Abstract

Silicon nitride films are prepared by a combined HIPIMS/UBMS deposition technique. Different unbalance coefficients and pulse on/off ratios are applied to improve the optical properties of silicon nitride films. The refractive index of Si₃N₄ films vary from 2.17 to 2.02 in the wavelength ranges of 400-700 nm and all the extinction coefficients are smaller than 1×10⁻⁴. From FTIR measurements, Si₃N₄ films reveal extremely low hydrogen content and very low absorption between NIR and MIR range. Compared to other deposition techniques, Si₃N₄ films deposited by the combined HIPIMS/UBMS deposition technique possess the highest refractive index, the lowest extinction coefficient and excellent structural properties.

© 2013 Optical Society of America