Surface stress effects during MBE growth of III-V semiconductor nanostructures

摘要

Surface and interface stress evolution measured in situ and in real time during molecular beam epitaxy of InAs/ GaAs and GaSb/GaAs systems, covering initial 2D growth, formation of QDs and subsequent GaAs capping. These Two systems with very similar lattice parameter mismatch but involving quite different surface chemistry show a similar Critical thickness for 2D/3D transition, 0.7-1.0 monolayer ML.Limited In incorporation during InAs/GaAs growth Affects the relaxation process. In segregation effects are observed during GaAs overgrowth. GaSb/GaAs system presents A strong 2D/3D relaxation associated with mass transport from the 2D layer. Sb/As exchange reactions are considered.