Charge-trapping properties of gate oxide grown on nitrogen-implanted silicon substrate

Charge-trapping properties of ultrathin gate oxide grown on a nitrogen-implanted silicon substrate were investigated using high-field Fowler-Nordheim injection. By applying an empirical model and monitoring threshold voltage shift due to current stress, it was found that both hole trapping and electron trapping are suppressed in the nitrogen-implanted oxide. Smaller trap-generation rate compared to pure SiO₂ film was also noticed. Our results indicate that nitrogen implantation into silicon substrate before gate oxide growth is an alternate way to incorporate nitrogen into the Si/SiO₂ interface.