SCANNING-TUNNELING-MICROSCOPY STUDY OF EPITAXIAL SILICIDE THIN-FILMS

We discuss the atomic surface structure of epitaxial silicide films as studied by scanning tunneling microscopy (STM). A strain-induced (2 x 1) reconstruction of the Si-rich CoSi2/Si(111) surface is shown to be closely related to the Si(111)-(2 x 1) reconstruction. Direct evidenc e for strain relaxation can be obtained by imaging buried misfit dislo cations by STM. The root 2 x root 2 R 45 degrees reconstruction on Co- rich CoSi2/Si(100) is compared with a similar reconstruction on the Si -rich surface and a model is developed for the former. Finally, STM ev idence for a subsurface disorder-order transition in (2 x 2) reconstru cted Fe1-xSi films is given which are stabilized by epitaxy on Si(111) .