Abstract

Silicon oxynitrides are extensively studied, because they are attractive for diverse applications in microelectronics or because of their low absorption in the near infrared. The change of their optical constants with composition makes these materials suitable for the production of graded index films. IR studies have been done in many cases by reflectivity R or transmittance T measurements, the optical constants being then calculated by using the Kramers-Kronig relation; p-polarized T measurements were also analyzed by a sum of classical oscillators^[1]. A detailed study has on the other hand been done from R and T measurements on different types of substrates^[2]. Very recently, high resolution electron-energy-loss-spectroscopy was used^[3] to determine the function $\mathrm{Im}\left(1/\tilde{\epsilon }\right)$ which was fitted with a simple three-oscillator model after subtraction of a phenomenological background.

© 1995 Optical Society of America