Study of silicon surface layers modified by hydrogen plasma immersion ion implantation and oxidation

We report a study of p-Si(100) surface layers modified by plasma immersion ion implantation (PIII) and dry oxidation. This is expected to allow one to engineer near-surface layers with different thicknesses and levels of amorphization. Hydrogen ions were introduced into a shallow near-surface Si region through PIII with energy of 2 keV and doses ranging from 1013 ion/cm2 to 1015 ion/cm2. The implanted Si surface was subjected to oxidation in dry oxygen atmosphere at temperatures ranging from 700 °C to 800 °C. The optical and structural properties of the modified Si layers were studied in detail by spectroscopic ellipsometry (SE) in the IR spectral range of 300 – 4000 cm−1. The surface morphology was examined by atomic force microscopy (AFM) imaging at different scales and by fractal analysis. Through decomposition of the main Si-O bands into Gaussian peaks, different Si oxidation states were identified, suggesting non-stoichiometric oxide layer composition.