STM study of successive Ge growth on 'V'-stripe patterned Si (001) surfaces at different growth temperatures
| Autor: | B. Sanduijav, D. Matei, Gunther Springholz |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Materials science
Silicon Condensed matter physics General Physics and Astronomy chemistry.chemical_element Germanium Surfaces and Interfaces General Chemistry Substrate (electronics) Condensed Matter Physics Surfaces Coatings and Films law.invention Crystallography chemistry Quantum dot law Monolayer Self-assembly Scanning tunneling microscope Molecular beam epitaxy |
| Zdroj: | Applied Surface Science. 257:10465-10470 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/j.apsusc.2011.06.162 |
| Popis: | The self-assembly process of Ge islands on patterned Si (0 0 1) substrates is investigated using scanning tunneling microscopy. The substrate patterns consist of one-dimensional stripes with “V”-shaped geometry and sidewalls inclined by an angle of 9° to the (0 0 1) surface. Onto these stripes, Ge is deposited in a step-wise manner at different temperatures from 520 °C to 650 °C. At low temperature, the Ge first grows nearly conformally over the patterned surface but at about 3 monolayers a strong surface roughening due to reconstruction of the surface ridges as well as side wall ripple formation occurs. At 600 °C, a similar roughening takes place, but Ge accumulates within the grooves such that at a critical thickness of 4.5 monolayers, 3D islands are formed at the bottom of the grooves. This accumulation process is enhanced at 650 °C growth, so that the island formation starts about 1 monolayers earlier. At 600 and 650 °C, all islands are all aligned at the bottom of the stripes, whereas at 550 °C Ge island form preferentially on top of ridges. The experimental observations are explained by the strong temperature dependence of Ge diffusion over the patterned surface. |
| Databáze: | OpenAIRE |
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