Metallic state of Si in Si−noble−metal vapor−quenched alloys studied by Auger electron spectroscopy

Thin vapor−quenched films of Si−Au (Ag, Cu) alloys were studied by using Auger electron spectroscopy (AES). In these films, when the concentration of the noble metal was more than a critical value (∼70 at.%), the Si (LVV) Auger spectrum had double peaks at 90 and 95 eV; these peak energies were all the same for Si−Au, Si−Ag, and Si−Cu. However, with smaller noble−metal concentrations, the Si (LVV) spectrum was nothing but that of pure Si having a single peak at 92 eV. These results are explained by the statement that the double−peaked spectrum reflects the metallic state of Si quenched from the liquid state and some amount of metal is necessary to stabilize the metallic Si.