X-ray absorption resonance spectroscopy as a local probe of the electronic structure at metal-semiconductor interfaces and silicide: Pt/Si, Pd/Si, and Yb/Si

Measurement of the distribution of the empty band states is one of the key problems for reaching a more complete understanding of the electronic structure of metal/semiconductor systems. X-ray absorption resonance on transition-metal (TM) L2,3edges are a probe of the presence and of the approximate distribution of d-like empty states. The results provide evidence of the existence of empty antibonding d-like states in the electronic structure of near-noble-metal/silicon interfaces and silicides; Yb L2.3resonances provide evidence of mixed valency in the Yb/Si system even for thin underreacted Yb/Si interfaces.