Structure and properties of Ta doped TiN films prepared using different sputtering powers for Ta target

Abstract

Ta doped TiN films were prepared on glass substrates by DC magnetron co-sputtering. The structure and properties of the obtained (Ti,Ta)N film were characterized by X-ray diffraction, Raman spectroscopy, ultraviolet/visible/near-infrared spectrophotometer and four probes method. The results show that with the increase of the sputtering power (PTa) for Ta target, the amount of Ta added to TiN lattice increases, resulting in a slight distortion of TiN lattice and stress transformation in the film. Correspondingly, the optical and electrical properties of the film changed. Raman spectrum was deconvoluted into five Lorentz peaks in the range of 50-1400 cm−1 and a new Raman peak appeared in all samples due to the substitution of Ta for Ti. The analysis of deconvolution results shows that the peak positions of different phonon modes and FWHM change, which may be related to the change of stress in the thin films caused by adding Ta to TiN lattice. The sample prepared with power of 50W has the maximum infrared emissivity of 1.35 and 0.43 at 2.5 and 25 μm wavelengths, respectively, indicating that (Ti,Ta)N film is promising candidate for replacing TiN in Low-E glass.

Keywords

• co-sputtering
• low-emission films
• raman spectroscopy
• (tita)n film