Raman spectroscopy and x-ray diffraction studies of (Ti,Al)N films deposited by filtered cathodic vacuum arc at room temperature

(Ti,Al)N films were deposited by an off-plane double bend filtered cathodic vacuum arc technique in N₂ ambient at room temperature. X-ray diffraction (XRD) and Raman spectroscopy were used to characterize the film structure. The influence of deposition pressure and the substrate bias on the XRD patterns and Raman spectra were systematically studied. As deposition pressure is increased, the film structure evolves from metallic, to metal rich (Ti,Al)₂N, and finally to a single face-centered cubic (Ti,Al)N. As substrate bias is increased, the structure evolves from amorphous to crystalline (Ti,Al)N for bias at 200 V. Further increase of substrate bias results in the decrease of the crystalline size and increase of disorder phase. Four peaks at 238, 326, 442, and 679 cm^-1, arisen from the transverse acoustic, longitudinal acoustic, transverse acoustic optical, and longitudinal acoustic modes of (Ti,Al)N phase, respectively, can be observed in the Raman spectra. The variation of the Raman spectra with the deposition pressure and substrate bias are in good agreement with that of the XRD measurements.