SURFACTANT-MEDIATED GROWTH OF GE ON SI(111)

The introduction of a surfactant changes the growth in the Si(111)/Ge system from islanding to a continuous film. A Sb monolayer floats at t he growth front without detectable incorporation in the growing film. The surfactant strongly influences the growth kinetics and prevents in termixing or indiffusion of Ge or Si. Up to 8 ML thickness the Ge film is completely strained and pseudomorphic; for thicker films the strai n due to the 4.2% misfit is relieved by the generation of defects, whi ch are finally all confined in a dislocation network at the interface. Low-defect, fully relaxed epitaxial Ge films of arbitrary thickness c an be grown. Similarly, low-defect relaxed Si can be grown on Ge(111). Medium-energy ion scattering, high-resolution transmission electron m icroscopy, x-ray-photoelectron spectroscopy, and Raman scattering show that the crystal quality of these Ge films is excellent.