INTERFACIAL REACTION IN A-SI/AU AND A-SI/CU THIN-FILM BILAYERS

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 grazing incidence EXAFS techniques. In the 0-degrees-C as-deposited samples, reaction between Si and Au is minimal, but reaction between Si and Cu is significant Upon annealing for ten minutes in argon, the a-Si crystallized and reacted quite extensively with Au at 160-degrees-C. Further reaction between Si and Cu proceeded at 130-degrees-C. The compounds formed appear to be metal-rich silicides in both the Si/Au and Si/Cu systems. For Au/Si the silicide is likely stabilized on the surface of the newly formed crystallites.