Electron-Beam-Induced Decomposition of SiO2 Overlay on Si in STM Nanolithography
Combined with thermal annealing, a locally confined low energy electronbeam from a STM tip can be used for nanofabrication of a Si oxide film on a Si substrate: the oxide layer within the e-beam exposed area can be decomposed and then evacuated from the surface at elevated temperatures above 300°C. We evaluate the quantum yield of the SiO2 decomposition over an electron energy range of 10 to 180 eV and find onsets near 30 and 120 eV. These onsets are close to those found previously for electron beam induced SiO2 dissociation by Auger electron spectroscopy and electron stimulated desorption. The SiO2 decomposition cross-section evaluated is about 10-21 cm2 at 150 eV which also agrees with the previously reported values. These findings indicate that the Si oxide layer is decomposed by electron irradiation in a STM nanolithography process by a Knotek-Feibelman-like mechanism: primary ionization of high-lying core levels, followed by Auger processes which lead to localized valence holes, constitutes important channels for SiO2 dissociation.
KeywordsScanning Tunneling Microscopy Incident Electron Energy Electron Stimulate Desorption Primary Electron Energy Electron Energy Range
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- 7.M. I. Datsiev: Zh. Tekhn. Fiz. 39 (1969) 1284.Google Scholar
- 9.R. A. Baragiola, T. E. Madey and A.-M. Lanzillotto: in Desorption Induced by Electronic Transitions, DIET IV, ed. By G. Bets and P. Varga, (Springer-Verlag, New York, 1990) pp. 322.Google Scholar
- 11.L. Calliari, M. Dapor, L. Gonzo and F. Marchetti: in Desorption Induced by Electronic Transitions, DIET IV, ed. By G. Bets and P. Varga, (Springer-Verlag, New York, 1990) pp. 373.Google Scholar
- 17.S. Fujita, S. Maruno, H. Watanabe and M. Ichikawa: J. Vac. Sci. Technol. A15 (1997) 1493.Google Scholar
- 19.E. g. see M. Liehr, J.E. Lewis, and G.W. Rublo., J. Vac. Sci. Technol. A5, 1559 (1987); G.W. Rublo., J. Vac. Sci. Technol. A 8, 1853, (1990).Google Scholar