Interfacial interactions at Au/Si3N4/Si(111) and Ni/Si3N4/Si(111) structures with ultrathin nitride films

Synchrotron photoemission spectromicroscopy has been used to study the interfacial interactions, metal diffusivity, and electronic barriers of Au and Ni contacts on ultrathin silicon nitride films. The Au/Si3N4 interface was found to be nonreactive, and only in the case of a very thin nitride film and elevated temperatures, Si can segregate from the Si(111) substrate and interact with Au. In the case of Ni/Si3N4/Si(111) structures, Ni diffusion and degradation of the Si3N4 lattice are evidenced even at room temperature and strongly enhanced at elevated temperatures, leading to formation of a Ni silicide interlayer.