Oxidation of very low energy nitrogen-implanted strained-silicon

In the present work we perform a systematic study of oxidation of very low energy nitrogen-implanted strained-silicon in terms of oxide growth, structural characterization of the implanted strained-silicon substrate and electrical properties of the ultra thin oxides as a function of the substrate strain level. Low energy (3 keV) nitrogen (N₂⁺) implantation was performed in strained-Si/SiGe/Si substrates of various strain levels and oxidations were carried out for different times at 850 °C. It has been found that nitrogen implantation efficiently blocks silicon oxidation, independently of the strain level of the substrate. TEM analysis revealed the full absence of extended defects in the strained-silicon substrate after the thermal treatments. The grown oxides exhibit very good electrical properties in terms of interface trap densities and leakage currents.