XPS study of nanoscale SiOxNy layers synthezised by plasma immersion implantation of nitrogen

Plasma immersion implantation (PII) of nitrogen into Si was used to prepare nanoscale SiOxNy layers. The SiOxNy layers were synthesized in a cycle of PII followed by a high-temperature treatment in O2 ambient. Nitrogen was implanted into the Si substrate with energy of 2 keV and a fluence in the range of 1016 – 1018 cm−2. The implanted structures were subjected to a high-temperature annealing at 1050 °C for 10 or 20 minutes in dry oxygen at atmospheric pressure. X-ray photoelectron spectroscopy (XPS) revealed the chemical bonds and surface layer composition. The atomic concentrations of the SiOxNy constituents were obtained. By a combination with a sputter experiment the N concentration was found to be about 2,6 at. %. The low N content is due to the nitrogen escaping from Si during the oxidizing annealling. The thickness of the SiOxNy layer for the highest implantation fluence did not exceed 10 nm as revealed from ellipsometric and XPS data analyses.