R.F. Sputtering of LiNbO₃ thin films

Using r.f. sputtering, LiNbO3 films were deposited onto amorphous and single-crystal substrates. Depending on the growth conditions, the films are either amorphous of polycrystalline, as shown by X-ray diffraction. Results are presented on the influence of the various parameters on the index of refraction of the films which is determined as a function of wavelength by using integrated optical methods with an argon ion laser, a dye laser and an HeNe laser. A single-term Sellmeier equation can be used to fit these refractive index data. The average oscillator positron λ0 is found to be 0.1834 μm and 0.2045 μm and the average oscillator strength 92.40 μm-2 and 81.8 μm-2 for the amorphous and polycrystalline LiNbO3 films respectively. © 1982.