Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-25T04:28:55.839Z Has data issue: false hasContentIssue false

Production of 0.1–3 eV reactive molecules by laser vaporization of condensed molecular films: A potential source for beam-surface interactions

Published online by Cambridge University Press:  31 January 2011

Lisa M. Cousins
Affiliation:
Joint Institute for Laboratory Astrophysics, National Institute of Standards and Technology and University of Colorado, and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0440
Stephen R. Leone
Affiliation:
Joint Institute for Laboratory Astrophysics, National Institute of Standards and Technology and University of Colorado, and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0440
Get access

Abstract

A versatile, repetitively pulsed source of translationally fast, reactive molecules is described that is suitable for materials processing experiments. The pulsed beams are generated by excimer laser vaporization of cryogenic molecular films that are continuously condensed on transparent substrates. The generation of fast, energy variable pulsed molecular sources of Cl2 and NO is demonstrated. The most probable translational energies of Cl2 and NO molecules can be reproducibly varied monotonically by adjusting the laser fluence or film thickness. Here, the most probable translational energy is quoted as the energy corresponding to the maximum of the time-of-flight trace. Using laser fluences of 2–25 mJ cm−2 from a 193 nm excimer laser, the most probable translational energies of Cl2 are 0.4–2 eV. Significant fractions of molecules with translational energies greater than 3 eV are observed at the leading edges of the distributions. Very similar results are obtained by vaporizing Cl2 with 248 and 351 nm radiation. Pulses of translationally fast NO molecules are generated in a similar manner; most probable energies from 0.1–0.4 eV, with the fastest molecules up to 0.8 eV, are obtained using laser fluences of 1–11 mJ cm−2 at 193 nm. Approximately 1013−1014 molecules per cm2 of the film are vaporized per laser pulse, depending on film thickness and laser fluence.

