KINETICS OF SILICON INTERACTION WITH TEXTURED TANTALUM RIBBONS

The kinetics of silicon interaction with textured tantalum ribbons hav ing a predominantly (100)-oriented surface has been studied by Auger e lectron spectroscopy. For T<700 K, silicon builds up on the surface. W ithin the 900<T<1000-K interval, after the formation of a monolayer co ating, the excess silicon enters into layer-by-layer growth of the sil icide TaSi2. Within 1150<T<1320 K, this excess silicon reacts with tan talum to produce in a layer-by-layer manner the Ta5Si3 silicide; this compound is unstable and decomposes for T> 1320 K to form Ta Si-4, wit h only one third of the original silicon monolayer being left on the s urface. The activation energy of Ta5Si3 decomposition is 4.3+/-0.2 eV. The activation energy of Si thermal desorption at low coverages is 5. 4+/-0.2 eV. (C) 1997 American Institute of Physics.