Details

Autor(en) / Beteiligte

• Persichetti, L.
• Fanfoni, M.
• Bonanni, B.
• De Seta, M.
• Di Gaspare, L.
• Goletti, C.
• Ottaviano, L.
• Sgarlata, A.

Titel

Islanding, growth mode and ordering in Si heteroepitaxy on Ge(001) substrates structured by thermal annealing

Ist Teil von

• Surface science, 2019-05, Vol.683, p.31-37

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2019

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •The novelty of the work which correlates the stability against islanding of tensile-strained Si/Ge wetting layers to the diverse relative contribution of step and surface energies on nearby substrate domains with different surface structure obtained by the high-temperature flash heating.•The wide interest for readers involved in the basic understanding of crystal growth, and those interested in device applications epitaxially built on semiconductor wafers. In contrast to the largely investigated Stranski–Krastanow at the Ge/Si interface, there are a few reports on the growth of tensile-strained islands at the reverse interface. This despite tensile strain is desirable for band-structure engineering in SiGe nanostructures.•The relevance of this work for further understanding of the relationship between nucleation and growth of epitaxial islands, lattice strain and surface properties of the substrate. Si/Ge heteroepitaxial dots under tensile strain are grown on nanostructured Ge substrates produced by high-temperature flash heating exploiting the spontaneous faceting of the Ge(001) surface close to the onset of surface melting. A very diverse growth mode is obtained depending on the specific atomic structure and step density of nearby surface domains with different vicinal crystallographic orientations. On highly-miscut areas of the Ge(001) substrate, the critical thickness for islanding is lowered to about 5 ML, in contrast to the 11 ML reported for the flat Ge(001) surface, while on unreconstructed (1 × 1) domains the growth is Volmer–Weber driven. An explanation is proposed considering the diverse relative contributions of step and surface energies on misoriented substrates. In addition, we show that the bottom-up pattern of the substrate naturally formed by thermal annealing determines a spatial correlation for the dot sites. [Display omitted]