Type
Articles
Copyright
Copyright © Materials Research Society 1988

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

REFERENCES

1Dry Etching for Microelectronics, edited by Powell, R. A. (Elsevier, Amsterdam, 1984).Google Scholar
2Materials Modification and Growth Using Ion Beams, edited by Gibson, U. J., White, A. E., and Pronko, P. P. (Materials Research Society, Pittsburgh, PA, 1987).Google Scholar
3Coburn, J. W. and Winters, H. F., J. Vac. Sci. Technol. 16, 391 (1979).CrossRefGoogle Scholar
4Coburn, J. W. and Winters, H. F., J. Appl. Phys. 50, 3189 (1979).CrossRefGoogle Scholar
5Winters, H. F., J. Vac. Sci. Technol. A 3, 700 (1985).Google Scholar
6Winters, H. F., J. Vac. Sci. Technol. B 3, 9 (1985).Google Scholar
7Mizutani, T., Dale, C. J., Chu, W. K., and Mayer, T. M., Nucl. Instrurn. Methods B 7/8, 825 (1985).Google Scholar
8Oostra, D. J., Haring, A., and deVries, A. E., J. Vac. Sci. Technol. B 4, 1278 (1986).Google Scholar
9Oostra, D. J., Haring, A., deVries, A. E., Sanders, F. H. M., and Veen, G. N. A. Van, Nucl. Instrum. Methods B 13, 556 (1986).Google Scholar
10Zuhr, R. A., Alton, G. D., Appleton, B. R., Herbots, N., Noggle, T. S., and Pennycock, S. J., in Ref. 2, p. 243.Google Scholar
11Appleton, B. R., Pennycock, S. J., Zuhr, R. A., Herbots, N., and Noggle, T. S., Nucl. Instrum. Methods B 19/20, 975 (1987).Google Scholar
12Zuhr, R. A., Appleton, B. R., Herbots, N., Larson, B. G., Noggle, T. S., and Pennycock, S. J., J. Vac. Sci. Technol. A 5, 2135 (1987).Google Scholar
13Dodson, B. W., Phys. Rev. B 36, 1068 (1987).Google Scholar
14Garrison, B. J., Mitchell, M T., and Brenner, D. W., Chem. Phys. Lett. 146, 553 (1988).CrossRefGoogle Scholar
15Dodson, B. W. and Taylor, P. A., J. Mater. Res. 2, 805 (1987).Google Scholar
16Flynn, G. W. and Weston, R. E. Jr , Ann. Rev. Phys. Chem. 37, 551 (1986).CrossRefGoogle Scholar
17Abauf, N., Anderson, J. B., Andres, R. P., Fenn, J. B., and Marsden, D. G. H., Science 155, 997 (1967).Google Scholar
18Friichtenicht, J. F., Rev. Sci. Instrum. 45, 51 (1974).CrossRefGoogle Scholar
19Tang, S. P., Utterback, N. G., and Friichtenicht, J. F., J. Chem. Phys. 64, 3833 (1976).CrossRefGoogle Scholar
20Wicke, B. G., Tang, S. P., and Friichtenicht, J. F., Chem. Phys. Lett. 53, 304 (1977).Google Scholar
21Wicke, B. G., J. Chem. Phys. 78, 6036 (1983).Google Scholar
22Domen, K. and Chuang, T. J., Phys. Rev. Lett. 59, 1484 (1987).CrossRefGoogle Scholar
23Harrison, I., Polanyi, J. C., and Young, P. A., J. Chem. Phys. 89, 1498 (1988).Google Scholar
24Nishi, N., Shinohara, H., and Okuyama, T., J. Chem. Phys. 80, 3898 (1984).Google Scholar
25Brinza, D. E., Coulter, D. R., Liang, R. H., Gupta, A., in Proceedings of the NASA Workshop on Atomic Oxygen Effects, edited by Brinza, D. E. (JPL, Pasadena, CA, 1987).Google Scholar
26Bauerle, D., Chemical Processing with Lasers, Springer Series in Materials Science (Springer, Berlin, 1986), Vol. 1.CrossRefGoogle Scholar
27Srinivasan, R., Science 234, 559 (1986); E. Sutcliffe and R. Srinivasan, J. Appl. Phys. 60, 3315 (1986).CrossRefGoogle Scholar
28Rothenberg, J. E. and Kelly, R., Nucl. Instrum. Methods B 1, 291 (1984).Google Scholar
29Dreyfus, R. W., Kelly, R., and Walkup, R. E., Appl. Phys. Lett. 49, 1478 (1986); M. Eyett and D. Bauerle, Appl. Phys. Lett. 51, 2054 (1988).CrossRefGoogle Scholar
30Brown, W. L., Lanzerotti, L. J., Marcantonio, K. J., Johnson, R. E., and Reimann, C. T., Nucl. Instrum. Methods B 14, 392 (1986).CrossRefGoogle Scholar
31Cousins, L. M. and Leone, S. R. (in preparation).Google Scholar
32Okabe, H., Photochemistry of Small Molecules (Wiley, New York, 1978), p. 185.Google Scholar
33Fajardo, M. E., Apkarian, V. A., Maustakas, A., Krueyer, H., and Weitz, E., J. Phys. Chem. 92, 357 (1988).CrossRefGoogle Scholar
34Suzuki, M., Yokoyama, T., and Ito, M., J. Chem. Phys. 50, 3392 (1969).CrossRefGoogle Scholar
35Herzog, T. and Schwab, G. M., Z. Phys. Chem. 66, 190 (1969).CrossRefGoogle Scholar
36Yakovenko, E. I., Serteev, G. B., and Kalinina, G. P., Dauk. Akad. Nauk. SSSR 173, 626 (1966).Google Scholar
37Dreyfus, R. W., Kelly, R., and Walkup, R. E., Nucl. Instrum. Methods B 23, 557 (1987).CrossRefGoogle Scholar
38Cowin, J. P., Auerbach, D. J., Becker, C., and Wharton, L., Surf. Sci. 78, 545 (1978).CrossRefGoogle Scholar
39Utterback, N. G., Tang, S. P., and Friichtenicht, J. F., Phys. Fluids 19, 900 (1976).CrossRefGoogle Scholar
40Cottet, F. and Romain, J. P., Phys. Rev. A 25, 576 (1982).CrossRefGoogle Scholar
41Dyer, P. E. and Srinivasan, R., Appl. Phys. Lett. 48, 445 (1986).Google Scholar
42Carls, J. C. and Brock, J. R., Opt. Lett. 13, 273 (1988).Google Scholar
41Schoeffman, H., Schmidt-Kloiber, H., and Reichel, E., J. Appl. Phys. 63, 46 (1987).CrossRefGoogle Scholar
44Srinivasan, R. and Ghosh, A. P., Chem. Phys. Lett. 143, 546 (1988).CrossRefGoogle Scholar
45Bitensky, I. S. and Parilis, E. S., Nucl. Instrum. Methods B 21, 26 (1987).Google Scholar