Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-27T02:29:03.044Z Has data issue: false hasContentIssue false

Reactive Ion Etching of Molybdenum In CF4/O2 Plasma

Published online by Cambridge University Press:  28 February 2011

Seong-Ju Park
Affiliation:
IBM T.J.Watson Research Center, Yorktown Heights, N.Y.10598
C. P. Sun
Affiliation:
IBM T.J.Watson Research Center, Yorktown Heights, N.Y.10598
J. T. Yeh
Affiliation:
IBM T.J.Watson Research Center, Yorktown Heights, N.Y.10598
J. K. Cataldo
Affiliation:
IBM T.J.Watson Research Center, Yorktown Heights, N.Y.10598
N. Metropoulos
Affiliation:
IBM T.J.Watson Research Center, Yorktown Heights, N.Y.10598
Get access

Abstract

A mechanistic study of Mo etching in a CF4/O2 plasma has been performed using optical emission spectroscopy, mass spectrometry and x-ray photoelectron spectroscopy.Etching characteristics of Mo for a wide range of conditions relevant to plasma processing are also reported.Addition of small amount of O2 to the CF4 plasma dramatically increases the Mo etch rates, as well as concentrations of 0 and F in plasma.However, further addition of O2 above 50 % leads to decrease in etch rates.Two types of neutral molybdenum oxifluorides and a trace amount of molybdenum hexafluoride were observed in the effluent gas.Comparing the etch rates with the concentration changes of F and 0 with and without Mo present in plasma, it is suggested that Mo is chemically etched by F and 0.Atomic oxygen enhances the etch rate by increasing the F concentration in the plasma as well as by removing a carbon layer forming desorbed CO on the surface.XPS and AES analysis results for the etched surface inferred that chemisorbed fluorocarbon radicals dissociate into carbon and fluorine atoms, which in turn form a passivating graphite-like layer and a volatile molybdenum oxifluoride and molybdenum hexafluoride layer.

Type
Articles
Copyright
Copyright © Materials Research Society 1986

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Mochizuki, T., Shibata, K., Inoue, T., and Ohuchi, K., Jpn.J.Appl.Phy. 17.Suppl.17–1, 37 (1977).CrossRefGoogle Scholar
2. Oda, M. and Hirata, K., Proc.2nd Symp.on Dry-Process, 87, Inst.Electr.Eng., Tokyo, 1980.Google Scholar
3. Chow, T.P. and Steckl, A.J., Appl.Phy.Lett. 36, 297 (1980).Google Scholar
4. Sinha, A.K., Lindenburger, W.S., Fraser, D.B., Muraka, S.P., and Fuls, E.N., IEEE Trans.Electron Devices ED–27, 1425 (1980).CrossRefGoogle Scholar
5. Chow, T.P. and Steckl, A.J., Appl.Phy.Lett. 37, 466 (1980).Google Scholar
6. T,Chow, P. and Steckl, A.J., J.Appl.Phy. 5 (1982).Google Scholar
7. Kurogi, Y. and Kamimura, K., Jpn.J.Appl.Phy. 21(1), 168 (1982).Google Scholar
8. Hosoya, T., Ohfuji, S., and Shibata, T., J.Electrochem.Soc. 131(5), (1984).Google Scholar
9. Turban, G. and Picard, A., ISPC-7, proceeding p.1073 (1985).Google Scholar
10. Coburn, J.W. and Chen, M., J.Appl.Phys. 51, 3134 (1980).Google Scholar
11. Walkup, R.E., Saenger, K.L., and Selwyn, G.S., J.Chem.Phys.(1986), to be published.Google Scholar
12. Coburn, J.W., unpublished results, cited by A.Dilks and E.Kay in “Plasma Polymerization”, ACS Symp.Series, 108, p.195 (1979) ed.by M.Shen and A.T.Bell.Google Scholar
13. Grant, J.T. and Hass, T.W., Surf.Sci. 24, 332 (1971).Google Scholar