Reflectance anisotropy oscillations of the heteroepitaxial growth of AlAs and Al1 − xGaxAs on GaAs(001) surfaces by molecular beam epitaxy

Reflectance anisotropy (RA) oscillations observed during the molecular beam epitaxial growth of AlAs and AlGaAs/AlAs heterostructures on singular GaAs(001) substrates have been investigated. A temperature dependence study of the AlAs oscillations was carried out in the temperature range 500-580 degrees C and oscillations of large amplitude were readily detected. The effect of alloy stoichiometry on the oscillation amplitude was investigated and the amplitude was found to decrease as the Ga content of the alloy was increased. The origin of these oscillations is discussed in terms of the microscopic nature of the step edges associated with the islands formed during growth. (C) 1997 Elsevier Science B.V.