THE NITRIDATION OF A SILICON POWDER STUDIED BY XPS AND X-RAY-INDUCED AES

XPS and x-ray-induced AE'S have been used to study the reaction layers formed on silicon powder samples heated in ultra-high purity nitrogen at temperatures between 1100 and 1200 degrees C. An equation was deri ved to calculate the average surface reaction layer thicknesses from t he silicon AES spectra. The results indicate that samples where the re action layer is relatively thin may have some silicon oxynitride withi n this layer. For samples will calculated reaction layer thicknesses > 1.5 nm, the N 1s peak binding energy and Si KLL peak kinetic energy a re characteristic of bulk Si3N4. The nitridation kinetics follow a lin ear rate law within this temperature range with a measured activation energy of 280 +/- 60 kJ mol(-1).