Epitaxial Formation of Rare Earth Silicides by Rapid Annealing

Abstract

ABSTRACTRapid electron beam and lamp heating have been used to form thin epitaxial films of rare-earth suicides by reacting overlayers of the rare earths with (111) Si substrates. Of the metals Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, all but Gd are found to form epitaxial suicide layers by rapid solid-phase reaction, while suicides of Gd, Dy, Tm, Yb and Lu have been formed epitaxially by liquid phase reaction. For all but Er this is the first demonstration of epitaxial growth on Si. Details obtained from ion beam channeling analysis and transmission electron microscopy confirm the expected epitaxial structure and also show that the Si vacancies in the suicide form an ordered superlattice, rather than a random array as had been assumed before.