We have studied the interdiffusion and compound formation at the a-Si/
Au and a-Si/Cu thin film interfaces using x-ray reflectivity and grazi
ng incidence EXAFS techniques. In the 0-degrees-C as-deposited samples
, reaction between Si and Au is minimal, but reaction between Si and C
u is significant Upon annealing for ten minutes in argon, the a-Si cry
stallized and reacted quite extensively with Au at 160-degrees-C. Furt
her reaction between Si and Cu proceeded at 130-degrees-C. The compoun
ds formed appear to be metal-rich silicides in both the Si/Au and Si/C
u systems. For Au/Si the silicide is likely stabilized on the surface
of the newly formed crystallites.