Preparation and characterization of epitaxial yttrium silicide on (111) silicon.

Epitaxial YSi sub (2-x) films have been fabricated. The smooth 515angstroms thick silicide films on Si(111) substrates were characterized by a Rutherford backscattering minimum channeling yield, CHI sub (min) = 8%. The best previously reported result, CHI sub (min) = 26%, was achieved using a relatively exotic e-beam heating method. By contrast we formed YSi sub (2-x) using a straightforward furnace annealing technique. We used improved Si surface cleaning procedures, sputter-deposited Y films, and performed two-stage anneals in a vacuum of ~ 10 sup (-8) torr. The results of our work establish YSi sub (2-x) as one of the best epitaxial silicides. We describe our preparation technique as well as the evidence for epitaxy. Electrical measurements (Schottky barrier, temperature dependent resistivity, Hall effect) are also presented.