Distinguishability of N composition profiles in SiON films on Si by angle-resolved x-ray photoelectron spectroscopy

Photoelectron intensities of N 1s and O 1s peaks at selected emission angles are reported for a SiON film on Si with different assumed amounts and distributions of N in the film. The intensities were determined from an efficient simulation tool for x-ray photoelectron spectroscopy (XPS) that incorporates appropriate values of elastic- and inelastic-scattering parameters in each region of the specimen as well as the finite angular acceptance of the analyzer. Appreciable dispersion of the intensities was found only for the N 1s peak at an emission angle of 75 degrees (with respect to the surface normal). Conventional analyses of angle-resolved XPS data that include such large emission angles are unlikely to be valid due to angle-dependent changes of the attenuation length. (c) 2006 American Institute of Physics.