Groupe de Physique des Etats Condensés-UMR 6631, Université de la méditerranée, Faculté de Luminy, case 901, 13288 Marseille Cedex 9, France
Abstract:
We report a UHV-CVD homoepitaxy study on the Si(111)7×7 surface investigated with Scanning Tunnelling Microscopy (STM). We have investigated the two-dimensional island density in the temperature range from 450 to 550°C and silane pressure range from 2 to 8×10−4 Torr. Contrary to experiments using molecular beam epitaxy, we find that the two-dimensional island density in UHV-CVD cannot be directly described by the standard nucleation theory. We discuss this point and show that the variation of the steady-state hydrogen coverage on the surface during pressure- or temperature-dependent experiments can explain the observed two-dimensional island density behaviour.