Hole injection into silicon nitride: Interface barrier energies by internal photoemission

Energy barrier heights at the interfaces of metal-silicon nitride-silicon structures have been measured by internal photoemission as a function of metal electrode material and substrate doping. These measurements have been interpreted in terms of a dominant hole internal photoemission mechanism. Hole energy barriers from the Au, Al, or Mg Fermi level and the Si valence band to the Si3N4 valence band were found to be 1.9±0.1, 3.0±0.1, 4.0±0.1, and 2.1±0.1 eV, respectively.