Growth and characterization of SiON thin films by using thermal-CVD machine

Abstract

Silicon oxynitride (SiON) films have been deposited by thermal-CVD system and characterized by the ellipsometry, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The present paper reports the effect of deposition temperature on the properties of deposited SiON films. The stress of the film has been observed to be tensile in nature and it is found to be increased by increasing the deposition temperature through ellipsometric study. The decrease in refractive index of the film has been observed with increasing deposition temperature. The Si–O–Si and Si–N stretching characteristic peaks of SiON films have been observed with significant intensities by using FTIR spectroscopy. The peak positions of Si–O–Si stretching and the corresponding full width at half maxima (FWHM) have also been analyzed. The FWHM observed to be increasing on corresponding increase in the deposition temperature, which indicates the improvement in the quality of the deposited films. However, these films deposited in the temperature range of 780 to 850 °C, have more Si–H and less Si–OH contents. The SEM has been used to carry the morphological study of the films.