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RIE Plasma and ETCH Mechanisms

Published online by Cambridge University Press:  28 February 2011

John H. Keller*
Affiliation:
IBM, GTD Division, East Fishkill, Hopewell Jct., NY.12533
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Abstract

Three independent models are presented: One for determining the plasma density and target sheath voltage, one for silicon etching using CF4plus O2, and one for RIE etching of silicon dioxide.

In most dry etching techniques the target and plasma voltages play a large role.In this paper, the dc and rf mechanisms which determine the plasma density, and thus the target voltage, are presented.The mechanisms used are: 1) secondary electron ionization in the sheath, 2) secondary electron ionization in the plasma, 3) ionization by tertiary electrons, 4) I2R heating of the plasma electrons, and 5) sheath heating of plasma electrons.An equivalent circuit for an rf discharge is presented, and the relationship between the plasma voltage and target sheath voltage are discussed.

The mechanisms used to model silicon etching include chemical etching, ion enhanced etching and diffusion of reactive species.Laser induced fluorescence data from G.S.Selwyn will be discussed.These data show spatial resolution of a reactive species in an RIE plasma and show the diffusion effects.

The ion-enhanced etching effect for SiO2, shows a much stronger voltage dependence than that for Si, which is almost independent of voltage.Data from G.Fortuno show that the voltage dependence for SiO2 is similar to that of sputtering.The mechanisms used to model SiO2 etching include the work by G.Fortuno (1985) and that by B.N.Chapman and V.J.Minkiewicz (1978).

Type
Articles
Copyright
Copyright © Materials Research Society 1986

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References

(1) Coburn, J.W. and Winters, H.F., J.Vac Sci.Technol., 15 327 (1972).CrossRefGoogle Scholar
(2) Coburn, J.W., and Winters, H.F., J.Appl.Phys., 50, 3189 (1979)CrossRefGoogle Scholar
(3) Schwartz, G.C, Rothman, L.B. and Schopen, T.J., J.Electrochem.Soc., 126, 464, (1979).CrossRefGoogle Scholar
(4) Flamm, D.L. and Donnelly, V.M., Plasma Chem.& Plasma Proc., 1, 317 (1981)CrossRefGoogle Scholar
(5) Lee, Y.H. and Chen, M-M, J.Appl.Phys., 54, 5966 (1983).CrossRefGoogle Scholar
(6) Us, N.C., Master Thesis Dept.Material Sci.& Eng., MIT, (1985) [see also N.C.Us, R.W.Sadowski, and J.W.Coburn, Plasma Chem.& Plasma Proc., 6, 1 (1986)].Google Scholar
(7) Fortuno, G., Abstract: Bull.Am.Phys.Soc.(1986).paper to be published J.Appl.Phys.Google Scholar
(8) Fortuno, G., to be published, J.Vac.Sci.Technol., 23, (1986).Google Scholar
(9) Ephrath, L.M., and Bennett, R.S., Microcircuit Engineering, 389 (1983).Google Scholar
(10) Keller, J.H. and Pennebaker, W.B. IBM J.Res.Develop. 23, 3 (1979).CrossRefGoogle Scholar
(11) Little, P.F. and von Engel, A., “The Hollow-Cathode Effect and Theory of Glow Discharges,” Proc.Roy.Soc.A 224, 209 (1954).Google Scholar
(12) Cuomo, J.J., Gambino, R.J. and Rosenberg, R., J.Vac.Sci.Technol., 11, 34 (1974).CrossRefGoogle Scholar
(13) Matskevich, T.L., “Investigation of Electron-Reflection by Dielectrics,” Zh.tekh.Fiz 27 (2) 289 (1957).Google Scholar
(14) Klyarfeld, B.N., Guseva, L.G., and Vlasov, V.V., “Effect of Electron Reflection from the Anode on the Cathode Fall in Glow Discharge” Soviet Phys.Tech.Phys. 13, (8) 1056 (1969).Google Scholar
(15) Gould, R.W., Phys.Letters, Vol.11, No.3 (Aug.1964), 236.CrossRefGoogle Scholar
(16) Taillet, J., Am.J.Phys. 37, 423 (1969).CrossRefGoogle Scholar
(17) Pennebaker, W.M., IBM J.Res.Develop., 23, 16 (1979)CrossRefGoogle Scholar
(18) Acton, and Swift, , “Cold Cathode Discharge Tubes,” Academic Press, New York (1963).Google Scholar
(19) Selwyn, G.S., and Kay, E., Plasma Chem.Plasma Proces., 5, 189 (1985); and unpublished data.CrossRefGoogle Scholar
(20) Ephrath, L.M., IEEE Trans Electron Devices ED 28, 1315 (1981)CrossRefGoogle Scholar
(21) Selwyn, G.S., MRS Fall Meeting, Boston, Ma.Nov.(1984); submitted for publication.[see also Dreyfus, R.W., Jasinski, J.M., Walkup, R.E. and Selwyn, G.S., Pure & Appl.Chem., 57, 1265 (1985)].Google Scholar
(22) Lee, Y.H. and Chen, M-M, (Personal Communications)Google Scholar
(23) Chapman, B.N. and Minkiewicz, V.J., J Vac.Sci.Technol., 15, 329 (1978)CrossRefGoogle Scholar
(24) Logan, J.S., Keller, J.H., and Simmons, R.G., J.Vac.Sci.Technol. 14, 92 (1977).CrossRefGoogle Scholar