GROWTH AND EPITAXY OF YB SILICIDES ON SI(111)

Yb silicides have been grown epitaxially on the Si(111) surface using solid-state epitaxy with annealing to 400-degrees-C. The amount of deposited Yb was varied from parts of a monolayer to films being about 40 monolayer thick. Auger- and photoelectron spectroscopy showed that Si segregates into the Yb overlayer at room temperature and that a strong reaction occurs during annealing to 400-degrees-C leading to the formation of thick silicides. The epitaxial silicides showed a 1 x 1 or a unroofed-radical 3 x unroofed-radical 3 low-energy electron diffraction pattern depending on the detailed preparation procedure. The composition of the silicide was found to be YbSi2-x.