We have investigated In reevaporation during MBE growth of InGaAs on GaAs substrates at various substrate temperatures (540oC∼680oC) and In/(Ga+In) flux ratios (0.1∼0.3). For comparison, we have performed similar experiments on lattice matched InGaAs on InP substrates. The growth rates RInGaAs for InGaAs and RGaAs for GaAs were determined by RHEED intensity oscillation. A proposed rate-equation model for surface processes has proved that the In surface segregation effects due to the In-Ga replacement on the activation energy for In desorption are negligibly small. The activation energy for In reevaporation decreases with an increase in strain in InGaAs/GaAs. The In incorporation fraction decreases with strain in InGaAs. The In incorporation fractions of unstrained InGaAs/InP systems are larger than those of strained InGaAs/GaAs systems. The compressive stress in InGaAs exerts stronger influence on decreasing In incorporation than tensile stress.
