SILICON HOMOEPITAXY ON HIGH-INDEX SURFACES AND THE EFFECT OF ANTIMONYON THIS GROWTH

We report on the structure of Si films grown by molecular beam epitaxy on highly misoriented Si(111) surfaces and on the influence of Sb on this growth. Although the equilibrium morphology of these surfaces is a mixture of single and triple height steps, one observes for temperat ures lower than the 1 X 1 to 7 X 7 transition one, by LEED, AFM and HR TEM, that the MBE growth gives rise to an important roughness. On the contrary, at higher temperature or when Si and Sb are coevaporated, we stabilize a regular array of steps. We show that these steps are tria tomic in the former case and monoatomic in the latter, Such a behaviou r illustrates the major role played by the 7 X 7 reconstruction on the growth morphology of Si films.