Oxidation of N+ implanted silicon: optical and structural properties

The optical and structural properties of oxidized silicon wafers, previously implanted with N+ ions at different doses, were investigated. A decrease in oxidation rate is observed as N+ ion dose increases due to the effect of incorporated nitrogen. Higher refractive index of the grown layer, deduced from spectroscopic ellipsometry, indicates the formation of silicon oxynitride thin films. X-Ray photoelectron spectroscopy shows a small amount of nitrogen in the oxidized Si region, where the nitrogen atoms are mainly bonded to silicon. The SiO vibration band at 1096 cm−1, measured by FTIR, is at the same position as that at oxidation of unimplanted silicon. No bands connected to NH and SiH vibration bonds are observed indicating low content of hydrogen in the silicon oxynitride film.