Interference enhanced Raman scattering study of the interfacial reaction of Pd on a‐Si:H

The application of interference enhanced Raman scattering to probe the structure of metal/semiconductor interfaces is described. This technique is used to study the interface structures of Pd on hydrogenated amorphous Si (a‐Si:H) with particular attention to the effects of a native oxide layer on the a‐Si:H. It is found that for deposition on lightly oxidized a‐Si:H, ∠20 Å of Pd is consumed to form a crystalline silicide interfacial structure with composition near Pd₂Si. Annealing causes growth of this phase and further consumption of Pd until a second phase of Pd₂Si is observed. If the deposition is repeated on more heavily oxidized a‐Si:H, no silicide formation is observed even at annealing temperatures of 400 °C.