Quantitative Auger sputter depth profiling of very thin nitrided oxide

Abstract

Plasma nitridation of thin oxides has been investigated at a temperature of 950 °C for 10 min–6 h and within an rf power of between 400 and 1100 W. The nitrogen composition in these films has been characterized in sputter depth Auger experiments. The sensitivity of this technique has been widely improved by the use of the sequential layer sputtering model. This model allows the actual nitrogen distribution in the film to be determined by taking into account the sputtering effect and by the escape depth of oxygen and nitrogen electrons. The results are observed to be independent of the oxide thickness in the range of 10–60 nm. Rapid thermal nitridation of 16-nm-thick oxides at 950 °C for 300 s and at 1150 °C for 15–300 s has also been studied by this method. Comparison of the results obtained using both techniques is made with a view to microelectronic applications.