Infrared ellipsometry as an investigation tool of thin layers grown into plasma immersion N+ implanted silicon

By applying ellipsometry and extending the measurements from visible to mid infrared spectral range we examined the complex dielectric function of thin layers grown into silicon. The layers were synthesized by high-temperature (1050 °C) annealing in oxidizing ambient of plasma immersion N+ ion implanted Si substrates. Sisingle bondN, Sisingle bondNsingle bondO and Sisingle bondSi chemical bonds in the silicon oxide network were identified and confirmed by X-ray photoelectron spectroscopy (XPS). Depending on N+ fluence (1016–1018 N+/cm2) and annealing duration (10 and 20 min) the grown layers were identified either as silicon oxynitride with considerably low N content or silicon dioxide enriched with nitrogen.