Effects of thermal treatment on infrared optical properties of SiO2 films on Si Substrates

The effects of thermal treatment on infrared optical properties of SiO2 films on Si substrates by ion beam sputtering technology were investigated. Complex refractive index of SiO2 films was calculated from Fourier transform infrared transmission spectrum from 400 to 4000 cm− 1. Absorption band properties associated with Si-O-Si stretching, bending, rocking mode at about 1080 cm− 1, 816 cm− 1, 460 cm− 1 were analyzed. With the increase of thermal annealing temperature, the absorption peak with Si-O-Si stretching, rocking mode shift to long wave number, but the bending mode shifts to short. After thermal treatment, the infrared optical constants are close to the value of the more stabilized thermal grown SiO2. So, it can be concluded that the structure of Si-O-Si network in SiO2 films deposited on Si was modified to the stable structure of thermal grown SiO2.