Synthesis of(Ti, Al)N films by ion beam assisted deposition

(Ti, Al)N films were prepared by ion beam assisted deposition (IBAD). The films were synthesized by depositing Ti and Al metal vapour under simultaneous bombardment with nitrogen ions in the energy range of 0.2-20 keV with the N/(Ti + Al) transport ratio in the range of 0.2-1.0. The films were formed on Si(111) wafers at room temperature. Structural characterization of the films was performed with X-ray diffraction and selected area electron diffraction measurements. The crystalline structure of the (Ti0.7Al0.3)N films was found to be a metastable single-phase B1-NaCl structure and an interplanar distance d(200) decreased with increasing N/(Ti + Al) transport ratio. With increasing Al content, (Ti0.2Al0.8)N films revealed a two-phase mixture consisting of NaCl and wurtzite structure phases, The ion-beam-induced crystallization effects in the early stage of the single-phase (Ti0.7Al0.3)N film growth was also examined using transmission electron microscopy. Preliminary results were obtained for the samples prepared with 5 and 20 keV N ions with transport ratio kept constant at 0.5, which suggests that the ion energy can significantly affect the crystallite growth but has less effects on the nucleation site density.