A Model for Ion-Assisted Molecular Beam Epitaxy and Application to Synthesis of Epitaxial SNxGE1-x Alloy Films

ABSTRACTIn this work, we develop a model for ion-assisted molecular beam epitaxy with application to synthesis of epitaxial SnxGe1-x/Ge/Si(001) with compositions up to x=0.34. The model describes the effect of energetic beam deposition on surface segregation during thin film growth. As the value of a Péclet number expressing the ratio of surface ion-mixing rate to growth rate exceeds unity, the segregation coefficient during ion-assisted growth exceeds the value during thermal growth. A comparison of the model with experiments for SnxGei.1-x synthesis is reported. The experimental results are consistent with the model.