AVS 46th International Symposium
    Surface Science Division Thursday Sessions
       Session SS2+EM+NS-ThM

Paper SS2+EM+NS-ThM4
Confined Intermixing of Ge and Si

Thursday, October 28, 1999, 9:20 am, Room 607

Session: Nucleation and Growth
Presenter: S.-J. Kahng, Seoul National University, Korea
Authors: S.-J. Kahng, Seoul National University, Korea
Y.H. Ha, Korea Research Institute of Standards and Science, Korea
D.W. Moon, Korea Research Institute of Standards and Science, Korea
Y. Kuk, Seoul National University, Korea
Correspondent: Click to Email
In Ge-Si superlattice system, the efficiencies of a possible optoelectric and fast devices can be improved by optimizing the composition at each layer and the abruptness at the interface. It is well- known that intermixing between Ge and Si atoms mainly occurs during the growth process of Si layers on the previously grown Ge layers. Ge atoms tend to segregate toward the surface since the surface free energy of Ge is lower than that of Si. Howerver, with hydrogen adsorbate, the surface free energy of Ge is lower than that of Si, possibly inducing segregation of Si in the Ge overlayer. In this study, Si surface segregation was studied quantitatively for the Ge overlayers grown on Si(100)-(2 x 1) with channeled medium energy ion scattering spectroscopy. The intermixing between Ge and Si presents only at the initial layer in the presence of hydrogen surfactant. Microscopic mechanism for the growth process will be discussed in the view point of kinetics as well as energetics.