Quantitative analysis of silicon-oxynitride films by EPMA

Thin films of silicon oxynitride with diverse compositions were prepared by dc-magnetron sputtering of silicon, utilising oxygen and nitrogen gas flows and the sputtering power to vary the composition. In order to investigate the composition of these films, a method of analysis by electron probe micro analysis with energy dispersive detection was developed and the figures of merit were compared to the wavelength dispersive method used by other authors. The precision and repeatability of the results are evaluated and the accuracy is checked by comparison with Rutherford backscattering and nuclear reaction analysis. Energy dispersive X-ray spectrometry was proven to be applicable to analyse silicon oxynitride films of any composition yielding quantitative results for nitrogen and oxygen as well as silicon. Besides the good analytical performance, electron probe micro analysis with energy dispersive X-ray spectrometry has turned out to be a non-destructive, quick, easy to use and cost effective tool for the routine analysis of light elements in thin films.