Quantitative XPS analysis of SiNx(:H) films using simple methods without sputtering

The use of Ar ion sputtering to remove the native surface oxide on SiNx(:H) is known to cause underestimation of its N/Si ration in XPS or AES analysis owing to preferential sputtering. We have carried out an XPS analysis of the N/Si ratio of plasma‐enhanced chemical vapour deposition SiNx:H (x <1.5) films using two simple methods without sputtering. In the first method samples were analysed with no surface treatment. In the second method the surface oxide was removed by chemical etching with HF solution. Curve fitting of Si 2p spectra was carried out to remove the influence of the surface oxide in both methods. There were good linearities between the N/Si ratios obtained by these methods and those estimated by RBS and absorption edge measurement. In particular, after correction for an error caused by differences in the attenuation length of photoelectrons, both methods proved to give results of sufficiently high precision for practical analysis.