Surface reconstruction limited mechanism of molecularhyphen;beam epitaxial growth of AlGaAs on (111)B face

摘要

We propose a model which gives a fundamental limiting factor for the growth of epilayers on (111)B face. Our model is that the Ashyphen;trimer structure of Ashyphen;stabilized (111)B surface with the (2times;2) reconstruction disturbs the incorporation of group III atoms into lattice sites. This model gives the explanation to most of the reported properties in the growth of GaAs and AlGaAs on (111)B substrates. This model has been verified by comparing the growth rate of GaAs layers grown by molecularhyphen;beam epitaxy over mesahyphen;shaped substrates with (111)A and (111)B sidewalls using As4and As2. Moreover, the cause of microtwins found in transmission electron microscopy images of AlGaAs grown on (111)B GaAs at a lowTscan be at least partly explained by this model.