Published online by Cambridge University Press: 31 January 2011
Pure bulk AlN substrates were prepared by hot-pressing to eliminate the influence of an aid-sintering substance on the interface reactions. AlN thin films were deposited on Si(111) substrates to decrease the influence of charging on the analysis of metal/AlN interfaces with x-ray photoelectron spectroscopy (XPS). Thin films of titanium were deposited on bulk AlN substrates by e-gun evaporation and ion beam assisted deposition (IBAD) and deposited on AlN films in situ by e-gun evaporation. Solid-state reaction products and reaction mechanism of the Ti/AlN system annealed at various temperatures and under IBAD were investigated by XPS, transmission electron microscopy (TEM), x-ray diffraction (XRD), and Rutherford backscattering spectrometry (RBS). Ti reacted with AlN to form a laminated structure in the temperature range of 600 °C to 800 °C. The TiAl3 phase was formed adjacent to the AlN substrate, TiN, and Ti4N3−x as well as Ti2N were formed above the TiAl3 layer at the interface. Argon ion bombardment during Ti evaporation promoted the interface reactions. No reaction products were detected for the sample as-deposited by evaporation. However, XPS depth profile of the Ti/AlN/Si sample showed that Ti–N binding existed at the interface between the AlN thin films and the Ti thin films.