10.1007/978-1-4899-2566-4.
4. Wolf S., Tauber R.N. Silicon Processing for the VLSI Era. V. 1. Prosess Technology. New York: Lattice Press. 2000. 416 p.
5. Rossnagel S.M., Cuomo J.J., Westwood W.D. Handbook of plasma processing technology. Park Ridge: Noyes Publications. 1990. 338 р.
6. Lieberman M.A., Lichtenberg A.J. Principles of plasma discharges and materials processing. New York: John Wiley & Sons Inc. 1994. 757 р.
7. Efremov A. M., Kim D.-P., Kim C.-I. Effect of gas mixing ratio on gas-phase composition and etch rate in an inductively coupled CF4/Ar plasma. Vacuum. 2004. V.75. P. 133. DOI:10.1016/j.vacuum.2004.01.077.
8. Kimura T., Noto M. Experimental study and global model of inductively coupled CF4/O2 discharges. J. Appl. Phys. 2006. V. 100. P. 063303. DOI:10.1063/1.2345461.
9. Kimura T., Ohe K. Probe measurements and global model of inductively coupled Ar/CF4 discharges. Plasma Sources Sci. Technol. 1999. V. 8. P. 553. DOI:10.1088/0963-0252/ 8/4/305.
10. Plumb I. C., Ryan K. R. A model of chemical processes occurring in CF4/O2 discharges used for plasma etching. Plasma Chem. Plasma Proc. 1986. V. 6. P. 205. DOI:10.1007/BF00575129.
11. Gogolides E., Stathakopolous M., Boudouvis A. Modelling of radio frequency plasmas in tetrafluoromethane (CF4): the gas phase physics and the role of negative ion detachment. J. Phys. D: Appl. Phys. 1994. V. 27. P. 1878. DOI:10.1088/ 0022-3727/27/9/011.
12. Chun I., Efremov A., Yeom G.Y., Kwon K.-H. A comparative study of CF4/O2/Ar and C4F8/O2/Ar plasmas for dry etching appli-cations. Thin Solid Films. 2015. V. 579. P. 136. DOI:10.1016/j.tsf.2015.02.060.
13. Ullal S.J., Godfrey A.R., Edelberg E., Braly L., Vahedy V., Aydil E.S. Effect of chamber wall conditions on Cl and Cl2 concen-trations in an inductively coupled plasma reactor. J. Vac. Sci. Technol. A. 2002. V. 20. P. 43. DOI:10.1116/ 1.1421602.
14. Yonemura S., Nanbu K., Sakai K. Electron energy distributions in inductively coupled plasma: comparison of chlorine discharge with argon discharge. Jpn. J. Appl. Phys. 2002. V. 41. P. 6189. DOI:10.1143/JJAP.41.6189.
15. Malyshev M.V., Donnelly V.M. Diagnostics of chlorine inductively coupled plasmas. Measurement of electron temperatures and electron energy distribution functions. J. Appl. Phys. 2000. V. 87. P. 1642. DOI:10.1063/1.372072.
16. Malyshev M.V., Fuller N.C.M., Bogart K.H.A., Donnelly V.M., Herman I.P. Diagnostics of inductively coupled chlorine plas-mas: Measurement of Cl2+ and Cl+ densities. J. Appl. Phys. 2000. V. 88. P. 2246. DOI:10.1063/1.1288156.
17. Efremov A.M., Kim G.-H., Kim J.-G., Kim C.-I. Self-consistent global model for inductively coupled Cl2 plasma: Comparison with experimental data and application for the etch process analysis. Thin Solid Films. 2007. V. 515. P. 5395. DOI:10.1016/j.tsf.2007.01.027.
18. Efremov A.M., Kim G.-H., Kim J.-G., Bogomolov A.V., Kim C.-I. Applicability of self-consistent global model for characteriza-tion of inductively coupled Cl2 plasma. Vacuum. 2007. V. 81. P. 669. DOI:10.1016/j.vacuum.2006.09.017.
