XPS and SIMS depth profiling of oxynitrides

The scaling down of mos devices into the submicron regime needs high-quality ultrathin (8 nm or less) gate dielectrics. Silicon oxide nitridation is widely used to achieve these requirements. Analytical issues in this field include nitrogen quantitative depth distribution and chemical characterization. In this work we have characterized oxynitride layers using two complementary techniques: SIMS and XPS. The study has been carried out on samples grown using different precursors either in conventional furnaces or by rapid thermal processes. Comparison between quantified SIMS depth profiles and the XPS HF etch-back method shows good agreement in nitrogen profile shape and quantification. In addition, XPS analyses have provided suitable chemical characterization of the different growth processes. We demonstrate that this analytical approach is really effective for the physicochemical characterization of present generation oxynitrides.