Optical properties of TiN films deposited by direct current reactive sputtering

Optical properties of TiN films have been studied using spectroscopic ellipsometry in the photon-energy range between 1.2 and 5.4 eV at room temperature. The TiN films are deposited on Si(100) substrates by reactive dc magnetron sputtering. The nearly stoichiometric golden-colored (g∼5.3 g/cm3) and brownish TiN films (g∼4.7 g/cm3) are investigated. The measured ε(E) spectra reveal distinct structures near the screened plasma edge and at interband critical points. These spectra are analyzed on the basis of a simplified model of the interband transitions including the Drude–Lorentz term contribution. Results are in satisfactory agreement with the experimental data over the entire range of photon energies. Dielectric-related optical constants, such as the complex refractive index, absorption coefficient, and normal-incidence reflectivity, of the sputter-deposited TiN films are also presented.