This paper discusses how the optical properties of Ta2O5 films are affected by the conditions under which they are produced by reactive magnetron sputtering of a Ta target with either direct current or ultrasound-frequency alternating current. The dispersion dependences of the refractive and absorption indices, as well as the growth rate of the films, are computed. The effect of currents in the magnetron-discharge plasma on the optical properties of the films is investigated.
O. D. Vol'pyan, P. P. Yakovlev, B. B. Meshkov, and Yu. A. Obod, "Optical properties of Ta2O5 films obtained by reactive magnetron sputtering," J. Opt. Technol. 70, 669-672 (2003)