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A thermodynamic approach is presented to assess the extent of anion exchange reactions during the heteroepitaxy (molecular beam epitaxy) of dissimilar anion III–V compound semiconductor structures. It is shown that the extent of anion exchange can be predicted by the change in the Gibbs free energy. Bond strength changes can only be used as a guide in comparing the relative tendency for exchange, rather than as a criterion. The driving force for anion exchange strongly depends on the conditions during interface formation. A number of important factors, including bond strength, misfit strain energy, surface structure and energy, the equilibrium between dimers V2 and tetramers V4, and segregation are discussed in terms of their contributions to the thermodynamics. [Copyright &y& Elsevier]

Abstract: The successful molecular beam epitaxial growth of single crystalline Sc x Er1− x Sb compounds on InAs(100) substrates has been demonstrated. Ex situ high-resolution X-ray diffraction and Rutherford backscattering spectrometry with ion channeling studies indicate high crystalline quality. The surface reconstruction was monitored in situ by reflection high-energy electron diffraction (RHEED) during the growth and low-energy electron diffraction post growth. The Sc x Er1− x Sb(100) surface exhibited a mixed (1×4)/(4×1) reconstruction. The RHEED patterns and the RHEED intensity oscillations during the growth are consistent with an embedded growth mechanism for the initial Sc x Er1− x Sb growth on InAs. [Copyright &y& Elsevier]

The growth interruption (GI) effect on GaSb quantum dot formation grown on GaAs by molecular beam epitaxy was investigated. The structure characterization was performed by reflection high-energy electron diffraction (RHEED), along with photoluminescence measurements. It is found that the GI can significantly change the surface morphology of GaSb QDs. During the GI, the QDs structures can be smoothed out and turned into a 2D-like structure. The time duration of the GI required for the 3D/2D transition depends on the growth time of the GaSb layer. It increases with the increase of the growth time. Our results are explained by a combined effect of the stress relaxation process and surface exchange reactions during the GI. [Copyright &y& Elsevier]