Desorption of Indium during the Growth of GaAs/InGaAs/GaAs Heterostructures by Molecular Beam Epitaxy

The desorption of indium during molecular beam epitaxy (MBE) growth of InGaAs and GaAs/InGaAs/GaAs quantum wells has been investigated by reflection high energy electron diffraction (RHEED). The indium desorption activation energy calculated from the temperature dependence of the InAs growth rate is shown to be almost same as the enthalpy of InAs decomposition. It was found that the RHEED pattern transition time, t1, from (4×2) of InGaAs to (2×4) of GaAs after GaAs heteroepitaxial growth on InGaAs began, was the desorption time of indium, which segregated to the growth front from the topmost layer of InGaAs. The activation energy determined from this process is close to the desorption enthalpy of indium from indium liquid.