Ni on Si: Interfacial compound formation and electronic structure

Photoemission and Auger electron spectroscopic measurements are done on Ni-Si interfaces prepared by Ni deposition onto cleaved Si(111) surfaces with the use of synchrotron radiation as a light source. Results show that an interfacial reaction takes place even at room temperature. The resultant compound formed at room temperature contains higher Ni concentration than for compounds formed at high temperatures. A simple rigid-band model for these interfacial compounds explains the change in valence-band spectrum near the Fermi level that occurs with increasing Ni content.