SPA-LEED STUDIES OF DEFECTS IN THIN EPITAXIAL NISI2 LAYERS ON SI(111)

Thin epitaxial NiSi2 layers were formed by deposition of 2 up to 20 monolayers Ni at room temperature and following steps of annealing in the range of 550 to 750 K. These very thin layers show not only a rough surface but also inhomogeneities as domain boundaries, variations of stoichiometry and interface roughness. Step density and inhomogeneities are reduced by annealing at temperatures of less than 750 K. The continuous NiSi2 film breaks up into islands of three-fold symmetry above 800 K. It is shown that the process of film formation, annealing and disruption is quantitatively described by careful spot profile analysis of electron diffraction (SPA-LEED). © 1989.