Effect of low temperature oxidation on dielectric properties of mercury sensitized photo-deposited silicon nitride films

Abstract Low temperature thermal oxidation of mercury-sensitized photo-CVD deposited silicon-rich silicon nitride films has been carried out to obtain high quality silicon oxynitride films with less incorporated hydrogen. The absence of Si H and N H stretching mode indicates that the incorporated hydrogen in these bonding forms is a few atomic percent, below the detection level of Fourier transform infrared spectroscopy (FTIR). X-ray photoelectron (XPS) studies suggest that oxygen is mainly incorporated in the film in the form of N (SiO) x . No significant change in the relative contributions from the Si 3 N 4 network to the overall N 1s peak takes place as a result of oxidation, but there is a decrease in the unreacted silicon from 15.3% to 5.5%. The interface electronic state densities, flat band voltage, fixed insulating charges and leakage current are reduced after oxidation, indicating an improvement of the electrical properties of the oxidized film.