Mechanism of the transport of nickel along a Si(111) surface in the presence of adsorbed cobalt atoms

The mechanism of the transport of nickel along a Si(111) surface in the pre sence of adsorbed cobalt atoms is established by LEED and Auger electronic spectroscopy. The mechanism consists of diffusion of nickel atoms through t he bulk and segregation of the atoms on the surface during annealing. This mechanism of nickel transport plays the governing role at temperatures belo w 700 degrees C, where nickel transport along clean silicon surfaces is not observed. It is found that the nickel segregation factor is what determine s the lowest temperature at which nickel transport is observed on clean sil icon surfaces. (C) 1999 American Institute of Physics. [S0021-3640(99)00606 -4].