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Focussed Ion Beams from Liquid Metal Ion Sources Theory and Applications

Published online by Cambridge University Press:  25 February 2011

David R Kingham
Affiliation:
VG Scientific Ltd, The Birches Industrial Estate, Imberhorne Lane, East Grinstead, Sussex, RH19 lUB, UK
Vincent J Mifsud
Affiliation:
VG Semicon Ltd, The Birches Industrial Estate, Imberhorne Lane, East Grinstead, Sussex, RH19 1XZ, UK
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Abstract

A theoretical model of liquid metal ion source (LMIS) operation has been developed by Kingham and Swanson. In this paper we consider beams from LMIS on the basis of this model. In particular we consider properties such as angular intensity, energy spread and relative abundance of differently charged species of the ion beam, and the dependence of these properties on source current and elemental composition. The conclusion is that the brightest focussed beam for a given probe size is attainable at the lowest possible source current as previously stated by Swanson. LMIS sources have an onset current of typically 1-2[A and will not operate stably below this current, thus limiting the maximum focussed ion beam brightness. The physical reason for this is discussed. The relevance of these properties to fine focussed ion beam applications, particularly semiconductor processing, is discussed. Useful, and in some cases unique, device manufacturing techniques can be postulated using one or more of the momentum, energy or atomic addition properties inherant tothis type of system. Advanced research tools are discussed, together with some examples of the use of microfocussed ion beams with probe sizes down to less than 50nm. Immediate applications include: high resolution ion imaging and SIMS microanalysis; ion beam machining and microfabrication; ion beam resist exposure and ion beam mask repair.

Type
Research Article
Copyright
Copyright © Materials Research Society 1985

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References

REFERENCES

1. Kingham, D.R. and Swanson, L.W., Applied Phys A34 123 (1984)Google Scholar
2. Kingham, D.R. and Swanson, L.W., Vacuum 34 941 (1984)CrossRefGoogle Scholar
3. Haydock, R. and Kingham, D.R., Phys.Rev.Letters.44 1520(1980)Google Scholar
4. Sujatha, N., Cutler, P.H., Kazes, E., Rogers, J.P. and Miskovsky, N.M., Applied. Phys. A32 55 (1983) and ref thereinGoogle Scholar
5. Taylor, G.I., Proc. Roy. Soc.(London) 280A 383 (1984).Google Scholar
6. Kang, N.K., Orloff, J., Swanson, L.W. and Tuggle, D., J.Vac. Sci Technol 19 1077 (1981).CrossRefGoogle Scholar
7. Swanson, L.W., Nucl. Instrum. Meth 218 347 (1983)Google Scholar
8. Namba, S., Proc.Inth.Ion Eng Congress ISIAT'83 Kyoto(1983).Google Scholar
9. Mifsud, V.J. (to be published)Google Scholar
10. Wagner, A. etal. Electron,Ion and Photon Beam Technol Symp. (1983).Google Scholar
11. Ochiai, Y., Gamo, K., and Namba, S. Elec. Ion, Photon Beam Technol. Symp. (1984)Google Scholar
12. Komuro, M., Hiroshima, H. etal. Elec, Ion Photon Beam Technol Symp. (1983).Google Scholar
13. Cleaver, J.R.A., Heard, P.J., Ahmed, H., Microcircuit Eng. 83 (Academic Press).Google Scholar
14. Broughton, D., Clampitt, R., Vacuum Vol 34(275-279) (1984)Google Scholar
15. Wang, V., Ward, J.W., Seliger, R.L., J.Vac Sci Technol 24(1981)Google Scholar
16. Mifsud, V.J. - Priv. comm with Prof. J.Correlli (Rensellaer)Google Scholar
17. Broughton, C., Beale, M., V.G. Deshmukh Appl. Microfocused Ion Beams Meeting (UK Inst. of Physics 1985).Google Scholar