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Thermally induced surface faceting on heteroepitaxial layers.
- Source :
-
Journal of Applied Physics . 2/21/2023, Vol. 133 Issue 7, p1-8. 8p. - Publication Year :
- 2023
-
Abstract
- Heteroepitaxial semiconductors such as Ge-on-Si are widely used in current opto-electronic and electronic applications, and one of the most important challenges for epitaxial Ge-on-Si is threading dislocations (TDs) in Ge layers caused by lattice mismatch between Ge and Si. Here, apart from traditional wet chemical etching, we report a convenient approach to evaluate the threading dislocation densities in heteroepitaxial layers through vacuum thermal annealing. More importantly, the controversial origin of thermal annealing induced pits on a Ge surface was addressed in this work. By combining both experiments and density functional theory (DFT) calculations, we find that the {111} facets defined thermal pits on Ge (001) surfaces are mainly caused by threading dislocation activation. Ge adatoms at the TD segments sublimate preferentially than the ones on dislocation-free Ge (001) surface regions, and its further evolution is determined by surface energies of {111} facets, leading to a construction of inverted pyramid-shaped thermal pits. [ABSTRACT FROM AUTHOR]
- Subjects :
- *DENSITY functional theory
*DISLOCATION density
*SURFACE energy
Subjects
Details
- Language :
- English
- ISSN :
- 00218979
- Volume :
- 133
- Issue :
- 7
- Database :
- Academic Search Index
- Journal :
- Journal of Applied Physics
- Publication Type :
- Academic Journal
- Accession number :
- 162006359
- Full Text :
- https://doi.org/10.1063/5.0133765