X-ray absorption and photoelectron spectroscopic study of plasma-nitrided SiO2 film

Plasma-nitrided SiO2 thin film has been analyzed by synchrotron-radiation-based x-ray absorption and photoelectron spectroscopies (XAS and XPS). High-resolution N 1s XAS and N 1s, O 1s, and Si 2p XPS spectral changes were obtained for different annealing temperatures. N 1s XPS and XAS spectra show that at room temperature, besides the main species of N[Si(O−)3−x]3, there exist free moleculelike N2 and HN[Si(O−)3]2, H2NSi(O−)3, and N–Si2O species with surface contaminants. The spectral intensities of the N2 and the HN[Si(O−)3]2, H2NSi(O−)3, and N–Si2O species decrease as the annealing temperature increases, and finally the nitrogen exists dominantly in the form of N[Si(O)3]3 species above 820K, indicating out-diffusion of molecular N2 and structural reconstruction to form a stable structure upon annealing. The Si 2p and O 1s XPS spectra show that Si>4+ 2p peak and O 1s peak appear at 103.7 and 534.0eV, respectively, which are higher binding energies than those of thermally grown oxynitride films with lower...