The Si(001) c(4 x 4) surface reconstruction: a comprehensive experimental study
| Autor: | H. Nörenberg, G. A. D. Briggs |
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| Rok vydání: | 2016 |
| Předmět: |
Auger electron spectroscopy
Reflection high-energy electron diffraction Chemistry Analytical chemistry Biasing Surfaces and Interfaces Condensed Matter Physics Crystallographic defect Surfaces Coatings and Films law.invention Electron diffraction law Vacancy defect Materials Chemistry Scanning tunneling microscope Surface reconstruction |
| Popis: | We have carried out a comprehensive experimental study of the Si(001) c(4×4) surface reconstruction by scanning tunneling microscopy (STM) (at room temperature and elevated temperatures), Auger electron spectroscopy (AES), reflection high-energy electron diffraction (RHEED) and low-energy electron diffraction (LEED). Si(001) samples were kept under ultra-high vacuum (UHV) at around 550°C until the c(4×4) reconstruction appeared. STM contrast of the c(4×4) reconstruction is strongly influenced by electronic effects and changes considerably over a range of bias voltages. The c(4×4) surface reconstruction is a result of stress which is caused by incorporation of impurities or adsorbates in sub-surface locations. The resulting c(4×4) reconstruction in the top layer is a pure silicon structure. The main structural element is a one-dimer vacancy (1-DV). At this vacancy, second layer Si-atoms rebond and cause the adjacent top Si-dimers to brighten up in the STM image at low bias voltages. At higher bias voltage the contrast is similar to Si-dimers on the (2×1) reconstructed Si(001). Therefore, besides the 1-DV and the two adjacent Si-dimers, another Si-dimer under tensile stress may complete the 4× unit cell. This is a refinement of the missing dimer model. |
| Databáze: | OpenAIRE |
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