Experimental results from spectroscopic ellipsometry on the (7 × 7)Si(111) surface reconstruction: dielectric function determination
| Autor: | G. Quentel, Z. Hammadi, M. Gauch, Pierre Müller |
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| Rok vydání: | 1995 |
| Předmět: |
Optical anisotropy
Chemistry Analytical chemistry Physics::Optics Surfaces and Interfaces Surface finish Condensed Matter Physics Molecular physics Spectral line Surfaces Coatings and Films Metal visual_art Materials Chemistry visual_art.visual_art_medium Spectroscopic ellipsometry Dielectric function Anisotropy Surface reconstruction |
| Zdroj: | Surface Science. 341:202-212 |
| ISSN: | 0039-6028 |
| DOI: | 10.1016/0039-6028(95)00592-7 |
| Popis: | The dielectric function of the (7 × 7) Si(111) surface has been directly determined in UHV conditions by ellipsometric measurements on a Si(111) clean surface. The dielectric function obtained from ellipsometric spectra near the pseudo-Brewster angle (PB) has been calculated by means of a three-phase model (bulk, (7 × 7) transition layer and vacuum) in which optical properties of bulk Si are deduced from literature data and the thickness of the (7 × 7) transition layer is taken from the DAS model. Our calculation allows us to confirm the metallic character of the (7 × 7) transition layer and to point out the previously found surface-state transitions at 2.6 and 3.4 eV and perhaps at 1.6 eV. Furthermore, a surface-state transition has also been confirmed at 3 eV. Ellipsometric results depend on the crystallographic direction. This optical anisotropy is ascribed to some roughness anisotropy induced by steps. |
| Databáze: | OpenAIRE |
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