SURFACE RECONSTRUCTION LIMITED MECHANISM OF MOLECULAR-BEAM EPITAXIAL-GROWTH OF ALGAAS ON (111)B FACE

We propose a model which gives a fundamental limiting factor for the growth of epilayers on (111)B face. Our model is that the As-trimer structure of As-stabilized (111)B surface with the (2 X 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 molecular-beam epitaxy over mesa-shaped substrates with (111)A and (111)B sidewalls using As4 and As2. Moreover, the cause of microtwins found in transmission electron microscopy images of AlGaAs grown on (111)B GaAs at a low T(s) can be at least partly explained by this model.