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 × 1) reconstruction of the Si-rich CoSi2/Si(111) surface is shown to be closely related to the Si(111)-(2 × 1) reconstruction. Direct evidence for strain relaxation can be obtained by imaging buried misfit dislocations by STM. The root2 × root2 R 45° 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 evidence for a subsurface disorder-order transition in (2 × 2) reconstructed Fe1-xSi films is given which are stabilized by epitaxy on Si(111).