Synchrotron radiation photoemission spectroscopy suggests that the room temperature grown Au/Si(111) interface is an abrupt interface with the contact made by metallic Au and bulk Si. Si 2p core level spectra show no sign of an interface component, but only the surface reacted and bulk Si components during the growth of the interface. A surface Au-Si alloy film is first formed for Au coverages below 3 monolayers. The alloy is then stabilized into an ${\mathrm{Au}}_3$Si-like film and detached from the Si substrate when metallic Au starts nucleation in between.

• Received 12 January 1993

DOI:https://doi.org/10.1103/PhysRevLett.70.3768