Hafnium Nitride Dielectric Phase Films Fabricated by Ion-Beam Sputtering

Hafnium nitride films were deposited by ion-beam sputtering, and characterized for their composition, electrical, structural, mechanical and optical characteristics. Films were found to vary widely in their properties, based upon the parameters under which they were deposited. The films were found to have a nitrogen to hafnium ratio of up to 1.45:1, resistivity varying from 10−2 to 105 Ω-cm, as well as widely variable optical characteristics, depending on process variables. Structural characterization of the dielectric phase HfNx (x>l) material by X-ray and electron diffraction reveals a distortion of the hafnium mononitride rock salt structure with increasing amounts of nitrogen, in accordance with previous findings. Infrared spectroscopic characterization of the thin film dielectric phase hafnium nitride optical properties reveals the likely existence of multiple bonding between nitrogen in the material.