Influence of the deposition temperature on the optical and electrical properties of TiN film by spectroscopic ellipsometry

Abstract

Abstract Low emission (Low-e) films are widely used in modern architectural glass. In this presentation, spectroscopic ellipsometry (SE) between 1.12 and 2.75 eV (wavelength range: 450–1100 nm) was used to investigate the temperature dependence of dielectric function of TiN films. A Drude-3Lorentz dispersion model was selected and the results show both the real part e 1 and the imaginary part e 2 increase with the deposition temperature increasing. The structure and performance of the obtained TiN samples were characterized by X-ray diffraction, Raman, scanning electron microscope, UV/Visible (UV/VIS) spectrophotometer and Hall measurements. Combining the measured results, it is found that with the deposition temperature increasing, the grain size of TiN film changed from 15.4 nm to 17.4 nm and the surface becomes rougher. The concentrations of titanium and nitrogen vacancies decrease with increasing deposition temperature. A combined Drude-3Lorentz model was used to analyze the dielectric and optical properties of the obtained TiN films. It is found that TiN samples exhibit typical Drude-Lorentz like behavior in the visible and near-infrared (NIR) regions. The results were verified by Hall measurements and UV/VIS measurements. With the deposition temperature increasing, the reflectivity increased in the NIR region and a peak reflectivity of about 93% can be obtained at the wavelength of 1000 nm. With the deposition increasing, the infrared emissivity decreased. The infrared emissivities of the TiN film deposited at 673 K are 0.26 and 0.08 at wavelength of 2.5 μm and 25 μm, respectively, which shows TiN may be a good candidate for low-e film.