Growth behaviour of epitaxial NiSi2 islands of A- and B-types during the reaction of nickel vapour with the Si(111) surface

Article abstract of DOI:10.1002/pssa.2211160108

Epitaxial NiSi₂ islands of both A- and B-orientation were grown in UHV by the reaction of nickel vapour with Si(111) surfaces at 670 K. Habit, structure, and relative volume share of A- and B-type islands, respectively, were investigated in plane view and cross section by SAED and TEM (diffraction contrast at 1 MV; high resolution at 400 kV) for different amounts of deposited nickel. A-type islands grow with a three-dimensional shape, B-type islands with a more two-dimensional shape. Both types of islands are bounded by {111}_Si faces, which represent {111} faces for the A-NiSi₂ lattice, but {111} and lateral {151} faces for B-NiSi₂. A-type islands grow about 10 times more rapidly than B-type ones. The observations are discussed with respect to R.T. Tung's model related to growing uniformly oriented NiSi₂ films.