Dynamic observations of the formation of thin Cu layers on clean and hydrogen-terminated Si(111) surfaces

The growth of Cu on the clean and hydrogen-terminated Si(1 1 1) surfaces is studied in situ by low-energy electron microscopy (LEEM). The dependence o f the growth of the "5 x 5" layer on the clean Si(1 1 1) 7 x 7 surface upon the deposition temperature is investigated by combining LEEM with LEED. Af ter completion of the "5 x 5" layer not only the regular-shaped three-dimen sional islands reported before are observed but also irregular shaped more two-dimensional islands. On the hydrogen-terminated Si(1 1 1) surface the f ormation of the "5 x 5" structure is suppressed and nano-scale islands form preferentially at the step edges and domain boundaries. This is attributed to the enhancement of the surface migration of Cu atoms by the elimination of the surface dangling bonds. (C) 2001 Elsevier Science B.V. All rights r eserved.