19. Kwon K.-H., Efremov A., Kim M., Min N.K., Jeong J., Kim K. Model-based analysis of plasma parameters and active species kinetics in Cl2/X (X=Ar, He, N2) inductively coupled plasmas. J. Electrochem. Soc. 2008. V. 155. P. D777. DOI:10.1149/1.2993160.
20. Kwon K.-H., Efremov A., Kim M., Min N.K., Jeong J., Kim K. A model-based analysis of plasma parameters and composition in HBr/X (X=Ar, He, N2) inductively coupled plasmas. J. Electrochem. Soc. 2010. V. 157. P. H574. DOI:10.1149/1.3362943.
21. Efremov A., Kim Y., Lee H.-W., Kwon K.-H. A comparative study of HBr-Ar and HBr-Cl2 plasma chemistries for dry etch appli-cations. Plasma Chem. Plasma Proc. 2011. V. 31. P. 259. DOI:10.1007/s11090-010-9279-7.
22. Efremov A., Kim J.H., Kwon K.-H. A model-based comparative study of HCl and HBr plasma chemistries for dry etching purpos-es. Plasma Chem. Plasma Process. 2015. V. 35. P. 1129. DOI:10.1007/s11090-015-9639-4.
23. Johnson E.O., Malter L. A floating double probe method for measurements in gas discharges. Phys. Rev. 1950. V. 80. P. 58. DOI:10.1103/PhysRev.80.58.
24. Sugavara M. Plasma etching: Fundamentals and applications. New York: Oxford University Press. 1998. 469 р.
25. Lee C., Lieberman M.A. Global model of Ar, O2, Cl2, and Ar/O2 high-density plasma discharges. J. Vac. Sci. Technol. A. 1995. V. 13. P. 368. DOI:10.1116/1.579366.
26. Ashida S., Lieberman M.A. Spatially averaged (global) model of time modulated high density chlorine plasmas. Jpn. J. Appl. Phys. 1997. V. 36. P. 854. DOI:10.1143/ JJAP.36.854.
27. Hsu C.-C., Nierode M.A., Coburn J.W., Graves D.B. Comparison of model and experiment for Ar, Ar/O2 and Ar/O2/Cl2 induc-tively coupled plasmas. J. Phys. D: Appl. Phys. 2006. V. 39. P. 3272. DOI:10.1088/0022-3727/39/15/009.
28. Christophorou L.G., Olthoff J.K., Rao M.V.V.S. Electron interactions with CF4. J. Phys. chem. Ref. Data 1996. V. 25. P. 1341. DOI:10.1063/1.555986.
29. Christophorou L.G., Olthoff J.K. Electron interactions with Cl2. J. Phys. chem. Ref. Data 1999. V. 28. P. 131. DOI:10.1063/1.556036.
30. Peterson L.R., Allen Jr. J.E., Electron impact cross sections for argon. J. Chem. Phys. 1972. V. 56. P. 6068. DOI:10.1063/1.1677156.
31. Jin W., Vitale S.A., Sawin H.H. Plasma-surface kinetics and simulation of feature profile evolution in Cl2+HBr etching of polysili-con. J. Vac. Sci. Technol. A. 2002. V. 20. P. 2106. DOI:10.1116/1.1517993.
32. Gray D.C., Tepermeister I., Sawin H.H. Phenomenological modeling of ion enhanced surface kinetics in fluorine-based plasma etching. J. Vac. Sci. Technol. B. 1993. V. 11. P. 1243. DOI:10.1116/1.586925.
33. Lee C., Graves D.B., Lieberman M.A. Role of etch products in polysilicon etching in a high-density chlorine discharge. Plasma Chem. Plasma Process. 1996. V. 16. P. 99. DOI:10.1007/BF01465219.
34. Efremov A.M., Kim D. P., Kim C.-I. Simple model for ion-assisted etching using Cl2/Ar inductively coupled plasma: effect of gas mixing ratio. IEEE Trans. Plasma Sci. 2004. V. 32. P. 1344. DOI:10.1109/TPS.2004.828413.

2016, Т. 59, № 10, Стр. 11-18

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