Dielectric properties in aged amorphous silicon oxide thin film

In this paper, we report structural and electrical characterization of amorphous silicon oxide films. We have investigated the effect of thermal accelerated ageing on the physico-chemical properties of a-SiOx by means of Infrared spectroscopy and fluorescence X. IR spectroscopy reveals the presence of Sn–O and Sn–H features in the studied samples. The transversal vibration ν(Si–O), which appeared at 1020 cm−1, is observed to disappear with the thermal ageing. The dielectric constant (ɛ) and dielectric loss (ɛ′′) have been measured for the frequency range between 20 Hz and 1 MHz. Results show an increase of the electric loss and a decrease in the electric conductivity with the ageing time thus aged samples tend to be insulator in character. These effects are related to the increase of structural defects. A Cole–Cole model is used to analyse the relaxation parameters and the distribution of relaxation time. A very good overlap of data was obtained.