Metallic seed layers for ion-beam assisted pulsed laser deposition of highly textured transition metal nitride films

Abstract

Ion-beam assisted deposition (IBAD) is a promising technique for preparing highly textured templates on various substrates. A major requirement for the textured nucleation of materials with a rocksalt structure using the IBAD approach is an amorphous seed layer. Metallic Ta0.75Ni0.25 films were used as amorphous layers on Si/Si3N4 as well as on electropolished Hastelloy tapes for the ion-beam assisted pulsed laser deposition of transition metal nitrides. Highly biaxially textured TiN and NbN films have been grown on these layers even at room temperature in a reactive deposition process using an ion beam with an energy of 800 eV under an angle of 45° relative to the substrate normal. The cube texture was preserved to higher thicknesses using homoepitaxial growth. Finally, 10 nm thick Au films were used to study the surface texture quantitatively using x-ray diffraction showing in-plane orientations down to 8°. The results offer the possibility to realize a fully conductive buffer layer architecture for high-temperature superconductors based on the IBAD approach.