Isopropoxy induced stabilisation of the 2x1 reconstruction of Si(100)
- Alcohols are successfully employed as an additive in the anisotropic etching of silicon. In this HREELS study, we modelled the silicon/etching interface by the adsorption of alcohols (ethanol, isopropanol, n-propanol, tert-butyl alcohol) on Si(100)-2x1 and post-exposure to H2O under ultra high vacuum conditions. The vibrational data show that the adsorption of the alcohol molecules involves the cleavage of the O-H bond and the formation of a Si-O-C linkage to the alkoxy species. The dissociated hydrogen saturates one of the neighbouring dangling Si bonds. The Si-Si dimer bonds are not involved in the adsorption process. We observe a considerable chemisorption of water on the ethoxy and tert-butoxy passivated Si(100)-2x1 surface. From the disappearance of the 2x1 LEED pattern it can be concluded that the chemisorption of water occurs through a cleavage of the Si-Si dimer bond. In contrast, isopropoxy species on Si(100)-2x1 reduces dramatically the reactivity of Si(100)-2x1 towards water. Even following extreme exposures to water (1012Alcohols are successfully employed as an additive in the anisotropic etching of silicon. In this HREELS study, we modelled the silicon/etching interface by the adsorption of alcohols (ethanol, isopropanol, n-propanol, tert-butyl alcohol) on Si(100)-2x1 and post-exposure to H2O under ultra high vacuum conditions. The vibrational data show that the adsorption of the alcohol molecules involves the cleavage of the O-H bond and the formation of a Si-O-C linkage to the alkoxy species. The dissociated hydrogen saturates one of the neighbouring dangling Si bonds. The Si-Si dimer bonds are not involved in the adsorption process. We observe a considerable chemisorption of water on the ethoxy and tert-butoxy passivated Si(100)-2x1 surface. From the disappearance of the 2x1 LEED pattern it can be concluded that the chemisorption of water occurs through a cleavage of the Si-Si dimer bond. In contrast, isopropoxy species on Si(100)-2x1 reduces dramatically the reactivity of Si(100)-2x1 towards water. Even following extreme exposures to water (1012 Torr s), a 2x1 LEED pattern was observed indicating the presence of intact Si-Si dimer bonds at the isopropoxy/Si(100)-2x1 surface.…
Author: | Thomas Heller, Alberto Lopez, Thomas BitzerGND, Neville V. Richardson, Dieter SchmeißerORCiD |
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URL: | http://www.dpg-verhandlungen.de/year/2000/conference/regensburg/part/o/session/11/contribution/55?lang=en |
Title of the source (German): | Verhandlungen der Deutschen Physikalischen Gesellschaft |
Publisher: | Deutsche Physikalische Gesellschaft |
Place of publication: | Bad Honnef |
Document Type: | Conference Proceeding |
Language: | English |
Year of publication: | 2000 |
Tag: | alcohol adsorption; anisotropic etching; high resolution electron energy loss spectroscopy (HREELS); low-energy electron diffraction (LEED) |
Series ; volume number: | Verhandlungen der Deutschen Physikalischen Gesellschaft ; Reihe 6, Band 35 |
Faculty/Chair: | Fakultät 1 MINT - Mathematik, Informatik, Physik, Elektro- und Informationstechnik / FG Angewandte Physik und Halbleiterspektroskopie |