Kinetics of silicide phase formation in the Yb-Si(111) thin-film system

Formation processes and some physical and chemical properties of ytterbium silicides in the Yb-Si(111) film system have been studied. It is shown that the transition from the metallic ytterbium to silicide films with the Yb$_5$Si$_3$, YbSi and YbSi$_{2-x}$ stoicheometry occurs upon annealing at 400, 470, and 600 K, respectively. The latter has the ordered (1$\times$ 1) structure and exists within the range of 600–1000 K. The work function and the valence of Yb atoms are determined for the silicide films. The optimum temperature for the formation of Yb disilicide film of epitaxial quality on the Si(111) surface is established.