An x-ray photoelectron spectroscopic analysis of plasma deposited silicon nitride films

The effect of deposition conditions on the structure and composition of plasma deposited silicon nitride films was studied using x-ray photoelectron spectroscopy. Plasma deposited silicon nitride films were transferred directly from the deposition chamber into a surface analysis system, thereby permitting analysis of as-deposited films without modification due to ion sputtering. Plasma deposited silicon nitride films with N:Si ratios from 1.8–0.3 were deposited using SiH4, NH3, N2, and H2 as the source gases. The N:Si ratio in the films increased with increasing nitrogen concentration in the gas phase. Changes in the deposition power or the substrate temperature also influenced the N:Si ratio. Large differences in the film structure were observed for plasma deposited silicon nitride films formed with NH3 compared to N2 with respect to deposition temperature variations.